High Flat Gain and Broadband Millimeter-Wave Distributed Doherty Low Noise Amplifier for 5G Applications Using GaAs-pHEMT Technology

A new structure of distributed Doherty low-noise amplifier is implemented on a GaAs pHEMT substrate, using the ED02AH process design kit tailored for 5G applications. This circuit exhibits high linear gain and a consistent noise factor across the frequency range of 22 to 42 GHz. The LNA comprises 10 cells distributed across two stages, with a performance adjustment circuit added to the source electrode of each transistor. Operating with a V GS = –0.15 V and V DS = 1.8 V bias, the LNA delivers an S 21 gain of 22.5 ± 2.5 dB and noise figure of 3 ± 0.55 dB, consuming 980 mW of power. The linear performance of the LNA is affirmed by an input 1 dB compression point (IP 1dB ) of 11 dBm and a third-order input intercept point (IIP3) of 13 dBm. With a surface area of 2.9 × 1.2 mm 2 , the LNA has a figure of merit of 73.14, demonstrating the high efficiency of the proposed Doherty distributed structure.