REDUCED VARIATION GaAs MESFETs THROUGH THE USE OF AN ON-CHIP RESISTOR
Original Publication Date: 1993-Mar-01
Included in the Prior Art Database: 2002-Jan-28
State-of-the-art RF Power Amplifier Modules used for portable communication transmitter applications use discrete, recessed gate, gallium arsenide (GaAs) MESFET devices for the driver and foal output stages as opposed to the silicon bipolar transistors used just a few years ago. Advantages of discrete recessed gate MFSFFT stmc- tures are an improvement in noise tigure, gain, and break- down voltage resulting in improved efficiency of the mod- ule and, consequently, the radio. One of the disadvantages of the recessed gate MESFET is the excessive variabil- ity of pinchoff voltage and saturated current due to the variation in channel thickness that is introduced during the recess etch process step. A method is presented here to compensate for some of that variability.