High-performance 450-GHz GaAs-based heterostructure barrier varactor tripler

In this letter, we report on the record performance of GaAs-based heterostructure barrier varactors (HBVs) in tripler circuits. Both fabrication technique of planar Al/sub 0.7/Ga/sub 0.3/As/GaAs heterostructure barrier varactors (HBVs) and measurements of a corresponding tripler circuit are presented. Planar transmission lines on a thin dielectric membrane and flip-chip technique without air bridges provide reduced parasitic losses and, hence, higher tripler efficiency. Frequency tripler measurements have shown more than 1 mW at 450 GHz.