What is another term for the mixing of two RF signals?

'Heterodyning' is the technical term for mixing two distinct radio frequency (RF) signals together in a non-linear device to produce new frequencies. When two signals heterodyne, the output contains the original frequencies plus their mathematical sum and difference. This physical principle is the entire foundation of the 'superheterodyne' receiver, which mixes incoming signals with a local oscillator to convert them to a standard intermediate frequency. While synthesizing refers to generating a stable frequency (often using a phase-locked loop), and phase inversion flips a signal's waveform, only heterodyning describes the actual mixing of two different RF signals.