Novel High-Speed Linear Gan Technology With High Efficiency

We report the first demonstration of graded-channel GaN HEMTs operating in the millimeter-wave frequency range. At 30 GHz, these graded-channel GaN HEMTs demonstrated excellent PAE of 65% at an associated power density of 3 W/mm. The measured PAE and output power density show great improvement over other mm-wave T-gated AlGaN/GaN HEMT devices. Under two-tone linearity characterization at 30 GHz, PAE of about 50% was demonstrated with C/IM3 of 30 dBc, which is very promising for mm-wave linear and efficient amplifiers without digital pre-distortion.