Design of a low-noise amplifier for ka-band phased array receivers

To achieve broadband noise matching, efficient interstage transmission, and output impedance co-optimization for Ka-band phased array receiver low-noise amplifiers (LNA), while addressing the multi-stage matching adaptability challenge of commercial broadband chips in millimeter-wave frequencies. Based on the Mini-Circuits AVA-0233LN+ chip, this paper proposes a solution utilizing ladder-shaped microstrip lines and fan-shaped microstrip lines for noise matching and conjugate matching. Within the 17–22 GHz frequency range, the ladder-shaped microstrip configuration achieves a 21.2% reduction in noise figure compared to conventional stepped-impedance matching approaches, demonstrating superior noise suppression capabilities while maintaining broadband impedance matching characteristics critical for Ka-band phased array applications. Through parameter optimization in ADS combined with K-factor stability analysis, we designed a Ka-band phased array receiver LNA using Rogers Duroid5880 substrate. The implemented LNA demonstrates a gain flatness of 31.0dB-32.8 dB across the target frequency band, with noise figure optimized to 2.07dB-2.65 dB.