Patent Publication Number: US-9847471-B2

Title: Method and remotely adjustable reactive and resistive electrical elements

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a divisional of, and claims priority to, U.S. patent application Ser. No. 13/664,391 filed on Oct. 30, 2012, titled “METHOD AND REMOTELY ADJUSTABLE REACTIVE AND RESISTIVE ELECTRICAL ELEMENTS” (to issue as U.S. Pat. No. 8,816,566 on Aug. 26, 2014); which is a divisional of, and claims priority to, U.S. patent application Ser. No. 12/719,841 filed on Mar. 8, 2010, titled “REMOTELY ADJUSTABLE REACTIVE AND RESISTIVE ELECTRICAL ELEMENTS AND METHOD” (which issued as U.S. Pat. No. 8,299,681 on Oct. 30, 2012); which claimed priority to U.S. Provisional Patent Application No. 61/158,345 filed Mar. 6, 2009, titled “REMOTELY ADJUSTABLE REACTIVE AND RESISTIVE ELECTRICAL ELEMENTS AND METHOD”; each of which is incorporated herein by reference in its entirety. 
    
    
     GOVERNMENT LICENSE RIGHTS 
     This invention was made with government support under EB015894, EB006835, EB007327, and EB013543 awarded by the National Institutes of Health. The government has certain rights in the invention. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to the field of variable resistance-inductance-capacitance (R-L-C) elements, and more specifically to a method and apparatus of electrically controlling a mechanical movement device (such as a linear positioner, rotary motor, or pump) that selectively controls an electrical element to vary, and maintain at a selected value, its electrical resistance, inductance, and/or capacitance—and, in some embodiments, the components are compatible with and function in high fields (such as a magnetic field of up to and exceeding one tesla or even ten tesla or more and/or an electric field of many thousands of volts per meter). 
     BACKGROUND OF THE INVENTION 
     Conventional electrical components that permitted one to vary resistance, inductance, and/or capacitance under electrical control typically have somewhat limited component values available and are not compatible with being located in high fields (e.g., the fields of 1 tesla or more that are typically found in high-energy physics experiments such as the $9 billion Large Hadron Collider that has been 20 years in making and is still being modified to be able to operate). 
     Low-power circuits can use varactors (electrically variable capacitors), field-effect transistors (used as variable gain elements or variable resistors) and like components that are directly electrically-adjustable, for use in adjusting frequency, impedance or other circuit characteristics and parameters, however such components are often unsuitable or inoperative in high fields. 
     U.S. Pat. No. 6,495,069 issued Dec. 17, 2002 to Lussey et al. titled “Polymer composition,” is incorporated herein by reference. Lussey et al. describe a polymer composition comprises at least one substantially non-conductive polymer and at least one electrically conductive filler and in the form of granules. Their elastomer material was proposed for devices for controlling or switching electric current, to avoid or limit disadvantages such as the generation of transients and sparks which are associated with the actuation of conventional mechanical switches. They described an electrical conductor composite providing conduction when subjected to mechanical stress or electrostatic charge but electrically insulating when quiescent comprising a granular composition each granule of which comprises at least one substantially non-conductive polymer and at least one electrically conductive filler and is electrically insulating when quiescent but conductive when subjected to mechanical stress. They did not propose a means for electrically activating such switches. 
     There is a long-felt need for components having resistance, inductance, and/or capacitance values that are variable under electrical control and are compatible with being operated in extremely high electromagnetic fields. 
     SUMMARY OF THE INVENTION 
     The present invention provides resistors, inductors, capacitors, and/or antenna elements that have their electrical-circuit values controlled by one or more electrically controlled non-magnetic mechanical movement devices (such as linear positioners or rotary motors (which move a solid material), or pumps (which move a liquid or gas)). In some embodiments, the electrically controlled mechanical movement devices (such as piezo-electrical linear motors, micro-electronic mechanical-system (MEMS) mechanical actuators or MEMS pumps) and other elements (which are used to make the resistors, inductors, capacitors, and/or antenna elements) include metals that have only substantially non-magnetic components such that the resistors, inductors, capacitors, robotic arms or similar mechanical devices, and/or antenna elements and the mechanical positioner(s) or pump(s) that adjust their variable values can be placed and operated within and/or near an extremely high electric field of many thousands of volts per meter (such as connected to or affecting electricity-transmission lines carrying hundreds of thousands of volts and very large currents), or extremely-high magnetic field such as within the very strong superconducting-wire magnets of high-energy particle-physics experiments (such as the Large Hadron Collider) or within magnets of a magnetic-resonance imaging machines, or during and after an electromagnetic pulse (EMP) from a nuclear event. 
     In other embodiments, the present invention provides the ability to adjust very sensitive circuits that do not involve high fields, but instead involve very low fields (such as within completely enclosed Faraday cages (which block low-frequency external fields) having radio-frequency (RF) shielding (which block high-frequency external fields) that are measuring very small parameters such as extremely low-voltage circuits where the presence of a person or magnetic mechanical movement device (such as a magnetic linear positioner, rotary motor, or pump) would change the field, but which use the mechanical movement device(s) to adjust the configuration of RLC (resistive-inductive-capacitive) components without modifying fields or introducing extraneous capacitances or inductances. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a block diagram of a variable capacitor subsystem  101  having a variable capacitor  110  according to one embodiment of the present invention. 
         FIG. 1B  is a block diagram of a variable capacitor subsystem  102  having a variable capacitor  120  according to one embodiment of the present invention, wherein variable capacitor  102  is set to a first capacitance value. 
         FIG. 1C  is a block diagram of variable capacitor subsystem  102  as was shown in  FIG. 1B , but wherein variable capacitor  120  is set to a second capacitance value. 
         FIG. 1D  is a block diagram of a variable capacitor subsystem  103  having a variable capacitor  130  according to one embodiment of the present invention, wherein variable capacitor  130  is set to a first capacitance value. 
         FIG. 2A  is a block diagram of a variable inductor subsystem  201  having a variable inductor  210  according to one embodiment of the present invention, wherein variable inductor  201  is set to a first inductance value. 
         FIG. 2B  is a block diagram of variable inductor subsystem  201  according to one embodiment of the present invention, wherein variable inductor  210  is set to a second inductance value. 
         FIG. 2C  is a block diagram of a variable inductor subsystem  203  having a variable inductor  230  according to one embodiment of the present invention, wherein variable inductor  203  is set to a first inductance value. 
         FIG. 2D  is a block diagram of variable inductor subsystem  203  according to one embodiment of the present invention, wherein variable inductor  230  is set to a second inductance value. 
         FIG. 2E  is a block diagram of a variable inductor subsystem  205  according to one embodiment of the present invention, wherein variable inductor  250  is set to a first inductance value. 
         FIG. 2F  is a block diagram of variable inductor subsystem  205  according to one embodiment of the present invention, wherein variable inductor  250  is set to a second inductance value. 
         FIG. 2G  is a block diagram of a variable inductor subsystem  207  according to one embodiment of the present invention, wherein variable inductor  270  is set to a first inductance value. 
         FIG. 2H  is a block diagram of variable inductor subsystem  207  according to one embodiment of the present invention, wherein variable inductor  270  is set to a second inductance value. 
         FIG. 2 i    is a block diagram of a variable-position inductor subsystem  208  according to one embodiment of the present invention, wherein variable-position inductor  280  is set to a first position. 
         FIG. 2J  is a block diagram of variable-position inductor subsystem  208  according to one embodiment of the present invention, wherein variable-position inductor  280  is set to a second position. 
         FIG. 2K  is a block diagram of a variable-shape inductor subsystem  209  according to one embodiment of the present invention, wherein variable-shape inductor  290  is set to a first shape. 
         FIG. 2L  is a block diagram of variable-shape inductor subsystem  209  according to one embodiment of the present invention, wherein variable-shape inductor  290  is set to a second shape. 
         FIG. 3A  is a block diagram of a variable resistor subsystem  301  according to one embodiment of the present invention, wherein variable resistor  320  is set to a first resistance value. 
         FIG. 3B  is a block diagram of variable resistor subsystem  301  according to one embodiment of the present invention, wherein variable resistor  320  is set to a second resistance value. 
         FIG. 3C  is a block diagram of a variable resistor subsystem  303  according to one embodiment of the present invention, wherein variable resistor  330  is set to a first resistance value. 
         FIG. 3D  is a block diagram of variable resistor subsystem  303  according to one embodiment of the present invention, wherein variable resistor  330  is set to a second resistance value. 
         FIG. 4A  is a block diagram of a variable resistor-inductor-capacitor subsystem  401  according to one embodiment of the present invention, wherein variable resistor  320  is set to a first resistance value, variable inductor  230  is set to a first inductance value, and variable capacitor  120  is set to a first capacitance value. 
         FIG. 4B  is a block diagram of variable resistor-inductor-capacitor subsystem  401  according to one embodiment of the present invention, wherein variable resistor  320  is set to a second resistance value, variable inductor  230  is set to a second inductance value, and variable capacitor  120  is set to a second capacitance value. 
         FIG. 5  is a block diagram of a variable resistor-inductor-capacitor subsystem  500  according to one embodiment of the present invention, wherein variable resistor  503  is set to a first resistance value, variable inductor  502  is set to a first inductance value, and variable capacitor  501  is set to a first capacitance value. 
         FIG. 6  is a block diagram of an entire system  600  according to one embodiment of the present invention, wherein variable electrical components of circuits  99 A and/or  99 B are controlled to parameters set by controller  601 . 
         FIG. 7A  is a block diagram of an impedance-matched high-frequency circuit  700  according to one embodiment of the present invention, and having an external impedance disturbance  66  having a first effect on circuit  700 . 
         FIG. 7B  is a block diagram of impedance-matched high-frequency circuit  700 , and having a different external impedance disturbance  66 ′ having a second effect on circuit  700 . 
         FIG. 8A  is a block diagram of a variable antenna subsystem  801  according to one embodiment of the present invention, wherein variable antenna  810  is set to a first length. 
