A 28/39 GHz Tri-Mode Frequency-Reconfigurable LNA for Multiband 5G Communications

This brief presents a three-mode frequency re-configurable millimeter-wave low noise amplifier (LNA) in 55-nm CMOS. By employing a topology of a shared reconfigurable input matching network and two parallel amplification paths, the LNA achieves three operation modes: 28 GHz band, 39 GHz band, and concurrent mode of both bands. The on/off parasitic gate-source capacitances Cgs, the magnetic coupling of shunt gate inductor and series source inductor, and parasitic capacitance of input GSG PAD are co-designed to achieve noise and input impedance matching simultaneously. The peak gain staggered tuning technique is employed to obtain adequate power gain, bandwidth, and gain flatness in each mode. The proposed LNA achieves measured peak gains of 23.5/22.9/20 dB in three modes, with 3-dB gain bandwidths of 23.8~31.2/35.4~43.7/23.5~43.7 GHz. The measured noise figures (NF) within 3-dB gain bandwidth are 3.0~3.6 dB, 4.0~4.5 dB, and 3.7~6.1 dB. The best measured IIP3 are -14.8/-15.0/-9.1 dBm with dc power consumption of 19.8/23.6/43.4 mW in three modes, respectively.