Title:
IMPEDANCE MEASURING DEVICE
Document Type and Number:
Japanese Patent JP3833565
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide an impedance measuring device capable of measuring the antenna impedance or a circuit constant at desired frequency with high accuracy even under the environment where the electric wave having strong electric field arrives at a measured object as an interference wave.
SOLUTION: This impedance measuring device has the configuration comprising an AC bridge 110 for measuring the circuit constant including the antenna impedance, a signal generating means 320 for supplying a signal obtained by modulating the amplitude of an AC signal on the basis of a specific modulation wave or suppressing the carrier wave and modulating the amplitude, to the AC bridge 110 as a signal for measuring the circuit constant, an RF orthogonal detection means 330 performing the orthogonal detection on the basis of the AC signal, and an AF orthogonal detection means 340 for performing the orthogonal detection of the signal of a specific frequency band among the signals obtained by the orthogonal detection, on the basis of the modulation wave, and the interference wave coming from the external has a frequency component same as or close to that of the signal for measurement.
Inventors:
Masahiko Yamazoe
Kazuaki Wakai
Takayuki Ishikawa
Masato Hamada
Kazuaki Wakai
Takayuki Ishikawa
Masato Hamada
Application Number:
JP2002122941A
Publication Date:
October 11, 2006
Filing Date:
April 24, 2002
Export Citation:
Assignee:
Japan Broadcasting Corporation
International Classes:
G01R27/02; (IPC1-7): G01R27/02
Domestic Patent References:
| JP7333269A | ||||
| JP7049361A |
Attorney, Agent or Firm:
Gunichiro Ariga
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