High-efficiency heterostructure-barrier-varactor frequency triplers using AlN substrates

The effects of heat dissipation and its implications for heterostructure barrier varactor (HBV) frequency multiplier design are investigated. Although this work focuses on the HBV as a research model, the analysis is applicable, in general, to all solid-state devices and circuits. To demonstrate and evaluate the thermal analysis presented in this work, several 300 GHz HBV frequency triplers are designed, fabricated, and tested. In particular, an HBV tripler fabricated on an aluminum nitride (AlN) substrate is shown to yield state-of-the-art performance, resulting in a conversion efficiency of 8% and 9.5 mW output power at 300 GHz.