William H Dixon

US Patent:

7015858, Mar 21, 2006

Filed:

Dec 3, 2003

Appl. No.:

10/726978

Inventors:

Troy D. Fuchser - Tucson AZ, US
William F. Dixon - Tucson AZ, US

Assignee:

Raytheon Company - Waltham MA

International Classification:

H01Q 3/02

US Classification:

342374, 4552771

Abstract:

An antijam module () for GPS utilizing the vertical and horizontal polarizations of signal output by each antenna element in an array of antenna elements. This effectively doubles the number of channels from the conventional number of channels (N) to 2N. Each of these channels is uniquely weighted in accordance with conventional teachings such that the system operates with a capability to null 2N−1 jammers. Another aspect of the invention is the provision of a system and method for moving the reference channel from one channel to another in respect to the detection of received power levels. In specific implementations, the applied weights are dithered in a predetermined direction and a predetermined amount to ascertain when and whether to pass the reference channel designation.

US Patent:

8159390, Apr 17, 2012

Filed:

Mar 29, 2007

Appl. No.:

11/693066

Inventors:

William F. Dixon - Tucson AZ, US
Troy D. Fuchser - Tuscon AZ, US
Abraham L. Craig - Tucson AZ, US

Assignee:

Raytheon Company - Waltham MA

International Classification:

G01S 19/21

US Classification:

34235759

Abstract:

A temporal nuller for removing or minimizing narrow band interference/jamming power from a global positioning system (GPS) receiver's input includes a first signal path having a first input and a first output, at least one time delay device and an adjustable phase shift device located within the first signal path, and a second signal path having a second input and a second output. The first signal input is connected to the second signal input, and the first signal output is connected to the second signal output. Further, the at least one time delay device is operative to introduce a time delay between a signal at an output of the at least one time delay device relative to a signal at an input of the at least one time delay device.

US Patent:

20200371250, Nov 26, 2020

Filed:

May 21, 2019

Appl. No.:

16/418498

Inventors:

- Waltham MA, US
Jason Kyle - Tucson AZ, US
Arnaldo J. Colon - Tucson AZ, US
William F. Dixon - Tucson AZ, US
Ender Barillas - Orlando FL, US

International Classification:

G01S 19/23
G01S 19/18
G01S 19/01
G01S 19/21
H04K 3/00
G01S 19/25
G06F 17/50
G06F 17/14
G06F 9/38

Abstract:

A GNSS hostile environment simulator for accurate real-time processor & hardware in the loop (PHIL) simulations of a multiple antenna GNSSR/AJ system models antenna effects over the entire signal bandwidth allowing direct injection of the RF into the GNSSR. Computational efficiency is achieved by applying the antenna patterns in the frequency domain. To preserve the integrity of the antenna signals, the transmitter signals are generated over an extended period to push any residual ringing outside the update window. Efficiency is further enhanced by using a combination of single-precision and double-precision floating-point units to generate the samples of the transmitter signals with single-precision floating-point. All subsequent calculations are then computed in single-precision.