Title:
【発明の名称】識別装置
Document Type and Number:
Japanese Patent JPH07509564
Kind Code:
A
Abstract:
PCT No. PCT/NO93/00103 Sec. 371 Date Mar. 30, 1995 Sec. 102(e) Date Mar. 30, 1995 PCT Filed Jun. 30, 1993 PCT Pub. No. WO94/28976 PCT Pub. Date Dec. 22, 1994An identification device is provided which includes an inactive code carrier, such as a standing acoustic wave component, a frequency mixing section, and a double antenna input. Each of the antennas are tuned to a separate predetermined transmitted signal wherein the frequencies are different. The two separately received RF frequencies are mixed to produce an intermediate frequency having the sum or difference of the two received frequencies. The intermediate frequency is coupled to the standing acoustic wave device which applies a coded signal to the intermediate frequency. The intermediate frequency is then recombined with one of the original incoming RF frequencies to be retransmitted from the identification device. The mixer section can include a diode and a coil for matching the impedance of the incoming signal with the inactive code carrier. The code carrier or standing acoustic wave component is usually tuned to the lower intermediate frequency and thus, is a selective filter for the frequencies emanating from the mixing section.
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Inventors:
Kirkness, Stephen
Application Number:
JP50520194A
Publication Date:
October 19, 1995
Filing Date:
June 30, 1993
Export Citation:
Assignee:
Micro design actiesl cub
International Classes:
G01S13/75; G01S13/76; G01S13/79; G06K19/07; H04B1/59; (IPC1-7): G01S13/75; G01S13/76; G01S13/79; H04B1/59
Attorney, Agent or Firm:
Mikio Hatta