High Gain and Low Noise Figure Single-to-Differential CMOS LNA for Ka-Band Communication System

This paper presents a 30GHz high gain, low-noise figure(NF)single-to-differential LNA for Ka-Band communication system. The proposed single-to-differential LNA consists of two stages. The first stage is a common source (CS) stage to reduce the noise figure and the second stage is a common source (CS)-common gate (CG) noise cancelling active balun stage to convert the single ended signal to differential mode signal. The use of active balun stage improves the gain by 16.772 dB and reverse isolation by -30.199 dB. The proposed LNA topology is designed using 0.18μm standard RF CMOS technology. The design simulated for an operating frequency of 30GHz gives an overall gain of 23.709 dB and an excellent noise figure of 0.927 dB. A bandwidth of 4.04GHz (28.11GHz-32.14GHz) is achieved and the LNA draws a current of 16.4 mA from a supply voltage of 1.8V.