Patent ID: 7573949

Claim:
A transmitter circuit operable to generate and output a transmission signal based on inputted data, comprising: a data generator for generating an amplitude signal and a phase signal; a delay adjuster for, based on an amplitude delay time which is set for adjusting the amplitude signal and/or a phase delay time which is set for adjusting the phase signal, adjusting a delay time of the amplitude signal generated by the data generator and/or a delay time of the phase signal generated by the data generator, and for outputting the amplitude signal and the phase signal; an angle modulator for angle-modulating the phase signal, which is outputted from the delay adjuster, to be outputted as an angle-modulated signal; a regulator for outputting a signal in accordance with a magnitude of the amplitude signal outputted from the delay adjuster; and an amplitude modulator for amplitude-modulating the angle-modulated signal, by amplifying the angle-modulated signal outputted from the angle modulator in accordance with the signal outputted from the regulator, to be outputted as a modulated signal which has been angle-modulated and amplitude-modulated, wherein a complex envelope of the modulated signal outputted from the amplitude modulator is detected, the detected complex envelope is observed periodically over a period of time, two observation points at which angle change amounts of the complex envelope are larger than a predetermined angle threshold value are selected and an observation point at which a magnitude of the complex envelope is larger than that at one of the two observation points is selected as a singular point, based on a positional relationship of the singular point with respect to a preceding symbol upon modulating the data and a succeeding symbol upon modulating the data, it is determined which one of the amplitude signal and the phase signal is advanced or delayed, and based on a result of the determination, the amplitude delay time and/or the phase delay time are/is set at the delay adjuster so as to decrease a difference between the delay times of an amplitude signal and a phase signal.