●●● ●●●● ●●●● ●●●● ●●●● ●●●● A mixer is a three-port device,that uses a nonlinearor time-varying element to achieve frequency conversion. Filter must be used to select the desired frequency. 7.1 Mixer characteristics §7.2 Diode mixers §7.3 FET mixers 3A mixer is a three-port device, that uses a nonlinear or time-varying element to achieve frequency conversion. Filter must be used to select the desired frequency. §7.1 Mixer characteristics §7.2 Diode mixers §7.3 FET mixers 3