Towards the determination of GaN HEMT large signal model parameters by Time Domain Reflectometry method

In this paper we report a development of the large signal model parameters extraction technique for gallium nitride (GaN) high electron mobility transistors (HEMT) from transient characteristics. An approach to nonlinear large-signal model parameter extraction of intrinsic model parameters namely capacitors C_GS, C_DS and C_GD and extrinsic resistance R_GS and R_DS has been investigated. The extraction procedure is based on electronic circuit parametric simulation of the transient characteristics of the investigated equivalent circuit and evaluation of corresponding RC time constants. This technique is improved using appropriate polarity of the input pulses in dual-head Time Domain Reflectometry (TDR) system, configured also for Time Domain Transmission (TDT) measurements.