Title :
A 3∼5-GHz low-phase-noise fractional-N frequency synthesizer with AFC for GSM/PCS/DCS/WCDMA tranceivers
Author :
Pan, Yaohua ; Huang, Yumei ; Hong, Zhiliang
Author_Institution :
State Key Lab. of ASIC & Syst., Fudan Univ., Shanghai, China
fDate :
Nov. 30 2011-Dec. 2 2011
Abstract :
A low-phase-noise Σ-Δ fractional-N frequency synthesizer for GSM/PCS/DCS/WCDMA transceivers is presented. The voltage controlled oscillator (VCO) is designed with modified digital controlled capacitor array (DCCA) to extend tuning range and minimize phase noise. A high-resolution adaptive frequency calibration (AFC) technique is proposed to choose frequency bands automatically in short time and increase phase noise immunity. A prototype is implemented in 0.13 μm CMOS technology. Experimental results show that the designed 1.2V wideband frequency synthesizer is locked from 3.05GHz to 5.17GHz within 30μs (20ppm), including 8μs AFC time. The measured in-band phase noise is -95.5 and -101dBc/Hz for 1.955GHz and 948MHz carriers, respectively, and accordingly the out-of-band phase noise is -123, -132dBc/Hz at 1MHz offset, and the reference spur is less than -69dBc.
Keywords :
CMOS integrated circuits; cellular radio; frequency multipliers; frequency synthesizers; phase noise; voltage-controlled oscillators; AFC technique; CMOS technology; DCCA; DCS tranceivers; GSM tranceivers; PCS tranceivers; VCO; WCDMA tranceivers; digital controlled capacitor array; frequency 1.955 GHz; frequency 3 GHz to 5.17 GHz; frequency 948 MHz; high-resolution adaptive frequency calibration; in-band phase noise; low-phase-noise Σ-Δ fractional-N frequency synthesizer; low-phase-noise fractional-N frequency synthesizer; out-of-band phase noise; phase noise immunity; phase noise minimization; size 0.13 mum; time 8 mus; voltage controlled oscillator; wideband frequency synthesizer; Frequency control; Frequency synthesizers; GSM; Multiaccess communication; Phase noise; Spread spectrum communication; Voltage-controlled oscillators; AFC; DCCA; Phase-locked loop (PLL); VCO; loop stability analysis; phase noise;
Conference_Titel :
Radio-Frequency Integration Technology (RFIT), 2011 IEEE International Symposium on
Conference_Location :
Beijing
Print_ISBN :
978-1-4577-0517-5
DOI :
10.1109/RFIT.2011.6141801
