Patent ID: 7787832

Claim:
A TX/RX antenna switch (TRAS) apparatus in a time division duplex (TDD) wireless communication system, comprising: a 180° hybrid coupler; a phase shifter; and a combiner/divider unit, wherein the 180° hybrid coupler divides a signal received from a transmitter into two in-phase signals and outputs the two in-phase signals to the phase shifter, and combines two signals with a phase difference of 180° received from the phase shifter and outputs the resulting signal to a receiver, wherein the phase shifter shifts the phases of two signals received from the 180° hybrid coupler by the same degree and outputs the resulting signals to the combiner/divider unit, and shifts two in-phase signals received from the combiner/divider unit into signals with a phase difference of 180° and outputs the resulting signals to the 180° hybrid coupler, and further wherein the combiner/divider unit combines two in-phase signals received from the phase shifter and outputs the resulting signal to an antenna, and divides an RX signal received from the antenna into two in-phase signals and outputs the resulting two in-phase signals to the phase shifter.