Transient thermal analysis of GaN HEMT under TDD-LTE signal operation

In this paper, we evaluate a transient temperature of a GaN HEMT amplifier under TDD-LTE signal operation. We extract thermal circuit parameters with which the transient temperature can be simulated under modulated signal operation. Overall, the surface temperature of the GaN HEMT was almost consistent with the temperature at steady state under continuous dissipation of the average power. At a time of switching between downlink and uplink, the temperature is observed to suddenly change. Furthermore, we confirm that the temperature does not follow the instantaneous power change due to the modulated signal both in measurement and in simulation. Therefore, we can conclude that our methodology is effective for temperature estimation of the GaN HEMT under high-speed modulation signal operation such as TDD-LTE.