04242663 is referenced by 79 patents and cites 5 patents.

An electronic identification system includes common transceiver and signal processing apparatus, and relative small electronic circuitry, referred to as a "tag", secured to each item of a population to be identified. Each tag is assigned a multi-bit digital code which may or may not be unique.

The common equipment determines whether any desired tag-bearing item is nearby by emitting a phase modulated radio frequency wave embodying the requisite tag code, and examining the output of a homodyne mixer, operating on a radar-like recovered reflection signal, for a predetermined signatory response. Such a response will be generated only by a tag circuit responding to a match between its stored encoding and that of the interrogation signal by changing the effective cross sectional reflecting area of the tag antenna.

Title
Electronic identification system
Application Number
6/8798
Publication Number
4242663
Application Date
February 1, 1979
Publication Date
December 30, 1980
Inventor
Leo Slobodin
Holmdel
NJ, US
Agent
Hopgood Calimafde Kalil Blaustein & Lieberman
Assignee
Lockheed Electronics Corporation
NJ, US
IPC
G01S 9/56
H04Q 9/00
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