Abstract: A double balanced modulator-demodulator consisting of two pairs of field ect transistors. A field effect transistor is connected in series between the source electrodes of each of the field effect transistor pairs. The field effect transistors making up each pair are biased so that they operate in the saturated mode. Each of the transistors connected between the source electrodes of the transistor pairs are biased to operate in the linear mode such that drain current varies linearly with drain voltage. A first input signal is connected across the gate electrodes of the transistor pairs while a second input signal is connected across the gate electrodes of the connecting transistors. Bias for each of the transistor pairs is provided by means of a field effect transistor connected between the source electrodes of the transistor pairs and ground. The gates and source electrodes of transistors forming the bias circuit are connected to ground.