A miniaturized, broadband MMIC frequency doubler

A miniaturized, broadband balanced MMIC (monolithic microwave integrated circuit) frequency doubler, composed of a common-gate FET and a common-source FET directly connected to each drain electrode, is proposed and demonstrated. The doubler is designed and fabricated as a function module. The chip size is only 0.5 mm*0.5 mm, an area about one-tenth that of the previously reported doublers. A conversion loss of 8 dB, a fundamental frequency suppression better than 17 dB, and an input return loss better than 8 dB are obtained in the output frequency range of 6 GHz to 16 GHz. The broadband doubler as a miniaturized MMIC function module can be applicable to small-size oscillator MMICs and multifunction MMICs.<>