Raytheon Company

William Kennedy

Kaichiang Chang

Jack Lee

Stephen M Sparagna

David A Ringheiser

Debra J Tonks

Jack J Schuss

Dennis E Nieskoski

Jama A Mohamed

An apparatus and method for enhanced calibration of radar at the module level supports dual polarization and array calibration and alignment without the use of external test equipment. Utilizing a delay line, loop back capability at the module level allows existing receiver exciter subsystem to be used for calibration. This approach eliminates the need for manual array calibration using external RF monitor subsystem or external test antennas.

Array and module calibration with delay line

A radar receiver includes a bank of matched filters for use in processing return signals received from a remote target. In some embodiments, the radar receiver is capable of generating accurate estimates of target range and range rate based on returns from a single transmitted pulse having a low time-bandwidth product. In at least one embodiment, a computationally efficient interpolation technique is used to generate an estimate of an actual target Doppler frequency based on output signals of the bank of matched filters.

Radar system using matched filter bank

Embodiments of the present invention are directed to techniques and systems for modifying the transmit beam of a phased array antenna in order to effect a shape change in the beam that pre-compensates for platform motion and clutter considerations in the local environment. The techniques and systems herein disclosed take advantage of the phase controlling capability of phased array antennas to adjust the performance of each element in a way that de-focuses or spoils the transmit beam. This spoiling, in turn, enables the transmission of a broader, tailored beam that provides illumination over an area that would otherwise require multiple scans from narrow transmit beams. The techniques described provide a closed-form solution that sacrifices some antenna pattern efficiency in exchange for greatly reduced computational complexity over prior art, optimal search techniques.

Broad beam antenna design for a tilted phased array with platform motion

An adaptive processing method of and system for clutter rejection in a phased array beam pattern. The amplitude distribution of the transmit elements of a two-dimensional phased array is determined. A desired pattern with low side lobes for a linear array is synthesized. The amplitude distribution of the transmit elements of the two-dimensional phased array is compared with the synthesized pattern. Select elements of the two-dimensional array are disabled to best fit the determined amplitude distribution of the transmit elements of the two-dimensional phased array to the synthesized beam pattern. Phase only pattern synthesis is performed to produce a desired two-dimensional beam pattern with low side lobes to minimize any best fit errors.

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Boston, MA, United States of America

William Kennedy