Abstract: The invention is a class of planar unidirectional traveling-wave (TW) antenna comprising a planar four-arm TW radiator ensemble, such as a 4-arm spiral, which is fed medially with a twin-lead feed connected with only a pair of opposite arms of the TW radiator, with the other two arms parasitically excited. The use of a mode suppressor enhances the purity of single-mode TW propagation and radiation. The twin-lead feed is connected with the balanced side of a balun, and is impedance matched with the TW radiator on one side and the balun on the other side. This simple feed structure using a single balun is generally smaller and much simpler, and thus much less costly than the conventional feed for a 4-arm spiral, which is a complex one-to-four power divider that contains hybrids, power dividers, couplers, matrices, etc.

Abstract: A miniaturized ultra-wideband multifunction antenna comprising a conducting ground plane at the base, a plurality of concentric feed cables, one or more omnidirectional one-dimensional (1-D) normal-mode and two-dimensional (2-D) surface-mode traveling-wave (TW) radiators, frequency-selective internal and external couplers, and a unidirectional radiator on top, stacked and cascaded one on top of the other. Configured as a single structure, its unidirectional radiator and plurality of omnidirectional TW radiators can cover, respectively, most satellite and terrestrial communications, with unidirectional and omnidirectional radiation patterns, respectively, needed on various platforms. This new class of multifunction antenna is ultra-wideband, miniaturized and low-cost, thus attractive for applications on automobiles and other small platforms.

Abstract: A class of ultra-wideband miniaturized traveling-wave (TW) antennas comprising a conducting ground surface at the base, a plurality of TW structures having at least one ultra-wideband low-profile two-dimensional (2-D) surface-mode TW structure, a frequency-selective coupler placed between adjacent TW structures, and a feed network. In one embodiment, a 2-D surface-mode TW structure is positioned above the conducting ground surface, a normal-mode TW structure placed on top with an external frequency-selective coupler placed in between; continuous octaval bandwidth of 14:1 and size reduction by a factor of 3 to 5 are achievable. In other embodiments using at least two 2-D TW structures and a dual-band feed network, a continuous bandwidth over 100:1, and up to 140:1 or more, is reachable. In yet another embodiment, ultra-wideband multi-band performance over an octaval operating bandwidth up to 2000:1 or more is feasible.

Abstract: A class of ultra-wideband miniaturized traveling-wave (TW) antennas comprising a conducting ground surface at the base, a plurality of TW structures having at least one ultra-wideband low-profile two-dimensional (2-D) surface-mode TW structure, a frequency-selective coupler placed between adjacent TW structures, and a feed network. In one embodiment, a 2-D surface-mode TW structure is positioned above the conducting ground surface, a normal-mode TW structure placed on top with an external frequency-selective coupler placed in between; continuous octaval bandwidth of 14:1 and size reduction by a factor of 3 to 5 are achievable. In other embodiments using at least two 2-D TW structures and a dual-band feed network, a continuous bandwidth over 100:1, and up to 140:1 or more, is reachable. In yet another embodiment, ultra-wideband multi-band performance over an octaval operating bandwidth up to 2000:1 or more is feasible.

Abstract: A class of ultra-wideband miniaturized traveling-wave (TW) antennas comprising a conducting ground surface at the base, a plurality of TW structures having at least one ultra-wideband low-profile two-dimensional (2-D) surface-mode TW structure, a frequency-selective coupler placed between adjacent TW structures, and a feed network. In one embodiment, a 2-D surface-mode TW structure is positioned above the conducting ground surface, a normal-mode TW structure placed on top with an external frequency-selective coupler placed in between; continuous octaval bandwidth of 14:1 and size reduction by a factor of 3 to 5 are achievable. In other embodiments using at least two 2-D TW structures and a dual-band feed network, a continuous bandwidth over 100:1, and up to 140:1 or more, is reachable. In yet another embodiment, ultra-wideband multi-band performance over an octaval operating bandwidth up to 2000:1 or more is feasible.

Abstract: A miniaturized ultra-wideband multifunction antenna comprising a conducting ground plane at the base, a plurality of concentric feed cables, one or more omnidirectional one-dimensional (1-D) normal-mode and two-dimensional (2-D) surface-mode traveling-wave (TW) radiators, frequency-selective internal and external couplers, and a unidirectional radiator on top, stacked and cascaded one on top of the other. Configured as a single structure, its unidirectional radiator and plurality of omnidirectional TW radiators can cover, respectively, most satellite and terrestrial communications, with unidirectional and omnidirectional radiation patterns, respectively, needed on various platforms. This new class of multifunction antenna is ultra-wideband, miniaturized and low-cost, thus attractive for applications on automobiles and other small platforms.

