Harris Corporation

James B Offner

Gregory H Marquardt

M Larry Goldstein

Alen Fejzuli

Emil G Svatik, Jr

William C Daffron

A novel system and method for a frequency tunable filter is described. The inventive system and method may be used, for example, in multi-band cellular phones and/or transceivers in wireless networks. The inventive system and method avoids the creation of undesired spurs thus minimizing design difficulties and obviating the need for complex multiple frequency conversions and the associated deleterious effects on performance. The inventive system and method provides at an output terminal an output signal at one of a plurality of predetermined frequencies. The inventive system and method comprises input circuitry for providing an input signal that is at least in part a function of a dynamic parameter, a processor for providing a control signal as a function of said input signal, and at least one adjustable resonance circuit capable of providing a filter signal at one of a plurality of predetermined frequencies in response to said control signal, wherein said filter signal is applied to said output terminal to thereby provide said output signal at one of a plurality of predetermined frequencies. The present inventive system and method also provides for reducing spurious signals from a composite signal created from mixing a plurality of signals by filtering the composite signal.

System and method for an electronically tunable frequency filter having constant bandwidth and temperature compensation for center frequency, bandwidth and insertion loss

A phased array antenna has a spatially periodic array of tapered pitch helical antenna elements disposed on a first side of a panel, and RF interface circuitry on a second side the panel. For a 'pseudo'-monopulse tracking mode of operation, single bit, digitally controlled phase shift elements of the RF circuitry impart sequentially different amounts of phase shift to the energy derived from the spatial sections of the antenna elements. This causes a sequential electrical tilting of the beam pattern of the array in a plurality of respectively different directions relative to boresight. For each sequential tilt of the beam pattern, signals representative of the energy received by each of plural quadrants of the array are summed and stored. The information in the summed and stored signals is processed in accordance with a monopulse-based beam tracking algorithm, and a positioning system control unit controllably adjusts the physical orientation of the panel in azimuth and elevation in accordance with processed information.

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Melbourne, FL, United States of America

James B Offner