Title:
【発明の名称】電子識別システムのための呼掛け器
Document Type and Number:
Japanese Patent JPH11504425
Kind Code:
A
Abstract:
Interrogator for an electronic identification system having a first oscillator arranged to vary in frequency in accordance with the frequency of a received signal, a second oscillator arranged to vary in accordance with the frequency of the first oscillator after a delay of a number of cycles of the received signal, a phase discriminator for detecting the phase difference between respective output signals of the first and second oscillators and a phase-change detector arranged to determine the frequency at which the phase changes occur. In this way, a modulation frequency of the received signal can be determined.
Inventors:
Joshua
Application Number:
JP53228296A
Publication Date:
April 20, 1999
Filing Date:
April 26, 1996
Export Citation:
Assignee:
British Technology Group Inter-Corporate Licensing Limited
International Classes:
G01R25/00; G01S13/75; G01S13/78; G01S13/74; G06K7/00; G06K7/08; H03D13/00; H04B1/59; H04B5/02; H04L7/027; H04L7/033; (IPC1-7): G01S13/74; H04B1/59; H04B5/02
Attorney, Agent or Firm:
Kazuo Shamoto (5 outside)