0.24 W F-Band Heterostructure Barrier Varactor Frequency Tripler

We have designed, grown, fabricated and characterized a 111 GHz frequency tripler. An AlAs/InAlAs/InGaAs heterostructure barrier varactor (HBV) was used as the nonlinear device for generating higher order harmonics. Four mesas were connected which amounted to a total of twelve barriers in series. This multiplier design was optimized for high output power using an aluminium nitride substrate for improved heat dispersion. The tripler consisted of an HBV device flip-chip soldered onto the AlN microstrip circuit and mounted in a waveguide block. No movable tuners were used for the characterization of the tripler. We measured a maximum output power of 0.24 W with a 6% bandwidth and 20% conversion efficiency. These state-of-the-art results constitute a marked improvement of HBV-based multiplier performance