Hughes Aircraft Company

Hughes Electronics Corporation

Raytheon Company

The Boeing Company

Victor S Reinhardt

Ronald E Sorace

Harold A Rosen

Andrew L Strodtbeck

Jennifer L Vollbrecht

Kim V Gould

Harry B Marr

Jar Jar Lee

Yi-Chi Shih

Arnold L Berman

Parthasarathy Ramanujam

Fangchou Yang

Steven O Lane

John Paul Gianvittorio

Shih-Chang Wu

Iradj Shahriary

Samuel C Reynolds

Kevin M McNab

Steven A Vaughn

George S Des Brisay, Jr

Gregory C Busche

Peter John Turley

Paul A Toth

Clinton Chan

Clinton Lew

Erik L Soderburg

System and method for signal modulation. In one embodiment, a circuit includes a channel for carrying an analog RF signal, a phase offset circuit on the channel, and configured to receive a phase code for modifying the analog RF signal to produce a modified RF signal, and a feedforward cancellation path coupled in parallel to the phase offset circuit for canceling a portion of the modified analog signal.

Binary high-power modulator

The present disclosure is directed towards an analog beamformer multiple beam feed (MBF). The analog beamformer MBF comprises a plurality of encoder elements to receive radiofrequency (RF) signals and generate coded analog signals. The RF signals may be coded using code division multiple access (CDMA) codes. The analog beamformer MBF further comprises a combiner to combine the coded analog signals received from the plurality of encoder elements and a divider to receive the combined coded analog signals and generate a plurality of coded analog outputs. The analog beamformer MBF further comprises a plurality of decoder elements to receive the plurality of coded analog outputs and generate decoded analog signals. In some embodiments, the RF signals may be decoded using CDMA codes. The analog beamformer MBF further comprises a plurality of beamformer elements configured to generate beam outputs corresponding to the decoded analog signals.

Analog multiple beam feed systems and methods

Methods and apparatus to cancel an interfering signal using an analog cancellation stage followed by a digital cancellation stage. In an exemplary embodiment, the interfering signal is processed to determine modulation type for removal in the analog domain. The digital stage provides further interference reduction in the digital domain.

Methods and apparatus for adaptive nonlinear coincident interference cancellation

A system and method for processing antenna signals are provided. For example, the method includes, in a receive mode, weighting and combining signals from at least one low-band antenna radiator element operable over a first bandwidth, at least one high-band antenna radiator element operable over a second bandwidth at least partially overlapping the first bandwidth, and, in some examples, at least one antenna radiator element operable over one or more intermediate bandwidths. The method also includes, in a transmit mode, separating and weighting a full-band input port signal into at least one low-band sub-system output port signal, at least one high-band sub-system port output signal, and, in some examples, at least one intermediate sub-system output port signal operable over one or more overlapping intermediate bandwidths. The weighted combination and weighted separation cover an uninterrupted continuous full-band frequency whose extent covers the full frequency range of all subbands.

Embedded element electronically steerable antenna for improved operating bandwidth

A switch matrix is provided comprising a plurality of input modules X and a plurality of output modules P. Each input module has a plurality of first input interconnections a plurality of first interconnected switches and a plurality of first output interconnections Each output module has a plurality of second input interconnections a plurality of second interconnected switches and a plurality of second output interconnections The plurality of input modules X is electrically coupled to the plurality of output modules P, forming a plurality of signal paths having a plurality of interconnected switches K per signal path A method is also provided minimizing the total number of interconnected switches Z within the switch matrix for a particular application. The method comprises determining switch matrix design requirements, calculating the values of X and P, and performing an integer partitioning process.

Switch matrix

An apparatus for reducing the amount of circuitry required to process satellite communication signals uses a beamformer to reduce the number of signals coupled to the communications circuitry, thereby reducing the amount of communication circuitry required to process received signals.

Hybridized space/ground beam forming

A multi-resonator filter, including a housing, at least one resonating element, at least one high dielectric constant element, at least one fine tuning screw located above the at least one resonating element and secured in a housing cover by a locking nut, housing screws to secure the housing cover to the housing. Where at least two resonating elements and at least two high dielectric constant elements are present, at least two slots are located in the at least two high dielectric constant elements to allow the easy installation and removal of at least one high dielectric coupling bridge used to increase the coupling between resonator sections, and at least one coupling probe.

Easily tunable dielectrically loaded resonators

An apparatus for limiting intermediate frequency variation in a multiple conversion phase locked loop includes a reference oscillator and a voltage controlled oscillator (VCO). The reference oscillator generates a first reference frequency, while the VCO generates an output frequency. The output frequency is divided by a first VCO divider and mixed with the first reference frequency to generate a first intermediate frequency. A second VCO divider also divides the output frequency and mixes it with the first intermediate frequency to generate a second intermediate frequency, which is filtered and used to control the VCO. An algorithm processor generates the division constants of the first and second VCO dividers as a function of the reference frequency and the output frequency to limit intermediate frequency variation.

System for limiting if variation in phase locked loops

Methods and systems for calibrating an array antenna are described. The array antenna has a plurality of antenna elements each having a signal with a phase and an amplitude forming an array antenna signal. For calibration, the phase of each element signal is sequentially switched one at a time through four orthogonal phase states. At each orthogonal phase state, the power of the array antenna signal is measured. A phase and an amplitude error for each of the element signals is determined based on the power of the array antenna signal at each of the four orthogonal phase states. The phase and amplitude of each of the element signals is then adjusted by the corresponding phase and amplitude errors.

