A Ka-Band LNA Base on 65nm CMOS for Communication System

Baseed on 65nm CMOS process, a low noise amplifier(LNA) was designede for Ka-band. By studying the influence of transistor size and bias voltage on noise figure and gain performance, the transistor size and bias voltage under low noise and high gain condition are determined. The transformer matching network is adopted for the input, output and inter-stage matching of LNA, which reduces the LNA size to 0.75 mm × 0.52mm and improves the circuit isolation. The test results show that the maximum in-band gain of the LNA is 18 dB, the minimum noise figure is 5 dB at 1 V supply voltage In the RF transmitter and receiver system, this LNA has a good application prospect.