Abstract: An anisotropic reactive frequency selective surface (FSS) ground plane for controlling the beam pattern of an antenna. More specifically, the ground plane comprises a plurality of FSS unit cells arranged in an elongated shape and operable to control the beam pattern of the antenna in at least two orthogonal directions. The ground plane may be incorporated into a system including a vehicle windshield and the antenna, and is mounted at, or embedded in, a top-center portion of the windshield, substantially centered on the antenna.

Abstract: A switch arrangement comprises a plurality of MEMS switches arranged on a substrate about a central point, each MEMS switch being disposed on a common imaginary circle centered on the central point. Additionally, and each MEMS switch is preferably spaced equidistantly along the circumference of the imaginary circle. Connections are provided for connecting a RF port of each one of the MEMS switches with the central point.

Abstract: A method for improving the efficiency of antennas having transparent thin-film conductive surfaces, and antennas improved by the method are disclosed. For a selected frequency of antenna operation, values for surface current density in areas distributed over the surface of the thin-film are determined. Regions of the surface containing areas having concentrated current flow are identified based upon the determined values of current density. Antenna efficiency is improved by increasing conductivity in areas of the thin-film surface found to have concentrated current flow. The method enables the improvement of the efficiency of antennas having transparent thin-film conducting surfaces, without unnecessarily obstructing the optical view through the thin-film surfaces of the antennas.

Abstract: A switch arrangement comprises a plurality of MEMS switches arranged on a substrate about, and close to, a central point, each MEMS switch being disposed on a common imaginary circle centered on the central point. Additionally, and each MEMS switch is preferably spaced equidistantly along the circumference of the imaginary circle and within one quarter wavelength of the central point for frequencies in the passband of the switch arrangement. Connections are provided for connecting a RF port of each one of the MEMS switches with the central point.

Abstract: Leaky wave antenna beam steering that is capable of steering in a backward direction, as well as further down toward the horizon in the forward direction than was previously possible, and also directly toward zenith. The disclosed antenna and method involve applying a non-uniform impedance function across a tunable impedance surface in order to obtain such leaky wave beam steering.

Abstract: A method of and apparatus for beam steering. A feed horn is arranged so that the feed horn illuminates a tunable impedance surface comprising a plurality of individually tunable resonator cells, each resonator element having a reactance tunable by a tuning element associated therewith. The tuning elements associated with the tunable impedance surface are adjusted so that the resonances of the individually tunable resonator cells are varied in a sequence and the resonances of the individually tunable resonator cells are set to values which improve transmission of information via the tunable impedance surface and the feed horn.

Abstract: An apparatus and method for building three-dimensional spatial power combiners for efficiently combining power from a large number of active devices are being disclosed. The apparatus discloses a plurality of grid amplifiers, each having a major surface, the plurality of grid amplifiers are arranged along an axis that is perpendicular to the major surface of each grid amplifier and spatially separated from each other by a selected resonant distance to generate a standing wave between adjacent grid amplifiers. The method discloses selecting a plurality of grid amplifiers each having a major surface, arranging the plurality of grid amplifiers along an axis that is perpendicular to the major surface of each grid amplifier, selecting a resonance distance, and spatially separating said plurality of grid amplifiers by the resonant distance to generate a standing wave between adjacent grid amplifiers.

Abstract: A method for improving the efficiency of antennas having transparent thin-film conductive surfaces, and antennas improved by the method are disclosed. For a selected frequency of antenna operation, values for surface current density in areas distributed over the surface of the thin-film are determined. Regions of the surface containing areas having concentrated current flow are identified based upon the determined values of current density. Antenna efficiency is improved by increasing conductivity in areas of the thin-film surface found to have concentrated current flow. The method enables the improvement of the efficiency of antennas having transparent thin-film conducting surfaces, without unnecessarily obstructing the optical view through the thin-film surfaces of the antennas.

Abstract: A method for guiding waves over objects, a method for improving a performance of an antenna, and a method for improving a performance of a radar are disclosed. The methods disclosed teach how an impedance structure can be used to guide waves over objects.

Abstract: A high impedance surface and a method of making same. The surface includes a molded structure having a repeating pattern of holes therein and a repeating pattern of sidewall surfaces, the holes penetrating the structure between first and second major surfaces thereof and the sidewall surfaces joining the first major surface. A metal layer is put on said molded structure, the metal layer being in the holes, covering at least a portion of the second major surface, covering the sidewalls and portions of the first major surface to interconnect the sidewalls with other sidewalls via the metal layer on the second major surface and in the holes.

