| 摘要 |
PROBLEM TO BE SOLVED: To provide a detector circuit capable of indicating a correct power level by following load variation of a high-frequency power amplifier and difference of a modulation wave mode in spite of being a simple circuit, and easily incorporated in a high-frequency amplifier; and a wireless communication system using the detector circuit. SOLUTION: This detector circuit includes a detecting resistor 11 for detecting a part of a current from a bias circuit 6, and a current-voltage conversion circuit 12 for converting a current obtained through the detecting resistor 11 into a voltage. A current supplied from the bias circuit 6 to an amplifying transistor 1 is detected, so that an output current from the amplifying transistor 1 varies when a load on the high-frequency power amplifier changes, and an input current and a current from the bias circuit change as well in proportion thereto, whereby a detection output voltage can follow the change of the load of the high-frequency power amplifier. COPYRIGHT: (C)2010,JPO&INPIT
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