Description.

Duplexer is a 3 ports device most commonly used to allow a transmitter and receiver to operate on different frequencies, to share a common antenna while operating simultaneously. The filters that make up the duplexer isolate the transmitter from the receiver by doing two important functions--Function1, to filter out any transmitter noise sidebands that are being generated on the receive frequency, function 1 is the most important. Function2, to protect the receiver from transmitter carrier overload.