A 70-97 GHz Low Noise Amplifier with 24.6 dB Peak Gain Using 0.1 μm GaAs pHEMT Process

This paper presents a W-band four-stage common source topology low noise amplifier (LNA) fabricated in GaAs 0.1 μm pHEMT technology. Inductor adopted between the source of the first stage and ground improves stability and tunes impedance, meanwhile reaches noise matching and impedance matching. Four-stage peak staggering matching is used to achieve broadband impedance matching, and the in-band gain fluctuation is reduced. The LNA demonstrates measured typical small signal gain of 23.1 dB with a 3-dB band from 70 - 97 GHz (32.3%), covering 77 GHz and 94 GHz radar frequencies. The simulated NF is 4.8 - 5.6 dB over 70 - 97 GHz which reaches the minimum at 86 GHz . The scale of the chip is 1.68 × 0.89 mm² including all pads. The results prove the designed amplifier reaches competitive performance of gain, working bandwidth and noise behavior.