W-band AlGaN/GaN MMIC PA with 3.1W output power

A balanced four-stage W-band GaN MMIC PA with Lange couplers and micro-strips matching elements is reported. Electron-beam lithography has been used to produce a 100 nm T-shaped gate on the AlGaN/GaN HEMT structure with ultrahigh aluminum content. The MMIC PA offers a small signal gain of greater than 18 dB and an output power of greater than 2.5W from 88GHz to 93GHz with an associated power gain of greater than 15 dB. Moreover, it achieves a peak output power of 3.1W (34.9dBm) at 91GHz in continuous-wave mode, with an associated power density of 3.23W/mm. Most notably, it is the first time that the peak output power and power density exceed 3W and 3W/mm in AlGaN/GaN HEMT at W-band simultaneously.