Resumes
Resumes
Adrian Devries Phones & Addresses
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865 Commonwealth Ave, Aurora, IL 60506
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Elmhurst, IL
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Mount Prospect, IL
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Kimmswick, MO
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Richland, WA
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871 N Commonwealth Ave, Aurora, IL 60506
Publications
Us Patents
Universal Decoder For Television Signal Scramble Systems
View pageUS Patent:
54467950, Aug 29, 1995
Filed:
Mar 25, 1993
Appl. No.:
8/036985
Inventors:
Adrian J. Devries - Aurora IL
Bruno A. Rist - Woodland Hills CA
Bruno A. Rist - Woodland Hills CA
Assignee:
International Telesystems, Inc. - Pacific Grove CA
International Classification:
H04N 7167
US Classification:
380 13
Abstract:
A universal decoder for scrambled television signals in which the signals are processed in a circuit by converting them to other frequencies and then removing the scrambling signal. One method uses one or more narrow filters at a fixed frequency with the television signal being heterodyned down to the frequency of the filters to place the scrambling signals in the rejection band of one of the filters. A second method eliminates scrambling signals by filters at video frequencies. In this method, the frequency in phase with the television signal carrier of a television channel is regenerated by filtering it with a narrow crystal filter and by means of an automatic phase comparison (APC) loop. The regenerated carrier is then used to synchronously demodulate the television signal. A third method for removing the scrambling signals is by use of one or more comb filters.
Low Reflectivity Apodized Surface Acoustic Transducer With Means To Prevent Wavefront Distortion
View pageUS Patent:
43330657, Jun 1, 1982
Filed:
Oct 9, 1980
Appl. No.:
6/195587
Inventors:
Adrian J. DeVries - Mount Prospect IL
Assignee:
Zenith Radio Corporation - Glenview IL
International Classification:
H03H 9145
H03H 925
H03H 964
H03H 925
H03H 964
US Classification:
333194
Abstract:
In order to reduce the reflectivity of an apodized surface acoustic wave transducer, one portion of the dummy area thereof is bare and another portion is 100% metallized, and the boundary between these two regions is shaped to equalize total acoustic transit times across the transducer aperture. This avoids any net refraction, and thus permits any acoustic wavefronts which traverse the two regions to remain flat.
Restricted Access Television Transmission System
View pageUS Patent:
49032976, Feb 20, 1990
Filed:
Nov 7, 1988
Appl. No.:
7/267964
Inventors:
Bruno A. Rist - Woodland Hills CA
Adrian J. DeVries - Aurora IL
Adrian J. DeVries - Aurora IL
Assignee:
International Telesystems, Inc. - Beverly Hills CA
International Classification:
H04N 7467
H07H 700
H07H 700
US Classification:
380 7
Abstract:
A Television Signal Transmission Security System which provides a higher degree of security then previously possible by utilizing encoding and decoding technology which effectively prevents pirating by amateurs or experimenters. The television signal transmitted is encoded by injecting one or more modulated interfering signals in specific frequency slots in close proximity to the video carrier. Continuous or alternating interfering signals can be injected either above or below the video carrier between harmonics of the horizontal frequencies. Combinations of interfering signals provide coding techniques making the system virtually pirate proof. The interfering signal is removed by very narrow band rejection filters having a rejection band attenuation greater than about 40 dB over a bandwidth equal to the bandwidth between adjacent harmonics of the horizontal sweep frequency. The filters are constructed using advanced technology to produce the quartz crystal bulk resonators or surface acoustic wave filters. Pre-compensation at the transmitter improves overall amplitude and phase response to provide a nearly perfect decoded picture.
Narrow Focus Compensating Transducer For Surface Acoustic Wave Filter
View pageUS Patent:
44609957, Jul 17, 1984
Filed:
Apr 21, 1982
Appl. No.:
6/370313
Inventors:
Adrian J. DeVries - Mount Prospect IL
Assignee:
Zenith Radio Corporation - Glenview IL
International Classification:
H03H 964
US Classification:
310313R
Abstract:
A compensation scheme is disclosed which avoids the requirement of high alignment accuracy, and thus reduces the production cost of a surface acoustic wave filter, by employing a compensating transducer system which is arranged with its fingers parallel to those of the receiving transducer. The requirement of receiver sensitivity at the trap frequencies is nevertheless achieved by using a very narrow compensating beam width. The narrowness of the compensating beam also allows it to pass directly through a multi-strip coupler. The degree of compensation achieved is controlled by aiming the compensating beam at a small region of the apodized receiving transducer located at the extremity of the major lobe; by restricting the aperture of the compensating transducer system; and by trimming the printed circuit capacitor which couples the compensating transducer system to the electrical input signal. The degree of compensation achieved is made to differ at the upper and lower trap frequencies by using a compound compensating transducer system employing two individual transducers spaced apart the proper distance to be more or less in phase opposition to each other at one of the trap frequencies. The individual transducers nevertheless remain largely in phase with each other at the other trap frequency, so as to aid each other in producing the compensation effect.
