Patent ID: 7671691

Claim:
A phase controller apparatus comprising: a quadrature modulator which divides a first signal input as a local signal into an I channel signal and a Q channel signal orthogonal to each other and outputs a second signal having a desired phase delay relative to the first signal by giving direct current voltages to the I channel signal and the Q channel signal respectively; a phase comparison unit which detects a phase difference θ between the first signal input to the quadrature modulator and the second signal output from the quadrature modulator; a setting unit which sets the desired phase delay; and a controller section which controls the direct current voltages given to the I channel signal and the Q channel signal respectively in the quadrature modulator so that an output value corresponding to the phase difference θ detected by the phase comparison unit is equal to a value corresponding to the desired phase delay set by the setting unit and controls the direct current voltages to be Vi and Vq satisfying the relation of Vi=cos θ and Vq=sin θ.