RADIO COMMUNICATION DEVICE

PURPOSE:To improve the economical performance of a radio communication device, by amplifying the output of a signal synthesizer for synthesizing the output of a transmission automatic gain amplifier of each system with a transmission power amplifier, and at the same time compensating the mutual modulation distortion generated from said amplifier to transmit the result from an antenna. CONSTITUTION:The intermediate frequency signal supplied from a signal input terminal 5 is amplified by a transmission automatic gain control amplifier 7 and undergoes the frequency conversion with the output of a transmission local oscillator 9 and through a transmission mixer 8. The output signal of the mixer 8 is synthesized with a signal of another system by a direct signal synthesizing circuit 11 and supplied to a common transmission power amplifier 1 through a pre-distortion generator 2. The output of the amplifier 1 is supplied to a transmission antenna 12 and converted into an intermediate frequency band with frequency conversion carried out by a distortion detecting mixer 10. A distortion detecting circuit 4 detects the mutual modulated distortion with the output signal of the mixer 10 and transmit it to a control circuit 3. The circuit 3 controls the generator 2 to reduce the mutual modulation distortion generated from the amplifier 1.