Patent Description:
Embodiments of the present invention relate to the field of antennas for wireless communication; more particularly, embodiments of the present invention relate to a portable container for satellite antenna that includes a radio-frequency (RF) transparent lid.

Rapid establishment of communications is required for military, public safety, humanitarian assistance and disaster response. Traditional communication solutions are isolated and non-integrated architectures not designed to work together. Furthermore, Very Small Aperture Terminals (VSATs) typically require SATCOM technicians to deploy with, install, and commission the terminals. Many deployable VSATs are not capable of on-the-move operations and must be manually or mechanically pointed (by hand or electrical actuators) at the satellite. These requirements make traditional satellite communications a non-optimal process when on-the-move and rapid satellite acquisition is mandatory for operations as is the case in disaster response, first responder and defense applications.

<CIT> describes techniques and mechanisms for providing a low-profile terminal for satellite communication. A communication terminal includes a radome, an array of radio frequency (RF) elements and a foam layer disposed therebetween. The foam layer includes a first side and a second side opposite the first side, wherein the array of RF elements and the radome are coupled to the foam layer via the first side and the second side, respectively. The communication device provides a contiguous structure between the radome and the array of RF elements. The radome may comprise dielectric materials that are transparent to RF signals.

<CIT> describes techniques and mechanisms to provide a motor vehicle with connectivity for satellite communications.

<CIT> describes a phased-array antenna assembly that includes an antenna board stack, a radome configured to cover the antenna board stack, and a casing configured to support the antenna board stack.

The problems of the related art are solved by a portable satellite antenna apparatus having the features of claim <NUM>. The portable satellite antenna apparatus comprises a flat panel antenna and a container to house the antenna, the container having at least one radio-frequency (RF) transparent material through which the antenna is operable to transmit and receive satellite communications. Additional features for advantageous embodiments of the present invention are provided in the dependent claims.

The present invention will be understood more fully from the detailed description given below and from the accompanying drawings of various embodiments of the invention, which, however, should not be taken to limit the invention to the specific embodiments, but are for explanation and understanding only.

In the following description, numerous details are set forth to provide a more thorough explanation of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form, rather than in detail, in order to avoid obscuring the present invention.

Embodiments of a portable flat panel antenna and method for using the same are disclosed. In one embodiment, the flat panel antenna is contained in and transported in a ruggedized rapidly deployable and self-contained container. In one embodiment, the container comprises a network system capable of establishing and bridging multiple terrestrial and on-orbit networks in fixed and on-the-move environments.

<FIG> illustrates one embodiment of a portable satellite antenna system. Referring to <FIG>, the portable satellite antenna system comprises a container to house a satellite antenna. In one embodiment, the container has a radio-frequency (RF) transparent lid <NUM> and a lower case <NUM>. RF transparent lid <NUM> and lower case <NUM> house antenna <NUM>. In one embodiment, antenna <NUM> comprises a flat-panel electronically steered antenna. Examples of such antennas are described in more detail below. The embodiments disclosed herein are not limited to use with the antennas described below, and other types of antennas may be used. For example, in alternative embodiments, the systems include a flat-panel antenna that is not electronically steered.

RF transparent lid <NUM>, or portion thereof, comprises an RF transparent material through which antenna <NUM> is operable to transmit and receive satellite communications when lid <NUM> is on top of or otherwise covering the surface of antenna <NUM>. Thus, in one embodiment, antenna <NUM> is able to transmit and receive satellite communications through the RF transparent portion of lid <NUM> during closed-container operation when the container is closed. In one embodiment, lid <NUM> operates as a radome of antenna <NUM>.

In one embodiment, the RF transparent material of RF transparent lid <NUM> comprises a material tuned to frequencies at which the antenna is designed to operate. For example, the RF transparent material of RF transparent lid <NUM> is selected to enable antenna <NUM> to transmit and receive in the Ku-band in one embodiment or the Ka-band in another embodiment. Note that while in one embodiment material selection may be based on operation over an entire band, the material selection may be based on operation of the antenna with respect to a single frequency or a preferred frequency (or subset of frequencies) of a band.

The tuning of the material is also a function of its thickness and the distance of lid <NUM> from the transmit and receive surface of antenna <NUM>. The thickness of lid <NUM> and distance of lid <NUM> from the surface of antenna <NUM> is such that it doesn't impede transmit and receive satellite communications of antenna <NUM>. Such communications are not impeded if signals at the antenna's designed frequency or frequency band of operation are minimally attenuated or reflected by lid <NUM>. In one embodiment, the distance between lid <NUM> and the surface of antenna <NUM> is dependent on the material used for the radome and the tuning. In one embodiment, the distance between lid <NUM> and the surface of antenna <NUM> is between ¼"-<NUM>/<NUM>" and is a function of radome tuning/thickness and could be greater.

In one embodiment, the design of lid <NUM> incorporates both RF and mechanical/environmental requirements. Several design approaches are available to the designer to address specific system requirements. For example, if the lid has minimal mechanical requirements, a very thin skin (e.g., <<NUM> wavelength) of thermoplastic material can be used, while if structural rigidity is required, a solid half wave wall design (wherein the dielectric thickness of the wall is ½ wavelength) or sandwich construction may be appropriate. A specific design necessarily includes consideration of material dielectric properties, design approach, and antenna RF requirements. Design selections inherently embody tradeoffs between these typically conflicting requirements.

Typically, lid attenuation (e.g., insertion loss) will vary from <NUM>'s db to an amount in excess of <NUM> db depending upon lid design approach and antenna scan angles. Determination of acceptable attenuation is a system design trade off issue with due consideration of RF, mechanical and throughput requirements.

With respect to antenna-to-lid spacing, it is desirable to have the lid sufficiently removed from the antenna to minimize interactions (coupling) between the antenna and the lid (in this discussion, the antenna includes both the antennas radiating elements and any impedance matching layers (e.g., WAIM) above the antenna elements). It is also desirable to have the lid be spaced from the antenna such that reflections caused by the lid do not destructively interact with fields in the antenna. In one embodiment, a minimal distance of <NUM> wavelength is generally recommended to reduce lip to antenna coupling. A spacing of <NUM>. 5λ (lambda) is not recommended because at this distance lid reflections will interact destructively with the antenna. In one embodiment, a spacing of <NUM> wavelength is preferred as it provides sufficient separation from the antenna and lid reflections constructively interact with fields in the antenna.

