Buried Gate MESFET with Frequency Dependence Transconductance Characteristic

Analytical model for transconductance ac characteristic of buried-gate GaAs MESFET has obtained by solving continuity equation. When optical fiber is inserted into the active layer of buried-gate GaAs MESFET, the modulated light with frequency is 0.1GHz and Photon absorption coefficient (α) = 1.0x106 m-1 are applied to the buried gate GaAs MESFET through the optical fiber without any deviation. The drain current has calculated from that transconductance is noted. Drain-source current has calculated from the mobility of carriers and absorption coefficient of light. The mobility of the carrier controls the transconductance. The number of holes crossing the Schottky junction calculates the photo voltage. The transconductance and photo voltage characteristic indicate very good performance of the device compared to other devices like MESFET under back illumination and MESFET with front illumination having surface gate. It is highly use full in the nanotechnology and high-speed device.