A compact X-band balanced frequency doubler on GaAs pHEMT 3D MMIC

A compact GaAs pHEMT monolithic microwave integrated circuit balanced frequency doubler is presented. It is composed of a common-source/common-gate active balun, a balanced frequency doubler, and a band pass filter. Excellent miniaturization is achieved by using double-and triple-layer stacked inductors and a miniaturized stub as a band-pass filter with a thin-film microstrip line. The chip size is only 0.95 mm × 1.05 mm and power consumption is 63 mW. The measured conversion gain is -4 dB, and the fundamental and 3rd order frequency leakage to the 2nd order harmonic signal are less than -25 dB and -35 dB respectively.