In one embodiment, RF transparent lid <NUM> comprises a thermoplastic material (e.g., polyethylene (e.g., low-density polyethylene (LDPE), high-density polyethylene (HDPE), etc.), polycarbonate used in either a thin skin or half wave wall construction. In another embodiment, the RF lid consists of a composite sandwich construction. In one embodiment in which lid <NUM> comprises LDPE, the thickness of lid <NUM> is approximately ¼''. The thickness for a specific application is determined based upon antenna operational requirements and material dielectric properties. In one embodiment, lid <NUM> is made of HDPE and is <NUM>/<NUM>" thick. Other examples of materials that may be used include polycarbonate and ABS plastic.

RF transparent lid <NUM> operates as the upper case that works with lower case <NUM> to form a closed container. Note that in one embodiment, the closed container is structurally sound such that it may be placed on any of its sides. In other words, RF transparent lid <NUM> comprises a material that is RF transparent and is structurally strong enough to support the container for transporting antenna <NUM>. However, the material is also light-weight to enable the container with antenna <NUM> to be easily transported.

In one embodiment, the outer or externally exposed surface of lid <NUM> has a convex shape. The convex surface prevents liquids (e.g., rain water) from pooling on top of lid <NUM>, which would cause attenuation in the transmit and receive satellite signals.

In one embodiment, an externally exposed portion of the at least one RF transparent surface has a hydrophobic coating. The hydrophobic coating causes water to bead, and thus, in cooperation with the convex shape of lid <NUM>, causes water to roll off the surface of lid <NUM>. Examples of coatings include Cytonix aerosol application hydrophobic coating and Cytonix Water Slip 41p additive for paint. Examples of coatings for super-hydrophobicity that may be used are RF-neutral and improve hydrophobicity include Mavcoat® XD and DryWired® Superhydrophobic Coating.

In one embodiment, the portable antenna system includes a modem and an input/output (I/O) mechanism for processing I/O operations in a manner well-known in the art. These may be transported in a container separate from the container that transports antenna <NUM>. An example of such a container is shown as modem and I/O container <NUM> in <FIG>.

<FIG> illustrate one embodiment of a container with an RF transparent lid. Referring to <FIG>, the container comprises a trim ring <NUM>, radome <NUM>, upper case <NUM>, RF mount <NUM>, antenna hinge mechanism <NUM>, and lower case <NUM>. Radome <NUM> is RF transparent and tuned as described above.

In one embodiment, radome <NUM> is secured to upper case <NUM> and covers a hole or opening in upper case <NUM>. In one embodiment, trim ring <NUM> is used to cover fasteners on the top of the lid that secure radome <NUM> to upper case <NUM>. Trim ring <NUM>, radome <NUM> and upper case <NUM> form a lid when coupled together. Note that in alternative embodiments, trim ring <NUM> is not included.

In one embodiment, upper case <NUM> is a molded plastic upper case. In one embodiment, the plastic of the molded plastic upper case comprises polyethylene (e.g., low-density polyethylene (LDPE), high-density polyethylene (HDPE), etc.). In one embodiment, the fasteners comprise screws. However, other well-known types of fasteners may be used instead of screws.

The container includes an RF mount <NUM> upon which antenna <NUM> is coupled. In one embodiment, RF mount <NUM> comprises a plate having a number of RF components to which antenna <NUM> is coupled. In one embodiment, these components include a diplexer and components such as, for example, a low noise block down converter (LNBs) and a BUC (up-convert and high pass amplifier) that are typically found in an out-door unit (ODU).

RF mount <NUM> is coupled to an antenna hinge mechanism <NUM>. In one embodiment, antenna hinge mechanism <NUM> allows the antenna to be positioned when the container is open and antenna <NUM> is exposed. In one embodiment, the hinge mechanism <NUM> comprises a mechanical elevation mechanism (non-motorized) that allows one side of antenna <NUM> to be moved to an inclined position to provide a desired look angle (e.g., the best look angle) at a satellite, facilitating network link establishment with the satellite. An example of inclined antenna positioning is shown in <FIG>.

Hinge mechanism <NUM> is coupled or otherwise attached to lower case <NUM>. In one embodiment, lower case <NUM> is a molded plastic upper case. In one embodiment, the plastic of the molded plastic upper case comprises polyethylene (e.g., low-density polyethylene (LDPE), high-density polyethylene (HDPE), etc.). Note that in alternative embodiments, lower case <NUM> is a different material than upper case <NUM>.

<FIG> illustrates container <NUM> with trim ring <NUM>, radome <NUM>, upper case <NUM>, RF mount <NUM>, antenna hinge mechanism <NUM>, and lower case <NUM> coupled together. In this configuration, in one embodiment, antenna <NUM> is able to operate in closed-container configuration to transmit and receive satellite communications. That is, even though the lid is still covering antenna <NUM>, antenna <NUM> still operates to transmit and receive satellite signals through the lid. This is possible through the antenna's coarse alignment mechanism that allows accurate pointing, acquisition, and tracking capabilities of antenna <NUM> while in a flat or non-moving antenna position. In other words, antenna <NUM> with electronic scanning and an RF-transparent material in the lid of the container provide a capability to operate with the lid of the case on, with the case resting flat on the ground. In one embodiment, this facilitates inconspicuous use, which is particularly useful in avoiding detection and potential destruction due to Imagery Intelligence (IMINT) and Signals Intelligence (SIGINT), because adversaries will not be able to see the antenna, or distinguish the case as a piece of satellite communications equipment. When the upper case (including the lid) and the lower case are black, imagery intelligence will only reveal a non-descript, black case.

<FIG> illustrate an alternative embodiment of a container with an RF transparent lid. Referring to <FIG>, the container comprises RF transparent lid <NUM>, RF mount <NUM>, antenna hinge mechanism <NUM>, and lower case <NUM>. Lid <NUM> acts as a radome and is RF transparent and tuned as described above. In one embodiment, lid <NUM> is a molded plastic upper case. In one embodiment, the plastic of the molded plastic upper case comprises polyethylene (e.g., low-density polyethylene (LDPE), linear polyethylene (HDPE), etc.).

RF mount <NUM> is coupled to an antenna hinge mechanism <NUM>. In one embodiment, antenna hinge mechanism <NUM> allows the antenna to be positioned (e.g., inclined) when the container is open and antenna <NUM> is exposed. Hinge mechanism <NUM> is coupled or otherwise attached to lower case <NUM>. Note that in alternative embodiments, lower case <NUM> is a different material than upper case <NUM>.

<FIG> illustrates container <NUM> with RF transparent lid <NUM>, RF mount <NUM>, antenna hinge mechanism <NUM>, and lower case <NUM> coupled together. In this configuration, in one embodiment, antenna <NUM> is able to operate in closed-container configuration to transmit and receive satellite communications.

