A Ka-band High Gain Wideband Low Noise Amplifier in $.18-\mu \mathrm{m}\ \text{SiGe}$ BiCMOS

This paper presents a design approach for Ka-band low noise amplifier (LNA) with both high gain and wide bandwidth. With a five-stage cascode structure, emitter degeneration is used in the first stage to implement the simultaneous power and noise matching and positive-feedback network is adopted to enhance the gain in the next four stages. By using stagger tuning technique, wide bandwidth can be achieved. For demonstration, a Ka-band LNA is designed and fabricated in a 0.18 $\boldsymbol{\mu}\mathbf{m}\ \mathbf{SiGe}$ BiCMOS process. It achieves a 3-dB bandwidth from 31.6 GHz to 38.2 GHz with a maximum gain of 42.9 dB. The circuit operates from a 2.5 V supply with a DC power consumption of 60 mW.