Patent ID: 7027778

Claim:
A radio frequency switching apparatus for controlling a connection between an antenna and a transmitter module and a connection between said antenna and a receiver module, said apparatus comprising: filtering means connected between said transmitter module and said antenna for passing a transmitted signal from said transmitter module to said antenna in a transmit(Tx) mode, said filtering means having an electrical length corresponding to about ¼ of a wavelength of a reception frequency in a receive(Rx) mode; first switching means connected between said filtering means and said transmitter module for connecting a connection point of said filtering means and transmitter module to a ground terminal in response to a switching signal in said receive(Rx) mode such that said filtering means is operated as an impedance transformer to isolate said transmitter module and said antenna from each other in an alternating current (AC) manner; and second switching means connected between said antenna and said receiver module for isolating said antenna and said receiver module from each other in response to said switching signal in said transmit(Tx) mode.