Abstract: A class of ultra-wideband miniaturized traveling-wave (TW) antennas comprising a conducting ground surface at the base, a plurality of TW structures having at least one ultra-wideband low-profile two-dimensional (2-D) surface-mode TW structure, a frequency-selective coupler placed between adjacent TW structures, and a feed network. In one embodiment, a 2-D surface-mode TW structure is positioned above the conducting ground surface, a normal-mode TW structure placed on top with an external frequency-selective coupler placed in between; continuous octaval bandwidth of 14:1 and size reduction by a factor of 3 to 5 are achievable. In other embodiments using at least two 2-D TW structures and a dual-band feed network, a continuous bandwidth over 100:1, and up to 140:1 or more, is reachable. In yet another embodiment, ultra-wideband multi-band performance over an octaval operating bandwidth up to 2000:1 or more is feasible.

Abstract: A planar broadband beam-steering phased array antenna with approximately 10:1 bandwidth is comprised of planar broadband traveling wave antenna elements positioned parallel to a conducting ground plane and spaced less than 0.5 wavelength at the highest operating frequency and more than 0.01 wavelengths at the lowest operating frequency. Each planar traveling wave antenna element is a planar frequency-independent antenna or planar self-complementary antenna, and is truncated to fit a unit cell of the phased array. Adjacent antenna elements are arranged to be tightly coupled together or connected with each other and spaced less than 0.5 wavelength apart between their centers throughout its operating frequency range. One or more layers of dielectric or magneto-dielectric substrates/superstrates can be added to enhance specific performances.

Abstract: The invention is a class of planar unidirectional traveling-wave (TW) antenna comprising a planar four-arm TW radiator ensemble, such as a 4-arm spiral, which is fed medially with a twin-lead feed connected with only a pair of opposite arms of the TW radiator, with the other two arms parasitically excited. The use of a mode suppressor enhances the purity of single-mode TW propagation and radiation. The twin-lead feed is connected with the balanced side of a balun, and is impedance matched with the TW radiator on one side and the balun on the other side. This simple feed structure using a single balun is generally smaller and much simpler, and thus much less costly than the conventional feed for a 4-arm spiral, which is a complex one-to-four power divider that contains hybrids, power dividers, couplers, matrices, etc.

Abstract: A planar broadband beam-steering phased array antenna with approximately 10:1 bandwidth is comprised of planar broadband traveling wave antenna elements positioned parallel to a conducting ground plane and spaced less than 0.5 wavelength at the highest operating frequency and more than 0.01 wavelengths at the lowest operating frequency. Each planar traveling wave antenna element is a planar frequency-independent antenna or planar self-complementary antenna, and is truncated to fit a unit cell of the phased array. Adjacent antenna elements are arranged to be tightly coupled together or connected with each other and spaced less than 0.5 wavelength apart between their centers throughout its operating frequency range. One or more layers of dielectric or magneto-dielectric substrates/superstrates can be added to enhance specific performances.

Abstract: The invention is a novel solution to circumvent the fundamental gain bandwidth limitations of an antenna of a given size by using a traveling-wave (TW) antenna and strongly coupling it with the mounting platform to enlarge the effective size of the antenna. A preferred form of this invention comprises a conducting ground surface generally curvilinear and conformal to said platform, a broadband TW surface radiator positioned above and spaced apart from said ground surface, an impedance matching structure between the surface radiator and the conducting ground surface, and a reactive impedance matching network positioned on the periphery of said surface radiator.

Abstract: A broadband/multiband circular array antenna is disclosed. One embodiment comprises a circular directional array antenna comprising a driven omnidirectional traveling-wave antenna element coupled to a transceiver via a feed and a plurality of surface-waveguide elements symmetrically positioned about and spaced from the driven omnidirectional traveling-wave antenna element. Each surface-waveguide element receives a control signal configured to selectively alter its waveguide characteristics to electronically direct a beam to/from the array. The array provides a directionally controllable antenna beam with broadband/multiband frequency performance in a low profile design that is both economical and practical to produce and maintain.

Abstract: A broadband/multiband circular array antenna is disclosed. One embodiment comprises a circular directional array antenna comprising a driven omnidirectional traveling-wave antenna element coupled to a transceiver via a feed and a plurality of surface-waveguide elements symmetrically positioned about and spaced from the driven omnidirectional traveling-wave antenna element. Each surface-waveguide element receives a control signal configured to selectively alter its waveguide characteristics to electronically direct a beam to/from the array. The array provides a directionally controllable antenna beam with broadband/multiband frequency performance in a low profile design that is both economical and practical to produce and maintain.

