Low phase-noise 5 GHz AlGaN/GaN HEMT oscillator integrated with Ba/sub x/Sr/sub 1-x/TiO/sub 3/ thin films

摘要

A C-band MMIC oscillator in GaN HEMT technology with Ba/sub x/Sr/sub 1-x/TiO/sub 3/ (BST) film capacitors integrated as DC block capacitors has been designed, fabricated and characterized. The lumped LC resonator works with the common gate HEMT to generate negative resistance. The oscillator, based on AlGaN/GaN HEMT with 0.7/spl mu/m gate length and 200/spl mu/m gate width, delivers 20.5 dBm output power when bias at V/sub ds/ = 15 V and V/sub gs/ = -3 V, with dc-to-RF efficiency of 12.5%. Phase noise was measured to be -105 dBc/Hz at 100 KHz offset from 5.3 GHz carrier. The results show that AlGaN/GaN HEMTs are attractive to both high power and low noise microwave source application.