Design of a current controlling circuit integrated with a power amplifier in gallium nitride process

There is an increasing demand for the gallium nitride-based power amplifiers for different applications. A current controlling circuit integrated with the power amplifier on the same chip is proposed in this paper, for the purpose of monitoring the reliable operation of the power amplifier. The designed broadband differential amplifier, which is the important building block of the controlling circuit, has a gain of 43 dB and a bandwidth up to 0.1 GHz. The amplifier is operated from a ± 28 V supply which results in a higher peak-to-peak swing than a CMOS based design.