Abstract: An apparatus and methods for operating a frequency selective surface are disclosed. The apparatus can be tuned to an on/off state or transmit/reflect electromagnetic energy in any frequency. The methods disclosed teach how to tune the frequency selective surface to an on/off state or transmit/reflect electromagnetic energy in any frequency.

Abstract: The present disclosure relates to a method and an antenna for transmitting/receiving a RF signal at a plurality of different frequencies. Transmitting/receiving a RF signal at a plurality of different frequencies is achieved by providing a F antenna comprising a plurality of switches which can be used to adjust the resonant frequency of the antenna. By providing a F antenna, the antenna will be much smaller than the wavelength at which the antenna is operating. This allows the antenna to be used in compact devices such as PDA's and cellular phones.

Abstract: A rectenna structure comprising a flexible, dielectric sheet of material; a plurality of metallic lenslets disposed on the sheet of material; and a plurality of diodes disposed on the sheet of material, each diode in said plurality of diodes being arranged at a focus of a corresponding one of said plurality of metallic lenslets.

Abstract: An antenna system improves the radiation pattern of an antenna on a vehicle. An antenna includes a ground plane and receives RF signals. The antenna is mounted on a vehicle surface in close proximity to a vehicle window. A conductive structure is located on the vehicle window adjacent to the vehicle surface and communicates with the antenna. The conductive structure extends the ground plane of the antenna.

Abstract: Disclosed is an antenna system including a Luneberg Lens having a spherically shaped outer surface and a spherically shaped focal surface spaced from its outer surface with a plurality of patch antenna elements disposed along the focal surface of the Luneberg Lens; and a power combiner for combining signals received by said plurality of patch antenna elements. The disclosed antenna system may be used a part of a robust GPS system having a plurality of GPS satellites each transmitting a GPS signal; a plurality of airborne GPS platforms, each GPS platform including a GPS transmitter for transmitting its own GPS signal, the GPS signals being transmitted from the plurality of airborne GPS platforms being differentiated from the GPS signals transmitted by visible GPS satellites; and at least one terrestrially located GPS receiver for receiving the GPS signals transmitted by visible ones of the GPS satellites and by visible ones of said airborne GPS platforms.

Abstract: A method and apparatus for creating uniform heating of an microwave absorptive target. A microwave housing has a longitudinal axis and propagates a waveguide mode at an operating frequency. The target is located in an axial cross-sectional area relative to the longitudinal axis. First layer conductive strips are layered proximal to an inner wall of the microwave housing, substantially parallel to the longitudinal axis and being separated from an adjacent first layer conductive strip by a respective first layer gap, the inner wall acting as a ground plane. Second layer conductive strips are layered proximal to the first layer of conductive strips, parallel to the longitudinal axis and being separated from an adjacent second layer conductive strip by a respective second layer gap. Each first layer gap is centered under a respective second layer conductive strip and each second layer gap is centered over a conductive layer.

Abstract: Leaky wave antenna beam steering that is capable of steering in a backward direction, as well as further down toward the horizon in the forward direction than was previously possible, and also directly toward zenith. The disclosed antenna and method involve applying a non-uniform impedance function across a tunable impedance surface in order to obtain such leaky wave beam steering.

Abstract: An antenna having at least one main element and a plurality of parasitic elements. At least some of the elements have coupling elements or devices associated with them, the coupling elements or devices being tunable to thereby control the degree of coupling between adjacent elements. Controlling the degree of coupling allows a lobe associated with the antenna to be steered.

Abstract: A low-profile antenna includes a metal plate having a feed tab and support tabs. The feed tab and support tabs are folded to create slots. The feed tab and support tabs contact a ground plane. The support tabs perform impedance matching. The ground plane includes a printed circuit board with a top metal layer, a bottom metal layer, and a dielectric middle layer. A feed hole and support holes are formed in the printed circuit board and align with the feed tab and support tabs. The antenna produces a radiation pattern that is substantially omnidirectional in an azimuth direction and substantially null in a zenith direction.

Abstract: A low-profile dual-band antenna includes a ground plane. An “E”-shaped metal plate is located a first distance from the ground plane and includes first and second outer extensions and an inner extension of the metal plate. A feed tab connects the inner extension and the ground plane. A shorting tab connects the inner extension and the ground plane. The low-profile dual-band antenna communicates first radio frequency (RF) signals in a first RF band and second RF signals in a second RF band. The first RF signals and the second RF signals are vertical polarized signals. The low-profile dual-band antenna produces a radiation pattern that is omnidirectional in the azimuth plane and vertically polarized in a horizontal plane when communicating the first RF signals and the second RF signals. The first RF band and the second RF band can be independently tuned.