Switch Integrated Ka-Band Low Noise Amplifier in GaN/AlN HEMT Technology

This paper presents low noise amplifiers (LNA) with integrated DC and RF switching features for multifunctional single chip RF front end (RFFE) applications. Two 28–32 GHz LNAs, with and without integrated switch, are fabricated using 150 nm GaN/AlN HEMT technology. An innovative approach of RF switch integration in the LNA is reported promising compact switch integrated LNA chips. The integrated DC supply switch turns off the DC supply of the idle LNA in the transmit mode of half-duplex operation. The measured LNA without switch demonstrates S21 of 15.8–16.3 dB, noise figure less than 3.6 dB, OP1dB of 12.8 dBm and OIP3 of 25 dBm. In the receive mode, the switch integrated LNA shows S21 of 12.5–13.7 dB, noise figure less than 4.8 dB, OP1dB of 12.5 dBm and OIP3 of 25.8 dBm. In the transmit mode, the LNA bias current sinks from mA- to µA-range and the small-signal performance having S11 higher than 3 dB and S21 less than −35 dB indicates the switch integrated−LNA befitting for RFFEs.