Hughes Network Systems, LLC

Hughes Electronics Corporation

George Eapen

Thomas Jackson

Emanuel Harrington

Yong Kang Yuan

Rajesh Joshi

Murali Regunathan

Peter Hou

Guy Bryan Montgomery

Kumud Patel

Jack Lundstedt

John Alfred Schmid

Yeqing Tang

Guo Chen

Bahman Salamat

Brian Smith

Peter McLaren

Yu Yung

Kunj Desai

Junyu Shen

Fa Dai

Foster Dai

Paul Lacasse

Joseph Chong

Emanuel Girard Harrington

Young Kang Yuan

Techniques are described for direct conversion and dynamic polarization control in a very small aperture terminal (VSAT) outdoor unit (ODU). The ODU includes a direct up-converter and/or a direct down-converter for converting in a single stage between a baseband frequency and a satellite radiofrequency band (e.g., Ka band). The ODU also includes a polarization amplifier that integrates high-power amplification with circular polarization orientation control. For example, the direct up-converter directly converts a baseband signal to a low-power satellite-RF transmit signal, and the polarization amplifier converts the low-power satellite-RF transmit signal to an uplink signal having high gain and selected circular polarization. The ODU can further include an integrated embedded computer and modem.

Very small aperture terminal for satellite communication with direct conversion and electronic polarization orientation control

Methods and apparatus are disclosed for uplink power control of a terminal in a satellite communication system. Calibration data that includes output backoff values corresponding to input backoff values for each of a first set of calibration frequencies is initially stored in the terminal. A normalized transmit power for the terminal is determined for multiple transmit frequencies based on the calibration data. Upon receiving an assigned frequency for communicating, the terminal selects one of the normalized transmit power previously determined and begins transmitting.

Transmit frequency based terminal uplink power control in a satellite communication system

An integral waveguide device herein includes a polarizer component comprising a waveguide and a dielectric slab, the dielectric slab configured to change a polarization of a signal passing through the waveguide. The integral waveguide device also includes a feed horn for conveying signals between the waveguide and a parabolic antenna. The waveguide of the polarizer and the feed horn are manufactured as an integral component with the feed horn disposed at a first end of the waveguide.

Integrated polarization converter and feed horn

A microstrip-to-waveguide transition includes a substrate and a waveguide. The substrate has a metal layer, a ground layer and a dielectric layer disposed between the metal layer and a ground layer. The substrate includes a microstrip line impedance transformer and a substrate integrated waveguide that is electromagnetically coupled to the microstrip line impedance transformer. The substrate integrated waveguide has a 90 degree substrate integrated waveguide bend section at an end portion thereof. The waveguide is arranged perpendicularly relative to the substrate. The waveguide is electromagnetically coupled to the substrate integrated waveguide at the 90 degree substrate integrated waveguide bend section. The microstrip-to-waveguide transition is free of a back-short at a location corresponding to the 90 degree substrate integrated waveguide bend section.

Microstrip-to-waveguide transition including a substrate integrated waveguide with a 90 degree bend section

A very small aperture terminal (VSAT) installation tool is provided having the ability to measure cable loss along an interfacility link (IFL) between an outdoor unit and an indoor unit of the VSAT. Radio frequency (RF) signals can be transmitted from the indoor unit to the outdoor unit, where the RF signals are intercepted along the IFL prior to reaching the outdoor unit, and the output power is determined. The determined output power is compared to an expected output power at the indoor unit. The delta between the determined output power and the expected output power can be used to adjust the power of the indoor unit such that the outdoor unit can operate without reaching its compression point.

Systems and methods for cable loss measurement between indoor and outdoor units

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

Systems and methods provide a receiver design capable of both wideband (high symbol rate) and narrowband (low symbol rate) operations requirements without compromising narrowband performance. Moreover, such a receiver design can be very low cost, and eschewing the need for any expensive and/or specialized elements. A receiver configured in accordance with various embodiments utilizes a fully integrated tuner in which narrowband filters are configured to be bypassable when in wideband (high symbol rate) mode in favor of fixed wideband filters. Additionally, an analog-to-digital converter (ADC) can be implemented with digital gain for wideband operation, as well as digital data bit mapping to accommodate industry standard application-specific integrated circuits (ASICs) interfaces, such as from a 12 bit ADC core to an 8 bit digital interface.

Wideband and narrowband receiver

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 mobile terminal for satellite communications receives communication, e.g., from a gateway via a satellite link. A frequency lock loop unit locks to the carrier frequency of the received communication. The mobile terminal includes a global positioning system for receiving global positioning data. The mobile terminal determines the Doppler frequency shift of the received communications based on the global positioning data. The mobile terminal generates a reference clock for return transmissions based on the frequency of the frequency lock loop, corrected for the Doppler shift. A correction factor of two times the determined Doppler frequency shift is used, to compensate for both a forward and return transmission link.

Mobile terminal with frequency lock loop

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.

Single cable VSAT interface with single conversion architecture for receive and transmit

A vector modulator including an offset QPSK modulator operative for receiving input data and generating a first output signal representing the modulation to be imposed on a carrier signal to effect offset QPSK modulation of the input signal and a second output signal representing an amplitude of the input data; and a frequency modulator including a sigma-delta modulator, operative for receiving the first output signal generated by the offset QPSK modulator, and generating a control signal representing the desired frequency of the carrier signal such that the carrier signal represents the input signal offset QPSK modulated. The vector modulator also includes a phase-lock loop circuit having a voltage controlled oscillator for generating the carrier signal and a programmable frequency divider for receiving the control signal as an input signal and for changing the frequency of the carrier signal in accordance with the control signal, and an amplifier having a variable gain which is operative for receiving and amplifying the carrier signal output by the phase-lock loop circuit in accordance with the amplitude of the second output signal.

Linearized offset QPSK modulation utilizing a sigma-delta based frequency modulator

A sigma delta interpolator for use in a fractional N synthesizer having a multi-modulus divider for controlling the output frequency of the synthesizer. The sigma delta interpolator includes an accumulator operative for receiving an input signal representing the desired frequency output of the fractional N synthesizer and for generating a digital output signal having M bits, which include N most significant bits and n least significant bits. The N most significant bits output by the accumulator are coupled to the multi-modulus divider and are operative for controlling the operation of the multi-modulus divider. The sigma delta interpolator further includes a delay circuit coupled to the accumulator, which functions to receive the n least significant bits and implement a delay function defined by equation: 1&#x2212;(1&#x2212;Z), where N corresponds to the order of the sigma delta interpolator.

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Boyds, MD, United States of America

George Eapen