A Double-Balanced Quadrature-Input Quadrature-Output Regenerative Frequency Divider for UWB Synthesizer Applications

This paper presents the design and analysis of a proposed double-balanced quadrature-input quadrature-output (QIQO) regenerative divider for ultra-wideband (UWB) synthesizer applications. By fully utilizing the quadrature phase outputs already existed in a quadrature voltage-controlled oscillator (QVCO) or any other quadrature signal generator (QSG), the proposed QIQO divider provides a mechanism to achieve an output IQ phase sequence that is inherently tracked with the input IQ phase sequence. Moreover, compared with conventional dividers, the QIQO divider provides not only smaller and better-matched input loading to the QSG but also improved quadrature phase accuracy, wider operation range, smaller third harmonics, and lower power consumption. Fabricated in a 0.18-mum CMOS process, the QIQO divider measures an image rejection of -62dBc with a frequency operation range of larger than 18.4% from 8.6 GHz to 10.34 GHz while consuming 7.2 mW at 0.9-V supply.