Diplexer

• A diplexer, in itself, is a coupling device combining audio and video signals permitting two radio transmitters to share the same antenna. Thereby transmitting and receiving two signals simultaneously.
  
  

Filter

• In electronics, a filter is a device that can change the distribution of energy. There are high-pass, low-pass, bandpass and band-stop filters.
  
  

Diplexer Filter

• A diplexer filter is a specific filter that consists of both a high-band filter and a low-band filter whereby signals can coexist without interfering with each other.