Hughes Aircraft Company

Other

Hughes Electronics Corporation

Mon N Wong

Gregory D Kroupa

Donald C Chang

Robert J Patin

Krishnan K Raghavan

Timothy A Crail

Harry Wong

Samuel S Wong

Frank A Taormina

Harold A Rosen

Parthasarathy Ramanujam

Sanford S Shapiro

Stanley S Chang

Ann L Peebles

Theodore S Fishkin

Cynthia A Dixon

Robert C Perpall

William N Klimczak

Wilbur J Linhardt

Clinton W Pederson

Thomas F Foster, Jr

Brennan J Trese

Gary A Hill

Stanley T Ibrao

Charles J Brandt

Robert D Ward

Frank J Alessi

Jeffrey D Steele

Sidney Kaplan

A dual band omni directional antenna is disclosed. A dielectric cylinder supports a cone shaped reflector over a corrugated radio frequency horn. Orthogonal mode transducers produce and conduct circularly polarized radio frequency waves within the horn. The reflector, the horn, and the transducers are all coaxially disposed. The antenna produces a torodial radiation pattern in a plane that is substantially orthogonal to the axis of the antenna. Transmit and receive functions may be performed simultaneously using a single reflector and two orthogonal mode transducers.

Omni directional antenna

A dual mode waveguide orthomode transducer has a section of circular waveguide (12) and a transition (16) from circular waveguide to rectangular waveguide disposed coaxially along a longitudinal axis (38). A terminus of the transition (16) opposite the circular waveguide (12) serves as a straight port (46) for input signals, and at the opposite end of the circular waveguide there is a front port (14) for outputting electromagnetic signals. A side port (48) connects via a tapered rectangular waveguide (40) perpendicularly to the longitudinal axis (38) to connect with the circular waveguide (12), and to couple electromagnetic energy into the circular waveguide (12) via a window (50) disposed in a sidewall (42) of the circular waveguide. A plane of polarization of a wave in one input port is perpendicular to a plane of polarization of a wave in the other input port. A plurality of vanes of differing widths (66, 68) is disposed in the tapered rectangular waveguide (40), the blades being parallel to broad walls of the rectangular waveguide. The blades (66, 68) are electrically conductive. Additional electrically conductive blades (60, 62) are disposed along the longitudinal axis 38 parallel to broad walls of the straight port (46) and are located between a center of the window (50) and the back end of the circular waveguide (12). A third blade (64) of electrically resistive material is located in the region of an interface between the circular waveguide and the transition.

Orthomode transducer with side-port window

A circularly polarized wave entering the horn is converted to a linearly polarized wave which appears in one of the ports depending on the sense of the polarization. The stepped configuration of the impedance matching section minimizes mutual coupling among horns of the respective assemblies of the array antenna.

Horn radiator assembly with stepped septum polarizer

A flat cavity RF power divider wherein a flat cavity and an input waveguide share a common wall, coupling slots being disposed in the common wall offset from the centerline of the input waveguide for exciting a dominant TE.sub.4,0 mode in the flat cavity, the power divider also including short circuit means for exciting the transverse axis column of the flat cavity, and RF absorber means in the cavity to improve the frequency response of the divider, output coupling means also being provided for providing an RF power output.

Flat cavity RF power divider

A bicone microwave antenna having an orthomode tee as an input/output terminal, an internal dielectric polarizer, a circular waveguide with eight longitudinal radiating slots, two 30 degree conical reflectors, an external meanderline polarizer, and a partial circular waveguide short. An RF signal from the input/output terminal is converted into a rotating TE.sub.11 mode by the internal dielectric polarizer. The radiating slots in combination with the conical reflectors radiate the RF signal as a horizontally polarized field in a doughnut-shaped pattern. The meanderline polarizer converts the horizontally polarized field into a circularly polarized field. The partial circular waveguide short leaks a predetermined amount of radiation out the end of the waveguide to fill the center hole of the doughnut-shaped radiation pattern, thus producing a hemispherical RF beam having an elevation angle from 110 to -110 degrees. The use of impedance-matching circular rings in the waveguide further enhances the ability of the antenna to operate in three frequency bands.

