Near-Junction Thermal Management of GaN-on-SiC MMIC Power Amplifier Through Substrate Embedded Microchannel
Dichen Lu, Yuxin Ye, Ruiwen Liu, Mei Wu, Xiangbin Du, Lihang Yu, Jingping Qiao, Ziyu Liu, Yanmei Kong, Binbin Jiao, Xiaohua Ma, Yue Hao
Abstract
Self-heating inhibits the electrical characteristics improvement of GaN devices. The local hotspots generated in the gate region significantly affect the output performance of GaN devices. This study proposes a near-junction cooling technique for the thermal regulation of a GaN-on-SiC monolithic microwave integrated circuit power amplifier (MMIC PA). An embedded microchannel structure is integrated into the GaN-on-SiC high-electron-mobility transistor (HEMT) substrate. The dc characteristic curve of the actual HEMT reveals that the designed embedded cooling microchannel induces a 22.32% increase in saturation current and an 11.74% enhancement in device transfer characteristics and effectively mitigates the impact of device heat on dc output properties. The microchannel design of a single HEMT model is applied to design the characteristic parameters of the MMIC PA. Embedded cooling can effectively eliminate the thermal coupling between two HEMTs on MMIC PA at a certain distance. Consequently, the implementation of embedded cooling in the thermal management of high-power MMIC PAs markedly augments the output performance. This is an effective and innovative method for the thermal management of high-power amplifiers.