Two heterostructure barrier varactor (HBV) frequency multipliers, a 300 GHz tripler and a 210 GHz quintupler, are designed, fabricated, and tested. The frequency tripler is fabricated with integrated technology, and the quintupler uses flip-chip mounted HBV diodes. The 210 GHz frequency quintupler shows record output power and efficiency. Moreover, the agreement between the simulation and measurement results validates our design methodology. The frequency tripler exhibits a measured output power of 4 mW and efficiency of 5% at 300 GHz. The 210 GHz frequency quintupler also achieves 5% conversion efficiency with 100 mW of input power. With an input E-H tuner, it can provide over 2 mW output power with over 10% bandwidth.
Design, modeling and testing of these frequency multipliers are described and presented in this paper. Some possible methods to improve these frequency multipliers are addressed.