Effect of the Gate Length on Terahertz Heterodyne detection Based on GaN HEMT

In this work, room-temperature terahertz heterodyne mixers based on GaN high-electron-mobility transistors are studied. For comparison, asymmetric antennas with gate lengths of L=170 nm and L=600 nm are specially designed to couple with terahertz waves ranging from 320-345 GHz, respectively. It is found that the performance of mixer for L=170 nm, such as the optical sensitivity and the conversion loss, is obviously superior to the one for L=600 nm.