In one embodiment, the container comprises a ruggedized case, such as one described above in conjunction with <FIG>, having outer dimensions that are <NUM>" L x <NUM>" W x <NUM>" H and inner dimensions that are <NUM>" L x <NUM>" W x <NUM>" H, while its weight is approximately <NUM> lbs. Note that the smaller case includes a modem. In one embodiment of the operational configuration, the equipment in the cases is connected by three cables (e.g., I/O cable plus two RF cables). In an alternative embodiment, all the components are contained in the container and there is no need for cable connections.

In one embodiment, the portable antenna system is used by law enforcement or military as a full-spectrum protected communications system with full interconnectivity to public safety and first responder networks for disaster response and humanitarian assistance. In one embodiment, the portable antenna system allows for seamless communications across terrestrial and on-orbit networks anywhere in the world. In one embodiment, the portable antenna system aggregates a wide variety of networking and computing capabilities to provide a continuous and interconnected communications experience over satellite, airborne and terrestrial networks, thereby enabling rapid establishment of essential communications in any environment.

In one embodiment, embodiments of the portable antenna system disclosed herein greatly reduce the need to deploy SATCOM technicians and to manually point the antenna for operations. Furthermore, it can be rapidly moved from site-to-site to provide satellite communications without the time-consuming satellite locating requirements associated with traditional deployable VSATs.

Embodiments of a portable flat panel antenna container system have one or more of a number of innovations. These innovations include, but are not limited to, the following:.

In one embodiment, the antenna is a rapidly deployable networking system. In one embodiment, the rapidly deployable networking system supports personnel, organizations and agencies with establishment of, connectivity to and bridging of a broad range of terrestrial and on-orbit networks. In one embodiment, the system supports traditional VSAT networks through the satellite terminal with the ability to connect to LEO and GEO satellite constellations. In one embodiment, additional terrestrial and airborne network connections are created and bridges to enable full-spectrum communications in a deployed environment. In one embodiment, the entire system is capable of operating as a self-contained and self-powered system (e.g., lithium ion batteries, solar panels. etc.) or may be connected to available power sources.

Embodiments of the antenna include one or more of the following advantages.

First, in one embodiment, the antenna configuration enables a portable solution for communications on the pause (COTP) or communications on the move (COTM) operation without a custom mounting solution, designed to operate from within the container. In one embodiment, the container is designed with D rings so that tie downs may be used to mount the antenna to a platform, such as, for example, a vehicle or vessel.

Time from deployment to operations is approximately <NUM> minutes and typically does not require a subject matter expert. Average time for traditional VSATs from deployment to operations is approximately <NUM> minutes (minimum) and requires a SATCOM technician.

The interconnected network architecture allows for communication from anywhere in the world to anywhere in the world. For example, a disaster recovery individual in a disaster zone can communicate via push to talk radios to personnel within range of the radio as well as support personnel on a cellular telephone on another continent without changing devices or physically connecting to a different network. This reduces the handheld communications equipment personnel must carry but allows assured communication.

In one embodiment, the antenna includes a coarse alignment mechanism. Because of the accurate pointing, acquisition, and tracking capabilities of flat panel antenna, a precise alignment mechanism is not needed for the surface of the antenna. That is, embodiments of the container containing a flat panel antenna with electronic scanning, in conjunction with an RF-transparent material in the lid of the case, provide a unique capability to operate with the lid of the case on, with the case resting flat on the ground, thereby providing for inconspicuous use. Therefore, adversaries will not be able to see the antenna, or distinguish the case as a piece of satellite communications equipment. Imagery intelligence will only reveal a non-descript, black case.

In one embodiment, the case used to house the antenna has a thin profile, which is a distinct advantage over existing portable airtight, watertight temperature-controlled packaging and protective systems used for dish-type VSAT. The thin case profile and wheel assembly is non-obvious because it is enabled by the flat-panel antenna. The case, including the wheels, enables the antenna system to be easily roll through doorways and other narrow spaces.

The techniques described above may be used with flat panel antennas. Embodiments of such flat panel antennas are disclosed. The flat panel antennas include one or more arrays of antenna elements on an antenna aperture. In one embodiment, the antenna elements comprise liquid crystal cells. In one embodiment, the flat panel antenna is a cylindrically fed antenna that includes matrix drive circuitry to uniquely address and drive each of the antenna elements that are not placed in rows and columns. In one embodiment, the elements are placed in rings.

In one embodiment, the antenna aperture having the one or more arrays of antenna elements is comprised of multiple segments coupled together. When coupled together, the combination of the segments form closed concentric rings of antenna elements. In one embodiment, the concentric rings are concentric with respect to the antenna feed.

In one embodiment, the flat panel antenna is part of a metamaterial antenna system. Embodiments of a metamaterial antenna system for communications satellite earth stations are described. In one embodiment, the antenna system is a component or subsystem of a satellite earth station (ES) operating on a mobile platform (e.g., aeronautical, maritime, land, etc.) that operates using either Ka-band frequencies or Ku-band frequencies for civil commercial satellite communications. Note that embodiments of the antenna system also can be used in earth stations that are not on mobile platforms (e.g., fixed or transportable earth stations).

In one embodiment, the antenna system uses surface scattering metamaterial technology to form and steer transmit and receive beams through separate antennas. In one embodiment, the antenna systems are analog systems, in contrast to antenna systems that employ digital signal processing to electrically form and steer beams (such as phased array antennas).

In one embodiment, the antenna system is comprised of three functional subsystems: (<NUM>) a wave guiding structure consisting of a cylindrical wave feed architecture; (<NUM>) an array of wave scattering metamaterial unit cells that are part of antenna elements; and (<NUM>) a control structure to command formation of an adjustable radiation field (beam) from the metamaterial scattering elements using holographic principles.

<FIG> illustrates the schematic of one embodiment of a cylindrically fed holographic radial aperture antenna. Referring to <FIG>, the antenna aperture has one or more arrays <NUM> of antenna elements <NUM> that are placed in concentric rings around an input feed <NUM> of the cylindrically fed antenna. In one embodiment, antenna elements <NUM> are radio frequency (RF) resonators that radiate RF energy. In one embodiment, antenna elements <NUM> comprise both Rx and Tx irises that are interleaved and distributed on the whole surface of the antenna aperture. Such Rx and Tx irises, or slots, may be in groups of three or more sets where each set is for a separately and simultaneously controlled band. Examples of such antenna elements with irises are described in greater detail below. Note that the RF resonators described herein may be used in antennas that do not include a cylindrical feed.

In one embodiment, the antenna includes a coaxial feed that is used to provide a cylindrical wave feed via input feed <NUM>. In one embodiment, the cylindrical wave feed architecture feeds the antenna from a central point with an excitation that spreads outward in a cylindrical manner from the feed point. That is, a cylindrically fed antenna creates an outward travelling concentric feed wave. Even so, the shape of the cylindrical feed antenna around the cylindrical feed can be circular, square or any shape. In another embodiment, a cylindrically fed antenna creates an inward travelling feed wave. In such a case, the feed wave most naturally comes from a circular structure.

