A Low Phase Noise, Wideband and Compact CMOS PLL for Use in a Heterodyne 802.15.3c Transceiver

A low phase noise, wideband, mm-wave, integer-N PLL that is capable of supporting an 802.15.3c heterodyne transceiver is reported. The PLL can generate 6 equally spaced tones from 43.2 GHz to 51.84 GHz, which is suitable for a heterodyne architecture with F-LO = (4/5) x F-TRX. Phase noise is measured directly at the F-LO frequency and is better than -97.5 dBc/Hz@1 MHz across the entire band. The reported frequency synthesizer is smaller, exhibits less phase noise, and consumes less power than prior art. In addition, the F-LO tone corresponds to the fundamental of the VCO as opposed to a higher harmonic. Central to the PLL performance is the design of a low-noise, wideband, mm-wave VCO with a 22.9% tuning range. Fine discrete tuning and minimization of parasitics is achieved using a programmable transmission line as a frequency tuning element.