A Compact 28/39 GHz Dual-Band Concurrent/Band-Switching LNA for 5G Multi-Band Multi-Stream Applications

This letter presents a 28/39 GHz dual-band low noise amplifier for 5G beamforming MIMO applications. The LNA input stage leverages a compact three-winding coupling technique to achieve wideband power gain and low noise figure across both bands. Driven by two gm-boosting reconfigurable common-gate amplifiers in parallel, the wideband signals could be separated into two signal chains independently supporting one/two stream communication. Benefiting from the independent band separation feature, the LNA output stages are designed with gm-boosting active gain cell and narrow-band matching networks, attaining both high power gain and out-of-band rejection. The proposed LNA is fabricated in a 65-nm CMOS, occupying a compact core chip size of only 0.1 mm2. Measurements indicate that the proposed LNA achieves 26.3/25.5 dB peak gain, 3.6/3.8 dB minimum NF， -18.5/-16.4 dBm IIP3 in switchable mode and achieves 22.9/23 dB peak gain, 4.97/4.9 dB minimum NF， -14.7/-12.4 dBm IIP3 in concurrent mode.