Double-frequency vehicle-mounted interphone

The invention discloses a double-frequency vehicle-mounted interphone with low cost and high performance. The double-frequency vehicle-mounted interphone adopts a single radio frequency power amplifier tube for realizing two high-performance broadband UHF and VHF radio frequency power amplifier circuits, and the technical difficulty that antenna port radio frequency output out-of-band rejection capability is poor when a double-frequency vehicle-mounted interphone adopts a single radio frequency power amplifier is solved by adding an isolation control circuit. Besides, an RDA1846S radio frequency single chip is taken as a UHF and VHF main radio frequency chip for a solution of the double-frequency vehicle-mounted interphone, and a UHF frequency selecting and amplifying circuit and a VHF frequency selecting and amplifying circuit adopt amplifying circuits with varator tuning frequency selecting function, an out-of-band interference signal can be filtered out and inhibited, and receivingand anti-interference cap