RADIO TRANSMITTER-RECEIVER, ITS RECEIVING HIGH FREQUENCY UNIT AND CONTROL UNIT

PROBLEM TO BE SOLVED: To improve the reception distortion characteristic and to extend a standby time or a communication time by suppressing increase in the current consumption of a reception high frequency unit, so as to prevent deterioration in the reception sensitivity of its own transmission wave and a disturbing wave. SOLUTION: A reception high frequency unit is provided with a low noise amplifier (low distortion LNA) 500a with a low distortion characteristic, a low current consumption type low noise amplifier (low current consumption LNA) 500b, and high frequency switches 502, 509 that select alternatively. A mode switching control function of a CPU generates an LNA switching control signal to select the low distortion LNA 500a, when the operation state of the radio transmitter-receiver is in a period of a transmission-reception state or to select the low current consumption LNA 500b, when the operating state of the radio transmitter-receiver is in a period of a standby state, thereby controlling the respective high frequency switches 502, 509 of a low noise amplifier circuit section 501.