A 40-GHz phase-locked loop for 60-GHz sliding-IF transceivers in 65nm CMOS

This paper presents a 40 GHz phase-locked loop as an enabling component for sliding-IF 60 GHz transceivers. The PLL front-end includes, a 40 GHz LC voltage controlled oscillator (VCO) and a quadrature injection locked frequency divider (ILFD), which are tuned simultaneously to align their tuning and locking range, respectively. The PLL back-end consists of an optimized divider chain, PFD, CP and a second-order passive loop filter integrated on chip. The PLL can be locked from 38.2 to 43.6 GHz corresponding to a down-conversion range of 57.3 to 65.4 GHz, thus covering all IEEE 802.15.3c channels. The phase noise for a 40.2 GHz output is -89.7, -94 and -112 dBc/Hz at 1 MHz, 4 MHz and 10 MHz offsets, respectively. The settling time is lower than 2μsec and reference spurs are lower than -42 dB. Implemented in a 65 nm bulk CMOS technology, the PLL consumes 22.8 mW, excluding buffers, from a 1.2 V supply and occupies 1.67 × 0.745 mm² silicon area.