In one embodiment, antenna elements <NUM> comprise irises and the aperture antenna of <FIG> is used to generate a main beam shaped by using excitation from a cylindrical feed wave for radiating irises through tunable liquid crystal (LC) material. In one embodiment, the antenna can be excited to radiate a horizontally or vertically polarized electric field at desired scan angles.

In one embodiment, the antenna elements comprise a group of patch antennas. This group of patch antennas comprises an array of scattering metamaterial elements. In one embodiment, each scattering element in the antenna system is part of a unit cell that consists of a lower conductor, a dielectric substrate and an upper conductor that embeds a complementary electric inductive-capacitive resonator ("complementary electric LC" or "CELC") that is etched in or deposited onto the upper conductor. As would be understood by those skilled in the art, LC in the context of CELC refers to inductance-capacitance, as opposed to liquid crystal.

In one embodiment, a liquid crystal (LC) is disposed in the gap around the scattering element. This LC is driven by the direct drive embodiments described above. In one embodiment, liquid crystal is encapsulated in each unit cell and separates the lower conductor associated with a slot from an upper conductor associated with its patch. Liquid crystal has a permittivity that is a function of the orientation of the molecules comprising the liquid crystal, and the orientation of the molecules (and thus the permittivity) can be controlled by adjusting the bias voltage across the liquid crystal. Using this property, in one embodiment, the liquid crystal integrates an on/off switch for the transmission of energy from the guided wave to the CELC. When switched on, the CELC emits an electromagnetic wave like an electrically small dipole antenna. Note that the teachings herein are not limited to having a liquid crystal that operates in a binary fashion with respect to energy transmission.

In one embodiment, the feed geometry of this antenna system allows the antenna elements to be positioned at forty-five-degree (<NUM>°) angles to the vector of the wave in the wave feed. Note that other positions may be used (e.g., at <NUM>° angles). This position of the elements enables control of the free space wave received by or transmitted/radiated from the elements. In one embodiment, the antenna elements are arranged with an inter-element spacing that is less than a free-space wavelength of the operating frequency of the antenna. For example, if there are four scattering elements per wavelength, the elements in the <NUM> transmit antenna will be approximately <NUM> (i.e., <NUM>/4th the <NUM> free-space wavelength of <NUM>).

In one embodiment, the two sets of elements are perpendicular to each other and simultaneously have equal amplitude excitation if controlled to the same tuning state. Rotating them +/-<NUM> degrees relative to the feed wave excitation achieves both desired features at once. Rotating one set <NUM> degrees and the other <NUM> degrees would achieve the perpendicular goal, but not the equal amplitude excitation goal. Note that <NUM> and <NUM> degrees may be used to achieve isolation when feeding the array of antenna elements in a single structure from two sides.

The amount of radiated power from each unit cell is controlled by applying a voltage to the patch (potential across the LC channel) using a controller. Traces to each patch are used to provide the voltage to the patch antenna. The voltage is used to tune or detune the capacitance and thus the resonance frequency of individual elements to effectuate beam forming. The voltage required is dependent on the liquid crystal mixture being used. The voltage tuning characteristic of liquid crystal mixtures is mainly described by a threshold voltage at which the liquid crystal starts to be affected by the voltage and the saturation voltage, above which an increase of the voltage does not cause major tuning in liquid crystal. These two characteristic parameters can change for different liquid crystal mixtures.

In one embodiment, as discussed above, a matrix drive is used to apply voltage to the patches in order to drive each cell separately from all the other cells without having a separate connection for each cell (direct drive). Because of the high density of elements, the matrix drive is an efficient way to address each cell individually.

In one embodiment, the control structure for the antenna system has <NUM> main components: the antenna array controller, which includes drive electronics, for the antenna system, is below the wave scattering structure (of surface scattering antenna elements such as described herein), while the matrix drive switching array is interspersed throughout the radiating RF array in such a way as to not interfere with the radiation. In one embodiment, the drive electronics for the antenna system comprise commercial off-the shelf LCD controls used in commercial television appliances that adjust the bias voltage for each scattering element by adjusting the amplitude or duty cycle of an AC bias signal to that element.

In one embodiment, the antenna array controller also contains a microprocessor executing the software. The control structure may also incorporate sensors (e.g., a GPS receiver, a three-axis compass, a <NUM>-axis accelerometer, <NUM>-axis gyro, <NUM>-axis magnetometer, etc.) to provide location and orientation information to the processor. The location and orientation information may be provided to the processor by other systems in the earth station and/or may not be part of the antenna system.

More specifically, the antenna array controller controls which elements are turned off and those elements turned on and at which phase and amplitude level at the frequency of operation. The elements are selectively detuned for frequency operation by voltage application.

For transmission, a controller supplies an array of voltage signals to the RF patches to create a modulation, or control pattern. The control pattern causes the elements to be turned to different states. In one embodiment, multistate control is used in which various elements are turned on and off to varying levels, further approximating a sinusoidal control pattern, as opposed to a square wave (i.e., a sinusoid gray shade modulation pattern). In one embodiment, some elements radiate more strongly than others, rather than some elements radiate and some do not. Variable radiation is achieved by applying specific voltage levels, which adjusts the liquid crystal permittivity to varying amounts, thereby detuning elements variably and causing some elements to radiate more than others.

The generation of a focused beam by the metamaterial array of elements can be explained by the phenomenon of constructive and destructive interference. Individual electromagnetic waves sum up (constructive interference) if they have the same phase when they meet in free space and waves cancel each other (destructive interference) if they are in opposite phase when they meet in free space. If the slots in a slotted antenna are positioned so that each successive slot is positioned at a different distance from the excitation point of the guided wave, the scattered wave from that element will have a different phase than the scattered wave of the previous slot. If the slots are spaced one quarter of a guided wavelength apart, each slot will scatter a wave with a one fourth phase delay from the previous slot.

Using the array, the number of patterns of constructive and destructive interference that can be produced can be increased so that beams can be pointed theoretically in any direction plus or minus ninety degrees (<NUM>°) from the bore sight of the antenna array, using the principles of holography. Thus, by controlling which metamaterial unit cells are turned on or off (i.e., by changing the pattern of which cells are turned on and which cells are turned off), a different pattern of constructive and destructive interference can be produced, and the antenna can change the direction of the main beam. The time required to turn the unit cells on and off dictates the speed at which the beam can be switched from one location to another location.

