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:
Aug. 26, 2003
Filed:
May. 14, 2002
Paul A. Nysen, Sunnyvale, CA (US);
Halvor Skeie, San Jose, CA (US);
X-Cyte, Inc., San Jose, CA (US);
Abstract
A backscatter transponder interrogator, comprising a transmitter, emitting an interrogation signal for interacting with a backscatter transponder within an interrogation field, a plurality of antennas, each having a different and complementary property, such that a backscatter response from a backscatter transponder is likely to be preferentially received by at least one of said at least two antennas, a receiver, selecting an output from a selected antenna, and demodulating the backscatter response to produce an information signal, and a digitally controlled oscillator, producing an output controlling said transmitter and employed by said receiver to demodulate the backscatter response. The interrogator may have a plurality of transmit antennas. The antennas may have respectively different polarization properties, e.g., horizontal and vertical polarization. The interrogator may implement null steered polarization cancellation to distinguish between backscatter transponders within the interrogation field.