A 22-30 GHz Single-Ended-To-Differential LNA Using Double Defected Ground Marchand Balun

In this paper, a 2-stage Ka-band single-ended-to differential LNA design is presented. Common source configuration with inductive degeneration is used for input stage to optimize noise Figure (NF) and input matching. The output stage with capacitive cross-coupling neutralization technique help to improve gain and reverse isolation for increasing stability. For the 1-st time, a double defected ground Marchand balun is implemented to convert single-ended signal to differential signal. The proposed LNA uses 2S-nm CMOS technology from TSMC and shows a typical NF below 3.9 dB, a 22.5 dB gain peak, a small amplitude and phase imbalance in the bandwidth from 22 to 30 GHz. The LNA has the die dimension of 764 |1mx50511m including test pads and consumes 25 mW from a supply voltage of 0.9 V.