Hughes Network Systems, LLC

Hughes Electronics Corporation

Hughes Aircraft Company

Brandon, Lee

Thomas Jackson

Peter Hou

George Eapen

Bingqian Lu

Hamad Alsawaha

Yilin Mao

Hai Quang Tang

David Bourner

Rajesh Joshi

Guo Chen

Barre Lankford

Edmund Lott

Larry Cronise

Michael Dauberman

Jack Lundstedt

Robert Hannah

Mohammad N Bukhari

Paul Lacasse

Stephen H Jones

Mark Murr

Prakash Hari

Foster Dai

Fa Dai

Keith Russell

Arul Thangavelu

Ross Thomson

Lee Brandon

An apparatus and method for mitigating polarization mismatch in reflector antenna systems. A feed unit is configured to determine a polarization mismatch between a first polarization associated with a first wave and a second polarization associated with a reflector unit. The feed unit pre-distorts the first wave to achieve a compensated polarization for reducing and/or eliminating a polarization mismatch. The pre-distorted first wave having the compensated polarization is used to illuminate the reflector unit. A re-radiated wave is reflected by the reflector unit. Furthermore, the level of the re-radiated wave is increased as a result of the pre-distortion.

Mitigation of polarization mismatch between reflector and feed antennas by feed predistortion

A phase shifter having both digital and analog shifting components is disclosed. The digital-analog phase shifter includes an input/output port configured, in part, for receiving an input radio frequency (RF) signal from an external source and outputting a phase shifted RF signal. A digital shifter performs coarse phase shifts of the input RF signal, while an analog shifter variably shift the phase of the input RF signal relative to the coarse phase shift. This produces a phase shifted RF signal having a total phase range that is output is continuously variable from 0&#xb0; to 360&#xb0;.

Low-loss, low-profile digital-analog phase shifter

A digital phase shifter is described where each bit of the phase shifter has a circuit block including one PIN diode in parallel with one transmission line. The phase shifter requires only one PIN diode and one transmission line per bit circuit block. Each PIN diode behaves like a simple switch for phase shifting. When the PIN diode is forward biased ('on' state), current flows through the PIN diode and the RF signal is not phase shifted. When the pin diode is not forward biased ('off' state), current flows through the transmission line parallel to the PIN diode and the RF signal is phase shifted by the transmission line. The digital phase shifter may have n circuit blocks in series, and adjacent PIN diodes may share a current when both are on. The phase shifter may be implemented in a phased array or reflect array antenna including multiple phase shifters.

Digital phase shifter switch and transmission line reduction

A device and method are described for duplex satellite communication over a single satellite antenna. A satellite ground terminal may utilize a frequency-selective surface module including a frequency-selective surface as a subreflector acting as a frequency diplexer to separate signals received and/or transmitted by a first feed and a second feed of a satellite ground terminal, where each feed has a separate antenna horn. The frequency-selective surface module may be used in combination with a second subreflector such that a first feed and a second feed of the satellite ground terminal are implemented on the same side of the frequency-selective surface module.

Satellite ground terminal utilizing frequency-selective surface subreflector

Systems and methods are provided for separating the uplink signal from the downlink signal in a satellite communication system. A communication terminal for satellite communications is provided, comprising a reflector having a prime focus; a first feed located at the prime focus of the reflector and in optical communication with the reflector; a frequency-selective surface module having a reflected focus and located at a point along a communication path between the main reflector and the first feed; and a second feed located at the reflected focus of the frequency-selective surface module and in optical communication with the frequency-selective surface module.

Satellite ground terminal utilizing frequency-selective surface diplexer

A radio frequency waveguide is disclosed. The radio frequency waveguide includes: a dielectric including an exterior input surface, an exterior output surface and other exterior surfaces; and a metal disposed on the other exterior surfaces of the dielectric, wherein the dielectric is voidless and adapted to propagate radio frequency radiation from the exterior input surface to the exterior output surface.

Radio frequency waveguide devices including a dielectric having other exterior surfaces with a feature thereon and coated by a metal layer

Systems and methods disclosed herein provide techniques for reducing quantization errors and side lobe levels in phased array antennas. The states of a quantized phase shifter of a phased array antenna may be dithered to achieve a time-averaged value that reduces quantization errors. By rapidly switching between the different states of the quantized phase shifter, a time-average value close to a desired phase state may be achieved with a low resolution phase shifter.