Phase array calibration orthogonal phase sequence

A frequency synthesizer having two atomic frequency standard inputs that is adapted to provide seamless switching or transition between the atomic frequency standard inputs with no change in the synthesizer output phase and frequency. The synthesizer includes a multichannel phase comparison system, each channel adapted for handling an atomic frequency standard input, a digital phase lock loop, a digital to analog converter, and a voltage controlled crystal oscillator which provides the synthesizer output. The phase comparison system is adapted to continually monitor the integrity of the atomic frequency standard inputs and to continually estimate the phase differences between the two atomic frequency standard inputs. The phase difference is used to estimate the proper phase and frequency offset between the primary and secondary inputs. The programmatically determined phase offset and the fractional frequency offset are then passed to the phase lock loop when switch-over is commanded to produce an output signal that tracks the phase of the original primary input.

Seamless switch-over frequency synthesizer

A plurality of biphase modulators (42) each modulate a sinusoidal radio frequency signal based upon a corresponding one of a plurality of bits contained in a time-dependent data word. The biphase modulators (42) form a plurality of biphase modulated signals which are communicated to a summing network (40). The summing network (40) contains a plurality of attenuators (44) which attenuate the modulated signals to form a plurality of attenuated signals. The summing network (40) combines the attenuated signals to form a radio frequency signal.

High-speed digital-to-RF-converter

A system (36, 98) for determining the linearity of an RF detector (46, 106). A first technique involves combining two RF signals from two stable local oscillators (38, 40) to form a modulated RF signal having a beat frequency, and applying the modulated RF signal to a detector (46) being tested. The output of the detector (46) is applied to a low frequency spectrum analyzer (48) such that a relationship between the power levels of the first and second harmonics generated by the detector (46) of the beat frequency of the modulated RF signal are measured by the spectrum analyzer (48) to determine the linearity of the detector (46). In a second technique, an RF signal from a local oscillator (100) is applied to a detector (106) being tested through a first attenuator (102) and a second attenuator (104). The output voltage of the detector (106) is measured when the first attenuator (102) is set to a particular attenuation value and the second attenuator (104) is switched between first and second attenuation values. Further, the output voltage of the detector (106) is measured when the first attenuator (102) is set to another attenuation value, and the second attenuator (104) is again switched between the first and second attenuation values. A relationship between the voltage outputs determines the linearity of the detector (106).

Detector power linearity requirements and verification techniques for

A satellite-based communication system providing high rate transfer of data between linked terminals. The system comprises a plurality of user terminals (VSAT's) that are linked by and that communicate with each other by way of a satellite-based relay system. A network control center provides configuration signals that control the satellite relay system and coordinate linking of terminals to each other. Frequency division multiplexing uplinks are used from the terminals and the network control center to the satellite relay system. Time division multiplexing are used on downlinks from the satellite relay system to the terminals and the network control center. Each user terminal comprises a data compression and decompression circuit, a transceiver, and an antenna for transmitting and receiving data to and from the satellite relay system. The satellite relay system comprises a satellite, a wide area antenna, a plurality of receive antennas, a plurality of transmit antennas, and a signal processor. The wide area antenna is provided for communicating control signals between the user terminals and the network control center. The plurality of receive antennas operate in a first frequency band and produce a first plurality of beams that cover a service area. The plurality of receive antennas receive time domain modulated data from the user terminals. The plurality of transmit antennas operate in a second frequency band and produce a second plurality of beams that cover the service area. The plurality of transmit antennas transmit frequency domain modulated data to the user terminals. The signal processor demodulates the time domain modulated data received from a user terminal, routes the demodulated data so that it is transmitted to a second user terminal, remodulates the data to provide frequency domain modulated data, and transmits the frequency domain modulated data to the second user terminal. Video cameras and monitors are coupled to the user terminals to provide for video teleconferencing.

High data rate satellite communication system

A system and method for polar digital beamforming of at least one independent transmit beam is disclosed. A computer generates a digital signal representing both pointing and modulation information which is communicated to a plurality of subarray controllers which generate the polar weighting signals corresponding to the appropriate antenna element for transmitting. The complex weighting signals may be generated by summing a sequence of complex multiplications or by simply inverting the real and imaginary components of the weighting signal for particular modulation schemes. A phasor may be used in conjunction with an attenuator to modulate a local carrier signal. Alternatively, phasors are utilized without attenuators to increase the efficiency of the power amplifiers. The antenna architecture disclosed permits a single set of phasors and attenuators to be utilized per antenna element regardless of the number of beams to be generated.

Polar digital beamforming method and system

A phased array antenna (10A, 10B, 10C) is constructed of an array of radiators (24), each of which has a radiating aperture, a first port (26) and a second port (26). The first port introduces a first radiation with a first polarization, and the second port introduces a second radiation with a second polarization which is orthogonal to the first polarization. Individual transmitting amplifiers, in the case of a transmitting array, or individual receiving amplifiers (16A), in the case of a receiving array, are connected to the ports of each of the radiators. The amplifiers associated with the first ports of the respective radiators are connected, in turn, to phase shifters (18A) and attenuators (20A) which constitute a first beamformer for forming a set of one or more beams of radiation. The amplifiers (16A) associated with the second ports of the respective radiators are connected, in turn, to phase shifters (18A) and attenuators (20A) which constitute a second beamformer for forming a set of one or more beams of radiation. The two beamformers operate independently of each other so as to permit separately weighted polarization signals of the antenna to be programmed electronically for various polarizations such as right and left circular polarization or horizontal and vertical polarization. Also, the separately polarized waves associated with the first ports and the second ports permit dual polarization frequency reuse transmission.

Growing community of inventors

Rancho Palos Verdes, CA, United States of America

Victor S Reinhardt