A fractional-N synthesizer for multi-mode positioning system with constant loop bandwidth

Author

Feng, Yan ; Chen, Guican

Author_Institution

Dept. of Microelectron., Xian Jiaotong Univ., Xian, China

fYear

2011

fDate

17-18 Nov. 2011

Firstpage

1

Lastpage

2

Abstract

A fractional-N frequency synthesizer with constant loop bandwidth is presented. This synthesizer can be applied to the multi-mode positioning receiver with seven modes in three positioning systems. In all seven modes it has constant loop bandwidth and can work stably by using the improved adjusting method in charge pump biasing current and the linear varactor in VCO (voltage-controlled oscillator). Simulations show that this synthesizer meets the requirements of high performance receiver. For each mode, the in-band and out-of-band phase noises are not lager than -95dBC/Hz and -119dBC/Hz@1MHz, respectively. The variation of normalized I_cpK_vco/wvco in seven modes is in the range of -8% and 7%. The setting time is less than 21μs. The total power consumption is 15.34mW at 1.8V voltage supply.

Keywords

charge pump circuits; frequency synthesizers; phase noise; receivers; varactors; voltage-controlled oscillators; VCO; charge pump biasing current; constant loop bandwidth; fractional-N frequency synthesizer; high performance receiver; linear varactor; multimode positioning receiver; multimode positioning system; phase noise; voltage-controlled oscillator; Bandwidth; Frequency synthesizers; Iterative closest point algorithm; Receivers; Synthesizers; Varactors; Voltage-controlled oscillators; Fractional-N synthesizer; GPS; constant loop bandwidth; multi-mode; phase noise;

fLanguage

English

Publisher

ieee

Conference_Titel

Electron Devices and Solid-State Circuits (EDSSC), 2011 International Conference of

Conference_Location

Tianjin

ISSN

Pending

Print_ISBN

978-1-4577-1998-1

Electronic_ISBN

Pending

Type

conf

DOI

10.1109/EDSSC.2011.6117626

Filename

6117626