Equivalent-circuit consideration of dual-gate MESFETs at high frequency

The simplified high-frequency equivalent circuit of a dual-gate FET is described. It is shown that the input impedance is similar to that of a single-gate FET but the output resistance and capacitance (parallel equivalent circuit) are higher. The output resistance and the transconductance decrease as frequency increases. The unilateral gain of a dual-gate FET rolls off 12 dB/octave.