In one embodiment, the antenna system produces one steerable beam for the uplink antenna and one steerable beam for the downlink antenna. In one embodiment, the antenna system uses metamaterial technology to receive beams and to decode signals from the satellite and to form transmit beams that are directed toward the satellite. In one embodiment, the antenna systems are analog systems, in contrast to antenna systems that employ digital signal processing to electrically form and steer beams (such as phased array antennas). In one embodiment, the antenna system is considered a "surface" antenna that is planar and relatively low profile, especially when compared to conventional satellite dish receivers.

<FIG> illustrates a perspective view of one row of antenna elements that includes a ground plane and a reconfigurable resonator layer. Reconfigurable resonator layer <NUM> includes an array of tunable slots <NUM>. The array of tunable slots <NUM> can be configured to point the antenna in a desired direction. Each of the tunable slots can be tuned/adjusted by varying a voltage across the liquid crystal.

Control module, or controller, <NUM> is coupled to reconfigurable resonator layer <NUM> to modulate the array of tunable slots <NUM> by varying the voltage across the liquid crystal in <FIG>. Control module <NUM> may include a Field Programmable Gate Array ("FPGA"), a microprocessor, a controller, System-on-a-Chip (SoC), or other processing logic. In one embodiment, control module <NUM> includes logic circuitry (e.g., multiplexer) to drive the array of tunable slots <NUM>. In one embodiment, control module <NUM> receives data that includes specifications for a holographic diffraction pattern to be driven onto the array of tunable slots <NUM>. The holographic diffraction patterns may be generated in response to a spatial relationship between the antenna and a satellite so that the holographic diffraction pattern steers the downlink beams (and uplink beam if the antenna system performs transmit) in the appropriate direction for communication. Although not drawn in each figure, a control module similar to control module <NUM> may drive each array of tunable slots described in the figures of the disclosure.

Radio Frequency ("RF") holography is also possible using analogous techniques where a desired RF beam can be generated when an RF reference beam encounters an RF holographic diffraction pattern. In the case of satellite communications, the reference beam is in the form of a feed wave, such as feed wave <NUM> (approximately <NUM> in some embodiments). To transform a feed wave into a radiated beam (either for transmitting or receiving purposes), an interference pattern is calculated between the desired RF beam (the object beam) and the feed wave (the reference beam). The interference pattern is driven onto the array of tunable slots <NUM> as a diffraction pattern so that the feed wave is "steered" into the desired RF beam (having the desired shape and direction). In other words, the feed wave encountering the holographic diffraction pattern "reconstructs" the object beam, which is formed according to design requirements of the communication system. The holographic diffraction pattern contains the excitation of each element and is calculated by <MAT>, with win as the wave equation in the waveguide and wout the wave equation on the outgoing wave.

<FIG> illustrates one embodiment of a tunable resonator/slot <NUM>. Tunable slot <NUM> includes an iris/slot <NUM>, a radiating patch <NUM>, and liquid crystal <NUM> disposed between iris <NUM> and patch <NUM>. In one embodiment, radiating patch <NUM> is co-located with iris <NUM>.

<FIG> illustrates a cross section view of one embodiment of a physical antenna aperture. The antenna aperture includes ground plane <NUM>, and a metal layer <NUM> within iris layer <NUM>, which is included in reconfigurable resonator layer <NUM>. In one embodiment, the antenna aperture of <FIG> includes a plurality of tunable resonator/slots <NUM> of <FIG>. Iris/slot <NUM> is defined by openings in metal layer <NUM>. A feed wave, such as feed wave <NUM> of <FIG>, may have a microwave frequency compatible with satellite communication channels. The feed wave propagates between ground plane <NUM> and resonator layer <NUM>.

Reconfigurable resonator layer <NUM> also includes gasket layer <NUM> and patch layer <NUM>. Gasket layer <NUM> is disposed between patch layer <NUM> and iris layer <NUM>. Note that in one embodiment, a spacer could replace gasket layer <NUM>. In one embodiment, iris layer <NUM> is a printed circuit board ("PCB") that includes a copper layer as metal layer <NUM>. In one embodiment, iris layer <NUM> is glass. Iris layer <NUM> may be other types of substrates.

Openings may be etched in the copper layer to form slots <NUM>. In one embodiment, iris layer <NUM> is conductively coupled by a conductive bonding layer to another structure (e.g., a waveguide) in <FIG>. Note that in an embodiment the iris layer is not conductively coupled by a conductive bonding layer and is instead interfaced with a nonconducting bonding layer.

Patch layer <NUM> may also be a PCB that includes metal as radiating patches <NUM>. In one embodiment, gasket layer <NUM> includes spacers <NUM> that provide a mechanical standoff to define the dimension between metal layer <NUM> and patch <NUM>. In one embodiment, the spacers are <NUM> microns, but other sizes may be used (e.g., <NUM>-<NUM>). As mentioned above, in one embodiment, the antenna aperture of <FIG> includes multiple tunable resonator/slots, such as tunable resonator/slot <NUM> includes patch <NUM>, liquid crystal <NUM>, and iris <NUM> of <FIG>. The chamber for liquid crystal <NUM> is defined by spacers <NUM>, iris layer <NUM> and metal layer <NUM>. When the chamber is filled with liquid crystal, patch layer <NUM> can be laminated onto spacers <NUM> to seal liquid crystal within resonator layer <NUM>.

A voltage between patch layer <NUM> and iris layer <NUM> can be modulated to tune the liquid crystal in the gap between the patch and the slots (e.g., tunable resonator/slot <NUM>). Adjusting the voltage across liquid crystal <NUM> varies the capacitance of a slot (e.g., tunable resonator/slot <NUM>). Accordingly, the reactance of a slot (e.g., tunable resonator/slot <NUM>) can be varied by changing the capacitance. Resonant frequency of slot <NUM> also changes according to the equation <MAT> where f is the resonant frequency of slot <NUM> and L and C are the inductance and capacitance of slot <NUM>, respectively. The resonant frequency of slot <NUM> affects the energy radiated from feed wave <NUM> propagating through the waveguide. As an example, if feed wave <NUM> is <NUM>, the resonant frequency of a slot <NUM> may be adjusted (by varying the capacitance) to <NUM> so that the slot <NUM> couples substantially no energy from feed wave <NUM>. Or, the resonant frequency of a slot <NUM> may be adjusted to <NUM> so that the slot <NUM> couples energy from feed wave <NUM> and radiates that energy into free space. Although the examples given are binary (fully radiating or not radiating at all), full gray scale control of the reactance, and therefore the resonant frequency of slot <NUM> is possible with voltage variance over a multi-valued range. Hence, the energy radiated from each slot <NUM> can be finely controlled so that detailed holographic diffraction patterns can be formed by the array of tunable slots.

