<p>Disclosed is a polar modulator that performs high efficiency operations and secures excellent modulating characteristics in response to changes in ambient temperature or the temperature of a power amplifier. A signal generator generates a phase signal and an amplitude signal from an input signal. An LDO linear regulator outputs an amplitude signal voltage on the basis of the amplitude signal. A phase modulator phase-modulates the phase signal. The power amplifier amplitude-modulates the phase-modulated phase signal using the amplitude signal voltage supplied by the LDO linear regulator, generating a modulated signal. A temperature sensor measures the ambient temperature or the temperature of the power generator, and outputs the measured temperature as temperature information. Based on the temperature information, a DC/DC output controller outputs a control signal that controls the power supply voltage that drives the LDO linear regulator. A DC/DC converter supplies a power supply voltage based on the control signal to the LDO linear regulator.</p>