Abstract: Disclosed is a broadband, miniaturized, slow-wave antenna for transmitting and receiving radio frequency (RF) signals. The slow-wave antenna comprises a dielectric substrate with a traveling wave structure mounted on one surface, and a conductive surface member mounted on the opposite surface. The traveling wave structure, for example, is of the broadband planar type such as various types of spirals and includes conductive arms which are coupled to feed lines which are routed through the dielectric substrate and the conductive surface member for connection to a transmitter or receiver. The dielectric substrate is of a predetermined thickness which is, for example, less than 0.04.lambda..sub.1, where .lambda..sub.1 is the free space wavelength of the lowest frequency f.sub.1 of the operating frequency range of the slow-wave antenna.

Abstract: A micro-electromechanical switch which comprises a flexible longitudinal beam disposed adjacent to first and second contact members which form a gap in, for example, a radio frequency transmission line to control the flow of the radio frequency signal. At least one actuating beam is attached to at least one end of the flexible longitudinal beam. Also an actuating member is disposed adjacent to the actuating beam so as to generate an electrostatic force therebetween upon the application of a voltage across the actuating beam and the actuating member. When the voltage is applied, the actuating beam bends and thus applies a longitudinal force and torque on the joint between the actuating beam and the flexible longitudinal beam. This longitudinal force and torque cause the flexible longitudinal beam to bend laterally toward the first and second contact members, thereby completing the electrical circuit attached to the first and second contact members.

Abstract: The present invention provides an integrated antenna and phase shifter which has frequency-independent performance. In its preferred form, the antenna phase shifter of the present invention comprises first and second conductive spirals which are identical to and aligned with each other and which are separated from each other by a thin sheet of dielectric material. The first spiral has arms which are connected in a central region of the spiral to a first line of a balun or a balanced transmission line via electronic or optoelectronic switches. The second spiral has arms which are connected in the central region of the second spiral to a second line of the balun or balanced transmission line via electronic or optoelectronic switches. A switching circuit is used to turn them on and off. When any one of the RF switches is turned on, an RF link is established between the arm connected to the switch and the line of the balun connected to the switch.

Abstract: A first spiral-mode microstrip (SMM) antenna has an antenna element situated over and spaced from a parallel ground plane. The antenna element is a frequency-independent planar structure having a plurality of spiraling arms extending outwardly in a plane from a central portion, the arms having respective feed points to excite the spiral modes. Of particular significance, a shorting mechanism connects one or more arms to the ground plane element for influencing the shape of the electromagnetic radiation pattern. A second embodiment of the SMM antenna is constructed as the first, but has a center feed and an off-center feed, and further comprises shorting mechanisms situated well within the periphery of the antenna element. A third embodiment of the SMM antenna is constructed similar to the first, but has a concentric gap situated within the arms so that there is, in effect, a first antenna element having a first plurality of arms and a second concentric antenna element having a second plurality of arms.

Abstract: A compact broadband microstrip antenna for mounting to one side of a ground plane comprises a closed (usually circular) array of antenna elements positioned to one side of a substrate for spacing the antenna elements a selected distance above the ground plane, the antenna elements being adapted to be electrically driven out of phase from one another to excite one or more spiral modes. In another form, a compact microstrip antenna comprises one or more antenna elements positioned to one side of a magnetic substrate for spacing the antenna elements a selected distance from a ground plane, the magnetic substrate being chosen to have a relative permittivity which is roughly equal to its relative permeability. In a third form, a microstrip antenna is adapted for operating in a single mode and radiation from other modes is suppressed by varying the spacing above the ground plane in the radiation zones so that only radiation in the desired mode is fostered.

Abstract: A shared aperture, multifunction conformable antenna has a spiral-mode microstrip (SMM) antenna portion having a spacer for maintaining the SMM antenna in spaced relationship to a ground plane, with dielectric material therebetween. The SMM antenna portion is substantially surrounded by a loop antenna which is spaced therefrom and which is electrically connected to the spiral-mode portion by a high frequency choke to block FM broadcast band signals from the SMM antenna. An AM-broadcast-band-blocking capacitor functions to route AM signals to the SMM antenna portion. The spiral-mode antenna receives signals at frequencies above 300 MHz, the loop antenna receives signals in the FM band, and both the loop antenna and the spiral-mode antenna receive signals in the AM band.

Abstract: A compact broadband microstrip antenna for mounting to one side of a ground plane comprises a closed (usually circular) array of antenna elements positioned to one side of a substrate for spacing the antenna elements a selected distance above the ground plane, the antenna elements being adapted to be electrically driven out of phase from one another to excite one or more spiral modes. In another form, a compact microstrip antenna comprises one or more antenna elements positioned to one side of a magnetic substrate for spacing the antenna elements a selected distance from a ground plane, the magnetic substrate being chosen to have a relative permittivity which is roughly equal to its relative permeability. In a third form, a microstrip antenna is adapted for operating in a single mode and radiation from other modes is suppressed by varying the spacing above the ground plane in the radiation zones so that only radiation in the desired mode is fostered.