MILLIMETER-WAVE FREQUENCY TRIPLING USING STACKED HETEROSTRUCTURE-BARRIER VARACTORS ON INP

Heterostructure-barrier varactors (HBVs) reported previously had limit ed power output. By using a pseudomorphic In0.52Al0.48As/AlAs/In0.52Al 0.48As barrier with good current blocking characteristics and stacking three MBE-grown varactor layers. we achieve a symmetric stacked varac tor on InP with low leakage and high breakdown voltage (similar to 14 V). Tripler experiments at Ka band using these varactors give 20 dBm o utput with 7 dB conversion loss using a waveguide multiplier: and 10.8 dBm with 11 dB conversion loss using a microstrip circuit. These are the first HBVs to demonstrate reduced device capacitance per unit area and freedom from resistive tripling effects.