Bicone antenna with hemispherical beam

A dual septum polarization rotator which, in the presently preferred embodiment thereof, includes a square waveguide and a pair of stepped septums disposed in spaced, orthogonal relation to each other within opposite end portions of the square waveguide. A first one of the septums extends horizontally between the side walls of the waveguide, parallel to the top and bottom walls of the waveguide, and the other/second one of the septums extends vertically between the top and bottom walls of the waveguide, parallel to the side walls of the waveguide. The first septum, in cooperation with the waveguide, defines first and second input ports, and, the second spectum, in cooperation with the waveguide, defines first and second output ports. The spacing between the first and second septums defines a central, open, nonseptum region within the waveguide. In operation, the first septum functions to convert the polarization of a first excitation signal introduced into the first input port from a first polarization to a second polarization, and the second septum functions to convert the second polarization into a third polarization orthogonal to the first polarization, for output, via the first output port, as a first output signal. For example, if the first polarization is horizontal polarization, then the second polarization is circular polarization, and the third polarization is vertical polarization. The polarization rotator of the present invention is also capable of dual mode operation, whereby the polarization of a second excitation signal introduced into the second input port is simultaneously rotated for output, via the second output port, as a second output signal.

Dual septum polarization rotator

A waveguide hybrid includes a generally rectangular superstructure defined by first and second conductive broad walls and first and second conductive narrow walls, and an intermediate, conductive narrow wall bifurcating the superstructure into first and second generally rectangular waveguides, with each of the waveguides being provided with a central, longitudinally extending land or ridge, preferably having a generally rectangular, cross-sectional profile. A coupling window is provided in a central portion of the intermediate narrow wall, which is shared in common by the first and second waveguides. Further, a capacitive button, which preferably takes the form of a square peg, is provided on the floor of the superstructure between the lateral surfaces of the common narrow wall which define the coupling window. In operation, RF energy, such as a microwave excitation signal, is injected into the input port of the first or primary waveguide, thereby launching a TE.sub.10 mode which propagates through the primary waveguide towards its output port. A portion of the RF energy is coupled through the coupling window to thereby excite a TE.sub.10 mode to propagate through the second or auxiliary waveguide. The capacitive button functions to enhance the coupling efficiency. The RF energy is ultimately output via the output ports of both the primary and auxiliary waveguides, with the output power present at the output port of the auxiliary waveguide phase-lagging the output power present at the output of the primary waveguide by 90 degrees. The input port of the secondary waveguide functions as an isolation port since it receives minimum power due to phase cancellation.

Ridged waveguide hybrid

A broad band omnidirectional monocone antenna 10 having a wide operative frequency spectrum and a large elevation angle A is disclosed herein. The antenna 10 of the present invention includes an input circular waveguide network 12 and 18 for providing electromagnetic energy of at least one polarization. Coupled to the circular waveguide network 12 and 18 is a dielectric-loaded waveguide arrangement 22 for projecting a first electromagnetic beam. The inventive antenna 10 further includes a parasitic element network 32, 34, and 36 positioned in the path of the first beam. The parasitic element network 32, 34, and 36 is disposed to form a parasitic beam in response to the first beam. In a particular embodiment of the inventive antenna 10 a beam shaping cone 40 circumscribes the dielectric waveguide arrangement 22. The cone 40 is adapted to augment the elevation angle A characterizing the antenna 10 of the present invention by redirecting the parasitic beam.

Broad band omnidirectional monocone antenna

A patch antenna is formed of one or more flat disc-shaped radiators disposed parallel to and spaced apart from a common ground-plane element. At each radiator, there is a feed assembly of two feeds positioned to one side of a center of the radiator in space quadrature and excited in phase quadrature for generating circularly polarized radiation from the radiator. Each of the feeds, in a preferred embodiment of the invention, is formed as a post extending through an aperture in the ground-plane element partway to the radiator for capacitive coupling with the radiator. At each radiator, a reactance element on the form of a capacitive block extends from the ground-plane element partway to the radiator at a location diametrically opposite the feed assembly. Capacitive reactance of the reactance element is approximately one order of magnitude less than the sum of the capacitive reactance of the two feeds at each radiator to reduce mutual coupling between the feeds of each radiator to counteract any elliptical polarization to produce accurately a circular polarization.

Patch antenna with polarization uniformity control

A multiband gridded focal plane array antenna 10 is disclosed which provides simultaneous beams of multiple frequencies. The antenna 10 includes a metallization pattern 11 providing a first set of conductive edges 18 having a first length L.sub.1 and a second set of conductive edges 20 having a second length L.sub.2. The first and second sets of conductive edges are separately fed to provide the first and second simultaneous output beams at first and second operating frequencies.

