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 Title: |
US5525993:
Microwave noncontact identification transponder using subharmonic interrogation and method of using the same
[ Derwent Title ]
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| Country: |
US United States of America
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| Inventor: |
Pobanz, Carl W.; Rancho Palos Verdes, CA
Itoh, Tatsuo; Los Angeles, CA
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| Assignee: |
The Regents of the University of California, Oakland, CA
other patents from UNIVERSITY OF CALIFORNIA, THE REGENTS OF (599425) (approx. 4,840)
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| Published / Filed: |
1996-06-11
/ 1995-05-12
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| Application Number: |
US1995000440003
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| IPC Code: |
Advanced:
G01S 13/75;
G06K 7/00;
G06K 19/07;
G07C 9/00;
Core:
G01S 13/00;
more...
IPC-7:
G01S 13/76;
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| ECLA Code: |
G01S13/75C; G06K7/00E; G06K19/07T; G07C9/00B10;
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| U.S. Class: |
Current:
342/051;
342/044;
Original:
342/051.000;
342/044;
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| Field of Search: |
342/042,44,51
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| Priority Number: |
| 1995-05-12 |
US1995000440003 |
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| Abstract: |
A credit-card sized microwave transponder for "wireless key" and surveillance applications uses a subharmonically-pumped quasi-optical mixer. The transponder is activated by a C-band interrogation beam to upconvert and radiate a digitally modulated identification tone at X-band frequencies nonharmonically related to the interrogation signal.
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| Attorney, Agent or Firm: |
Dawes, Daniel L. ;
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| Primary / Asst. Examiners: |
Sotomayor, John B.;
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| Maintenance Status: |
E1 Expired Check current status
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| INPADOC Legal Status: |
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| Family: |
None
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First Claim:
Show all 20 claims |
We claim:
1. An improvement in a contactless transponder having a modulation oscillator, a quasi-optical mixer having a first input coupled to said modulation oscillator and an antenna having an input coupled to an output of said mixer comprising:
- an identification code generator coupled to a second input of said mixer, wherein said mixer modulates an interrogation signal received by said antenna having a frequency, fi, with a data carrier signal having a frequency, fd, generated by said modulation oscillator to transmit supressed-carrier double sideband response signals, wherein each sideband response signal is modulated by an identification code generated by said identification code generator, said data frequency, fd, being at a nonharmonic value of said interrogation frequency, fi,
- whereby false detection arising from reflections of transmitted harmonics of said interrogation signal is avoided.
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| Background / Summary: |
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| Drawing Descriptions: |
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| Description: |
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| Forward References: |
Show 22 U.S. patent(s) that reference this one
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