         FIG. 8B  is a block diagram of variable antenna subsystem  801  according to one embodiment of the present invention, wherein variable antenna  810  is set to a second length. 
         FIG. 8C  is a block diagram of a variable antenna array subsystem  802  according to one embodiment of the present invention, wherein variable antenna array  820  is set to a first spacing. 
         FIG. 8D  is a block diagram of variable antenna array subsystem  802  according to one embodiment of the present invention, wherein variable antenna array  820  is set to a second spacing. 
         FIG. 8E  is a block diagram of a variable antenna array subsystem  803  according to one embodiment of the present invention, wherein variable antenna array  830  is set to a first length. 
         FIG. 8F  is a block diagram of variable antenna array subsystem  803  according to one embodiment of the present invention, wherein variable antenna array  830  is set to a second length. 
         FIG. 8G  is a block diagram of an antenna array subsystem  806  having one or more active-variable-antenna element subsystems  804  and/or one or more passive-variable-antenna element subsystems  805  according to one embodiment of the present invention, wherein active-variable-antenna element subsystems  804  is set to a first impedance-frequency value and passive-variable-antenna element subsystems  805  is set to a second impedance-frequency value. 
       FIG.  8 G 1  is a circuit diagram of antenna array subsystem  806  having one or more active-variable-antenna element subsystems  804  and/or one or more passive-variable-antenna element subsystems  805  according to one embodiment of the present invention (such as shown in  FIG. 8G ). 
         FIG. 8H  is a block diagram of variable antenna array subsystem  807  according to one embodiment of the present invention, wherein variable antenna array  870  is set to a first dielectric configuration. 
         FIG. 8 i    is a block diagram of variable antenna array subsystem  807  according to one embodiment of the present invention, wherein variable antenna array  870  is set to a second dielectric configuration. 
         FIG. 8J  is a block diagram of variable antenna array subsystem  808  having a reconfigurable dielectric fluid according to one embodiment of the present invention, wherein variable antenna array  880  is set to a first dielectric-fluid configuration. 
         FIG. 8K  is a block diagram of variable antenna array subsystem  809  having a reconfigurable dielectric fluid according to one embodiment of the present invention, wherein variable antenna array  890  is set to a first dielectric-fluid configuration. 
         FIG. 8L  is a block diagram of a variable antenna subsystem  811  according to one embodiment of the present invention, wherein variable antenna  891  is set to a first length. 
         FIG. 8M  is a block diagram of a variable antenna subsystem  813  according to one embodiment of the present invention, wherein variable antenna  893  is set to a first length. 
         FIG. 9  is a block diagram of feedback-controlled system  901  having one or more variable-RLC, antenna, robotics, gain, ω, λ, φ, and the like elements in a circuit  920 , controlled by a feedback circuit  930  according to one embodiment of the present invention. 
         FIG. 10  is a flowchart of a method  1000  according to some embodiments of the invention. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     Although the following detailed description contains many specifics for the purpose of illustration, a person of ordinary skill in the art will appreciate that many variations and alterations to the following details are within the scope of the invention. Accordingly, the following preferred embodiments of the invention are set forth without any loss of generality to, and without imposing limitations upon the claimed invention. Further, in the following detailed description of the preferred embodiments, reference is made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration specific embodiments in which the invention may be practiced. It is understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention. 
     The leading digit(s) of reference numbers appearing in the Figures generally corresponds to the Figure number in which that component is first introduced, such that the same reference number is used throughout to refer to an identical component which appears in multiple Figures. Signals and connections may be referred to by the same reference number or label, and the actual meaning will be clear from its use in the context of the description. 
     As used herein, a non-magnetic mechanical movement device is any electrically-controlled device (such as a linear positioner, rotary motor, or pump) made of materials that do not move (or move to a substantially negligible amount) due to a high magnetic field when subjected to the high magnetic field. Such devices can be placed within the high magnetic field of a magnetic-resonance machine or the superconducting magnet of a particle accelerator without the danger of the device moving due to the magnetic field and/or without the undesirable result of changing the magnetic field due to their presence. In many of the descriptions herein, the term “motor” (such as motor  140 ) will be used as an example of such a non-magnetic mechanical movement device, however one of skill in the art will recognize that in other embodiments, the “motor” can be implemented as a linear or rotary motor device using suitable linkages, or as a pump that uses a liquid or pneumatic fluid to effectuate the described movement. 
       FIG. 1A  is a block diagram of a variable capacitor subsystem  101  having a variable capacitor  110  according to one embodiment of the present invention. In some embodiments, variable capacitor system  101  controls variable capacitor  110 , which includes a first plate  111  and a second plate  112  that together form a capacitor having a capacitance substantially proportional to the overlapping area A between the plates and inversely proportional to the distance d between the plates (and also dependent on the permittivity c of any material between the plates). In some embodiments, plate  112  is substantially parallel to plate  111  (such that C=∈A/d where in a vacuum, ∈ 0 =8.85 pF/m, which is approximately the same permittivity as in air). In the embodiment shown, a non-magnetic mechanical movement device (e.g., motor or pump)  140  is used to vary the distance d between the plates. In some embodiments, plate  111  is affixed to a fixed location  113 , while the other plate  112  is connected to a movable connecting rod  141 , which is moved to a desired position by motor  140  (in some embodiments, a linear motor, and in some such embodiments, a piezoelectric motor  140 ) under the control of motor controller  145 . In some embodiments, a feedback signal  146  is used by motor controller  145  to control the position. In some embodiments, electrical circuit  99  uses the variable capacitor  110  as part of its circuitry (e.g., to set a frequency, phase, gain/attenuation, temporal properties, spatial properties (the shape of magnetic or electric fields), pulse width or other capacitance-controlled parameter). In some embodiments, electrical circuit  99  generates feedback signal  146  (e.g., as negative feedback to stabilize the circuit at a given set of parameters). In some embodiments, motor  140  is also affixed to a set location  143  relative to location  113 . In some embodiments, connecting rod  141  is connected to movable plate  112  using a mechanically advantaged linkage such as a lever (e.g., such as shown in  FIG. 4A  and  FIG. 4B  below). 
     In some embodiments, electric circuit  99  (as shown in any of the figures herein) includes a detector that measures or senses one or more parameters (such as capacitance, complex impedance (such as the real and imaginary components of impedance or the magnitude and phase angle), frequency, voltage-standing-wave ratio (VSWR) or other suitable parameter), and automatically adjusts the parameter (e.g., capacitance) value of the adjustable component (e.g., variable capacitor  110 ) to obtain a desired value(s) for the parameter(s). In some embodiments, the adjustment is part of a feedback loop (e.g., to stabilize, maximize or minimize a signal) in an analog circuit. 
     In some embodiments, circuit  99  is connected to the variable component by a transmission line  119  having a characteristic impedance. In some embodiments, the variable capacitor subsystem  101  is adjusted such that the impedance of circuit  99  at its connection to transmission line  119  is matched to the characteristic impedance of transmission line  119 , and such that the variable component (e.g., variable capacitor  110  and the other components or effective equivalent resistance, inductance and capacitance) have matched impedances. For example, in some embodiments, the circuit  99  includes a transmitter having an output impedance of 50 ohms, the transmission line  119  has a characteristic impedance of 50 ohms, and at the frequency of interest, capacitor  110  (and any antenna or other elements or parasitic resistance-inductance-capacitance) has a characteristic impedance of 50 ohms. Of course the characteristic impedance can have other values in other embodiments. 
     In some embodiments, the parameter adjustment is programmable and a suitable computer program uses computer-readable instructions from a computer-readable medium to control a method that automatically adjusts the parameter value. 
     In some embodiments, a plurality of adjustable non-magnetic components, such as that shown in  FIG. 1A  and/or any of the other Figures herein, are combined in a single system, and the parameter(s) of each are iteratively adjusted (i.e., the first component is adjusted, then the second component (and optionally further components) are then adjusted in sequence (or optionally two or more are simultaneously adjusted), then the first component is again adjusted, then the second component (and optionally further components) are then again adjusted (or optionally two or more are again simultaneously adjusted) in an iterative sequence) in order to obtain an improved or optimum characteristic (such as frequency response, distance, range, direction of a transmitted or received radio signal and/or other like parameters to obtain a desired result (such as image quality)). 
       FIG. 1B  is a block diagram of a variable capacitor system  102  having variable capacitor  120  according to one embodiment of the present invention, wherein variable capacitor  120  is set to a first capacitance value. In some embodiments, variable capacitor  120  includes a first set of parallel plates  121  and a second set of parallel plates  122  that together form a capacitor having a capacitance substantially proportional to the overlapping area A between the plates and inversely proportional to the distance d between the plates (and also dependent on the permittivity c of any material between the plates). In some embodiments, the horizontal plates of set of parallel plates  122  is interleaved substantially parallel to the horizontal plates of set of parallel plates  121  (such that C=∈A/d where in a vacuum, ∈ 0 =8.85 pF/m, which is approximately the same permittivity as in air). In the embodiment shown, motor  140  is used to vary the area A overlapped between the plates. In some embodiments, the set of parallel plates  121  is affixed to a fixed location  113 , while the other set of parallel plates  122  is connected to a movable connecting rod  141 , which is moved to a desired position by motor  140  (in some embodiments, a linear motor, and in some such embodiments, a piezoelectric motor  140 ) under the control of motor controller  145 . In some embodiments, a feedback signal  146  is used by motor controller  145  to control the position. In some embodiments, electrical circuit  99  uses the variable capacitor  120  as part of its circuitry (e.g., to set a frequency or pulse width or other capacitance-controlled parameter). In some embodiments, electrical circuit  99  generates feedback signal  146  (e.g., as negative feedback to stabilize the circuit at a given set of parameters). In some embodiments, motor  140  is also affixed to a set location  143  relative to location  113 . In some embodiments, connecting rod  141  is connected to movable set of parallel plates  122  using a mechanically advantaged linkage such as a lever (e.g., such as shown in  FIG. 4A  and  FIG. 4B  below). In some embodiments, the mechanical linkage is configured to produce a non-linear change in capacitance per change in position of rod  141  (in some embodiments, the capacitance per unit rod movement is a function of position (such as to produce a logarithmic capacitance scale). In some embodiments, motor controller  145  produces a non-linear relationship between a value of signal  146  and the capacitance obtained by moving rod  141  according to some predetermined function, equation, or look-up table. In the configuration shown in  FIG. 1B , the value of the capacitance is relatively low due to the small amount of overlapped area between set of parallel plates  121  and set of parallel plates  122 . 
