108–316- and 220–290-GHz Ultrabroadband Distributed Frequency Doublers

An analysis and design of distributed frequency doublers is presented at millimeter-wave (mm-wave) frequencies, including the D-, G-, and H-bands. The phase condition required for coherent output summation in the distributed multipliers is analyzed to maximize the output power and bandwidth. Based on the analysis, two mm-wave distributed frequency doublers are designed and experimentally demonstrated. The first doubler combines three unit cells...