A Novel 0.1-44 GHz Linear Common-Drain-Cascode 0.15µm GaN Distributed Amplifier Architecture with Improved IP3-BW

This paper reports on a novel 0.1-44 GHz linear common-drain-Cascode (CD-Cascode) GaN distributed amplifier architecture with improved IP3-BW performance. The CD-Cascode DA MMIC is based on a 0.15μm GaN-HEMT wafer process technology. By exploiting the common-drain-Cascode as a transconductance device cell, an improvement in IP3 of 9 dB at mid-band (20GHz) and > 3 dB from 30-44 GHz were achieved as compared to a conventional Cascode DA implementation without sacrificing gain-bandwidth. The resulting amplifier achieves IP3's of 45.2, 34.5, and 33.5 dBm at 20, 40, and 44 GHz, respectively. To the author's knowledge this is believed to be the highest IP3 reported for a GaN DA at these frequencies. The amplifier obtains a nominal gain of 17 dB and maintains greater than 10 dB of gain up to 45 GHz with good input and output return-loss. The new linear CD-Cascode GaN DA MMIC architecture has far-reaching implications to linear coherent fiber optic, broadband wireless, SDR, and instrumentation applications.