Distortion phenomena in a switching transistor mixer

It is shown that the nonlinear distortion generated in a switching transistor mixer may be accurately predicted by a suitable modification of an analysis which has hitherto been restricted to diode-modulator and mixer circuitry. Of particular practical importance are the 3rd-order intermodulation- and cross-modulation-distortion products produced by interaction between the local oscillator and the two input signals; these products are examined in detail. Good agreement is demonstrated between the measured and predicted levels of distortion.