Publication Details
Rana ElKashlan, Rana Yasser ElKashlan, Ahmad Khaled, Raul Rodriguez, Vamsi Putcha, Uthayasankaran Peralagu, AliReza Alian, Nadine Collaert, Nadine Collaert, Piet Wambacq, Bertrand Parvais

2021 16th European Microwave Integrated Circuits Conference (EuMIC)

Contribution To Book Anthology


We investigate the effect of varying the gate-to-drain spacing and the gate field-plate on the device linearity of GaN HEMTs on Si for 0.11µm, 0.15µm, and 0.19µm gate lengths. The gain compression, phase distortion, and harmonic distortion metrics are measured using a nonlinear characterisation setup calibrated at 6GHz up to the third harmonic. The acquired nonlinearity metrics are correlated with the extrinsic device parasitics extracted from S-parameter measurements. We observe that excessive gate field-plate length scaling down to 0.05µm lowers the total phase distortion at the expense of gain linearity and harmonic distortion in Class AB while minimising the gate-to-drain spacing alleviates the harmonic distortion only for devices of 0.19µm gate length. Further evaluation, under matched conditions, using a passive load-pull measurement setup points to a decline in the peak achievable PAE and PSAT at gate field-plates smaller than 0.12µm.

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