In one embodiment, tunable slots in a row are spaced from each other by λ/<NUM>. Other spacings may be used. In one embodiment, each tunable slot in a row is spaced from the closest tunable slot in an adjacent row by λ/<NUM>, and, thus, commonly oriented tunable slots in different rows are spaced by λ/<NUM>, though other spacings are possible (e.g., λ/<NUM>, λ/<NUM>). In another embodiment, each tunable slot in a row is spaced from the closest tunable slot in an adjacent row by λ/<NUM>.

Embodiments use reconfigurable metamaterial technology, such as described in <CIT> and <CIT>.

<FIG> illustrate one embodiment of the different layers for creating the slotted array. The antenna array includes antenna elements that are positioned in rings, such as the example rings shown in Figure 1A. Note that in this example the antenna array has two different types of antenna elements that are used for two different types of frequency bands.

<FIG> illustrates a portion of the first iris board layer with locations corresponding to the slots. Referring to <FIG>, the circles are open areas/slots in the metallization in the bottom side of the iris substrate, and are for controlling the coupling of elements to the feed (the feed wave). Note that this layer is an optional layer and is not used in all designs. <FIG> illustrates a portion of the second iris board layer containing slots. <FIG> illustrates patches over a portion of the second iris board layer. <FIG> illustrates a top view of a portion of the slotted array.

<FIG> illustrates a side view of one embodiment of a cylindrically fed antenna structure. The antenna produces an inwardly travelling wave using a double layer feed structure (i.e., two layers of a feed structure). In one embodiment, the antenna includes a circular outer shape, though this is not required. That is, non-circular inward travelling structures can be used. In one embodiment, the antenna structure in <FIG> includes a coaxial feed, such as, for example, described in <CIT>.

Referring to <FIG>, a coaxial pin <NUM> is used to excite the field on the lower level of the antenna. In one embodiment, coaxial pin <NUM> is a 50Ω coax pin that is readily available. Coaxial pin <NUM> is coupled (e.g., bolted) to the bottom of the antenna structure, which is conducting ground plane <NUM>.

Separate from conducting ground plane <NUM> is interstitial conductor <NUM>, which is an internal conductor. In one embodiment, conducting ground plane <NUM> and interstitial conductor <NUM> are parallel to each other. In one embodiment, the distance between ground plane <NUM> and interstitial conductor <NUM> is <NUM> - <NUM>". In another embodiment, this distance may be λ/<NUM>, where λ is the wavelength of the travelling wave at the frequency of operation.

Ground plane <NUM> is separated from interstitial conductor <NUM> via a spacer <NUM>. In one embodiment, spacer <NUM> is a foam or air-like spacer. In one embodiment, spacer <NUM> comprises a plastic spacer.

On top of interstitial conductor <NUM> is dielectric layer <NUM>. In one embodiment, dielectric layer <NUM> is plastic. The purpose of dielectric layer <NUM> is to slow the travelling wave relative to free space velocity. In one embodiment, dielectric layer <NUM> slows the travelling wave by <NUM>% relative to free space. In one embodiment, the range of indices of refraction that are suitable for beam forming are <NUM> - <NUM>, where free space has by definition an index of refraction equal to <NUM>. Other dielectric spacer materials, such as, for example, plastic, may be used to achieve this effect. Note that materials other than plastic may be used as long as they achieve the desired wave slowing effect. Alternatively, a material with distributed structures may be used as dielectric <NUM>, such as periodic sub-wavelength metallic structures that can be machined or lithographically defined, for example.

An RF-array <NUM> is on top of dielectric <NUM>. In one embodiment, the distance between interstitial conductor <NUM> and RF-array <NUM> is <NUM> - <NUM>". In another embodiment, this distance may be λeff/<NUM>, where λeff is the effective wavelength in the medium at the design frequency.

The antenna includes sides <NUM> and <NUM>. Sides <NUM> and <NUM> are angled to cause a travelling wave feed from coax pin <NUM> to be propagated from the area below interstitial conductor <NUM> (the spacer layer) to the area above interstitial conductor <NUM> (the dielectric layer) via reflection. In one embodiment, the angle of sides <NUM> and <NUM> are at <NUM>° angles. In an alternative embodiment, sides <NUM> and <NUM> could be replaced with a continuous radius to achieve the reflection. While <FIG> shows angled sides that have angle of <NUM> degrees, other angles that accomplish signal transmission from lower level feed to upper level feed may be used. That is, given that the effective wavelength in the lower feed will generally be different than in the upper feed, some deviation from the ideal <NUM>° angles could be used to aid transmission from the lower to the upper feed level. For example, in another embodiment, the <NUM>° angles are replaced with a single step. The steps on one end of the antenna go around the dielectric layer, interstitial the conductor, and the spacer layer. The same two steps are at the other ends of these layers.

In operation, when a feed wave is fed in from coaxial pin <NUM>, the wave travels outward concentrically oriented from coaxial pin <NUM> in the area between ground plane <NUM> and interstitial conductor <NUM>. The concentrically outgoing waves are reflected by sides <NUM> and <NUM> and travel inwardly in the area between interstitial conductor <NUM> and RF array <NUM>. The reflection from the edge of the circular perimeter causes the wave to remain in phase (i.e., it is an in-phase reflection). The travelling wave is slowed by dielectric layer <NUM>. At this point, the travelling wave starts interacting and exciting with elements in RF array <NUM> to obtain the desired scattering.

To terminate the travelling wave, a termination <NUM> is included in the antenna at the geometric center of the antenna. In one embodiment, termination <NUM> comprises a pin termination (e.g., a 50Ω pin). In another embodiment, termination <NUM> comprises an RF absorber that terminates unused energy to prevent reflections of that unused energy back through the feed structure of the antenna. These could be used at the top of RF array <NUM>.

<FIG> illustrates another embodiment of the antenna system with an outgoing wave. Referring to <FIG>, two ground planes <NUM> and <NUM> are substantially parallel to each other with a dielectric layer <NUM> (e.g., a plastic layer, etc.) in between ground planes. RF absorbers <NUM> (e.g., resistors) couple the two ground planes <NUM> and <NUM> together. A coaxial pin <NUM> (e.g., 50Ω) feeds the antenna. An RF array <NUM> is on top of dielectric layer <NUM> and ground plane <NUM>.

In operation, a feed wave is fed through coaxial pin <NUM> and travels concentrically outward and interacts with the elements of RF array <NUM>.

