JOHN ALFRED EVANS
Pilots at Tschiffely Sq Rd, Gaithersburg, MD
License number
Maryland C1036834
Category
Airmen
Address
Address
610 Tschiffely Square Rd, Gaithersburg, MD 20878
Professional information
Switch Matrix Including Both B Switching Elements And Crossbar Switch Matrices
US Patent:
5220320, Jun 15, 1993
Filed:
Feb 10, 1992
Appl. No.:
7/831731
Inventors:
Francois T. Assal - Bethesda MD
John V. Evans - Gaithersburg MD
Christoph E. Mahle - Washington DC
Amir I. Zaghloul - Bethesda MD
Ramesh K. Gupta - Rockville MD
John V. Evans - Gaithersburg MD
Christoph E. Mahle - Washington DC
Amir I. Zaghloul - Bethesda MD
Ramesh K. Gupta - Rockville MD
Assignee:
COMSAT - Washington DC
International Classification:
H04B 100
US Classification:
34082579
Abstract:
A "modified rearrangeable" switch matrix combines both. beta. switching elements and crossbar switch matrices in a single switch configuration, with. beta. switching elements used at the input and output and at least one crossbar switch matrix in the middle to receive its inputs from. beta. switching elements and provide its outputs to. beta. switching elements.
System And Method For Tracking A Signal Source
US Patent:
4067015, Jan 3, 1978
Filed:
Jul 11, 1975
Appl. No.:
5/595254
Inventors:
Louis N. Mogavero - Alexandria VA
Edwin G. Johnson - Kensington MD
John M. Evans - Gaithersburg MD
James S. Albus - College Park MD
Edwin G. Johnson - Kensington MD
John M. Evans - Gaithersburg MD
James S. Albus - College Park MD
Assignee:
The United States of America as represented by the National Aeronautics
and Space Administration - Washington DC
and Space Administration - Washington DC
International Classification:
H04B 708
US Classification:
343225
Abstract:
A system for tracking moving signal sources is disclosed which is particularly adaptable for use in tracking stage performers, although a wide range of other uses is possible. A miniature transmitter is attached to the person or object to be tracked and emits a detectable signal of a predetermined frequency. A plurality of detectors positioned in a preset pattern sense the signal and supply output information to a phase detector which applies signals representing the angular orientation of the transmitter to a computer. The computer provides command signals to a servo network which drives a device such as a motor driven mirror reflecting the beam of a spotlight, to track the moving transmitter.
Multiple Spot-Beam Systems For Satellite Communications
US Patent:
4931802, Jun 5, 1990
Filed:
Mar 11, 1988
Appl. No.:
7/167287
Inventors:
Francois T. Assal - Bethesda MD
John V. Evans - Gaithersburg MD
Christoph E. Mahle - Washington DC
Amir I. Zaghloul - Bethesda MD
Ramesh K. Gupta - Rockville MD
John V. Evans - Gaithersburg MD
Christoph E. Mahle - Washington DC
Amir I. Zaghloul - Bethesda MD
Ramesh K. Gupta - Rockville MD
Assignee:
Communications Satellite Corporation
International Classification:
H04B 719
US Classification:
342356
Abstract:
On-board satellite switching is performed in three stages, an outer stage of switching on the up-link side for routing the received signals to either demodulators or frequency translators, a first inner stage of switching, preferably a baseband switch and processor, for routing and processing the outputs of the demodulators, a second inner stage of switching, e. g. , a microwave switch matrix, for routing the outputs of the frequency translators, and an outer stage on the down-link side for assembling and routing the down-link spot beams. For a multiple hopping-beam system, the outer stages are microwave switch matrices, and for a hybrid scanning-hopping system the outer stages are beam forming matrices. A general purpose modified rearrangeable switch matrix is also disclosed.