GaAs integrated digital-to-analogue convertor for control of power dual-gate FETs

We are reporting the design, fabrication and performance of a TTL compatible 4-bit GaAs integrated digital-to-analogue convertor with an output voltage between –2.8 V and +2.8 V. This circuit has been especially designed to control the gain of power dual-gate FETs by applying a voltage on the capacitively terminated second gate.