The transceiver has a transmitter, a receiver, and a three-port network. The transmitter is configured to transmit an outgoing RF signal. The receiver is configured to receive an incoming RF signal. The three-port network includes: a transmission line, configured to have a line length less than a quarter of a wavelength of the incoming RF signal; an antenna port, configured to connect to an antenna; a receiver port, configured to connect the receiver to the antenna port; and a transmitter port, configured to connect the transmitter to the antenna port and the receiver port through the transmission line.