A 23.4 mW -72-dBc Reference Spur 40 GHz CMOS PLL Featuring a Spur-Compensation Phase Detector

This letter introduces a novel phase detector (PD) for suppressing the reference spur in a 40 GHz integer-N phase-locked loop (PLL). Coined as a spur-compensation phase detector (SCPD), the proposed SCPD duplicates itself to an auxiliary path for an edge-combined phase alignment, such that the spurs generated by the two paths mutually compensate for each other, achieving a net effect of spur canceling. Implemented in a 40-nm CMOS technology, the proposed PLL shows less than -71.4-dBc reference spur, -98- and -117-dBc/Hz phase noise at 1- and 10-MHz offset, respectively, and a minimum rms jitter of 114 fs (10 k-100 MHz). It consumes 23.4-mW power from a 1.1-V power supply, leading to a figure of merit (FoM) of -245 dB.