Multiband gridded focal plane array antenna

An antenna system for an array antenna includes an array of radiators formed as patch antenna elements on a dielectric substrate, there being a shielding metallic sheet on a side of the substrate opposite the radiators. A further dielectric substrate and a bottom metallic sheet are disposed on a side of the shielding sheet opposite the radiators. An antenna feed system is disposed in the further sheet. Coupling devices such as orthogonal slots, in one embodiment, or a microwave crossover in a second embodiment, couple electromagnetic power from the feed system to the radiators through the shielding sheet. In the case of the coupling slots, the feed system provides phase quadrature signals for development of circularly polarized radiation. The crossover provides only a linearly polarized wave, and is formed of two coplanar waveguides, one in the shielding sheet and one in the bottom sheet. Each of the coplanar waveguides includes a pair of coupling pads, the pads of one waveguide being in registration with the pads of the other waveguide.

Plural layer co-planar waveguide coupling system for feeding a patch

A microstrip focal plane array antenna is disclosed which includes a planar dielectric board 18 having a first surface 22 and second surface 28. A second radiating element 30 is located on the second surface 28 of the dielectric board 18 and a first radiating element 12 is located on the first surface 22 of the dielectric board 18. Energy is coupled to the first radiating element 12 from the second radiating element 30 and is reradiated by the first radiating element 12. In a specific embodiment, the second radiating element 30 is a resonator 30 at one end of a coplanar waveguide, 24, having longitudinal and traverse axes, 32 and 34 respectively. The first radiating element 12 is a microstrip patch 12 of conductive material, having longitudinal and traverse axes, 14 and 16 respectively. The microstrip patch 12 is aligned over the resonator 30 such that electromagnetic energy from the resonator 30 is reradiated as linearly polarized energy by the microstrip patch 12. In an alternative embodiment, the microstrip patch 12 is aligned relative to the resonator 30 such that the longitudinal axis 32 of the microstrip patch 12 is at an angle of 45 degrees with respect to the longitudinal axis 32 of the resonator 30. This orientation, is effective to cause the patch 12 to radiate circularly polarized energy.

Focal plane array antenna

A diplexer for electromagnetic signals of higher and lower frequency is formed of a common waveguide channel for both signals, the common channel branching into a through waveguide channel and a side waveguide channel. The through channel includes a filter having a pass band for propagation of the lower frequency signal and inhibiting propagation of the higher frequency signal. The side channel is formed as a waveguide below cut-off frequency with respect to the lower frequency signal for inhibiting propagation of the lower frequency signal while permitting propagation of the higher frequency signal. A coupling aperture formed as a slot resonant at the higher frequency is located in a waveguide wall at an integral number of quarter guide wavelengths in front of the filter for coupling the higher frequency signal between the common and the side channels.

Microwave diplexer

A polarization selector system, suitable for use with an antenna for radiating electromagnetic waves at a variety of preselectable polarizations, is formed of an orthogonal mode launcher of electromagnetic waves, and a hybrid coupling assembly for driving the launcher. The coupling assembly has a pair of waveguides sharing a common wall. A set of hybrid couplers of differing coupling ratios, and including a mechanically displaceable gate within each coupler, is disposed serially along the common wall. The gates are individually positionable to provide for coupling of differing amounts of electromagnetic power with 90 degree phase shift between the waveguides. Output signals of the waveguides connect with respective ones of a pair of mode launching probe assemblies in the mode launcher to energize the probe assemblies for producing a resulting electromagnetic wave having selectively right and left hand circular or elliptical polarization as well as linear polarization which can be advanced in orientation in increments of ninety degrees.

Electromagnetic polarization selector

A lightweight, low profile phased array antenna 10 is disclosed which includes an electromagnetically coupled integrated subarray in a multilayer structure with no vertical electrical connections and no phase shifters. The integrated subarray includes a first layer 11 having an array of patches 20 of electrically conductive material. A second layer 15, is provided, in parallel registration with the first layer 11, which includes an array of resonators 22, each resonator 22 being electromagnetically coupled to a corresponding patch 20 in the first layer 11. A third layer 19 is provided which is in parallel registration with the second layer 15. Electromagnetic couplers 24 and 34 in the second and third layers 15 and 19 couple energy received by resonators 22 in the second layer 15, to processing circuitry in the third layer 19. The antenna of the present invention is adapted for transmit and receive modes of operation.

Growing community of inventors

Torrance, CA, United States of America

Mon N Wong