Cubic Corporation

Cubic Defense Systems, Inc.

Cubic Communications, Inc.

Wayne Edward Richards

Richard Newell Jekel

James W Schafer

Lloyd E Landen

Nathan Labadie

Jeffrey Morris Keefer

In a phased-array communications system with a distributed processing architecture, channelized beamforming is used to minimize sampling and computational requirements, as well as reduce the data rates required for the communication of data and control information between system components. A central processor within the phased array system performs parallelized synthesis of channelized beams to form beams composite beams in sub-bands that overlap multiple channels. The phased array system incorporates a flexible scheme for channelization, channelized beamforming, and synthesis so that any number of composite beams may be synthesized in parallel at any one time. The system is capable of simultaneously processing beams that occupy overlapping subbands, and does not require restriction on the bandwidths or center frequencies of the subbands which the beams occupy.

Efficient signal processing for receive and transmit DBF arrays

Methods, systems, computer-readable media, and apparatuses for locally generating and synchronizing oscillation signals in a phased array system are presented. Multiple sub-array modules are used for collectively transmitting any number of beams on carrier frequencies, wherein each of the sub-array modules includes a transmit antenna, an oscillator configured to generate an oscillation signal, and a control element configured to phase lock the oscillation signal with other oscillation signals used in the system. The control element determines a phase difference measure that represents an average difference in phase between the oscillation signal and other oscillation signals used in the system, generates an average error signal, wherein the average error signal represents the phase difference measure, obtains information regarding oscillator trim signals applied with respect to the other oscillation signals generated in the system, and adjusts a frequency of the oscillation signal using the generated local oscillator trim signal.

Distributed local oscillator generation and synchronization

A multi-pole filter antenna may include aperture-coupled non-dominant mode cavity resonators, and an aperture-coupled dominant mode patch antenna. The filter antenna may be implemented in a multilayer printed circuit board or similar structure. The filter antenna may for example operate in the Ku-Band, the Ka-Band, the C-Band, or another band.

Filter antenna

A method and system for beamforming a multi-element array using time delays is provided. The array includes transmit array elements and receive array elements. Each of the array elements includes a processor. Modulation and demodulation functions are performed at the processors of each array element. The modulation and demodulation functions utilize receive time offsets and phase shifts, and transmit time offsets and phase shifts, respectively. The receive time offsets and phase shifts, and the transmit time offsets and phase shifts are determined by a central processing unit in order to beam form received signals and transmitted signals, respectively. The array elements are arranged in a daisy chain fashion in order to facilitate communication of control parameters, communication of bits to be transmitted and distributed combining of demodulated baseband samples from one array element to another and communicating the combined samples to the central processing unit.

Digital beamforming antenna and datalink array

A method and system for beamforming a multi-element array using time delays is provided. The array includes transmit array elements and receive array elements. Each of the array elements includes a processor. Modulation and demodulation functions are performed at the processors of each array element. The modulation and demodulation functions utilize receive time offsets and phase shifts, and transmit time offsets and phase shifts, respectively. The receive time offsets and phase shifts, and the transmit time offsets and phase shifts are determined by a central processing unit in order to beamform received signals and transmitted signals, respectively. The array elements are arranged in a daisy chain fashion in order to facilitate communication of control parameters, communication of bits to be transmitted and distributed combining of demodulated baseband samples from one array element to another and communicating the combined samples to the central processing unit.

Shaped Offset Quadrature Amplitude Modulation (QAM) can be implemented within a communication system. A train or sequence of orthogonal sinc pulses can be generated for each of the in-phase and quadrature signal paths. The sinc pulses in the quadrature signal path can have a predetermined time offset relative to the pulses in the in-phase signal path. An in-phase or quadrature antipodal data signal can be used to modulate the respective sinc pulse train. Each of the in-phase and quadrature pulses can be shaped using a time domain windowing function, such as a Kaiser-Bessel window, to adjust the spectral width and spectral sidelobe level of the signal. The beta parameter of the window can be adjusted to achieve the desired signal response. The timing of the sinc pulses may need to be adjusted following the window function in order to maintain orthogonality of the pulses.

Shaped-offset quadrature amplitude modulation methods and apparatus

Phase errors and gain errors are reduced in a receiver to increase the dynamic range of the receiver. An input signal is shifted to an intermediate frequency (IF) and divided into a first channel and a second channel. The first and second channels are multiplied by a complex intermediate frequency signal having a frequency equal to the negative of the IF and by the complex conjugate of the intermediate frequency signal to produce a complex normal signal and a complex conjugate signal. A gain correction factor and a phase correction factor are adjusted based on a correlation signal produced by multiplying the complex normal signal by the complex correlation signal.

Apparatus and method for improving dynamic range in a receiver

An inexpensive numerically-controlled fast frequency-hopping microwave synthesizer. A voltage-controlled oscillator (VCO) output phase remains locked to an internal direct digital synthesizer (DDS) reference signal over the entire output frequency band, which is an order of magnitude larger than the internal sampling clock frequency. A &ldquo;Nyquist-boundary hopping&rdquo; scheme compares signals from an alias band of the DDS with signals from an alias band of the sampled VCO output to derive an output phase error signal, which is forced to zero in a manner that locks the VCO output phase to the DDS output phase over a frequency hop-distance greater than the DDS bandwidth. Accordingly, in a single second, the synthesizer can hop phase-continuously in a single clock cycle to each of hundreds of thousands of different microwave output frequencies with relatively low clock rates (up to 100 MHz) commensurate with silicon application-specific integrated circuits (ASICs). Synthesizer performance is enhanced by several other features, such as a digital &ldquo;whitening&rdquo; filter to compensate for the anti-aliasing effects of the analog filters employed, a digital VCO control linearization loop to adaptively compensate for the effects of VCO and digital-to-analog convertor (DAC) nonlinearities, a digital cyclic error removal loop to adaptively compensate for the effects of elliptical distortion in the complex output phase samples, and a Sigma-Delta quantizer to provide a higher DAC resolution with inexpensive DACs while minimizing quantizing noise effects in the output signal.

Numerically-controlled nyquist-boundary hopping frequency synthesizer

An ASIC chip interfaces with multiple data protocol specifications and includes a demodulator for data messages in a protocol at a first data rate, such as the TACTS protocol, and includes a demodulator for data messages in a protocol at a second data rate, such as the NACTS protocol. The ASIC chip is installed in a system for the transmission and receipt of data messages in the two protocols, and operates under control of a microprocessor, which selects between the available message protocols. Additional data rates and protocols beyond the first two can be accommodated. The different demodulators share processing structures that reduce the circuit components otherwise necessary for operation. This reduces the weight and power requirements of the chip. In this way, the ASIC chip provides a processing system that can operate with multiple data protocol specifications and data rates, while ensuring accurate and reliable detection of data streams in an aircraft operational environment.

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La Mesa, CA, United States of America

Wayne Edward Richards