TRANSMITTER CIRCUIT USING POLAR MODULATION SYSTEM, AND COMMUNICATION DEVICE

摘要

Provided is a transmitter circuit capable of adjusting the difference between the amounts of signal delay in the amplitude path and the phase path while consuming low power. An amplitude modulation unit (15) receives a phase modulation signal output from a phase modulation unit (14), amplitude-modulates the phase modulation signal using a voltage control signal supplied from a regulator (13), and generates a transmission signal for antenna output. Likewise, a feedback signal generation unit (16) amplitude-modulates the phase modulation signal with the voltage control signal to generate a feedback signal (FB). This signal (FB) is fed back to a delay adjustment unit (12) and used to calculate and adjust the difference between the amounts of signal delay in the amplitude path and the phase path. The feedback signal generation unit (16) has the same circuit configuration as the amplitude modulation unit (15), but is implemented by a power amplifier which is smaller in circuit size than that used to implement the amplitude modulation unit (15).