A 3–50 GHz Ultra-Wideband PHEMT MMIC Balanced Frequency Doubler

A novel configuration of ultra-wideband (UWB) GaAs PHEMT monolithic microwave integrated circuit balanced frequency doubler is presented. By using two different terminal impedances of the common-source/common-gate active balun, the doubler exhibits UWB characteristic with more than a four octave frequency range. From 3 to 50 GHz, the measured conversion gain and fundamental frequency suppression of the doubler are better than -4 dB and 15 dB.