Autonomous Biasing Circuit for GaN RF Amplifiers

GaN Transistors offer many advantages in Power Conversion and RF Amplification applications. GaN devices are operated in enhancement mode and to avoid inrush current during power cycling, GaN devices are powered on in depletion mode by applying negative bias to Gate. Procedure of switching operating modes adds biasing complexity. This work proposes a unique add-on circuitry to automatically bias GaN transistor amplifier in RF amplifier application. The gate bias voltage is automated on application of input RF signal. Proposed circuits are simulated in LTspice. Results have yielded measurable electrical parameters which could be considered for designing an ASIC biasing semiconductor chip for GaN devices.