In the present paper efforts have been made to optimize InAlAs/InGaAs HEMT by enhancing the effective gate voltage ($(V_c-V_off)$) using pulsed doped structure from uniformly doped to delta doped for microwave frequency applications and reliability. The detailed design criteria to select the proper design parameters have also been discussed in detail to exclude parallel conduction without affecting the del ice performance. Then the optimized value of $V_c-V_off$and breakdown voltages corresponding to maximum value of transconductance has been obtained. These values are then used to predict the transconductance and cut-off frequency of the del ice for different channel depths and gate lengths.