POWER DETECTOR CIRCUIT AND POWER DETECTION METHOD

摘要

A power detector circuit comprises: a variable-frequency oscillator (2) that is operative to oscillate a local oscillation frequency; a mixer (1) that is operative to receive the local oscillation frequency and a detection signal and to use the local oscillation frequency to frequency-convert the detection signal; a complex band-pass filter (3) that is operative to limit the band of the detection signal as frequency-converted to a predetermined band; and an energy detector circuit (4) that is operative to detect, based on an output from the complex band-pass filter (3), a power of the predetermined band. The local oscillation frequency is established such that the predetermined band of the detection signal as frequency-converted is a frequency range the 1/f noise of which is low. This invention can provide a high-speed, high-sensitivity power detector circuit.