Stephen Lewis Taylor

US Patent:

56525346, Jul 29, 1997

Filed:

Dec 21, 1995

Appl. No.:

8/576328

Inventors:

Stephen D. Taylor - Agoura CA
Steve I. Hsu - Rancho Palos Verdes CA
Howard S. Nussbaum - Los Angeles CA
William P. Posey - Palos Verdes Estates CA

Assignee:

Hughes Aircraft Company - Los Angeles CA

International Classification:

H03D 302

US Classification:

327237

Abstract:

A phase shifter that employs digital circuitry to achieve arbitrarily fine phase control of reference signals at frequencies extending to the Gigahertz region. The phase shifter includes a cascade of identical phase shift units that provide progressively finer phase control resolution over a full 360 degree range. The phase precision is set by the number of stages used.

US Patent:

49689681, Nov 6, 1990

Filed:

Nov 9, 1989

Appl. No.:

7/434968

Inventors:

Stephen D. Taylor - Agoura CA

Assignee:

Hughes Aircraft Company - Los Angeles CA

International Classification:

H04B 102

US Classification:

342174

Abstract:

A system is disclosed for measuring and correcting for waveform modulation errors in a radar system employing FM signals and a digitally controlled waveform generator. The system relies on the assumption that the transmitter and other waveform phase and amplitude error contributions are slowly varying with respect to the radar mode data collection time and that instantaneous pulse-by-pulse correction is not necessary. During a calibration mode, a small portion of the transmitter output is input into the receiver and mixed with the waveform generator signal, with the waveform modulation being removed from the mixer signal, such that the mixer signal is at a constant IF but with phase and amplitude variations that result from the distortions. The radar digital processor measures these distortions, and during normal radar operation predistorts the waveform generator signal with phase distortions in antiphase with the measured distortions to compensate for the measured distortions. Amplitude distortions are compensated by control of a variable attenuator device.

US Patent:

50159712, May 14, 1991

Filed:

Dec 22, 1989

Appl. No.:

7/455675

Inventors:

Stephen D. Taylor - Agoura CA
Paul I. Tanaka - Lawndale CA

Assignee:

Hughes Aircraft Company - Los Angeles CA

International Classification:

H03L 712
H03L 720

US Classification:

331 16

Abstract:

A frequency synthesized, microwave signal generator is disclosed that provides multiple channel frequency selection capability with rapid channel change time and low levels of spurious signals and noise. The generator uses a microwave harmonic phase locked loop to lock a microwave VCO to a programmable harmonic of a VHF reference crystal oscillator to provide coarse frequency control in steps equal to that reference frequency. The phase lock loop includes an offset mixer for injecting an offset signal frequency to achieve fine frequency control. A harmonic detection and counting scheme is used to rapidly sweep the harmonic loop and obtain phase lock at the desired harmonic.

US Patent:

56507380, Jul 22, 1997

Filed:

Dec 21, 1995

Appl. No.:

8/576330

Inventors:

Stephen D. Taylor - Agoura CA
Howard S. Nussbaum - Los Angeles CA
Steve I. Hsu - Rancho Palos Verdes CA
William P. Posey - Palos Verdes Estates CA

Assignee:

Hughes Aircraft Company - Los Angeles CA

International Classification:

H03K 2342

US Classification:

327237

Abstract:

A precision digital phase shift element for achieving precise phase shift of an input pulse train signal. The output is a pulse train at a frequency equal to the input signal frequency divided by N, and having N equally spaced phase states. The relative phase state of the output signal is reliably controlled by selective deletion of pulses from the input signal pulse train. The selective deletion can be achieved by selectively gating the input pulse train, or by use of a dual modulus frequency divider circuit.

US Patent:

51307146, Jul 14, 1992

Filed:

May 23, 1991

Appl. No.:

7/704488

Inventors:

Stephen D. Taylor - Agoura CA

Assignee:

Hughes Aircraft Company - Los Angeles CA

International Classification:

G01S 1326

US Classification:

342132

Abstract:

Unique stretch and chirp waveform formats are described which allow significant simplification of radar signal generation and receive processing hardware. The new formats produce a non-zero intermediate frequency (IF) to facilitate in-phase and quadrature (I/Q) processing but allows the use of a homodyne type of receiver architecture. That architecture greatly simplifies the receiver hardware because the first local oscillator (LO) signal is simply a sample of the transmitter drive signal and no second LO is required. The non-zero IF is achieved by control of the timing and start frequency of the first LO waveform for stretch processing and timing of the transmit signal gating for chirp processing.