A 0.55-V 25-GHz transformer-coupled frequency divider with quadrature outputs

This paper presents the design of an ultra-low-voltage (ULV) transformer-coupled (TC) frequency divider. On-chip transformers are used to cross-couple two regenerative dividers for quadrature-phase generation while achieving low-voltage, low-power and wideband operation. Implemented in a standard 0.13-mum CMOS process, the ULV-TC divider measures an input operation range of 19.2% from 22.6 GHz to 27.4 GHz and an IQ sideband rejection of 41 dB while consuming a minimum 6.8 mW from a 0.55 V power supply.