William G Hwang

US Patent:

54102766, Apr 25, 1995

Filed:

Dec 28, 1993

Appl. No.:

8/174541

Inventors:

William B. Hwang - Los Angeles CA
Michael Brand - Los Angeles CA
Ronnie B. Chan - Gardena CA
Robert S. Boiles - Torrance CA

Assignee:

Hughes Aircraft Company - Los Angeles CA

International Classification:

H03K 704

US Classification:

330297

Abstract:

Circuits for modulating an RF input signal applied to an RF high power amplifier to produce a modulated RF output signal. The present invention employs a VHF power supply or converter with a modulation control circuit that enables the power supply to be pulsed at frequencies commensurate with a radar in which it is employed, for example. Modulation of the high power amplifier is accomplished by applying a pulsed voltage output signal to a DC bias input of the high power amplifier. More particularly, the modulation control circuit receives a logic control signal, generates a pulse control signal in response thereto, and modulates a DC input signal processed by the converter. The VHF converter receives and modulates the DC input signal in response to the pulse control signal to cause the pulsed voltage output signal from the converter to pulse at a rate and duty cycle determined by the logic control signal. The output signal modulates the RF input signal amplified by the RF high power amplifier. The modulation control circuit comprises a digital input buffer for receiving the logic control signal, a driver circuit for generating the pulse control signal, and a modulation switch coupled to the converter for modulating the DC input signal in response to the logic control signal.

US Patent:

56105690, Mar 11, 1997

Filed:

Jan 31, 1996

Appl. No.:

8/599524

Inventors:

William B. Hwang - Los Angeles CA
David M. Lusher - Torrance CA

Assignee:

Hughes Electronics - Los Angeles CA

International Classification:

H01F 2728

US Classification:

336200

Abstract:

A co-fired inductor structure that includes a plurality of planar co-fired ceramic dielectric insulating layers (13); a plurality of elongated conductive strips (11-1-11-4, 12-1-12-4, 21-1-21-3, 22-1-22-3) arranged in four groups of parallel elongated conductive strips each group disposed on a respective dielectric insulating layer; and a plurality of via columns (101, 102, 103, 104) for interconnecting the ends of the elongated conductive strips such that the elongated conductive strips and the via columns form a winding.