A novel analytical model for small signal parameter for Separate Gate InAlAs/InGaAs DG-HEMT

This paper presents a 3-port Small Signal Equivalent circuit (SSEC) for Separate Gate InAlAs/InGaAs/InP DG-HEMT. The various small signal parameters like transconductance, drain conductance and gate to source capacitance are obtained. The effect of donor layer doping concentration (N_d), gate width (W), donor layer doping thickness (d_d) and dual gate control on the various RF performance parameter including transconductance, drain conductance, gate to source capacitance and cut-off frequency are studied. The dual gate control achieved in the DG-HEMT is observed to exhibit improved cut-off frequency. The analytical results obtained are compared with Silvaco Altas 2D device simulation results and found to be in good agreement.