Fabrication and performance of InP-based heterostructure barrier varactorsin a 250-GHz waveguide tripler

High-performance InGaAs/InAlAs/AlAs heterostructure barrier varactors (HBV' s) have been designed, fabricated, and RF tested in a 250-GHz tripler block . The devices with two barriers stacked on the same epitaxy are planar inte grated with coaxial-, coplanar-, and strip-type configurations. They exhibi t state-of-the-art capacitance voltage characteristics with a zero-bias cap acitance C-j(O) of 1 fF/mu m(2) and a capacitance ratio of 6:1, Experiments in a waveguide tripler mount show a 9.8-dBm (9.55-mW) output power for 10. 7% conversion efficiency at 247.5 GHz. This is the highest output power and efficiency reported from an HBV device at J-band (220-325 GHz).