Experimental Validation of ASM-HEMT Nonlinear Embedding Modeling of GaN HEMTs at X-band

This paper presents the experimental results from a validation of a newly-developed nonlinear embedding model for the GaN ASM-HEMT model. An extracted ASM-HEMT model was used together with the nonlinear embedding model to synthesize on-wafer Class F operation at 10 GHz for a 150 nm 1W GaN HEMT. The embedding model provided a set of multi-harmonic terminations at the transistor's source and load, which were then applied to the physical transistor in an experimental setup. The transistor's performance with only the predicted load termination at the fundamental is compared with its Class F performance when terminated at the predicted fundamental, second, and third harmonic load terminations, as well as second harmonic source termination. A phase sweep of each harmonic termination is further used to verify that the terminations predicted by the embedding model are optimal. The transistor's PAE when terminated with the embedding model's predicted terminations reaches 71%, in dose agreement to the model's PAE prediction at peak power.