       FIG. 1C  is a block diagram of variable capacitor system  102  as was shown in  FIG. 1B , but wherein variable capacitor  120  is set to a second capacitance value. In the configuration shown in  FIG. 1B , the value of the capacitance is relatively high due to the large amount of overlapped area between set of parallel plates  121  and set of parallel plates  122 . 
       FIG. 1D  is a block diagram of a variable capacitor system  103  having a variable capacitor  130  according to one embodiment of the present invention, wherein variable capacitor  130  is set to a first capacitance value. In some embodiments, connecting rod  141  moves a block or sheet of dielectric material  133  (e.g., in some embodiments, a high-K dielectric material (i.e., a dielectric material having a high dielectric constant, K)) by a variable amount into or out of the air space separating the plates  132  and  131  of variable capacitor  130 . The varied area of high-K dielectric material  133  located between the plates  132  and  131  based on the position of connecting rod  141  and the varied remaining area between the plates  132  and  131  that does not have the high-K dielectric material  133  thus varies the effective overall or distributed dielectric constant between the plates, thus varying the capacitance. In some embodiments, the block or sheet of dielectric material  133  has a variable thickness, such that in a first position of connecting rod  141  a first thickness of dielectric material  133  is between the plates  131  and  132  and in a second position of connecting rod  141  a second thickness of dielectric material  133  is between the plates  131  and  132 , thus varying the capacitance of variable capacitor  130 . In some embodiments, dielectric material  133  is ramp shaped (having a longitudinal cross-section thickness that gradually increases in a straight or curved ramp from one end to the other), stepped (having a longitudinal cross-section thickness that increases in one or more steps from one end to the other), or is convex, concave or otherwise curved (having a longitudinal cross-section thickness that increases and then decreases from one end to the other, or that decreases and then increases from one end to the other, or that has some other desired shape). In other embodiments, numerous other thickness or area-shape or dielectric variations are used for dielectric material  133 . 
       FIG. 2A  is a block diagram of a variable inductor subsystem  201  according to one embodiment of the present invention, wherein variable inductor  210  is set to a first inductance value. In some embodiments, variable inductor  210  includes a coil  221  having a plurality of N turns in a length l and a cross-sectional area of A (and also dependent on the permeability constant μ of any material within the field of the coil  221 ). In some embodiments, the inductance is substantially L=(μN 2 A)/l, where the value μ is dependent on the material, position and size of the core  222 ). In the embodiment shown, motor  140  is used to vary the position of the core  222  (which has a permeability or permittivity that affects inductance of the inductor or reactance of the entire structure), withdrawing it to reduce the inductance and inserting the core to increase the inductance. In some embodiments, coil  221  is affixed (e.g., at both ends) to a fixed mechanical location  223 , while the core  222  is connected to a movable connecting rod  141 , which is moved to a desired position by motor  140  (in some embodiments, a linear motor, and in some such embodiments, a piezoelectric motor  140 ) under the control of motor controller  145 . (Of course, other embodiments may choose to attach the coil  221  to the connecting rod  141  and to attach the core  222  to a fixed location.) In some embodiments, a feedback signal  146  is used by motor controller  145  to control the position. In some embodiments, electrical circuit  99  uses the variable inductor  210  as part of its circuitry (e.g., to set a frequency or pulse width or other inductance-controlled parameter). In some embodiments, electrical circuit  99  generates feedback signal  146  (e.g., as negative feedback to stabilize the circuit at a given set of parameters). In some embodiments, motor  140  is also affixed to a set location  143  relative to location  223 . In some embodiments, connecting rod  141  is connected to core  222  using a mechanically advantaged linkage such as a lever (e.g., such as shown in  FIG. 4A  and  FIG. 4B  below). In some embodiments, motor controller  145  produces a non-linear relationship between a value of signal  146  and the inductance obtained by moving rod  141  according to some predetermined function, equation, or look-up table. In the configuration shown in  FIG. 2A , the value of the inductance is relatively low (i.e., lower than when the core is in the position shown in  FIG. 2B ) due to the small amount of overlapped length between coil  221  and core  222 . 
       FIG. 2B  is a block diagram of variable inductor subsystem  201 , wherein variable inductor  210  is set to a second inductance value. In the configuration shown in  FIG. 2B , the value of the inductance is relatively high (i.e., higher than when the core is in the position shown in  FIG. 2A ) due to the large amount of overlapped length between coil  221  and core  222 . 
       FIG. 2C  is a block diagram of a variable inductor subsystem  203  according to one embodiment of the present invention, wherein variable inductor  230  is set to a first inductance value. In some embodiments, variable inductor  230  includes a coil  224  having a plurality of N turns in a length l and a cross-sectional area of A (and also dependent on the permeability constant μ of any material within the field of the coil  221 ). In some embodiments, the inductance is substantially L=(μ 0  N 2 A)/l, where the value μ 0 =4π×10 −7  H/m is permeability of free space, which substantially equals that of air). In the embodiment shown, motor  140  is used to vary the length of coil  224 . In some embodiments, one end of coil  224  is affixed (e.g., at only one end) to a fixed location  223 , while the other end of coil  224  is connected to a movable connecting rod  141 , which is moved to a desired position by motor  140  (in some embodiments, a linear motor, and in some such embodiments, a piezoelectric motor  140 ) under the control of motor controller  145 . In some embodiments, the coil  224  is wrapped on an elastomeric support core (or one side of each turn is connected to an elastomeric support substrate), such that the spacings between turns remains proportional to the length l of the coil  224 . In some embodiments, a feedback signal  146  is used by motor controller  145  to control the position. In some embodiments, electrical circuit  99  uses the variable inductor  230  as part of its circuitry (e.g., to set a frequency or pulse width or other inductance-controlled parameter). In some embodiments, electrical circuit  99  generates feedback signal  146  (e.g., as negative feedback to stabilize the circuit at a given set of parameters). In some embodiments, motor  140  is also affixed to a set location  143  relative to location  223 . In some embodiments, connecting rod  141  is connected to the movable end of coil  224  using a mechanically advantaged linkage such as a lever (e.g., such as shown in  FIG. 4A  and  FIG. 4B  below). In some embodiments, motor controller  145  produces a non-linear relationship between a value of signal  146  and the inductance obtained by moving rod  141  according to some predetermined function, equation, or look-up table. In the configuration shown in  FIG. 2C , the value of the inductance is relatively low (i.e., lower than when the inductor  230  is closely spaced as in the position shown in  FIG. 2D ) due to the extended length of coil  224  and thus the smaller amount of flux linkage through each turn. 
       FIG. 2D  is a block diagram of variable inductor subsystem  203  according to one embodiment of the present invention, wherein variable inductor  230  is set to a second inductance value. In the configuration shown in  FIG. 2D , the value of the inductance is relatively high (i.e., higher than when the inductor  230  is spread out as in the position shown in  FIG. 2C ) due to the shortened length of coil  224  and thus the larger amount of flux linkage through each turn. 
       FIG. 2E  is a block diagram of a variable inductor subsystem  205  according to one embodiment of the present invention, wherein variable inductor  250  is set to a first inductance value. In some such embodiments, the number of loops of coil  251  is varied (e.g., by using a sliding contactor  257  that makes an electrical connection to different loops of coil  251  as connecting rod  141  is moved by motor  140 ). In the present position of connecting rod  141  shown in  FIG. 2E , about eight (8) loops are between connector  257  at the left end of the coil  251  and the electrical connection  256  at the right end of coil  251  next to its mechanical connection at fixed mechanical location  223 . In some embodiments, the left end of the coil  251  is mechanically connected to fixed location  227 , and in some such embodiments, the left end of the coil  251  also has an electrical connection  258  (e.g., to an electrical ground), and in the present position of connecting rod  141  shown in  FIG. 2E  about one-half (0.5) loop is between connector  257  near the left end of the coil  251  and the electrical connection  258  (e.g., to ground) at the far left end of coil  251  next to its mechanical connection at fixed mechanical location  227 . Note that in some embodiments, electrical connection  258  is omitted and a single set of loops of coil  251  are in the circuit (between connection  257  and connection  256  connected to electrical circuit  99 , while in other embodiments, electrical connection  258  is included (e.g., connected to ground or some other node in circuit  99 ) and two coupled sets of loops of coil  251  are in the circuit (a first set of loops between connection  257  and connection  256  connected to electrical circuit  99 , and a second set of loops between connection  257  and connection  258  connected to ground or some other node in electrical circuit  99 ). 
       FIG. 2F  is a block diagram of variable inductor subsystem  205  according to one embodiment of the present invention, wherein variable inductor  250  is set to a second inductance value. This system is substantially the same as that shown in  FIG. 2E , except that the connecting rod  141  is in a different position that changes the inductance value(s) due to the different number of loops of the coil as determined by wiper  257 . In the alternate position of connecting rod  141  shown in  FIG. 2F , about four (4) loops are between connector  257  near the middle of the coil  251  and the electrical connection  256  at the right end of coil  251  next to its mechanical connection at fixed mechanical location  223 . In some embodiments, the left end of the coil  251  is mechanically connected to fixed location  227 , and in some such embodiments, the left end of the coil  251  also has an electrical connection  258  (e.g., to an electrical ground), and in the alternate position of connecting rod  141  shown in  FIG. 2F  about four-and-a-half (4.5) loops are between connector  257  near the middle of the coil  251  and the electrical connection  258  (e.g., to ground) at the far left end of coil  251  next to its mechanical connection at fixed mechanical location  227 . Thus, in some embodiments, a variable differential coil  250  is provided. 
