RF (radio frequency) refers to the range of frequencies that are used for wireless communication and broadcasting. RF signals are typically used for transmitting data, audio, and video over long distances.
An RF mixer is a type of electronic circuit that is used to combine two or more RF signals. This is typically done in order to convert the frequency of an RF signal, or to combine it with another signal in order to create a new signal with different characteristics. RF mixers are commonly used in radio and telecommunications systems, as well as in other applications such as radar and medical imaging.