High-power high-efficiency SiGe Ku- and Ka-band balanced frequency doublers

High-efficiency monolithic SiGe balanced frequency doublers have been developed for Ku- and Ka-band applications. A novel miniature second harmonic reflector is presented, and the impact of the parasitic inductor from emitter to ground is also explored to optimize the conversion efficiency of the doubler. The Ku-band design presents an output power of 5-6 dBm from 15.4-18 GHz for an input power of 1.5 dBm. DC power consumption is 28 mW and the corresponding power-added efficiency (PAE) is 9.2%. The Ka-band design demonstrates an output power of 10.5 dBm at 36 GHz for an input power of 6 dBm while consuming 114 mW of dc power, which results in a PAE of 6.4%. It also shows high spectral purity operation with the fundamental suppression of 35 dB. To our knowledge, these are the best results for active doublers using any technology.