GaAs FET Oscillator is designed and fabricated. The fabricated MESFET with 1μm gate length and 200μm gate width has the maximum extrinsic transconductance of 13.8mS and the current density of 44.96mA at zero gate bias condition.
A method of study is that the basic theory of oscillator is studied, and applied to linear and nonlinear simulation. Finally, the design of oscillator is completed by simulating the microwave spice. The parameter values of oscillator are approximated to real values. The designed oscillation frequency is 2.5GHz ∼ 3.0GHz, and output power is 0∼2dBm.
The fabrication of oscillator using MMIC is completed and measured. Measurement of oscillator using jig and spectrum analyzer is executed. Oscillation frequency is 4.5GHz ~ 4.8GHz, and output power is -35dBm. The loss of microstrip line is large. Therefore, output power is very low. Second harmonic is 22dBc.
The fabrication of Reactive Ion Beam Etching (RIBE) is completed. Etching rate of GaAs is 1000$\mbox{\AA}$/min, and uniformity is less than ±5%.