       FIG. 2G  is a block diagram of a variable inductor subsystem  207  according to one embodiment of the present invention, wherein variable inductor  270  is set to a first inductance value and a first spatial orientation (e.g., elongated left-to-right in  FIG. 2G ). By varying the position of coil-squeezing bar  272 , the shape of the loops of coil  271  can be varied (e.g., from elongate left-to-right, to circular, and to elongate up-to-down), which varies both the inductance and the spatial shape of the magnetic field that is transmitted if a transmitted signal is sent to the coil  271  from circuit  99 , and/or the magnetic field that is detected if the signal from the coil  271  is received by the electrical circuit  99 . In some embodiments, the coil  99  is used simultaneously to both transmit and receive an AC magnetic signal, wherein the magnitude and phase angle of the received signal is detected by applying the transmitted signal through a known impedance (such as a resistor) and then subtracting the signal at the coil from the original transmitted signal and subtracting the signal at the coil from a quadrature phase version of the transmitted signal, and then multiplying the two difference values by each other, as is well known in the art (e.g., see U.S. Pat. No. 6,636,037 and U.S. Pat. No. 6,002,251, both of which are incorporated herein by reference). 
       FIG. 2H  is a block diagram of variable inductor subsystem  207  according to one embodiment of the present invention, wherein variable inductor  270  is set to a second inductance value and a second spatial orientation (e.g., elongated up-to-down in  FIG. 2G ). In some embodiments, the second inductance (from  FIG. 2H ) is the same as the first inductance (from  FIG. 2G ), but the spatial shape and/or direction of the magnetic field has been changed. In other embodiments, both the inductance and the spatial shape are varied. 
       FIG. 2 i    is a block diagram of a variable-position inductor subsystem  208  according to one embodiment of the present invention, wherein variable-position inductor  280  is set to a first position (e.g., such that the direction of the AC magnetic is upper-right-to-lower-left in  FIG. 2 i   ). In some embodiments, the second inductance (from  FIG. 2J ) is the same as the first inductance (from  FIG. 2 i   ), but the spatial direction of the magnetic field has been changed. 
       FIG. 2J  is a block diagram of variable-position inductor subsystem  208  according to one embodiment of the present invention, wherein variable-position inductor  280  is set to a second position (e.g., such that the direction of the AC magnetic is upper-left-to-lower-right in  FIG. 2 i   ). In some embodiments, the second inductance (from  FIG. 2J ) is the same as the first inductance (from  FIG. 2 i   ), but the spatial direction of the magnetic field has been varied. 
       FIG. 2K  is a block diagram of a variable-shape inductor subsystem  209  according to one embodiment of the present invention, wherein variable-shape inductor  290  is set to a first shape. This configuration is substantially similar to that of  FIG. 2G , except that the number of loops of coil  290  is just one in some embodiments. 
       FIG. 2L  is a block diagram of variable-shape inductor subsystem  209  according to one embodiment of the present invention, wherein variable-shape inductor  290  is set to a second shape. This configuration is substantially similar to that of  FIG. 2H , except that the number of loops of coil  290  is just one in some embodiments. In some embodiments, the second inductance (from  FIG. 2L ) is the same as the first inductance (from  FIG. 2K ), but the spatial shape and/or direction of the magnetic field has been changed. In other embodiments, both the inductance and the spatial shape are varied. 
       FIG. 3A  is a block diagram of a variable resistor subsystem  301  according to one embodiment of the present invention, wherein variable resistor  320  is set to a first resistance value. In some embodiments, variable resistor  320  includes a resistive element  321  having a resistance r per unit length, and a conductive wiper  322  configured to move along the length of and to contact resistive element  321  at a plurality of locations. In some embodiments, the wiping motion provides a smoothly continuous plurality of locations for the location of contact and the length l for the resistor, and thus a smoothly continuous plurality of resistances. In some embodiments, the resistance between wiper  322  and the left end  324  is substantially R=rl, where the length l is dependent on the position of wiper  322  relative to the left end, and the resistance between wiper  322  and the left end  324  is substantially R=r(L−l) where L is the entire resistance length between left end electrical contact  324  and right end electrical contact  325 . In some embodiments, the resistance per unit length is a function of position (such as to produce a logarithmic resistance scale). In the embodiment shown, motor  140  is used to vary the position of the wiper  322 , moving it left to decrease the resistance to the left end and increase the resistance to the right end, while conversely moving it right to increase the resistance to the left end and decrease the resistance to the right end. In some embodiments, resistive element  321  is affixed (e.g., at both ends) to a fixed location  323 , while the wiper  322  is connected to a movable connecting rod  141 , which is moved to a desired position by motor  140  (in some embodiments, a linear motor, and in some such embodiments, a piezoelectric motor  140 ) under the control of motor controller  145 . In some embodiments, a feedback signal  146  is used by motor controller  145  to control the position. (Of course, other embodiments may choose to attach the resistive element  321  to the connecting rod  141  making the resistive element  321  movable, and to attach the wiper  322  to a fixed location.) In some embodiments, electrical circuit  99  uses the variable resistor  320  as part of its circuitry (e.g., to set a frequency or pulse width, to control a gain, or other resistance-controlled parameter). In some embodiments, electrical circuit  99  generates feedback signal  146  (e.g., as negative feedback to stabilize the circuit at a given set of parameters). In some embodiments, motor  140  is also affixed to a set location  143  relative to location  323 . In some embodiments, connecting rod  141  is connected to wiper  322  using a mechanically advantaged linkage such as a lever (e.g., such as shown for the variable inductor or variable capacitor in  FIG. 4A  and  FIG. 4B  below). In some embodiments, motor controller  145  produces a non-linear relationship between a value of signal  146  and the resistance obtained by moving rod  141  according to some predetermined function, equation, or look-up table. In the configuration shown in  FIG. 3A , the value of the resistance between wiper  322  and left end  324  is relatively low due to the small resistance length between wiper  322  and left end  324 , while the value of the resistance between wiper  322  and right end  325  is relatively high due to the larger resistance length between wiper  322  and right end  325 . Thus, in some embodiments, variable resistor  320  forms a three-connection (i.e., connections  322 ,  324  and  325 ) potentiometer. In other embodiments, only two connections (e.g., connections  322  and  325 ) are used. 
       FIG. 3B  is a block diagram of variable resistor subsystem  301  according to one embodiment of the present invention, wherein variable resistor  320  is set to a second resistance value. In the configuration shown in  FIG. 3B , the value of the resistance between wiper  322  and left end  324  is relatively high due to the larger resistance length between wiper  322  and left end  324 , while the value of the resistance between wiper  322  and right end  325  is relatively low due to the smaller resistance length between wiper  322  and right end  325 . 
       FIG. 3C  is a block diagram of a variable resistor subsystem  303  according to one embodiment of the present invention, wherein variable resistor  330  is set to a first resistance value. In some embodiments, variable resistor  330  includes an elasto-resistive element  331  having a resistance R that varies as the length of elasto-resistive element  331  is stretched or compressed, and which provides a smoothly continuous plurality of resistances, or a substantially-off/substantially-on switch behavior. In some embodiments, elasto-resistive element  331  is made of non-magnetic materials in order to avoid being affected by high magnetic fields. In some embodiments, an elastomeric material such as described in U.S. Pat. No. 6,495,069 that issued Dec. 17, 2002 to Lussey et al. titled “POLYMER COMPOSITION,” which is incorporated herein by reference. In the embodiment shown, motor  140  is used to move connecting rod  141  to vary the length of (or vary the compression on) elasto-resistive element  331 , moving it left to increase the resistance to the right end, while conversely moving it right to decrease the resistance to the right end. In some embodiments, one end of elasto-resistive element  331  is affixed (e.g., at its right-hand end) to a fixed location  323 , while the other end of elasto-resistive element  331  is connected to a movable connecting rod  141 , which is moved to a desired position by motor  140  (in some embodiments, a linear motor, and in some such embodiments, a piezoelectric motor  140 ) under the control of motor controller  145 . In some embodiments, a feedback signal  146  is used by motor controller  145  to control the position. In some embodiments, electrical circuit  99  uses the variable resistor  330  as part of its circuitry (e.g., to set a frequency or pulse width, to control a gain, or other resistance-controlled parameter). In some embodiments, electrical circuit  99  generates feedback signal  146  (e.g., as negative feedback to stabilize the circuit at a given set of parameters). In some embodiments, motor  140  is also affixed to a set location  143  relative to location  323 . In some embodiments, connecting rod  141  is connected to the movable end of elasto-resistive element  331  using a mechanically advantaged linkage such as a lever (e.g., such as shown for the variable inductor or variable capacitor in  FIG. 4A  and  FIG. 4B  below). In some embodiments, motor controller  145  produces a non-linear relationship between a value of signal  146  and the resistance obtained by moving rod  141  according to some predetermined function, equation, or look-up table. In the configuration shown in  FIG. 3C , the value of the resistance between the movable left end  326  and the fixed right end  325  is relatively high due to stretching of (or lack of compression on) elasto-resistive element  331 . 
       FIG. 3D  is a block diagram of variable resistor  303  according to one embodiment of the present invention, wherein variable resistor  330  is set to a second resistance value. In the configuration shown in  FIG. 3D , the value of the resistance between the movable left end  326  and the fixed right end  325  is relatively low due to non-stretching of (or the compression on) elasto-resistive element  331 . 
