A 10.8–14.5-GHz Eight-Phase 12.5%-Duty-Cycle Nonoverlapping LO Generator With Automatic Phase-and-Duty-Cycle Calibration

A 10.8–14.5-GHz eight-phase 12.5%-duty-cycle nonoverlapping LO generator is proposed for 60-GHz eight-path-filtering subsampling receivers. A four-stage ring oscillator (RO) is followed by reconfigurable injection-locked-oscillator nor gates to generate eight-phase 12.5%-duty-cycle signals featuring automatic successive phase calibration and automatic frequency-domain duty-cycle calibration. The generator prototype measures minimum phase errors of <tex-math notation="LaTeX">~</tex-math> 0.1 <tex-math notation="LaTeX">∘</tex-math> and maximum fourth-harmonic output power of <tex-math notation="LaTeX">$-$</tex-math> 5 dBm with <tex-math notation="LaTeX">$>$</tex-math> 30-dB improvement while consuming 77.8 mW from a 1-V supply over the entire frequency tuning range from 10.8 to 14.5 GHz.