AlGaN/GaN High Electron Mobility Transistor Amplifier for High-Temperature Operation

This paper presents a high gain voltage amplifier based on AlGaN/GaN metal-insulator-semiconductor high-electron-mobility transistors (MIS-HEMTs) with monolithically integrated enhancement-mode (E-mode) and depletion-mode (D-mode) devices. The GaN amplifier consists of differential pair based on E-mode devices, active loads based on D-mode devices and a current source, and the influence of the current source on voltage gain was evaluated. The proposed amplifier demonstrates a high gain and high unity-gain frequency at both room temperature (25 °C) and high-temperature (250 °C). The gain is 37.4 dB at room temperature, slightly decreasing to 32.7 dB when the temperature rises to 250 °C. Moreover, the power consumption reported in this work is decreased to 60 mW by reducing the static current, and the chip area of this work is reduced to $2.806{\times 10^{5}\mu {\mathrm { m^{2}}}}$ . These results indicate that the proposed amplifier is suitable for small signal sensing or driving circuits, which would promise high power density for GaN-on-Si integration circuits with high-temperature operation.