0324564-A2 is referenced by 35 patents and cites 6 patents.

An identification system for personal, freight items and such like comprises a tag-like electronic responder device (1) which comprises an antenna (4a, 4b) which reflects, and thereby modifies, an electrical wave incident thereon from a separate interrogator device. The device (1) modifies the reflection in accordance with binary data generated by data generating means (9) by varying the impedance loading of the antenna (4a, 4b) by switching a FET (8) in accordance with the binary data. The binary data may comprise identification data as well as synchronising data for decoding purposes. The responder device (1) may be reprogrammed with new identification data by means of a programmer.

Title
System for communicating identification information and the like.
Application Number
EP19890300147 19890109
Publication Number
0324564 (A2)
Application Date
January 9, 1989
Publication Date
July 19, 1989
Inventor
Oshiba Katsuyuki
Iga Akira
Assignee
Sony
JP
IPC
G08B 13/24
G01S 13/02
G08B 13/24
G06K 19/07
G01S 13/00
B61L 25/00
G08B 13/24
G06K 19/07
G01S 13/82
G01S 13/75
B61L 25/04
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