Effect of the HEMT’s Periphery to Achieve Low Recovery Time in GaN LNAs

This letter presents the effect of the periphery of the high electron mobility transistor (HEMT) on the reverse recovery time (RRT) in gallium nitride low-noise amplifiers (LNAs). A low RRT for an LNA is desirable for the receive chain, especially for radar applications. In this study, two single-stage LNAs are designed, characterized, and analyzed based on different HEMT peripheries. Both LNAs exhibit promising performance in terms of small-signal (SS), large-signal, and noise parameters. The survivability performance is analyzed after subjecting the LNAs to an input power (Pin) level of 25 dBm. Moreover, RRT measurements related to the trap-excitation phenomenon are performed. In contrast to SS nanosecond-scale RRT related to the RC time constant, the millisecond-scale dynamics are associated with traps excited at higherPinlevels. It is experimentally proven that the LNA with the bigger periphery HEMT resulted in lower trap-dependent recovery times compared to the LNA with the smaller periphery HEMT.