Design of GaN-based balanced cascode cells for wide-band distributed power amplifier

Abstract

This paper reports on the design of a cascode GaN HEMT cell dedicated to 4-18 GHz flip-chip distributed power amplifier. The active device is a 8x50 mum AlGaN/GaN HEMT grown on SiC substrate. The GaN-based die which integrates the active cascode cell and its matching elements is flip-chipped via electrical bumps onto an AIN substrate. The matching elements of the balanced cascode cell are composed of series capacitances on the gate of both transistors with additional resistances to insure stability and bias path. The series capacitor on the gate of the 1st transistor is added for the distributed amplifier optimisation while the series capacitor on the gate of the 2 nd transistor is dedicated