Answer Happy

4) Assume a thin film MESFET Pinch off voltage, Vp, is given buy IND V = (, ) a? (4) Where a is the depletion width (W) required to completely deplete the conducting channel of the device. For a thin film MESFET, a would be equal to the thin film thickness t for a normally on thin film MESFET with gate length L as shown in Fig. (2). - -Hil Source Gate Drain Ohmic Ohmic Schottky n-type GaAs L Semi insulating substrate Figure 2: Thin film MESFET t 个 Assume all data was generates from this MESFET wafer which is known to have an epilayer thickness of t = 0.2um. VG - Vbi 21-VG - Vbi) Ipsat Vp 3 Vp losar = cov, MW)"+1 13

ID (VD) = G. Vp = **3--09 21-(VG - Vbi)/2 + Vp Vp - (VG - Vbi) Vp and 2 a z GE ρι Assuming the Z/L ratio is 50, determine, for a zero gate bias: Vp; Go; Ipsat and Vpsat 5) If the gate length for the above MESFET is L = 2um, what is the gate capacitance of this MESFET.