| 摘要 |
PROBLEM TO BE SOLVED: To make a directional coupler compact in an electronic component for high-frequency power amplification which constitutes a radio communication system detecting output electric power and performing feedback control, and to perform high-precision output electric power control by eliminating an influence of a reflected wave of the directional coupler on a monitor voltage. SOLUTION: This electronic component has the directional coupler 250 composed of a sub-line MS4 arranged closely to a portion of the final output stage side of a power amplifying circuit of a main line MS1 in parallel, a capacity element Ce connected between the main line and sub-line, and a resistance element Rt connected between an end terminal of the sub-line and a constant-potential point. Then an output power detecting circuit 220 comprises a first detecting circuit 221 which detects an AC signal taken out of a start terminal of the sub-line, a second detecting circuit 223 which detects an AC signal taken out of the end terminal of the sub-line, and a subtracting circuit 224 which obtains the difference between the output of the first detecting circuit and the output of the second detecting circuit. COPYRIGHT: (C)2007,JPO&INPIT
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