Microwave Characterization of an Optically Controlled High Electron Mobility Transistor

Abstract

The effect of optical illumination on the microwave characteristics of a conventional HEMT has been studied theoretically. The paper describes an integral approach to the problem which includes the calculation of the capacitance and the sheet concentration of the 2-D electron gas in the illuminated condition. The Y-parameters of the device under direct optical control at microwave frequencies have been calculated by considering the changes in the various intrinsic parameters of the device under illuminated condition. The lumped circuit model of the device in the illuminated condition has been obtained with the various components determined from the Y-parameters. The attractive feature of the present model is that it is fully compatible with commonly used circuit simulation packages like SPICE.

Indexing terms:

• HEMT
• Microwave characterization
• Optical effect