Abstract:
A self-structuring antenna system comprises a plurality of antenna elements, a plurality of switch elements arranged with the antenna elements to, when selectively closed, electrically couple ones of the antenna elements to one another, and a switch controller for opening and closing the switch elements. The switch controller is operatively associated with the plurality of switch elements via a plurality of addressable switch controllers.

Description:
FIELD OF THE INVENTION 
     This invention relates to a self-structuring antenna. 
     BACKGROUND OF THE INVENTION 
     Self-structuring antenna systems are already known. For instance, U.S. Pat. No. 6,175,723 B1 issued to Edward Joseph Rothwell, III, Jan. 16, 2001, discloses a self-structuring antenna system with a switchable antenna array. The antenna array comprises a plurality of antenna elements that are selectively electrically connectable to each other by a series of switch elements so that the physical shape of the antenna array can be altered. The antenna elements include wires, whereby the wires of adjacent antenna elements are connected by a mechanical or solid state switch element. One or more feed points are electrically connected to predetermined locations within the antenna array and to a receiver associated with the antenna array. A feed back signal from the receiver provides an indication of signal reception and antenna performance. The feed back signal is applied to a computer that selectively opens and closes the switch elements. An algorithm is used to program the computer so that the opening and closing of the switch elements attempts to achieve antenna optimization and performance. 
     A drawback of the self-structuring antenna systems disclosed in the Rothwell III &#39;723 patent is the necessity of including several electric or optic cables to control the switch elements at the junctions of the antenna elements. 
     SUMMARY OF THE INVENTION 
     The invention provides a self-structuring antenna system that does not require several electric or optic cables to control switch elements at the junctions of the antenna elements. 
     In one preferred embodiment, the switch elements are operated by wireless communication to addressable switch controllers associated with the respective switch elements. 
     In another preferred embodiment, the switch elements are operated by communication via the antenna to addressable switch controllers associated with the respective switch elements. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of a self-structuring antenna system that embodies the invention; 
         FIG. 2  is an enlargement of a portion of  FIG. 1 ; 
         FIG. 3  is a schematic diagram of another self-structuring antenna system that embodies the invention; and 
         FIG. 4  is an enlargement of a portion of  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring now to  FIG. 1 , a self-structuring antenna (SSA) system  10  comprises an antenna  11  having antenna elements  12  that are arranged with switch elements  14  in a pattern such as the pattern shown in  FIG. 1 . Switch elements  14  are controllable so as to be open or closed. Closing a particular switch element  14  establishes an electrical connection between the two adjacent antenna elements  12  associated with the particular switch element  14 . On the other hand, opening a particular switch element  14  disconnects the electrical connection between the two adjacent antenna elements associated with the particular switch element  14 . Consequently closing some switch element elements  14  and opening other switch element elements  14  results in an antenna of a particular shape or configuration. Selecting which switch element elements  14  are closed and which switch element elements  14  are opened enables the antenna system  10  to implement a wide variety of antenna shapes or configurations. 
     The self-structuring antenna system  10  further comprises a switch controller  16 , a processor  18  and a receiver  20 . Receiver  20  receives a radiated electromagnetic signal, for example, a radio frequency signal via antenna  11 . Receiver  20  feeds the appropriate received signal information, for example, the receiver Automatic Gain Control (AGC) voltage level, to the processor  18  which uses an algorithm to determine appropriate configurations for antenna  11 . Processor  18  then communicates the required control signals to switch controller  16  which opens or closes various ones of the switch elements  14  to form the antenna configurations as determine by the algorithm. This process continues until acceptable reception is achieved. 
     The self-structuring antenna system as thus far described is already known, more or less from U.S. Pat. No. 6,175,723 B1 entitled, “Self-structuring Antenna System with a Switchable Antenna Array and an Optimizing Controller” issued to Edward Joseph Rothwell, III, Jan. 16, 2001, and my co-pending U.S. Patent application Ser. No. 10/818,559 entitled “Self-Structuring Hybrid Antenna System” filed Apr. 5, 2004. 
     However, as pointed out above, particularly with regard to the Rothwell, III &#39;723 patent, control of the switch elements  14  has been a long standing problem because of the need for several electric or optic cables leading from the switch controller  16  to each of the respective switch elements  14 . The self-structuring antenna system  10  of the invention overcomes the multiple cable need problem by wireless communication incorporating a transmitter  22  in switch controller  16  and receivers associated with the respective switch elements in miniature wireless switch controller modules  24 . 
     A typical wireless switch controller module  24  which replaces each switch element  14  is shown in  FIG. 2 . Switch controller module  24  comprises a switch element  26  and an addressable switch element controller  28  equipped with a receiver  29  for opening and closing its associated switch element  26 . Thus the self-structuring antenna system  11  of the invention utilizes “wireless” connections from switch controller  16  to each of the addressable switch element controllers  28  for operating switch elements  26  in antenna  11 . 
     The use of a transmitter  22  by switch controller  16  and the use of wireless switch controller modules  24  with addressable switch element controllers  28  and receivers  29  for operating switch elements  26  eliminates the need for the several cables of the prior art by using wireless communication techniques. One example of a possible wireless communication from switch element controller  16  to switch controller modules  24  is a “low data rate” radio frequency (RF) communication signal that is broadcast thru the air to the switch controller modules  24  by the local RF transmitter  22  in the switch controller  16  as indicated by antenna  30 . 
