Abstract: A diesel particulate filter including a microwave-absorbing target within a waveguide cavity. The cavity accepts microwave-frequency electromagnetic radiation through input couplers 90 degrees out of phase with each other to excite circular polarization heating modes. Through excitation of circularly polarized modes, heating patterns are time-averaged azimuthally to smooth out the hot and cold spots, thereby providing greater uniformity relative to heating patterns for corresponding linearly polarized modes.

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 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: The present invention provides a RF-lightwave modulator with improved efficiency by making use of a broken loop resonator having a gap therein. In the present invention a RF input signal is coupled into a broken loop resonator, thereby producing a RF output signal. An optical modulator connected across the gap receives the RF output signal and modulates a lightwave with the RF output signal to produce a RF modulated lightwave. Because the optical modulator is connected across the gap in the broken loop resonator, the voltage of the RF output signal applied to the optical modulator will be greater than the voltage of the RF input signal applied to the broken loop resonator.

Abstract: A dual-band monopole antenna includes a ground plane. A metal plate is located a first distance from the ground plane and includes first and second portions connecting to form a first angle therebetween. A slot is formed in the metal plate that isolates a center portion of the metal plate. The dual-band monopole antenna communicates first radio frequency (RF) signals in a first RF band and second RF signals in a second RF band. A feed tab contacts an outer surface of the metal plate and is located the first distance from the ground plane. The first RF signals and the second RF signals are vertical polarized signals. The dual-band monopole antenna produces a radiation pattern that is omnidirectional in the azimuth plane and vertically polarized in a horizontal plane. The first RF band and the second RF band are independently tuned.

Abstract: An antenna array comprises a substrate; a plurality of projecting, tapering structures disposed in an array and attached to a first major surface of said substrate, the plurality of projecting, tapering structures defining a plurality of waveguides therebetween; and a plurality of box-shaped structures disposed in an array and attached to a second major surface of the substrate, the plurality of box-shaped structures defining a plurality of waveguides therebetween, the plurality of waveguides defined by the plurality of projecting, tapering structures aligning with the plurality of waveguides defined by the plurality of box-shaped structures. The substrate includes a plurality of probes for feeding the plurality waveguides.

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.

Abstract: A method for designing a multiple layer frequency selective surface structure. An overall response for the structure is specified. The desired response may be modeled as a filter response. Parameters for each of the layers making up the structure that provide the overall response are determined based on the polarization modes between the layers being decoupled. To provide for decoupling, the individual layers are rotated with respect to each other. The overall response of the structure is then calculated and compared to the desired response. Adjustments are made in the parameters of each layer until the calculated response is equal or nearly equal to the desired response.

Abstract: A spiral antenna system optimized to transmit and/or receive linearly polarized signals and circularly polarized signals. The antenna system includes a spiral antenna and a circuit for exciting the spiral antenna to transmit or receive linearly polarized and circularly polarized signals simultaneously.

Abstract: A low-profile antenna provides dual simultaneous operation. A first antenna has a circular polarization radiation pattern. A monopole antenna includes a hollow tube and is top-loaded by locating a disk on top of the hollow tube. A support structure positions the monopole antenna between the first antenna and a ground plane. The first antenna is a four arm spiral antenna. The four arm spiral antenna and monopole antenna are each fed by a cable with a first conductor and a second conductor. The radiation pattern of the four arm spiral antenna is maximum at forty-five degrees above the horizon and is null toward the horizon. The cable excites the monopole antenna with respect to the ground plane to transmit/receive vertical polarized signals. The radiation pattern of the monopole antenna is maximum towards the horizon. The first antenna and the monopole antenna operate simultaneously.

Abstract: A low-profile antenna provides dual simultaneous operation. A first antenna has a circular polarization radiation pattern. A monopole antenna includes a hollow tube and is top-loaded by locating a disk on top of the hollow tube. A support structure positions the monopole antenna between the first antenna and a ground plane. The first antenna is a four arm spiral antenna. The four arm spiral antenna and monopole antenna are each fed by a cable with a first conductor and a second conductor. The radiation pattern of the four arm spiral antenna is maximum at forty-five degrees above the horizon and is null toward the horizon. The cable excites the monopole antenna with respect to the ground plane to transmit/receive vertical polarized signals. The radiation pattern of the monopole antenna is maximum towards the horizon. The first antenna and the monopole antenna operate simultaneously.

Abstract: The present invention provides a RF-lightwave modulator with improved efficiency by making use of a broken loop resonator having a gap therein. In the present invention a RF input signal is coupled into a broken loop resonator, thereby producing a RF output signal. An optical modulator connected across the gap receives the RF output signal and modulates a lightwave with the RF output signal to produce a RF modulated lightwave. Because the optical modulator is connected across the gap in the broken loop resonator, the voltage of the RF output signal applied to the optical modulator will be greater than the voltage of the RF input signal applied to the broken loop resonator.

Abstract: A spiral antenna system optimized to transmit and/or receive linearly polarized signals and circularly polarized signals. The antenna system includes a spiral antenna and a circuit for exciting the spiral antenna to transmit or receive linearly polarized and circularly polarized signals simultaneously.

Abstract: A method for designing a multiple layer frequency selective surface structure. An overall response for the structure is specified. The desired response may be modeled as a filter response. Parameters for each of the layers making up the structure that provide the overall response are determined based on the polarization modes between the layers being decoupled. To provide for decoupling, the individual layers are rotated with respect to each other. The overall response of the structure is then calculated and compared to the desired response. Adjustments are made in the parameters of each layer until the calculated response is equal or nearly equal to the desired response.

Abstract: An antenna array comprises a substrate; a plurality of projecting, tapering structures disposed in an array and attached to a first major surface of said substrate, the plurality of projecting, tapering structures defining a plurality of waveguides therebetween; and a plurality of box-shaped structures disposed in an array and attached to a second major surface of the substrate, the plurality of box-shaped structures defining a plurality of waveguides therebetween, the plurality of waveguides defined by the plurality of projecting, tapering structures aligning with the plurality of waveguides defined by the plurality of box-shaped structures. The substrate includes a plurality of probes for feeding the plurality waveguides.