Acoustic Surface Wave Filter Having Combined Split-Isolated And Split-Connected Coupler
View pageUS Patent:
39873790, Oct 19, 1976
Filed:
Jan 2, 1976
Appl. No.:
5/646117
Inventors:
Adrian J. DeVries - Elmhurst IL
Assignee:
Zenith Radio Corporation - Chicago IL
International Classification:
H03H 926
H03H 932
H01L 4104
H01L 4110
H03H 932
H01L 4104
H01L 4110
US Classification:
333 72
Abstract:
An acoustic surface wave filter has offset transmitting and receiving transducers formed on the wave propagating surface of a piezoelectric substrate. A two-segment multistrip coupler is interposed on the propagating surface and provides "track switching" or "sidestepping" action for signals within the coupler passband. The coupler includes a split-connected portion formed by electrically connected filamentary conductor pairs and a split-isolated portion formed by electrically continuous filamentary conductors and interleaved conductors having a discontinuity at their center. The split-connected portion attenuates the symmetrical mode components of acoustic waves within the coupler stop band while the split-isolated portion attenuates the anti-symmetrical mode portion of acoustic waves within the coupler stop band, producing an improved trap response.
Master Decoder For Television Signal Scramble Systems
View pageUS Patent:
52356400, Aug 10, 1993
Filed:
Dec 21, 1989
Appl. No.:
7/455512
Inventors:
Adrian J. Devries - Aurora IL
Bruno A. Rist - Woodland Hills CA
Bruno A. Rist - Woodland Hills CA
Assignee:
International Telesystems, Inc. - Pacific Grove CA
International Classification:
H04N 7167
US Classification:
380 13
Abstract:
A master decoder for scrambled television signals in which the signals are processed in a circuit by converting them to other frequencies and then removing the scrambling signal. One method uses one or more narrow filters at a fixed frequency with the television signal being heterodyned down to the frequency of the filters to place the scrambling signals in the rejection band of one of the filters. A second method eliminates scrambling signals by filters at video frequencies. In this method, the frequency in phase with the television signal carrier of a television channel is regenerated by filtering it with a narrow crystal filter and by means of an automatic phase comparison (APC) loop. The regenerated carrier is then used to synchronously demodulate the television signal. A third method for removing the scrambling signals is by use of one or more comb filters.
Acoustic Surface Wave Device Having Split-Isolated Or Split-Connected Multistrip Coupler
View pageUS Patent:
39887030, Oct 26, 1976
Filed:
Dec 31, 1975
Appl. No.:
5/645488
Inventors:
Adrian J. DeVries - Elmhurst IL
Assignee:
Zenith Radio Corporation - Chicago IL
International Classification:
H03H 926
H03H 904
H03H 932
H01L 4110
H03H 904
H03H 932
H01L 4110
US Classification:
333 72
Abstract:
An acoustic surface wave filter has offset transmitting and receiving transducers formed on a wave propagating surface of a piezoelectric substrate. A multistrip coupler interposed between the transducers on the propagating surface includes a plurality of identical conductor groups forming coupler elements uniformly spaced on the surface and selectively attenuates either of the symmetrical or anti-symmetrical mode components of coupled waves within a predetermined range of acoustic wavelengths. In one embodiment, each conductor group includes electrically connected pairs which attenuates the symmetrical mode component while in another embodiment each conductor group includes a first continuous filamentary conductor and a second filamentary conductor having a discontinuity at its approximate center which attenuates the anti-symmetrical mode component.
Surface Wave Device For Use In A Ghost Cancellation System
View pageUS Patent:
40657892, Dec 27, 1977
Filed:
Jan 5, 1977
Appl. No.:
5/757118
Inventors:
Adrian J. DeVries - Elmhurst IL
Assignee:
Zenith Radio Corporation - Glenview IL
International Classification:
H04N 521
H03H 730
H01V 700
H03H 730
H01V 700
US Classification:
358167
Abstract:
A ghost cancellation system includes a surface-wave device operable for developing a replica of the ghost component of a video signal, which replica is combined with the video signal to eliminate or cancel the ghost component. The surface-wave device comprises an input transducer responsive to a modulated video signal for launching uniform acoustic surface-waves along a path traversing a balanced pair of output transducers and impinging upon a reflector array. The reflector array includes means for initiating non-uniform surface-wave reflections suitable for causing the output transducers to develop an output electrical signal comprising the ghost replica.