Allen D Davidson

US Patent:

60185147, Jan 25, 2000

Filed:

Jun 29, 1998

Appl. No.:

9/106401

Inventors:

Richard S. Bickham - Cary IL
Allen L. Davidson - Crystal Lake IL

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H04L 100

US Classification:

370217

Abstract:

A desirable operating condition is maintained in a communication device (100) that is operating in an undesirable environment by reducing the number of radio frequency signals being amplified and subsequently transmitted by the communication device (100). The remaining radio frequency signals transmitted will be transmitted at full power, so that coverage area is maintained in a tradeoff for reduced capacity.

US Patent:

58024840, Sep 1, 1998

Filed:

Jul 12, 1996

Appl. No.:

8/678899

Inventors:

Douglas M. Hamilton - Elgin IL
Allen L. Davidson - Crystal Lake IL
Mark A. Gannon - Sleepy Hollow IL
Leigh M. Chinitz - Palatine IL
Roger J. B. Jellicoe - Woodstock IL

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H04B 138

US Classification:

455558

Abstract:

An antenna structure (108) operates in the presence of narrow or wide band interference and yet is able to enjoy high receiver sensitivity. This is done by steering the antenna structure (108) radiation pattern null in its near field at the noise source.

US Patent:

43014321, Nov 17, 1981

Filed:

Aug 11, 1980

Appl. No.:

6/176892

Inventors:

Richard L. Carlson - Lake in the Hills IL
Allen L. Davidson - Crystal Lake IL

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H01P 1185
H01P 122

US Classification:

333164

Abstract:

A complex RF weighter provides an RF output signal controlled in amplitude and phase with respect to an input signal. The input signal is applied to a quadrature hybrid that is terminated with two PIN diodes, one of which is one-eighth wavelength farther from the hybrid than the other. Independent control of the bias on the PIN diodes provides control of the relative amplitude and phase of the output signal.

US Patent:

43631290, Dec 7, 1982

Filed:

Dec 11, 1980

Appl. No.:

6/215589

Inventors:

Jona Cohn - Morton Grove IL
Allen L. Davidson - Crystal Lake IL
Anthony P. van den Heuvel - Arlington Heights IL

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H04B 716

US Classification:

455 17

Abstract:

Simulcast distortion in a receiver when using a same-frequency repeater is minimized by applying double modulation to a signal that is broadcast to the same-frequency repeater. A voice signal is applied without delay as AM on a carrier to a modulation index of up to 30%, and the same signal is also applied as FM on the same carrier with a time delay equal to the time delay in the same-frequency repeater. The same-frequency repeater detects the AM and applies the detected signal as FM on a carrier that is rebroadcast. Received FM signals are thus delayed by substantially the same amount whether they are received from the original broadcast or the same-frequency repeater.

US Patent:

55488374, Aug 20, 1996

Filed:

Mar 28, 1994

Appl. No.:

8/218385

Inventors:

Garry C. Hess - Elgin IL
Allen L. Davidson - Crystal Lake IL

International Classification:

H04B 708

US Classification:

4552781

Abstract:

A receiver (100) that includes an antenna (101) employs a method and apparatus for producing diversity gain of a signal (106) received by the antenna (101), wherein the signal (106) is subject to a time-variant fading condition. Upon receiving the signal (106), the receiver (100) determines a signal quality metric of the signal (106) and compares the signal quality metric to a quality threshold. When the signal quality metric is below the quality threshold, the receiver (100) orients a predetermined antenna pattern (304) of the antenna (101) to improve the signal quality metric, thereby producing the diversity gain.