Digital dithering for reduction of quantization errors and side-lobe levels in phased array antennas

An apparatus and method for continuously shifting the phase of an input signal includes a quadrature hybrid having an input/output port for receiving an input radio frequency (RF) signal and outputting a phase shifted RF signal. An analog shifting unit is connected to the quadrature hybrid for performing an intermediate phase shift on the input RF signal. An additional analog shifting unit is connected to an isolation port of the quadrature hybrid to receive an intermediate output signal based on the intermediate phase shift, and shifting a phase of the intermediate output signal to produce an intermediate input signal. The analog shifting unit performs a final phase shift of the intermediate input signal and the final phase shifted intermediate input signal is output, at the input/output port, as the phase shifted RF signal.

90 degree hybrid with varactor diodes for low loss, simple bias and zero power consumption phase shifter

A linear radio and a method for performing automatic level control are provided. A demultiplexer, within the linear radio, receives multiplexed signals from an indoor unit via a cable connecting the indoor unit with the linear radio. The demultiplexer demultiplexes the multiplexed signals to produce a transmit signal of an intermediate frequency. A variable gain amplifier within the linear radio, receives the transmit signal and a signal from an operational amplifier and produces the transmit signal with a changed gain, which is provided to a coupler. The coupler provides the transmit signal with the changed gain to a mixer and a power detector simultaneously. The power detector produces a second signal, which is provided to the operational amplifier, thereby forming a closed automatic level control loop. In some embodiments, the demultiplexer produces a power control signal, which is provided to the operational amplifier as a second input.

Radio based automatic level control for linear radio calibration

An apparatus for PLL bandwidth expansion including a compensation filter and a phase locked loop, where the compensation filter is programmed with a compensation function derived based on programmable coefficients and parameters of a transmitting device, a frequency response of the phase locked loop, and a wanted frequency response.

Apparatus and method for phase locked loop bandwidth expansion

A linear technology radio for use in satellite communication is provided. The linear technology radio includes: a pre-amplifier to amplify a Local Oscillator (LO) reference signal; an intermediate frequency (IF) amplifier to amplify an IF signal; a frequency multiplier to multiply the LO reference signal; and a mixer to mix the amplified LO reference signal and the amplified IF signal to generate a Radio Frequency (RF) signal, wherein a frequency band of the IF signal is fixed, a frequency band of the LO reference signal is variable, and a highest frequency of the LO reference signal frequency band is less than a lowest frequency of the IF signal frequency band.

Fixed intermediate frequency signal with tuned low frequency local oscillator reference for linear transmitter

A modem to interface with a constant envelope saturated and/or linear radio, the modem including: a synthesizer modulator configured to generate a reference signal; a prescaler configured to reduce the reference signal to a lower frequency signal; a switch configured to enable the prescaler; and an output configured to output the reference signal when the prescaler is disabled, and configured to output the lower frequency signal as the reference signal when the prescaler is enabled.

Switchable linear and saturated very small aperture terminal (VSAT) modem

A communication system, an apparatus and a method for communicating with a radio disposed in an outdoor unit are provided. The apparatus including: a de-multiplexor configured to separate a multiplexed signal received on an inter-facility link (IFL) into a first signal; a demodulator configured to demodulate the first signal based-on a first modulator control information to obtain data; a modulator configured to modulate a portion of the data based-on a second modulator control information to generate a second signal; and an amplifier configured to amplify a transmission signal prior to transmission of the transmission signal with an antenna, wherein the transmission signal is based on the second signal, the second modulator control information is received by the de-multiplexor and the second modulator control information controls the modulation scheme used by the modulator.

Outdoor digital modulator system for use with a linear radio, and a method thereof

A VSAT system modem has three chips and a block. A first chip generates a modulated carrier signal and a local oscillator signal having a same frequency. A second chip receives the local oscillator signal from the first chip and produces a reference signal. The reference signal and the modulated carrier signal are received by the block, which multiplexes the reference signal and the modulated carrier signal onto a single inter-facility link. The single inter-facility link transmits the modulated carrier signal and the reference signal and provides a received modulated carrier signal to a third chip. The first chip may be a synthesizer/modulator chip, the second chip may be a prescaler chip, the third chip may be a DVB-S2 tuner chip and the block may be a multiplexer. The chips may be standard semiconductor chips. Alternatively, a digital-to-analog converter chip may produce the reference signal.

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Monrovia, MD, United States of America

Thomas Jackson