| This dissertation discusses the use of high frequency modeling techniques for the design of planar HBV frequency multipliers at millimeter and sub-millimeter wave wavelengths. The goal of this research was to understand the HBV frequency multiplying, and to develop a methodology to design HBV frequency multipliers for optimum performance. In particular, the design and testing of a series of 300 GHz HBV frequency triplers and a series of 200 GHz HBV frequency quintuplers are covered in this dissertation. The 300 GHz HBV frequency triplers yield 8% conversion efficiency and 9.5 mW output power. 5.2% conversion efficiency and 5.2 mW output power were measured from the 210 GHz HBV frequency quintuplers. These results represent state-of-the-art performance for planar varactor frequency multipliers.; For the first time, a detailed thermal analysis has been performed to aid HBV frequency multiplier design. Furthermore, the thermal analysis has helped to improve the HBV frequency multiplier performance.; In addition to the success of the HBV frequency tripler design, also for the first time, varactor frequency quintuplers with the performance comparable to frequency triplers have been designed, fabricated, and tested. This result proves the statement that higher-order varactor multipliers can exhibit nearly the same conversion efficiency as lower-order multipliers, such as doublers and triplers, when compared on the basis of the same ratio of output frequency to cutoff frequency. Furthermore, the performance of HBV multipliers can be improved by using smaller devices, which can be obtained by switching from wet-etching to dry-etching during the HBV device fabrication process.; In conclusion, this dissertation has demonstrated that with accurate modeling and appropriate design methodology, it is possible to design and build optimized HBV frequency multipliers at millimeter wavelengths. The symmetric C-V characteristic of the HBV device makes it a more attractive choice than Schottky varactors for high order frequency multipliers, such as frequency triplers, quintuplers, or higher order frequency multipliers. |
