High Performance GaAs RF Switch with a P-Type Capping Layer

摘要

Due to its low insertion loss and the high linearity, the Junction Pseudomorphic High Electron Mobility Transistor (JPHEMT) is widely used for RF switches in wireless communications. In this paper, we describe a JPHEMT with a p-type capping layer from the gate to source/drain regions for improving the off-state characteristics. The device parameters of the p-layer are optimized using device simulation technology to enhance the off-state characteristics. It has been demonstrated that gate-source breakdown voltage (BVgs) is 11 V higher, off-state capacitance (Coff) is 25% lower, the power handling capability is better and the 3rd harmonic distortion is 6 dB lower than those of the conventional JPHEMT. The obtained Ron*Coff product of < 160 fsec is very favorable compared with RF switches based upon conventional JPHEMT, silicon-on-insulator (SOI), and silicon-on-sapphire (SOS) technologies.