       FIG. 4A  is a block diagram of a variable resistor-inductor-capacitor device  401  according to one embodiment of the present invention, wherein variable resistor  320  is set to a first resistance value, variable inductor  230  is set to a first inductance value, and variable capacitor  120  is set to a first capacitance value. In some embodiments, a single piezoelectric motor  140  is linked to simultaneously control a plurality of variable elements as shown in  FIG. 4A  and  FIG. 4B  (which may provide lower cost and a smaller less-massive footprint), while in other embodiments, separate piezoelectric motors  140  are used to control each of a plurality of individual RLC and/or antenna element separately (as shown in  FIGS. 1A-3D  described above and  FIGS. 8A-8M  described below))(which may have a high cost and a larger more-massive footprint, but provides greater programmability and individual adjustments of the various parameters). In some embodiments, device  401  includes a lever arm  449  connected to a fixed position at a pivot point  448 . In some embodiments, a plurality of connecting arms  445  are attached to one or more leverage points on level arm  449 , in order that the movement of motor connecting rod  141  can provide different amounts of movement to each of a plurality of variable electrical components, such as capacitor  120 , inductor  230  and resistor  320 . In the embodiment shown, capacitor  120  is provided the greatest movement per unit of motion of motor connecting rod  141 , inductor  230  a middle amount of movement per unit of motion of motor connecting rod  141  and resistor  320  (in this case, directly connected to motor connecting rod  141 ) the least amount of movement per unit of motion of motor connecting rod  141 . Note also that some components can be attached to receive a compression motion using the same movement of motor connecting rod  141  that provides an expansion motion to other elements (note capacitor  120  is compressed (increasing capacitance) while inductor  230  is extended (decreasing inductance) when motor connecting rod  141  moves left, and capacitor  120  is extended (decreasing capacitance) while inductor  230  is compressed (increasing inductance) when motor connecting rod  141  moves right). Further, the proportions of change can be varied using simple levers or by using more complex mechanical embodiments such as four-arm devices and the like. 
     In the embodiment shown, motor  140  is used to vary the position of the wiper  322  to vary the resistance, to change the amount of area of capacitor  120  to vary the capacitance, and to stretch or compress coil  230  to vary the inductance, each via a single movable connecting rod  141 , which is moved to a desired position by motor  140  (in some embodiments, a linear motor, and in some such embodiments, a piezoelectric motor  140 ) under the control of motor controller  145 . In some embodiments, a feedback signal  146  is used by motor controller  145  to control the position. In some embodiments, electrical circuit  99  uses the variable resistor  320 , variable inductor  230  and variable capacitor  120  as part of an RLC (resistive-inductive-capacitive) part of its circuitry (e.g., to set a frequency or pulse width, change a Q (quality) factor, to control a gain, or other RLC-controlled parameter). In some embodiments, electrical circuit  99  generates feedback signal  146  (e.g., as negative feedback to stabilize the circuit at a given set of parameters). In some embodiments, motor  140  is also affixed to a set location  143  relative to fixed locations  323  and  447 . In some embodiments, connecting rod  141  is connected to wiper  322  also using a mechanically advantaged linkage such as lever  449 . In some embodiments, motor controller  145  produces a non-linear relationship between a value of signal  146  and the position of moving rod  141  according to some predetermined function, equation, or look-up table. In the position configuration shown in  FIG. 4A , the value of the resistance between wiper  322  and left end  324  is relatively low, while the value of the resistance between wiper  322  and right end  325  is relatively high, the value of the inductance is relatively low and the value of the capacitance is relatively high. 
       FIG. 4B  is a block diagram of variable resistor-inductor-capacitor  401  according to one embodiment of the present invention, wherein variable resistor  320  is set to a second resistance value, variable inductor  230  is set to a second inductance value, and variable capacitor  120  is set to a second capacitance value. In the position configuration shown in  FIG. 4A , the value of the resistance between wiper  322  and left end  324  is relatively high, while the value of the resistance between wiper  322  and right end  325  is relatively low, the value of the inductance is relatively high and the value of the capacitance is relatively low. 
       FIG. 5  is a block diagram of a variable resistor-inductor-capacitor  500  according to one embodiment of the present invention, wherein variable resistor  503  is set to a first resistance value, variable inductor  502  is set to a first inductance value, and variable capacitor  501  is set to a first capacitance value. In some embodiments, one or more of the variable resistor-inductor-capacitor components  500  are switched to a plurality of discrete values using switches  546  that are controlled by the motion of connecting rod  141  as it is moved by motor  140  as described above. In some embodiments (not shown here), each switch  546  is an elastomeric switch (such as described in U.S. Pat. No. 6,495,069 issued Dec. 17, 2002 to Lussey et al. which is incorporated herein by reference) that avoids transients and sparking by compressing the granule-filled polymer using the mechanical pressure of the end of lever arm  449  against the polymer material to make the connection to one or another of the capacitor, inductor, and/or resistors that can thus be selectively switched in or out to circuit  99 . In some embodiments, the switched components includes a switch between an open (infinite resistance) and a short (zero resistance), or a switch that variously connects different nodes in circuit  99 . In some embodiments, the switched components includes a switch that connects different antenna elements to circuit  99 , or selectively switches between two or more antenna elements connected to one another or disconnected from one another. 
       FIG. 6  is a block diagram of an entire system  600  according to one embodiment of the present invention, wherein variable electrical components of circuits  99 A and/or  99 B (particularly those in the portion labeled  99 A in a remote environment  602 ) are controlled to values set by controller  601 . In some embodiments, circuit  99  has two portions, a first portion  99 A that is remote from a second portion  99 B. In some embodiments, circuit portion  99 A is coupled to circuit portion  99 B by a transmission line  119  (having a characteristic impedance Z at a given operating frequency or spectrum) such as a coaxial cable. In some embodiments, controller  601  is well outside of the remote environment  602  (such as a high magnetic field enclosure, or a broadcast television antenna on a tower, or a remote weather sensor) that includes circuit portion  99 A and its RLC components controlled by piezo motor  140  and/or its controller rod  141 . In other embodiments, both portions  99 A and  99 B of circuit  99  (not explicitly labeled as such, but which includes both circuit portions  99 A and  99 B) are in a remote location. In some embodiments, electrical circuit  99 B includes a transmitter, a receiver, or both. 
     One use of the present invention is to balance an RLC circuit wherein the inductance and/or capacitance parameters of at least a portion of the RLC circuit is affected by an external and variable disturbance  66  such as weather conditions or a conductive and/or dielectric body (e.g., such as when the frequency and/or impedance in relation to a transmission-line-signal connection of the circuit must be maintained for optimal performance, but the environment changes over time), wherein the variable disturbance  66  must be accommodated by changing the variable inductor and/or the variable capacitor. Accordingly, in some embodiments, an impedance-mismatch detector  641  and/or a voltage-standing-wave-ratio (VSWR) detector  642  are used to determine whether and how to modify the values of the inductance and capacitance in order to rebalance the impedance. For example, if circuit portion  99 A has a characteristic impedance Z 0 , transmission line  641  has the same characteristic impedance Z 0 , and circuit portion  99 B has the same characteristic impedance Z 0 , then the circuit would be considered balanced. In some embodiments, the characteristic RLC values also determine a characteristic frequency F 0  or characteristic Q 0  (the quality of a resonant circuit). If then the variable disturbance  66  modifies the characteristic impedance of circuit portion  99 A to a changed characteristic impedance Z 0 +ΔZ, then impedance-mismatch detector  641  and/or a voltage-standing-wave-ratio detector  642  would detect the change, and they send signal(s) to motor controller  145 , which causes motor  140  to modify the variable portion(s) of capacitance and/or inductance to rebalance the impedances of each portion. If then the variable disturbance  66  changes and modifies the characteristic frequency F 0  or characteristic Q 0  of circuit portion  99 A (by changing an RLC parameter) combined with circuit portion  99 B to a changed characteristic frequency F 0 +ΔF or characteristic Q 0 +ΔQ, then frequency detector  643  and/or a Q detector (not shown) would detect the change, and they send signal(s) to motor controller  145 , which causes motor  140  to modify the variable portion(s) of capacitance and/or inductance to reset the frequency and/or Q of each portion. 
     In some embodiments, each of the components within remote environment  602  is made of materials that do not contain combinations of iron, nickel, cobalt, or the like that may be moved (physically displaced) by the high field, in order that the high field does not move these components. 
     In some embodiments, all or the relevant components are in a single location, and the present invention is used to adjust component parameters to compensate for some environmental change or a change in the physical surroundings of the circuit that affected any of the RLC parameters. For example, the mere presence of a person or other modality (that might be used to tune some aspect of a circuit) might adversely affect a resistance, inductance or capacitance. In those cases, some embodiments of the invention facilitate the adjustment of the resistance, inductance or capacitance values without a person needing to be in the vicinity. As another example, some circuits may need to be tuned to have a certain resistance, inductance and capacitance in the presence of a person (where a person in the vicinity changes these parameters by their presence, or due to physical or physiological motion (e.g., breathing, heart beating, gastrointestinal movement, and the like) by the person), but the position, body composition and size of the person is unknown and must be compensated for, and some embodiments of the invention facilitate the adjustment of the resistance, inductance or capacitance values to automatically compensate for those characteristics of the person in the vicinity. In some embodiments, conventional magnet-based motors or electric-field based motors themselves would have an undesired effect on the resistance, inductance and capacitance of a sensitive circuit (or such motors could themselves be adversely affected by high magnetic or electric fields), so piezo-electric motors as described herein have the advantage of not interacting (or interacting very little) with the resistance, inductance and capacitance being adjusted. 
