A mixer is a core passive or active component widely used in RF, microwave communication and radar systems.
It leverages nonlinear devices to complete spectrum conversion of two signals with different frequencies. When radio frequency (RF) signal and local oscillator (LO) signal are fed into the mixer, frequency components including sum frequency and difference frequency will be generated.
A subsequent filter removes unwanted frequency components and retains the required intermediate frequency (IF) signal.
Mixers are classified into passive diode mixers and active transistor mixers by structure, or up-conversion mixers and down-conversion mixers by function.
They are essential building blocks for transceivers, phased array T/R modules, Ku-band radars and broadband wireless transmission equipment, realizing frequency conversion and spectrum shifting.
Key performance parameters include insertion loss, isolation, conversion loss and linearity.