A 91.9–113.2GHz Compact Frequency Tripler with 44.6dBc Peak Fundamental Harmonic-Rejection-Ratio Using Embedded Notch-Filters and Area-Efficient Matching Network in 65nm CMOS

This article presents a W-band mixer-based frequency tripler. The folded four-coil transformer is proposed to achieve the input matching and input power distribution to the push-push frequency doubler and the mixer simultaneously. The mixer mixes the second-harmonic current with the input fundamental harmonic to obtain the third harmonic. A single-stage class-AB amplifier follows to drive the output load. The fundamental harmonic notch-filters composed of parallel inductor and capacitance tanks are embedded into the interstage and output matching networks to save the chip area and improve the harmonic-rejection-ratio (HRR). The proposed frequency tripler has been fabricated in 65nm CMOS process with a 160 µm × 420 µm core chip area. Measurement results show a conversion gain of -2.35 dB, a 44.6 dBc peak fundamental HRR and a 3.88% DC-RF efficiency for an input power of 6 dBm at 102 GHz. The measured output 3 dB bandwidth is 91.9–113.2 GHz.