A 13.7-41 GHz Ultra-wideband Frequency Doubler with Cross-coupled Push-push Structure Achieving 10.6% Peak Efficiency and 7-dBm Psat

This paper presents a 13.7-41 GHz frequency doubler with high conversion gain and efficiency. A cross-coupled push-push structure is proposed to extend the bandwidth and increase the high-frequency output power. In addition, an output-matching network based on the coupled inductor is adopted to further extend the bandwidth to low frequencies. Fabricated in a 40nm CMOS process, the proposed frequency doubler achieves a 3-dB bandwidth of 27.3 GHz (fractional bandwidth of 99.8 %) and a peak conversion gain of -2.7 dB at an input power of 3 dBm. The measured saturated output power is 7 dBm and the measured peak power-added efficiency is 10.6%. Across the entire bandwidth, the fundamental harmonic rejection ratio and the third harmonic rejection ratio are greater than 21.3 dBc and 35.6 dBc, respectively. The maximum DC power consumption is 24 mW, and the core area is 0.3x0.4 mm2.