To reduce deterioration in propagation efficiency of a transmission signal even if impedance changes in a signal transmission apparatus which uses a human body as a transmission medium.
Test signals are transmitted through a transmission electrode at test frequencies which are changed monotonously in a specified frequency band (S410), the test return loss value and insertion loss value for each test signal are derived, and then the test return loss value and insertion loss value thus derived are stored in a memory (S420). Furthermore, based on the test return loss value and insertion loss value stored in the memory, the insertion loss values are compared, respectively, for the test frequencies at which the test return loss goes below a specified threshold (S470), and a test frequency corresponding to a maximum insertion loss value (minimum absolute value), as a result of comparison, is set as a candidate frequency (S480). Consequently, the carrier frequency of a transmission signal to be transmitted next becomes the optimal frequency.
COPYRIGHT: (C)2010,JPO&INPIT
Ryoichi Sugawara
Osamu Katayama
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| WO2007013310A1 |