Building the radio frequency (RF) front end to support new sub-6-GHz 5G applications is challenging. With needs for expanding infrastructure, an increase in power consumption drives the need for power efficiency while still accommodating the complexity and higher frequency range demanded in such applications. Gallium-nitride (GaN) based power amplifiers (PAs) help further this goal by maintaining high power efficiency at high data rates while supporting high frequencies and high power. Specifically, GaN high-electron-mobility transistors (HEMTs) can achieve higher efficiency, sustain higher voltages, and operate at higher switching frequencies versus other conventional transistor candidates for power amplifier topologies. Unfortunately, one issue occurring when operating GaN devices at high voltage and high frequency is a drop-off in possible output power resulting from reduced current carrying capacity. This reduction in current after the application of a high voltage swing across the drain terminal of the device is referred to as current collapse. High-speed pulsed-IV setups can replicate and measure this behavior in GaN devices and aid in parametric testing to develop and evaluate this class of semiconductor devices, and the design and testing of one is the focus of this project.

I’m participating in this SuperUROP because I seek research experience. My circuit design experience in industry and my relevant coursework hopefully serve as a useful skillset, but this is clearly an opportunity to learn more about the research process and the intersection of circuit design and nano-scale devices. I find the possibility of fabricating integrated circuits in the bleeding-edge MIT.nano prototyping lab amazing!