Lockheed Martin Corporation

The Boeing Company

Hughes Electronics Corporation

Lockhead Martin Corp.

Chih-Chien Hsu

Sudhakar K Rao

Hanching Grant Wang

Gerard Joseph Matyas

Stephen A Robinson

George Voulelikas

Mirwais Zeweri

Jim Wang

Chris G Baran

Surjit S Dhillon

Robert Rink

Jack Bauer

A dual-band feed horn having a connection surface configured for connection to a waveguide and a first surface coupled to the connection surface. The first surface has a cylindrical surface with a length and a first diameter chosen to propagate TE11 modes for both a low frequency band and a high frequency band. The horn has a bandwidth ratio of the high-frequency band to the low frequency band in the range of 1.6-4.0. The horn also has a substantially conical surface coupled to the first surface at a first slope discontinuity. The conical surface includes multiple surfaces each having a respective slope and coupled to adjacent surfaces by a respective plurality of slope discontinuities each having a respective diameter. The slopes and diameters are chosen to generate primarily TM1,m modes (m=1, 2, 3, etc.) in the high-frequency band and primarily higher order TE1,n modes (n=2, 3, etc.) in the low-frequency band such that the low frequency band and the high frequency band have approximately equal beam widths.

Dual-band feed horn with common beam widths

A dual-band antenna system configured to transmit and/or receive microwave beams over two or more frequency bands with substantially similar beam widths and substantially similar sidelobe levels is disclosed. The antenna system includes at least one reflector and at least one feed horn, the horn configured to provide a first efficiency over a first frequency band and lower efficiencies over one or more second frequency bands. The horn includes a substantially conical wall having an internal surface with a variable slope. The internal surface includes one or more slope discontinuities, wherein the slope discontinuities are configured to generate primarily TEmodes within the first frequency band and within the second frequency bands and generate TMmodes substantially only within the second frequency bands.

Dual-band antenna using high/low efficiency feed horn for optimal radiation patterns

An antenna assembly includes a reflector having a focal plane, a first feed element located along the focal plane that illuminates the reflector to create a first contour beam at a first frequency and a second feed element located further from the reflector than the first feed element that illuminates the reflector to create a first spot beam at a second frequency, the second frequency being different than the first frequency.

Common aperture antenna for multiple contoured beams and multiple spot beams

A horn antenna includes smooth-walls with multiple slope discontinuities. The horn antenna may have more than an octave bandwidth with a 2.25:1 bandwidth ratio to cover the frequencies of 20 GHz, 30 GHz, and 45 GHz, or all the desired bands for military or other communications.

Horn antenna and system for transmitting and/or receiving radio frequency signals in multiple frequency bands

An antenna system for transmitting and/or receiving radio frequency (RF) signals in multiple frequency bands includes a horn antenna and a feed network. The horn antenna may transmit and/or receive RF signals in multiple frequency bands that are spread over more than an octave bandwidth with at least a 2.44-to-1 bandwidth ratio. The horn antenna includes a throat, an aperture, and an interior surface. The feed network includes a first waveguide section, a first junction, one or more first filters, and a first step-down waveguide section. The first waveguide section can provide a matching network and transmit and/or receive the RF signals in the multiple frequency bands. The first junction can transmit and/or receive the RF signals in first selected band(s) of the multiple frequency bands. The first step-down waveguide section may transmit and/or receive the RF signals in second selected band(s) of the multiple frequency bands.

Antenna systems for multiple frequency bands

A method, apparatus for reducing errors in a plurality of beacon beams is disclosed. The method comprises the steps of computing quantized channel weights {tilde over (W)}from channel weights Wfor at least some of the channels; estimating the quantization error &#x394;Bfor each of the beacon beams from a difference between the channel weights Wand the computed quantized channel weights {tilde over (W)}; and adding the estimated quantization error &#x394;Bto the beacon beams. Similarly, a beacon biases equivalent to the beacon asymmetry error can be computed by the ground beacon beam forming software and uploaded to the on-board software for error compensation. The apparatus comprises one or more means, such as a processor communicatively coupled to a memory storing instructions for performing these operations.

Digital beacon asymmetry and quantization compensation

A wideband antenna element includes first and second spaced-apart, mutually parallel conductive plates. Each plate defines a through aperture and a tapered slot extending from the aperture to an edge of the plate. The apertures and the slots of the two plates are registered. A feed structure including a strip conductor extends in the region between the plates, and crosses the slot at a location remote from both the edges of the plates and the apertures. A stub terminates the strip conductor. Through vias or conductors extend from one plate to the other near the edges of the slots, and near the feed. One embodiment includes dielectric sheets lying between the conductive plates.

Wideband antenna element and array thereof

A method, apparatus for reducing errors in a plurality of beacon beams is disclosed. The method comprises the steps of computing quantized channel weights {tilde over (W)} from channel weights W for at least some of the channels; estimating the quantization error &Dgr;B for each of the beacon beams from a difference between the channel weights W and the computed quantized channel weights {tilde over (W)} ; and adding the estimated quantization error &Dgr;B to the beacon beams. Similarly, a beacon biases equivalent to the beacon asymmetry error can be computed by the ground beacon beam forming software and uploaded to the on-board software for error compensation. The apparatus comprises one or more means, such as a processor communicatively coupled to a memory storing instructions for performing these operations.

A method and system for reconfiguring an antenna system are disclosed. The system comprises a feed horn, a subreflector, and a main reflector. The feed horn is pointed at an axis removed from the bisector axis of the subreflector. The distance between the feed horn and the subreflector can be changed to defocus the feed horn with respect to the subreflector, wherein a size of the outgoing beam emanating from the main reflector changes when the distance between the feed horn and the subreflector is changed. The method comprises pointing an axis of a feed horn at a subreflector, wherein the axis of the feed horn is aligned differently from the bisector axis of the subreflector, and changing the distance between the feed horn and the subreflector to defocus the feed horn with respect to the subreflector, wherein a size of an outgoing beam emanating from a main reflector changes when the distance between the feed horn and the subreflector is changed.

Method and apparatus for zooming and reconfiguring circular beams for satellite communications

A synthesized reflector surface ( ) for directing communication signals ( ) in a communication system ( ) that operates in a plurality of orbital slots and to a plurality of regions ( ) within a first coverage area ( ) is provided. The synthesized reflector surface ( ) includes a plurality of contiguous profile surfaces ( ) that form the reflector surface ( ). Each of the plurality of contiguous profile surfaces ( ) alters the phase-of the communication signals ( ) to provide a first gain for a first satellite orbit location ( ) and a second gain for a second satellite orbit location ( ). The plurality of contiguous profile surfaces ( ) directs the signals from the location ( ) in a first orientation to the first coverage area ( ) or from the location ( ) in a second orientation to the first coverage area ( ). A method is provided for synthesizing the reflector surface ( ). A satellite system ( ) and a method of configuring the satellite system ( ) are also provided utilizing the synthesized reflector surface ( ).

Growing community of inventors

Cherry Hill, NJ, United States of America

Chih-Chien Hsu