RADIO FREQUENCY SWITCH

PROBLEM TO BE SOLVED: To provide a radio frequency switch capable of meeting the duplex mode. SOLUTION: A radio frequency switch 21 is mainly constituted of ten main switching elements 22-31, a transmission pass circuit 40, a coupler 45, a low-pass filter 50, auxiliary switching elements 65-70 shunt connected. As these main switching elements 22-31, there are employed GaAs switches (MOS-FET transistors) which are easy to synchronize mutually with the ON/OFF control. For example, when a transmission port and a reception port Tx, Rx are simultaneously connected to an antenna port ANT1, the entire or a part of main switching elements 24, 27 and auxiliary switching elements 70, 65, 66 and 68 are simultaneously turned ON, and the remainder switching elements OFF.