AMPLITUDE AND PHASE MODULATIONS IN RESISTIVE DIODE MIXERS

This paper presents some new aspects of mixer operation and shows that the behavior of a mixer, using a resistive diode, can in general be represented by means of an equivalent circuit consisting of two transducers connected in cascade. The first of these two transducers transforms the input signals into amplitude modulations; the second is an AM detector which transforms these amplitude modulations into output signals. An important feature of this equivalent circuit is that it gives the dependence of the conversion loss upon certain important mixer parameters. We also show that extremely low (< 0.3 dB) conversion losses can be achieved from a Schottky barrier diode, if the pump frequency wo is much smaller than the cutoff frequency of the diode. To achieve such low conversion losses the diode must be open‐circuited, at the harmonics 2wo, 3wo, 4wo, and so on, of the pump frequency. © 1969 The Bell System Technical Journal