     Switch modules  24  preferably contain electronics for module addressing purposes, switch element state changing capability, miniature energy storage devices and circuitry for converting the same or other independent RF signals into an energy form suitable for charging the miniature energy storage device. In this example of the invention, the frequency of operation could range from MHz to GHz, and be of low power. For example, the frequency of operation may be within the RF bands associated with Bluetooth, 802.11b, 802.11a, ZigBee, etc. Therefore, switch controller modules  24  can be self-contained “battery less” switch element modules that can be placed on various antenna elements while not requiring physical switch element control interconnections, such as control and/or power wires. 
     Switch modules  24  are preferably as small as possible, i.e. tiny, nano, or micro in size, to avoid any possibility of interfering with the operation of antenna  11 . For example, (CMOS) switches are available in a die form package (1.2 mm×1.2 mm), (GaAs) switches are in a six-pin package (1.2 mm×1.2 mm), and (MEMS) switches in a six-pin package (3 mm×4 mm) with much smaller dimensions (0.1 mm×0.1 mm) in development. 
     Referring now to  FIG. 3 , another self-structuring antenna (SSA) system  100  of the invention comprises an antenna  111  having antenna elements  112  that are arranged with switch elements  114  in a pattern such as the pattern shown in  FIG. 3 . Switch elements  114  are controllable so as to be open or closed. Closing a particular switch element  114  establishes an electrical connection between the two antenna elements  112  associated with the particular switch element  114 . On the other hand, opening a particular switch element  114  disconnects the electrical connection between the two antenna elements associated with the particular switch element  114 . Consequently closing some switch elements  114  and opening other switch element elements  114  results in an antenna of a particular shape or configuration. Selecting which switch elements  114  are closed and which switch elements  114  are opened enables the antenna system  100  to implement a wide variety of antenna shapes or configurations. 
     The self-structuring antenna system  100  further comprises a switch controller  116 , a processor  118  and a receiver  120 . Receiver  120  receives a radiated electromagnetic signal, for example, a radio frequency signal via antenna  111 . Receiver  120  feeds the appropriate received signal information, for example, the receiver Automatic Gain Control (AGC) voltage level, to the processor  118  which uses an algorithm to determine appropriate configurations for antenna  111 . Processor  118  then communicates the required control signals to controller  116  which opens or closes various ones of the switch elements  114  to form the antenna configurations as determine by the algorithm. This process continues until acceptable reception is achieved. 
     The self-structuring antenna system  110  as thus far described is already known, more or less from U.S. Pat. No. 6,175,723 B1 entitled, “issued to Edward Joseph Rothwell, III, Jan. 16, 2001, and my co-pending U.S. patent application Ser. No. 10/818,559 entitled “Self-Structuring Hybrid Antenna System” filed Apr. 5, 2004. 
     However, as pointed out above, particularly with regard to the Rothwell, III &#39;723 patent, control of the switch elements  114  has been a long standing problem because of the need for several electric or optic cables. The alternative self-structuring antenna system  100  of the invention overcomes the multiple cable need problem by coupling switch controller  116  to antenna  111  by a single conductor  121  and using antenna  111  to communicate with respective switch elements in a miniature switch controller module  124 . 
     A typical switch controller module  124  is shown in  FIG. 4 . Switch controller module  124  comprises a switch element  126  and an addressable switch element controller  128  with a power converter circuit for opening and closing switch element  126 . The power converter circuit acts like a low-pass frequency filter device that permits low frequency switch address signals (i.e., the signals are at frequencies below the AM band) to pass through it and communicate with all antenna switches. Thus the alternative self structuring antenna system of the invention utilizes wire connections from switch controller  116  to antenna  111 , to each of the antenna elements  112 , and each addressable switch controller  128 . In addition, each addressable switch controller  128  is powered by an RF power converter circuit or a low frequency power converter circuit with the power need for the switch to opening and closing switch element  126 . 
     The coupling of the switch controller  116  to the antenna  111  and the use of addressable switch controllers  128  in switch controller modules  124  for operating switch elements  126  eliminates the need for several electric or optic cables by using multiplexing communication techniques. 
     The “wireless” connection and communication techniques of the respective embodiments reduce weight by eliminating control cables and connectors, improve ease of installation by eliminating the control cable bundle and connectors, and increase reliability by reducing the number of cables and connectors. The use of a RF wireless battery charging system eliminates the need for a “wired-in” charging system or battery replacement. In addition, the ability to frequently use the RF charging technique allows the switch modules to use a much smaller energy storage device or battery. 
     Another possibility for the switch controller modules  24  or  124  is the use of miniature electromechanical system (MEMS) switch element modules that use low voltage power supply (e.g. 3-10 volts) with a charge pump to generate its required low power switching voltage (e.g., 70 volts). This same charge pump could be used with a RF wireless battery charging system to obtain this same low power switching voltage. 
     In other words, it will be readily understood by those persons skilled in the art that the present invention is susceptible of broad utility and application. Many embodiments and adaptations of the present invention other than those described above, as well as many variations, modifications and equivalent arrangements, will be apparent from or reasonably suggested by the present invention and the foregoing description, without departing from the substance or scope of the present invention. Accordingly, while the present invention has been described herein in detail in relation to its preferred embodiment, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude any such other embodiments, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the following claims and the equivalents thereof.