POWER DETECTION DEVICE

PROBLEM TO BE SOLVED: To provide a power detection device that is capable of precise temperature compensation without adding any special components nor using positive and negative power supplies.SOLUTION: A power detection circuit 51a and a power detection circuit 51b have the same circuit configuration except for input signals and, specifically, comprise FETs 2a and 2b, FETs 3a and 3b, an FET 4 and a capacitor 5 and FETs 12a and 12b, FETs 13a and 13b, an FET 14 and a capacitor 15. Since the power detection circuit 51a and the power detection circuit 51b have the same circuit characteristic, a subtraction circuit can compute a difference between a detected output of the power detection circuit 51a and a reference of the power detection circuit 51b to precisely cancel signal fluctuation components due to temperature changes.