The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 16, 1988
Filed:
Jun. 30, 1983
Paul A Nysen, Sunnyvale, CA (US);
Halvor Skeie, San Jose, CA (US);
Donald Armstrong, Belmont, CA (US);
X-Cyte, Inc., Mountain View, CA (US);
Abstract
A 'passive interrogator label system' (PILS) comprises an interrogator for transmitting an interrogation signal, one or more 'labels' or passive transponders which produce a reply signal containing coded information in response to the interrogation signal, and a receiver and decoder for receiving the reply signal and decoding the information contained in it. The frequency of the interrogation signal assumes a plurality of frequency values within a prescribed frequency range. The decoder includes a mixer (4 quadrant multiplexer) for mixing together the interrogation and reply signals (or signals derived therefrom) to produce a further signal containing frequencies which are the sum and difference of the interrogation and reply signals. A signal processor, responsive to this further signal produced by the mixer, detects at least some of the frequencies contained in this further signal and determines the informational code associted with the transponder.