Patent ID: 8000659

Claim:
A polar modulation transmission apparatus comprising: a power amplifier that amplifies power of a phase component signal of a predetermined signal; a power supply; a regulator that changes a power supply voltage of the power supply according to an amplitude component signal of the predetermined signal and supplies the power supply voltage to a power supply input terminal of the power amplifier; a current detecting section that detects a value of current flowing from the power supply to the power amplifier; a power control section that limits, based on the current value detected in the current detecting section, a value of a transmission power control signal specifying transmission power; a power apply section that adjusts a level of the amplitude component signal of the predetermined signal based on the transmission power control signal outputted from the power control section; and a comparison section that compares the current value detected in the current detecting section to a predetermined threshold, wherein: the power control section limits the value of the transmission power control signal when the comparison result shows that the current value is greater than the predetermined threshold, and the predetermined threshold used for comparison with the value of current detected in the current detecting section is a first threshold when the power supply voltage supplied to the power supply input terminal of the power amplifier has a limit, and the predetermined threshold is a second threshold different from the first threshold when the limit for the power supply voltage supplied to the power supply input terminal of the power amplifier is cancelled.