RADIO COMMUNICATION APPARATUS

摘要

A transmitter circuit comprises a first synthesizer unit and a second synthesizer unit which consumes less current than the first synthesizer unit, and power consumption by the transmitter circuit is reduced by switching states so as to cause the first synthesizer unit to operate and the power supply of the second synthesizer unit to be turned off at the time of polar modulation, and cause the second synthesizer unit to operate and the power supply of the first synthesizer unit to be turned off at the time of quadrature modulation. While the first synthesizer unit is operating, the transmitter circuit compensates the oscillation frequency of the first synthesizer unit. Then, when the first synthesizer unit stops operating, the transmitter circuit stores a compensation value. When operation of the first synthesizer unit restarts, the transmitter circuit corrects the thus stored compensation value by an amount corresponding to a temperature change. Thus, accuracy of the compensation is improved, and transmission signals are prevented from being deteriorated in quality.