题目/Title：A ΔΣ fractional-N synthesizer with customized noise shaping for WCDMA/HSDPA applications

作者/Author：
                        Xueyi Yu,Yuanfeng Sun,Woogeun Rhee,Hyung Ki Ahn,Byeong-Ha Park,Zhihua Wang

期刊/Journal：IEEE Journal of Solid-State Circuits

年份/Issue Date：2009Aug.

卷（期）及页码/Volume（No.）&pages：Vol.44, No.8, pp. 2193 - 2201

摘要/Abstract：
This paper describes a quantization noise reduction method in delta-sigma fractional-N synthesizer design based on a semidigital approach. By employing a phase shifting technique, a low power hybrid finite impulse response (FIR) filtering is realized which is suitable for RF applications. Combined with the hybrid FIR filtering, single-loop topology makes 4th-order and 5th-order delta-sigma modulators possible for the type-2 4th-order PLL. A prototype fractional-N synthesizer is implemented in 180 nm CMOS for WCDMA/HSDPA applications. Experimental results show that the proposed method can effectively suppress out-of-band phase noise to meet the phase noise mask requirements in various RFapplications.