Beat Frequency

In signal processing and electronics:

• Beat frequency refers to the difference between two frequencies, typically produced by the interference or superposition of two nearly identical frequencies. This phenomenon creates a periodic variation in amplitude known as beats. For example, if two sound waves of slightly different frequencies overlap, the beat frequency is the frequency of the periodic variation in loudness that you hear.
• Intermediate frequency (IF) in a superheterodyne receiver is a specific application of beat frequency. In this context, the incoming radio frequency (RF) signal mixes with a local oscillator signal to produce an intermediate frequency. This intermediate frequency is easier to process and filter than the original RF signal, improving selectivity and sensitivity in the receiver.

Thus, while beat frequency generally refers to the difference between two frequencies, in the context of a superheterodyne receiver, it specifically denotes the intermediate frequency generated during signal processing.