High-Q anti-series AlGaN/GaN high electron-mobility varactor

This paper gives a first presentation of an anti-series AlGaN/GaN high electron-mobility varactor with a tuning ratio of 4.7 and a Q factor above 100. The losses could be decreased by 30% by omitting the ohmic junctions in the signal path. The devices are characterized and a large-signal model is extracted. Comparing the anti-series varactor to a similar single varactor device shows an increased Q factor and superior linearity. The second harmonic could be decreased by 50 dB.