       FIG. 7A  is a block diagram of an impedance-matched high-frequency circuit  700  according to one embodiment of the present invention, and having an external impedance disturbance  66  having a first effect on circuit  700 . In some embodiments, a driver circuit  720  has a characteristic impedance Z 0  composed of (or modeled by) an equivalent capacitance  721 , equivalent inductance  722 , equivalent resistance  723 , and ideal voltage source driver  745  (which outputs a voltage signal having one or more frequency components and optionally a DC component, but is modeled as having a very high or infinite impedance such that its impedance does not affect the circuit). In other embodiments, ideal voltage source driver  745  is replaced by an ideal voltage sensor or transceiver (transmitter-receiver combination) (having a very high or infinite impedance such that its impedance does not affect the circuit). Of course, in other embodiments, the parallel connection of equivalent capacitance  721 , equivalent inductance  722 , equivalent resistance  723  and voltage source  745  can be replaced with a series-wired connection of a capacitance, inductance, resistance and an ideal current source (and/or ideal current detector, each having zero or negligible impedance) that can provide the same characteristic impedance Z 0 . Driver circuit  720  is electrically coupled to a transmission line segment  730  (i.e., of transmission line  119  as shown in the other various Figures herein) also having the characteristic impedance Z 0  at the respective frequencies of interest in the signal, and transmission line segment  730  is in turn electrically coupled to a tuned circuit  710 , which, in some embodiments, includes an equivalent capacitance (that includes a fixed capacitance component  711  and a variable capacitance component  701  that can be tuned as described above for  FIG. 1A ,  FIG. 1B ,  FIG. 1C , and  FIG. 1D ), an equivalent inductance (that includes a fixed inductance component  712  and a variable inductance component  702  that can be tuned as described above for  FIG. 2A ,  FIG. 2B ,  FIG. 2C ,  FIG. 2D ,  FIG. 2E ,  FIG. 2F ,  FIG. 2G ,  FIG. 2H ,  FIG. 2 i   ,  FIG. 2J ,  FIG. 2K , and  FIG. 2L , as well as the inductance of the antenna elements in  FIG. 8A ,  FIG. 8B ,  FIG. 8C ,  FIG. 8D ,  FIG. 8L  and  FIG. 8M ), and an equivalent resistance (that includes a fixed resistance component  713  and a variable resistance component  703  that can be tuned as described above for  FIG. 3A ,  FIG. 3B ,  FIG. 3C  and  FIG. 3D ). In some embodiments, at least one variable antenna element  704  is optionally included (e.g., in some embodiments, coupled to the upper nodes of variable capacitor  701 , variable inductor  702 , and variable resistor  702 , wherein the physical length, position and shape of one or more antenna elements are varied (such as described in  FIGS. 8A-8M ) under the control of detector-controller  601 ). In some embodiments, when in the presence of a variable disturbance  66  having a first characteristic (such as a piece of material, a person, or a weather situation), the capacitance, inductance and/or resistance of tuned circuit  710  are adjusted by varying the variable aspects of variable capacitance component  701 , variable inductance component  702  and variable resistance component  703  using one or more sensing units (such as detectors  641 ,  642  and  643  of  FIG. 6 ) and one or more motor controllers  145  and motors  140 . In some embodiments, a detector-controller  601  (which may include circuit and/or microprocessor components, such as described above for  FIG. 6 ) is coupled (e.g., in some embodiments, connected to transmission line  119 ) to measure electrical parameters of the signals (e.g., at the left end of transmission line  119 ), and based on the measurement(s), to control the variable parameters (e.g., resistance, inductance, capacitance, antenna length, resonant frequency, impedance at a given frequency, field shape, field direction, field spatial shape, field intensity, and like characteristics) in the remote tuned circuit  710 . 
       FIG. 7B  is a block diagram of impedance-matched high-frequency circuit  700 , and having a different external impedance disturbance  66 ′ having a second effect on circuit  700 . In some embodiments, the present invention is used to adjust the RLC parameters of variable components  703 ,  702  and  701  in order to rebalance the circuit (in terms of characteristic impedance, frequency, Q, and/or other factor) in the presence of the changed external impedance disturbance  66 ′. In some embodiments, the present invention provides the capability to automatically adjust such parameters in the adjusted tuned circuit  710 ′ “in real time” (i.e., quickly as the external impedance disturbance  66 ′ changes over time). 
       FIG. 8A  is a block diagram of a variable antenna subsystem  801  according to one embodiment of the present invention, wherein variable antenna  810  is set to a first length. In some embodiments, variable antenna  810  includes a plurality of slidingly connected conductor segments (e.g., concentric metal tubes or a central metal rod and a close-fitting metal sleeve)  812  and  815  (which, in some embodiments, are touching one another, and in other embodiments, are separated from one another by a dielectric material such as a TEFLON™ tube separator or air), such that when segment  812  is inserted further into segment  815 , the antenna gets shorter, and thus the characteristic resonant frequency of antenna  810  goes up. In the configuration shown in  FIG. 8A , the length of the antenna is resonant at a frequency that is relatively low (i.e., lower than when the conductive central  812  is in the position shown in  FIG. 8B ) due to the longer antenna because of the small amount of overlapped length between central conductor  812  and sleeve conductor  815 . 
       FIG. 8B  is a block diagram of variable antenna subsystem  801  according to one embodiment of the present invention, wherein variable antenna  810  is set to a second length (e.g., by conductive central segment  812  being pushed a distance into. In the configuration shown in  FIG. 8B , the length of the antenna is resonant at a frequency that is relatively high (i.e., higher than when the conductive core  812  is in the position shown in  FIG. 8A ) due to the shorter antenna because of the larger amount of overlapped length between conductor  812  and conductor  815 . 
       FIG. 8C  is a block diagram of a variable antenna array subsystem  802  according to one embodiment of the present invention, wherein variable antenna array  820  is set to a first spacing. In some embodiments of the configuration shown in  FIG. 8C , the phase difference of the signals at a given frequency between the various antenna segments  825  is relatively large (i.e., larger than when the antenna segments  825  are in the positions shown in  FIG. 8D ) due to the longer spaces between antenna segments  825 . For example, for a phased-array antenna system, the varied phase differences between antenna segments  825  can be used to point the resulting radio beam in different directions. In other embodiments of the configuration shown in  FIG. 8C , the frequency supported for a given (predetermined) phase difference between the various antenna segments  825  is relatively low (i.e., lower than when the antenna segments  825  are in the positions shown in  FIG. 8D ) due to the longer spaces between antenna segments  825 . 
       FIG. 8D  is a block diagram of variable antenna array subsystem  802  according to one embodiment of the present invention, wherein variable antenna array  820  is set to a second spacing. In some embodiments of the configuration shown in  FIG. 8D , the phase difference of the signals at a given frequency between the various antenna segments  825  is relatively small (i.e., smaller than when the antenna segments  825  are in the positions shown in  FIG. 8C ) due to the shorter distances between antenna segments  825 . In other embodiments of the configuration shown in  FIG. 8C , the frequency supported for a given (predetermined) phase difference between the various antenna segments  825  is relatively high (i.e., higher than when the antenna segments  825  are in the positions shown in  FIG. 8D ) due to the shorter distances between antenna segments  825 . 
       FIG. 8E  is a block diagram of a variable antenna array subsystem  803  according to one embodiment of the present invention, wherein variable antenna array  830  is set to a first length. In some embodiments, variable antenna array  830  includes a plurality of antenna elements  838  each having sliding segments  832  and  835  (e.g., concentric segments that slide one inside the other, or side-by-side wires clamped to one another) or extendable single elements such as described in  FIG. 8L  and  FIG. 8M  below. In some embodiments, a fixed base frame  223  holds one end of all the antenna elements and a movable frame  833  holds the opposite ends of all the antenna elements  838 , wherein movable frame  833  is attached to connecting rod  141 , which is controlled by motor  140 , in order to simultaneously extend or shorten the lengths of a plurality of antenna elements  838  simultaneously. In some embodiments, each of a plurality of the antenna elements  838  is also individually adjustable in physical length such as described in  FIG. 8A ,  FIG. 8B ,  FIG. 8C ,  FIG. 8D ,  FIG. 8L , and  FIG. 8M , and/or adjustable in electrical length, resonant frequency, impedance and/or other characteristic (such as controlling the length(s), direction(s), strength, shape, and/or temporal changes of the radio-frequency electromagnetic field) such as described in  FIG. 8G ,  FIG. 8H ,  FIG. 8 i   ,  FIG. 8J , and/or  FIG. 8K . In some embodiments, a plurality of the antenna elements  838  are driven by a transmitted radio-frequency signal (for example, as shown in  FIG. 8E , in some embodiments, the two antenna elements  838  that are labeled element  837  and element  839  are driven by two different phases of the same transmitted RF signal (e.g., the signal with zero phase shift can be applied to element  837  and the same signal but with a ninety-degree phase shift can be applied to element  839 , wherein element  837  and element  839  are physically located ninety degrees from one another relative to a central (left-to-right) horizontal axis of antenna array  830 ; in other embodiments, other phase shifts and corresponding physical angular displacements can be used). In some such embodiments, each of the remaining antenna elements  838  (those other than element  837  and  839 ) are each connected to a respective receiver (such as electrical circuit  99  configured as a receiver but not shown here) through a respective transmission line (such as transmission line  119  but not shown here), such that the antenna lengths of the transmitting antenna elements  837  and  839  and the passive and/or receiving antenna elements  838 , can all be adjusted simultaneously, and optionally also individually. In some embodiments, a mechanical linkage is provided (e.g., such as shown in  FIG. 4A  and  FIG. 4B ) such that each of a plurality of the antenna elements is length-adjusted by a different amount (e.g., in some embodiments, by adjusting the tilt of movable frame  833  by a lever such as lever  449  connected to pivot  448  connected to fixed location  447  as shown in  FIG. 4A ). In some embodiments, a plurality of the antenna elements  838  are each a different length relative to one another (i.e., a first set of lengths applied to the set of antenna elements  838 ) at this setting of connecting rod  141 . 
       FIG. 8F  is a block diagram of variable antenna array subsystem  803  according to one embodiment of the present invention, wherein variable antenna array  830  is set to a second length that is different than the first length shown in  FIG. 8E . As shown in  FIG. 8F , the connecting rod  141  has been extended to the right, which has shortened each of a plurality of the antenna elements  838  by a respective physical-length amount controlled by electrical circuit  99 , motor controller  145  and motor  140 . In some embodiments, the plurality of the antenna elements  838  are each a different length relative to one another (i.e., a second set of lengths applied to the set of antenna elements  838  that is different than the first set of lengths shown and described for  FIG. 8E  above) at this setting of connecting rod  141 . 
