Some observations on parametric action in transistor mixers

Experimental results are presented for the type 2N502 micro-alloy graded-base transistor, which show the significance of parametric amplification at the collector-base diode in addition to normal mixing at the emitter-base diode. The latter is primarily due to the resistive non-linearity at the emitter, the parametric action at the collector being due to the non-linear junction capacitance.