| 摘要 |
PROBLEM TO BE SOLVED: To provide a mirror detection circuit that generates an accurate detection signal by avoiding a part being not a mirror part from being mis-detected to be the mirror part when the amplitude of an input RF signal is smaller. SOLUTION: The mirror detection circuit is provided with a 1st peak detection circuit 1 that detects a peak of the RF signal, a 1st bottom detection circuit 2 that detects a bottom of the RF signal, a sbutractor 7 that provides an output of a value resulting from subtracting an output of the 1st bottom detection circuit from an output of the 1st peak detection circuit, a 2nd peak detection circuit 8 that detects a peak of the output of the sbutractor, a 2nd bottom detection circuit 9 that detects a bottom of the output of the sbutractor, an intermediate voltage point generating circuit 10 that outputs an intermediate voltage of outputs of the 2nd peak detection circuit 8 and the 2nd bottom detection circuit 9, a comparator input voltage selection circuit 11 that receives an output of the intermediate voltage point generating circuit and a 1st reference bias V1, selects a value which is higher in the output of the intermediate voltage point generating circuit and the bias V1 and provides an output of the selected value, and a comparator 12 that compares the output of the subtractor with an output of the comparator input voltage selection circuit 11 and provides an output of the comparator result as a mirror signal.
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