       FIG. 8G  is a block diagram of an antenna array subsystem  806  having one or more active-variable-antenna element subsystems  804  and/or one or more passive-variable-antenna element subsystems  805  according to one embodiment of the present invention, wherein active-variable-antenna element subsystems  804  is set to a first impedance-frequency value and passive-variable-antenna element subsystems  805  is set to a second impedance-frequency value (in some embodiments, the first impedance-frequency value and the second impedance-frequency value are equal to one another). In some embodiments, each active-variable-antenna element subsystem  804  includes an electrical circuit  99  (e.g., each electrical circuit  99  is configured to transmit an RF signal to (and/or receive an RF signal from) its active-variable-antenna element subsystem  804 ) connected by a transmission line  119  through subsystem  804 &#39;s series-connected variable capacitor  102 ′ (i.e., the left-hand end of transmission line  119  is connected to the left-hand node of capacitor  102 ′ of active-variable-antenna element subsystem  804 , while the right-hand node of series-connected variable capacitor  102 ′ of subsystem  804  is connected to the right-hand node of parallel-connected variable capacitor  102  of subsystem  804  and to the right-hand end of variable antenna  801  of subsystem  804 ) to subsystem  804 &#39;s parallel-connected variable capacitor  102  (i.e., wherein parallel-connected capacitor  102  is connected between the right-hand node of series-connected variable capacitor  102 ′ and electrical ground  896 ) and to a point (e.g., to one end) on subsystem  804 &#39;s variable antenna element  801 . 
     In some embodiments, each passive-variable-antenna element subsystem  805  is not connected to an electrical circuit  99  (in contrast to the passive-variable-antenna element subsystem(s)  805 ), but instead (in order to be otherwise symmetrical and equivalent to the active-variable-antenna element subsystem(s)  804 ) may be connected by a terminated transmission line  119 ′ (e.g., in  FIG. 8G , terminated transmission line  119 ′ is shown connected at its right-hand end to a matched terminating resistive impedance  897  to a ground  898 ) through subsystem  805 &#39;s series-connected variable capacitor  102 ′ (i.e., the left-hand end of terminated transmission line  119 ′ is connected to the left-hand node of capacitor  102 ′ of passive-variable-antenna element subsystem  805 , while the right-hand node of series-connected variable capacitor  102 ′ of subsystem  805  is connected to the right-hand node of parallel-connected variable capacitor  102  of subsystem  805  and to the right-hand end of variable antenna  801  of subsystem  805 ) to subsystem  805 &#39;s parallel-connected variable capacitor  102  (i.e., wherein parallel-connected capacitor  102  of subsystem  805  is connected between the right-hand node of series-connected variable capacitor  102 ′ of subsystem  805  and electrical ground  896 ) and to a point (e.g., to one end) on variable antenna element  801  of subsystem  805 . In some embodiments, the impedance of subsystem  805 &#39;s circuit portion that includes antenna  801 , parallel-connected capacitor  102  and series-connected capacitor  102 ′ together, is matched to the impedance of terminated transmission line  119 ′. In other embodiments, series-connected variable capacitor  102 ′ and terminated transmission line  119 ′ are omitted (since they would be matched to the impedance of subsystem  805 &#39;s antenna  801  and parallel-connected capacitor  102 , and motor controller  141 ′ controls the characteristics of parallel-connected variable capacitor  102  of subsystem  805  and of variable antenna  801  of subsystem  805  to match the characteristics of the one or more active-variable-antenna element subsystems  804 . 
     In some such embodiments, the set of active-variable-antenna element subsystems  804  includes one or more elements  810  each connected to an RF transmitter (e.g., in some embodiments, two elements that are physically located ninety degrees apart are driven by two respective RF signals that have phases that are ninety degrees apart from each other) (e.g., see  FIG. 8E ). In some embodiments, the set of passive-variable-antenna element subsystems  805  includes one or more elements  810  each configured to shape and/or set a direction for the RF electromagnetic field created by the set of active-variable-antenna element subsystems  804  connected to the transmitter. In some embodiments, the set of active-variable-antenna element subsystems  804  also includes one or more elements  810  each connected to an RF receiver configured to receive an RF signal from its respective active-variable-antenna element subsystem  804 . In some embodiments, such a set of active-variable-antenna element subsystems  804  configured to receive an RF signal is also part of the system used to shape and/or set a direction for the RF electromagnetic field created by the set of active-variable-antenna element subsystems  804  connected to the transmitter. 
     FIG.  8 G 1  (on the last sheet of Figures) is a circuit diagram of antenna array subsystem  806  having one or more active-variable-antenna element subsystems  804  and/or one or more passive-variable-antenna element subsystems  805  according to one embodiment of the present invention (such as shown in  FIG. 8G ). This is just a circuit diagram of the subsystem  806  shown in  FIG. 8G  described above. 
     In other embodiments, any combination of variable reactance elements (variable resistor elements, variable inductor elements and/or variable capacitor elements) can be substituted for the variable capacitors  102  and  102 ′ shown in  FIG. 8G  and FIG.  8 G 1 . 
       FIG. 8H  is a block diagram of variable antenna array subsystem  807  according to one embodiment of the present invention, wherein variable antenna array  870  is set to a first dielectric configuration (which can be used to generally change the impedance, which affects the magnitude and phase angle of the signal in the RF field). In some such embodiments, a dielectric material such as a dielectric slug  872  is moved within the RF field of a plurality of antenna elements  875  and  876 . Moving the dielectric slug  872  to different positions within the field of the array of antenna elements  875  and  876  changes the direction and/or shape of the field, and/or changes the resonant frequency and/or impedance of the antenna elements  875  and  876 . In some embodiments, the movement of one or more of such dielectric slugs  872  is used to automatically adjust for other varying conditions such as the presence or physical movement of a patient in a magnetic-resonance machine for imaging. 
       FIG. 8 i    is a block diagram of variable antenna array subsystem  807  according to one embodiment of the present invention, wherein variable antenna array  870  is set to a second dielectric configuration. In some embodiments, the automatic movement to this second dielectric configuration compensates for the presence or movement of some other dielectric material (such as a person) in the RF field of the antenna elements  876  and  875 . 
       FIG. 8J  is a block diagram of variable antenna array subsystem  808  having a reconfigurable dielectric fluid according to one embodiment of the present invention, wherein variable antenna array  880  is set to a first dielectric-fluid configuration. The concept of moving dielectric material (in this case, a dielectric fluid) in variable antenna array subsystem  808  of  FIG. 8J  is similar to the concept of moving dielectric material (in that case, a dielectric solid) in variable antenna array subsystem  807  of  FIG. 8H  and  FIG. 8 i   , except that subsystem  808  uses a pump  880  and tubing  881  to convey one or more volumes of dielectric fluid  882  and/or  883  into and out of (or back-and-forth between) corresponding chambers in the RF field of the plurality of antenna elements  876  and  875 . When the dielectric fluid is pumped, a plurality of different dielectric configurations can be automatically controlled via circuit  99  and pump controller  885 . 
     Note that the dotted-line enclosure labeled  710  in  FIG. 8J  and  FIG. 8K  represents the environment in which the components therein are located (e.g., the remote environment labeled  710  in  FIG. 7A ). In each of the other Figures herein, a similar dotted line can be assumed to designate the non-magnetic mechanical movement device (e.g., motor  140  or pump  880 ) and the resistor, inductor, capacitor, antenna, dielectric, or mechanical devices that are controlled or varied by the non-magnetic mechanical movement device. 
       FIG. 8K  is a block diagram of variable antenna array subsystem  809  having a reconfigurable dielectric fluid according to one embodiment of the present invention, wherein variable antenna array  890  is set to a first dielectric-fluid configuration. In some embodiments, subsystem  809  is conceptually similar to subsystem  808  of  FIG. 8J , except that the shapes of the containers  884 ,  885  and  886  (e.g., bladders that can be filled or emptied and shaped to compensate for the presence or movement of other dielectric bodies such as a person) are variable (e.g., when the dielectric fluid is pumped, a plurality of different dielectric volume configurations can be automatically controlled via circuit  99  and pump controller  885 , and the shape of the containers  884 ,  885  and  886  can be controlled by their inherent shape as manufactured and/or by the shapes they take on due to the presence or movement of a person pressing against them). 
       FIG. 8L  is a block diagram of a variable antenna subsystem  811  according to one embodiment of the present invention, wherein variable-length antenna  891  is set to a first length. In some embodiments, variable-length antenna  891  includes a small-diameter metal spring that can be extended from its relaxed state by pulling from connecting rod  141  to form an antenna whose length is controlled by motor  140 , motor controller  145  and electrical circuit  99 . In some embodiments, both the physical length and the electrical inductance of the antenna element  891  are varied as its length is extended or shortened by connecting rod  141 . 
       FIG. 8M  is a block diagram of a variable antenna subsystem  813  according to one embodiment of the present invention, wherein variable antenna  893  is set to a first length. In some embodiments, a rotary motor  894  rotates a spool of metal wire such that a variable length of wire  897  extends into a constrained linear shape (e.g., such as constraining the wire  897  to extend or shorten within a glass tube  896  (which in some embodiments, can be straight, or in other embodiments, can be curved to a variety of desired shapes (e.g., curves or spirals) by the shape of the tube  896 )). 
       FIG. 9  is a block diagram of feedback-controlled system  901  having one or more variable-resistance, variable inductance, variable capacitance, variable-antenna, variable-mechanical-position or shape robotics, variable-gain, variable-frequency (ω) or variable-wavelength (λ), variable-phase (φ), and like variable-component-value elements in a circuit  920 , controlled by a feedback circuit  930  according to one embodiment of the present invention. In some embodiments, system  901  includes an input signal  960  that is transmitted to or in a circuit  920  in remote environment  910 . Output signal  950  is the desired result, and in some embodiments, provides feedback signal  931  to feedback circuit  930 , which generates a control signal  932  based on the feedback signal  931 , wherein the control signal  932  is used to control electrically controlled non-magnetic mechanical movement devices to vary the variable-component-value or position or shape elements of circuit  920 . 
     In some embodiments, the present invention provides an algorithm to drive the tuning and matching, which includes dual directional couplers that monitor the forward, V + , and reflected, V − , voltage at some distance, l, from the coil. The reflection coefficient, Γ(l), is the ratio of the reflected to forward voltage at the dual directional couplers. 
                     Γ   ⁡     (   l   )       =         V   -     ⁡     (   l   )           V   +     ⁡     (   l   )                 [     Eqn   .           ⁢   1     ]               
The reflection coefficient at the coil, Γ(0) is:
 
