A novel 0.72–6.2GHz continuously-tunable ΔΣ fractional-N frequency synthesizer

This paper presents a wideband ΔΣ-based fractional-N synthesizer with three integrated quadrature VCOs for multiple-input multiple-output (MIMO) wireless communication applications. It continuously covers a wide range frequency from 0.72 GHz to 6.2 GHz that is suitable for multiple communication standards. The synthesizer is designed in 0.13-μm RF CMOS process. The dual clock full differential multi-modulus divide (MMD) with low power consumption can operate over 9 GHz under the worst condition. In the whole range frequency from 0.72 GHz to 6.2 GHz, the maximal tuning range of the QVCOs reaches 33.09% and their phase noise is -119 dB/Hz~-124 dB/Hz @1 MHz. Its current is less than 12 mA at a 1.2 V voltage supply when it operates at the highest frequency of 6.2 GHz.