Method for measuring source resistance R/sub s/ in saturation region of GaN HEMT device over bias conditions (V/sub gs/,V/sub ds/)

To accurately model distortion effects using a large signal model the variation of all the elements of the equivalent circuit model under bias conditions are required. A technique is presented to extract the source resistance R/sub s/ under bias conditions for the aluminium gallium nitride/gallium nitride (AlGaN/GaN) HEMT. The source resistance R/sub s/ is found to decrease as V/sub gs/ is increased, implying that the conduction channel becomes wider, which indicates a parallel conduction path to the 2D electron-gas.