18-44GHz K/Ka-band Robust-35.5dBm Reconfigurable 90nm GaN HEMT LNA

This paper describes the design and measured performance of a robust millimeter-wave reconfigurable low noise MMIC amplifier based on a 90nm T-gate GaN technology. The GaN technology is characterized by a peak fT of 145 GHz, an NF min of <1.2dB up to 50GHz, and a FET Switch FOM of −900GHz. The 3-bit reconfigurable LNA was designed for tunable performance over the 18-44GHz octave-plus operating band encompassing the 5G mmW wireless frequencies. Under optimized high-band gain and low NF setting, the amplifier achieves gains of 24.2, 23, 21, 18, and 14.3dB and NF's of 1.9, 1.5, 1.6, 2.1, and 2.5dB at 18, 24, 28, 39, and 44GHz, respectively. Under an input IP3 linearity optimized setting and bias, the LNA achieves an input IP3 greater than −1.7dBm across the full band. The amplifier survives a CW RF step stress up to 35.5 dBm with no significant broadband S-parameter degradation. The robust and reconfigurable capabilities are attractive for adaptive EW, radar, as well as future commercial mmW communication systems.