A Ka-Band Front-End in 100nm GaAs Process for In-Band Full Duplex Communications

Abstract

In this study the authors introduce a Ka-band front-end to be used for in-band full-duplex (IBFD) communications. The design consists of a Rat-Race coupler to provide self-interference cancellation (SIC), a low noise amplifier (LNA), a power amplifier (PA) and an electrical balancing impedance; all implemented in 100nm low noise GaAs process provided by UMS. The circuit provided an isolation above 40 dB between the PA and the LNA. The 1 dB compression point of the transmitter at the antenna terminal is 12 dBm and the total noise Figure (NF) is better than 5 dB. The balancing impedance covers 3:1 voltage standing wave ratio (VSWR) circle in Smith chart. The chip consumes 500 mW power and has a die area of 7mm2.