Patent ID: 8520766

Claim:
A transmitter which generates a transmission signal on the basis of an input signal, the transmitter comprising: a signal generation circuit for outputting an amplitude component of the input signal as an amplitude signal and outputting a phase component of the input signal as a phase signal in a normal transmission mode; a delay adjustment circuit for, on the basis of at least one of an amplitude delay time which is set to adjust a delay time of the amplitude signal and a phase delay time which is set to adjust a delay time of the phase signal, adjusting at least one of the delay time of the amplitude signal and the delay time of the phase signal; a phase modulator for phase-modulating the phase signal which is inputted via the delay adjustment circuit to a phase modulated signal and outputting the phase modulated signal; a regulator for outputting a signal in accordance with a magnitude of the amplitude signal which is inputted via the delay adjustment circuit; an amplitude modulator for, by amplifying the phase modulated signal outputted from the phase modulator in accordance with the signal outputted from the regulator, amplitude-modulating the phase modulated signal to a modulated signal and outputting the modulated signal which has been phase-modulated and amplitude-modulated; a multiplier for multiplying the phase signal outputted from the signal generation circuit by the signal outputted from the regulator and outputting a multiplication signal; a power measurement circuit for measuring a power of the multiplication signal; and a control circuit for calculating at least one of the amplitude delay time and the phase delay time on the basis of a value measured by the power measurement circuit, wherein the signal generation circuit outputs a predetermined AM test signal as the amplitude signal and outputting a predetermined PM test signal as the phase signal in a test mode, the AM test signal and the PM test signal are set such that an average power of the multiplication signal becomes a maximum value when there is no delay error between the AM test signal and the PM test signal, and the average power of the multiplication signal shows a convex shape with the maximum value at the peak thereof with respect to a delay error within a predetermined time range, and the control circuit estimates a delay error between the AM test signal and the PM test signal on the basis of the value measured by the power measurement circuit, calculates at least one of the amplitude delay time and the phase delay time so as to cancel the delay error, and sets the calculated delay time in the delay adjustment circuit.