A Highly Linear Non-Magnetic GaN Circulator Based on Spatio-Temporal Modulation with an IIP3 of 56 dBm

In this work, we demonstrate a non-magnetic circulator based on spatio-temporal conductivity modulation (STCM) with cutting edge gallium nitride (GaN) high-electron mobility transistors (HEMTs). The circulator exhibits low insertion loss of -2.56 dB from transmitter (TX) to antenna (ANT) and -3.01 dB from ANT to receiver (RX). Additionally it demonstrates a maximum TX to RX isolation of 40 dB. Due to the virtues of GaN, the circulator also exhibits a record input referred third-order intercept point (IIP3) of 56.12 dBm for TX to ANT transmission. These advanced performance metrics achieved in this first demonstration point to the feasibility of GaN non-magnetic circulators that can achieve the stringent performance metrics required by DoD and commercial applications.