                     Γ   ⁡     (   0   )       =       Γ   ⁡     (   l   )         ⅇ       -   2     ⁢           ⁢   γ   ⁢           ⁢   l                 [     Eqn   .           ⁢   2     ]               
where γ is the complex propagation constant which takes into account of the cable&#39;s attenuation and phase constants.
 
The complex impedance of the coil, Z C  is:
 
     
       
         
           
             
               
                 
                   
                     Z 
                     C 
                   
                   = 
                   
                     
                       
                         Z 
                         0 
                       
                       ⁢ 
                       
                         
                           1 
                           + 
                           
                             Γ 
                             ⁡ 
                             
                               ( 
                               0 
                               ) 
                             
                           
                         
                         
                           1 
                           - 
                           
                             Γ 
                             ⁡ 
                             
                               ( 
                               0 
                               ) 
                             
                           
                         
                       
                     
                     = 
                     
                       
                         R 
                         C 
                       
                       + 
                       
                         j 
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         
                           X 
                           C 
                         
                       
                     
                   
                 
               
               
                 
                   [ 
                   
                     Eqn 
                     . 
                     
                         
                     
                     ⁢ 
                     3 
                   
                   ] 
                 
               
             
           
         
       
     
     where Z 0  is the nominal cable impedance (50Ω) and R C  and X C  the real and imaginary complex impedance of the coil, respectively. Tuning and matching the coil becomes simple. Tuning occurs by minimizing jX C ; similarly matching is defined by driving R C  to 50Ω. 
       FIG. 10  is a flowchart of a method  1000  according to some embodiments of the invention. In some embodiments, method  1000  starts by selecting  1010  one or more (e.g., in some embodiments, a plurality of) criteria (in some embodiments, parameters such as impedance and frequency, in other embodiments, any other desired condition) to optimize. Next, a circuit (e.g., under control of non-magnetic mechanical movement devices) performs configuring  1011  for excitation (e.g., transmitting to or receiving from) the remote circuit elements. The next block includes delivering  1012  the excitation. The next block includes detecting  1014  a received signal from the remote elements. The next block includes checking  1015  for satisfactory parameters (e.g., the impedance and frequency of the signal) of the received signal from the remote elements. If the result is unsatisfactory, the method then includes adjusting  1017  one or more of the variable reactance elements using the non-magnetic mechanical movement device(s) and going to block  1011  to iteratively repeat the process  1011  through  1015 . If the result of checking  1015  is satisfactory, the method goes to performing  1016  the operation for which the components were adjusted (e.g., obtaining a magnetic resonance result (such as an image). 
     In some embodiments, the present invention uses a piezo motor such as the model SQL-3.4 or the SQ-100 series devices available from Squiggle Motors, New Scale Technologies, Rochester, N.Y. (www.newscaletech.com/product_finder.html) or the model NEXACT N-310 available from NexLine/NexAct and PILine motors, Physik Instrumente (PI) GmbH &amp; Co. Kg, Karlsruhe, Germany (e.g., a N-310 NEXACT® OEM Miniature Linear Motor/Actuator, which provides a Compact, High-Speed PiezoWalk® Drive, such as N-310 Actuator with E-861 Servo-Controller (integrated drive electronics) having a 20 mm standard travel range, a flexible choice of the runner length, a compact and cost-effective design, a 0.03 nm resolution, up to 10 n push/pull force, a low operating voltage, a self-locking rest position, no head dissipation, nanometer stability, and a non-magnetic and vacuum-compatible working principle, in a compact package of only 25×25×12 mm. (www.physikinstrumente.com/en/products/piezo_motor/linear_motor_selection.php?table=all). 
     The present invention provides variable resistors, inductors and/or capacitors that have their electrical-circuit values controlled by one or more electrically controlled mechanical positioners. In some embodiments, the electrically controlled mechanical positioners (such as piezo-electrical linear motors) and other elements that are used to make the resistors, inductors and/or capacitors include metals that have only substantially non-magnetic components such that the resistors, inductors and/or capacitors and the mechanical positioner(s) that adjust their variable values can be placed and operated within and/or near an extremely high electric field of many thousands of volts (such as connected to or affecting electricity-transmission lines carrying hundreds of thousands of volts and very large currents), or extremely-high magnetic field such as within the very strong superconducting-wire magnets of high-energy particle-physics experiments (such as the Large Hadron Collider) or within magnets of a magnetic-resonance imaging machines, or during and after an electromagnetic pulse (EMP) from a nuclear event. 
     In other embodiments, the present invention provides the ability to adjust very sensitive circuits that do not involve high fields, but instead involve very low fields (such as within completely enclosed Faraday cages (which block low-frequency external fields) that also have radio-frequency (RF) shielding (which block high-frequency external fields) that are measuring very small parameters such as extremely low-voltage circuits where the presence of a person or magnetic motor would change the field, but use of the piezo-electric positioners and motors to adjust the configuration of RLC components without modifying fields or introducing extraneous capacitances or inductances. 
     Some embodiments of the invention include a method that includes providing an electrical component, and based on an electrical signal, automatically moving a movable portion of the electrical component in relation to another portion of the electrical component to vary at least one of its parameters. 
     In some embodiments of the method, the moving further comprises moving using a piezo-electric motor. 
     In some embodiments of the method, the electrical component includes an inductor, and wherein the at least one of its parameters includes an inductance. In some embodiments of the method, the electrical component includes a capacitor, and wherein the at least one of its parameters includes a capacitance. In some embodiments of the method, the electrical component includes a resistor, and wherein the at least one of its parameters includes a resistance. 
     Some embodiments of the method further include using a programmable information-processing device operatively coupled to control the moving of the movable portion of the electrical component in order to vary an electrical parameter of the electrical component. 
     Some embodiments of the method further include using an analog feedback-circuit device operatively coupled to control the moving of the movable portion of the electrical component in order to vary an electrical parameter of the electrical component. 
     Some embodiments of the method further include using a feedback signal operatively coupled to the programmable information-processing device to provide feedback control in order to maintain the electrical parameter of the electrical component. 
     Some embodiments of the invention include a computer-readable medium having instructions stored thereon for causing a suitably programmed information processor to execute a method that includes controlling moving of a movable portion of the electrical component in relation to another portion of the electrical component to vary at least one electrical parameter of the electrical component. 
     In some embodiments of the medium, the method further includes using a feedback signal operatively coupled to the programmable information-processing device to provide feedback control in order to maintain the electrical parameter of the electrical component. 
     In some embodiments of the medium, the method further includes controlling resistance, inductance and capacitance (RLC) values of a circuit. In some embodiments of the medium, the method further includes controlling antenna length, resonant frequency, impedance matching between transmitters, transmission lines and receivers of a signal, and/or shape, direction, and/or amplitude of a static and/or temporally varying AC electromagnetic field. 
     Some embodiments of the invention include an apparatus that includes a non-magnetic positioner, and an electrical component connected to the motor and configured to have at least one of its parameters varied by the positioner. In some embodiments of the apparatus, the positioner comprises a piezo-electric motor. In some embodiments of the apparatus, the electrical component includes an inductor, and wherein the at least one of its parameters includes an inductance. In some embodiments of the apparatus, the electrical component includes a capacitor, and wherein the at least one of its parameters includes a capacitance. In some embodiments of the apparatus, the electrical component includes a resistor, and wherein the at least one of its parameters includes a resistance. Some embodiments further include a programmable information-processing device operatively coupled to control the positioner in order to vary an electrical parameter of the electrical component. Some embodiments further include a feedback circuit operatively coupled to the programmable information-processing device to provide feedback control of the positioner in order to maintain the electrical parameter of the electrical component. 
     Some embodiments of the invention include an apparatus that includes an electrical component, and means, as described and shown herein and equivalents thereof, for automatically moving, based on an electrical signal, a movable portion of the electrical component in relation to another portion of the electrical component to vary at least one of its parameters. In some embodiments of the apparatus, the means for automatically moving further comprises means for automatically moving using a piezo-electric motor. In some embodiments of the apparatus, the electrical component includes an inductor, and wherein the at least one of its parameters includes an inductance. In some embodiments of the apparatus, the electrical component includes a capacitor, and wherein the at least one of its parameters includes a capacitance. In some embodiments of the apparatus, the electrical component includes a resistor, and wherein the at least one of its parameters includes a resistance. Some embodiments of the apparatus further include a programmable information-processing device operatively coupled to control the means for automatically moving of the movable portion of the electrical component in order to vary an electrical parameter of the electrical component. Some embodiments of the apparatus further include means for automatically controlling using feedback control in order to maintain the electrical parameter of the electrical component. 
     In some embodiments, the method of the present invention is executed on a computer at a location remote from a user, and controlled by the user across the internet. In some embodiments, the method is executed on a computer at a location remote from the variable electrical components. In some such embodiments, the method is controlled by the computer across a network. 
     In some embodiments, the system of the present invention includes one or more non-magnetic (e.g., piezoelectric) motors adjusted by its own respective motor controller(s) and feedback circuit(s) to robotically move mechanical parts (levers, hoops, sheets of resilient elastic material, and the like) to achieve robotic control within the high-field or sensitive-field environment in which the RLC and/or antenna elements are adjusted by their own respective motor controllers and feedback circuits. In some such embodiments, the system sets an initial set of parameters (for example, resistance, inductance, capacitance, dielectric shape, frequency, phase, gain/attenuation, temporal properties, spatial properties (the shape of magnetic or electric fields), pulse width, mechanical position and orientation, or other controlled parameter) and a feedback circuit senses the result (one or more characteristics or parameters) and automatically adjusts the components (for example, variable resistors, inductors, capacitors, antennas, dielectric shapes, mechanical positioners and the like) in the system to compensate or control the system to achieve a desired result (e.g., a radar signal, magnetic-resonance or electron-spin image, or other desired system output). 
     In some embodiments, the one or more non-magnetic (e.g., piezoelectric) motors actuate control over electrical switches, amplitude modulators, frequency controllers, phase controllers, gain controllers, frequency modulators and the like by using, for example, control of variable resistor(s), inductor(s), capacitor(s), antenna(s), dielectric shape(s), mechanical positioner(s) and the like. 
     In some embodiments, the system uses non-magnetic (e.g., piezoelectric) motors (or other mechanical-movement devices) that include linear actuators, rotary actuators, pumps (pneumatic (pressure or vacuum) and/or liquid pumps) and/or the like. In some embodiments, the system optionally includes non-magnetic sensors (e.g., using piezoelectric or other suitable technologies) that include linear strain gauges, rotary sensors, pressure or sound sensors (e.g., pneumatic (pressure or vacuum) and/or liquid), position sensors, light and image sensors, voltage or current sensors, and/or the like. In some embodiments, such actuator elements and/or sensor elements are used for remotely controlled robotic diagnosis and examination, surgery, biopsy, and the like in a medical environment (such as a magnetic-resonance machine). 
     In some embodiments, the present invention includes one or more of any one or more of the devices in any of the figures herein in a combined circuit that connects the described variable components, optionally including other conventional components. 
     It is to be understood that the above description is intended to be illustrative, and not restrictive. Although numerous characteristics and advantages of various embodiments as described herein have been set forth in the foregoing description, together with details of the structure and function of various embodiments, many other embodiments and changes to details will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should be, therefore, determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein,” respectively. Moreover, the terms “first,” “second,” and “third,” etc., are used merely as labels, and are not intended to impose numerical requirements on their objects.