Broadband LNA with Dual-Resonance Matching Network with Capacitive Feedback for Improved Gain and Noise Figure Using 0.1-µm GaAs pHEMT Technology

This paper proposes a three-stage broadband low-noise amplifier (LNA) featuring dual resonance. In the first stage, a feedback capacitor is added between the gate and source, creating an additional resonance with the series inductor. This approach achieves broadband input matching, flat gain, and excellent noise performance. In the final stage, R-C feedback is applied to achieve both stability and wideband characteristics simultaneously. The proposed LNA was designed and fabricated using 0.1-µm GaAs pHEMT process to validate its feasibility, and its performance was verified through precise measurements. The measurement results show that the proposed LNA achieves input and output matching below -10 dB, an average NF of 2.8 dB, and an average gain of 21.2 dB across the 16–38.8 GHz frequency range. It consumes 60 mW of power at 1.2 V supply voltage and has chip size of 1.12 mm² including pads.