Patent ID: 6998912

Claim:
A high frequency composite switch module for switching between transmission of a transmission signal and reception of a reception signal using a common terminal, said switch module comprising: a) a transmitter circuit for processing said transmission signal, said transmitter circuit comprises: a transmitter side impedance converter including an impedance matching circuit and an impedance converter circuit, and connected to said common terminal, an amplifier for amplifying and outputting said transmission signal to said transmitter side impedance converter, and a power supply unit for supplying electric power to said amplifier; and b) a receiver circuit for processing said reception signal, said receiver circuit comprises: a receiver side impedance converter including a phase shifting circuit and a surface acoustic wave (SAW) filter, and connected to said common terminal, wherein: at least one of said impedance matching circuit, said power supply unit and said phase shifting circuit is formed inside a multilayer board comprising a conductor layer and a dielectric layer, during transmission, said transmitter circuit applies said transmission signal to said phase shifting circuit, said phase shifting circuit having a sufficiently high impedance over a first frequency band of said transmission signal to cause said transmission signal to be reflected at an input port of said receiver circuit, and during reception, said receiver circuit applies said reception signal to said impedance converter circuit, said impedance converter circuit having a sufficiently high impedance over a second frequency band of said reception signal to cause said reception signal to be reflected at an output port of said transmitter circuit.