The cylindrical feed in both the antennas of <FIG> improves the service angle of the antenna. Instead of a service angle of plus or minus forty-five degrees azimuth (±<NUM>° Az) and plus or minus twenty-five degrees elevation (±<NUM>° El), in one embodiment, the antenna system has a service angle of seventy-five degrees (<NUM>°) from the bore sight in all directions. As with any beam forming antenna comprised of many individual radiators, the overall antenna gain is dependent on the gain of the constituent elements, which themselves are angle-dependent. When using common radiating elements, the overall antenna gain typically decreases as the beam is pointed further off bore sight. At <NUM> degrees off bore sight, significant gain degradation of about <NUM> dB is expected.

Embodiments of the antenna having a cylindrical feed solve one or more problems. These include dramatically simplifying the feed structure compared to antennas fed with a corporate divider network and therefore reducing total required antenna and antenna feed volume; decreasing sensitivity to manufacturing and control errors by maintaining high beam performance with coarser controls (extending all the way to simple binary control); giving a more advantageous side lobe pattern compared to rectilinear feeds because the cylindrically oriented feed waves result in spatially diverse side lobes in the far field; and allowing polarization to be dynamic, including allowing left-hand circular, right-hand circular, and linear polarizations, while not requiring a polarizer.

RF array <NUM> of <FIG> and RF array <NUM> of <FIG> include a wave scattering subsystem that includes a group of patch antennas (i.e., scatterers) that act as radiators. This group of patch antennas comprises an array of scattering metamaterial elements (e.g., metamaterial surface scattering antenna elements).

In one embodiment, each scattering element in the antenna system is part of a unit cell that consists of a lower conductor, a dielectric substrate and an upper conductor that embeds a complementary electric inductive-capacitive resonator ("complementary electric LC" or "CELC") that is etched in or deposited onto the upper conductor.

In one embodiment, a liquid crystal (LC) is injected in the gap around the scattering element. Liquid crystal is encapsulated in each unit cell and separates the lower conductor associated with a slot from an upper conductor associated with its patch. Liquid crystal has a permittivity that is a function of the orientation of the molecules comprising the liquid crystal, and the orientation of the molecules (and thus the permittivity) can be controlled by adjusting the bias voltage across the liquid crystal. Using this property, the liquid crystal acts as an on/off switch for the transmission of energy from the guided wave to the CELC. When switched on, the CELC emits an electromagnetic wave like an electrically small dipole antenna.

Controlling the thickness of the LC increases the beam switching speed. A fifty percent (<NUM>%) reduction in the gap between the lower and the upper conductor (the thickness of the liquid crystal) results in a fourfold increase in speed. In another embodiment, the thickness of the liquid crystal results in a beam switching speed of approximately fourteen milliseconds (<NUM>). In one embodiment, the LC is doped in a manner well-known in the art to improve responsiveness so that a seven millisecond (<NUM>) requirement can be met.

The CELC element is responsive to a magnetic field that is applied parallel to the plane of the CELC element and perpendicular to the CELC gap complement. When a voltage is applied to the liquid crystal in the metamaterial scattering unit cell, the magnetic field component of the guided wave induces a magnetic excitation of the CELC, which, in turn, produces an electromagnetic wave in the same frequency as the guided wave.

The phase of the electromagnetic wave generated by a single CELC can be selected by the position of the CELC on the vector of the guided wave. Each cell generates a wave in phase with the guided wave parallel to the CELC. Because the CELCs are smaller than the wave length, the output wave has the same phase as the phase of the guided wave as it passes beneath the CELC.

In one embodiment, the cylindrical feed geometry of this antenna system allows the CELC elements to be positioned at forty-five-degree (<NUM>°) angles to the vector of the wave in the wave feed. This position of the elements enables control of the polarization of the free space wave generated from or received by the elements. In one embodiment, the CELCs are arranged with an inter-element spacing that is less than a free-space wavelength of the operating frequency of the antenna. For example, if there are four scattering elements per wavelength, the elements in the <NUM> transmit antenna will be approximately <NUM> (i.e., <NUM>/4th the <NUM> free-space wavelength of <NUM>).

In one embodiment, the CELCs are implemented with patch antennas that include a patch co-located over a slot with liquid crystal between the two. In this respect, the metamaterial antenna acts like a slotted (scattering) wave guide. With a slotted wave guide, the phase of the output wave depends on the location of the slot in relation to the guided wave.

In one embodiment, the antenna elements are placed on the cylindrical feed antenna aperture in a way that allows for a systematic matrix drive circuit. The placement of the cells includes placement of the transistors for the matrix drive. <FIG> illustrates one embodiment of the placement of matrix drive circuitry with respect to antenna elements. Referring to <FIG>, row controller <NUM> is coupled to transistors <NUM> and <NUM>, via row select signals Row1 and Row2, respectively, and column controller <NUM> is coupled to transistors <NUM> and <NUM> via column select signal Column1. Transistor <NUM> is also coupled to antenna element <NUM> via connection to patch <NUM>, while transistor <NUM> is coupled to antenna element <NUM> via connection to patch <NUM>.

In an initial approach to realize matrix drive circuitry on the cylindrical feed antenna with unit cells placed in a non-regular grid, two steps are performed. In the first step, the cells are placed on concentric rings and each of the cells is connected to a transistor that is placed beside the cell and acts as a switch to drive each cell separately. In the second step, the matrix drive circuitry is built in order to connect every transistor with a unique address as the matrix drive approach requires. Because the matrix drive circuit is built by row and column traces (similar to LCDs) but the cells are placed on rings, there is no systematic way to assign a unique address to each transistor. This mapping problem results in very complex circuitry to cover all the transistors and leads to a significant increase in the number of physical traces to accomplish the routing. Because of the high density of cells, those traces disturb the RF performance of the antenna due to coupling effect. Also, due to the complexity of traces and high packing density, the routing of the traces cannot be accomplished by commercially available layout tools.

In one embodiment, the matrix drive circuitry is predefined before the cells and transistors are placed. This ensures a minimum number of traces that are necessary to drive all the cells, each with a unique address. This strategy reduces the complexity of the drive circuitry and simplifies the routing, which subsequently improves the RF performance of the antenna.

More specifically, in one approach, in the first step, the cells are placed on a regular rectangular grid composed of rows and columns that describe the unique address of each cell. In the second step, the cells are grouped and transformed to concentric circles while maintaining their address and connection to the rows and columns as defined in the first step. A goal of this transformation is not only to put the cells on rings but also to keep the distance between cells and the distance between rings constant over the entire aperture. In order to accomplish this goal, there are several ways to group the cells.

In one embodiment, a TFT package is used to enable placement and unique addressing in the matrix drive. <FIG> illustrates one embodiment of a TFT package. Referring to <FIG>, a TFT and a hold capacitor <NUM> is shown with input and output ports. There are two input ports connected to traces <NUM> and two output ports connected to traces <NUM> to connect the TFTs together using the rows and columns. In one embodiment, the row and column traces cross in <NUM>° angles to reduce, and potentially minimize, the coupling between the row and column traces. In one embodiment, the row and column traces are on different layers.

In another embodiment, the combined antenna apertures are used in a full duplex communication system. <FIG> is a block diagram of an embodiment of a communication system having simultaneous transmit and receive paths. While only one transmit path and one receive path are shown, the communication system may include more than one transmit path and/or more than one receive path.

Referring to <FIG>, antenna <NUM> includes two spatially interleaved antenna arrays operable independently to transmit and receive simultaneously at different frequencies as described above. In one embodiment, antenna <NUM> is coupled to diplexer <NUM>. The coupling may be by one or more feeding networks. In one embodiment, in the case of a radial feed antenna, diplexer <NUM> combines the two signals and the connection between antenna <NUM> and diplexer <NUM> is a single broad-band feeding network that can carry both frequencies.

Diplexer <NUM> is coupled to a low noise block down converter (LNBs) <NUM>, which performs a noise filtering function and a down conversion and amplification function in a manner well-known in the art. In one embodiment, LNB <NUM> is in an out-door unit (ODU). In another embodiment, LNB <NUM> is integrated into the antenna apparatus. LNB <NUM> is coupled to a modem <NUM>, which is coupled to computing system <NUM> (e.g., a computer system, modem, etc.).

Modem <NUM> includes an analog-to-digital converter (ADC) <NUM>, which is coupled to LNB <NUM>, to convert the received signal output from diplexer <NUM> into digital format. Once converted to digital format, the signal is demodulated by demodulator <NUM> and decoded by decoder <NUM> to obtain the encoded data on the received wave. The decoded data is then sent to controller <NUM>, which sends it to computing system <NUM>.

Modem <NUM> also includes an encoder <NUM> that encodes data to be transmitted from computing system <NUM>. The encoded data is modulated by modulator <NUM> and then converted to analog by digital-to-analog converter (DAC) <NUM>. The analog signal is then filtered by a BUC (up-convert and high pass amplifier) <NUM> and provided to one port of diplexer <NUM>. In one embodiment, BUC <NUM> is in an out-door unit (ODU).

Diplexer <NUM> operating in a manner well-known in the art provides the transmit signal to antenna <NUM> for transmission.

Controller <NUM> controls antenna <NUM>, including the two arrays of antenna elements on the single combined physical aperture.

The communication system would be modified to include the combiner/arbiter described above. In such a case, the combiner/arbiter after the modem but before the BUC and LNB.

Note that the full duplex communication system shown in <FIG> has a number of applications, including but not limited to, internet communication, vehicle communication (including software updating), etc..

There is a number of example embodiments described herein.

Example <NUM> is a portable satellite antenna apparatus comprising a flat panel antenna and a container to house the antenna, the container having at least one radio-frequency (RF) transparent material through which the antenna is operable to transmit and receive satellite communications.

Example <NUM> is the antenna apparatus of example <NUM> that may optionally include that the at least one RF transparent material comprises a lid of the container.

Example <NUM> is the antenna apparatus of example <NUM> that may optionally include that the lid is operable as a radome of the antenna.

Example <NUM> is the antenna apparatus of example <NUM> that may optionally include that the at least one RF transparent material comprises plastic or fiberglass.

Example <NUM> is the antenna apparatus of example <NUM> that may optionally include that the at least one RF transparent material is tuned to frequencies at which the antenna is designed to operate.

Example <NUM> is the antenna apparatus of example <NUM> that may optionally include that the at least one RF transparent material has a convex shape with respect to a surface of the antenna through which the antenna transmits and receives the satellite communications.

Example <NUM> is the antenna apparatus of example <NUM> that may optionally include that an externally exposed portion of the at least one RF transparent material has a hydrophobic coating.

Example <NUM> is the antenna apparatus of example <NUM> that may optionally include that the antenna is operable to transmit and receive satellite communications through the at least one RF transparent material during closed-container operation when the container is closed.

Example <NUM> is a portable satellite antenna apparatus comprising a flat panel antenna and a container to house the antenna, the container having at least one RF transparent lid through which the antenna is operable to transmit and receive satellite communications, wherein the lid comprises a material that is a predetermined distance from the antenna surface and tuned to frequencies at which the antenna is designed to operate, wherein the antenna is operable to transmit and receive satellite communications through the at least one RF transparent lid for closed-container operation when the container is closed.

Example <NUM> is the antenna apparatus of example <NUM> that may optionally include that the material has a thickness that provides a protective shell and structure support for the container as a transit case while not impeding RF transmission.

Example <NUM> is the antenna apparatus of example <NUM> that may optionally include a rapidly deployable and self-contained network system.

Some portions of the detailed descriptions above are presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. An algorithm is here, and generally, conceived to be a self-consistent sequence of steps leading to a desired result. The steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated.

Unless specifically stated otherwise as apparent from the following discussion, it is appreciated that throughout the description, discussions utilizing terms such as "processing" or "computing" or "calculating" or "determining" or "displaying" or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices.

The present invention also relates to apparatus for performing the operations herein. This apparatus may be specially constructed for the required purposes, or it may comprise a general-purpose computer selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a computer readable storage medium, such as, but is not limited to, any type of disk including floppy disks, optical disks, CD-ROMs, and magnetic-optical disks, read-only memories (ROMs), random access memories (RAMs), EPROMs, EEPROMs, magnetic or optical cards, or any type of media suitable for storing electronic instructions, and each coupled to a computer system bus.

Various general-purpose systems may be used with programs in accordance with the teachings herein, or it may prove convenient to construct more specialized apparatus to perform the required method steps. The required structure for a variety of these systems will appear from the description below. In addition, the present invention is not described with reference to any particular programming language.

A machine-readable medium includes any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer). For example, a machine-readable medium includes read only memory ("ROM"); random access memory ("RAM"); magnetic disk storage media; optical storage media; flash memory devices; etc..

Claim 1:
A portable satellite antenna apparatus comprising:
a flat panel antenna (<NUM>); and
a container (<NUM>) to house the antenna (<NUM>), the container (<NUM>) having at least one radio-frequency (RF) transparent material through which the antenna (<NUM>) is operable to transmit and receive satellite communications, wherein the at least one RF transparent material comprises a lid (<NUM>) of the container (<NUM>) that is at a distance from the flat panel antenna and removable from over the antenna (<NUM>) to open the container (<NUM>) for operation in which the antenna is operable to transmit and receive satellite communications when the container is open, wherein the antenna (<NUM>) is operable to transmit and receive satellite communications through the at least one RF transparent material during closed-container operation when the container (<NUM>) is closed.