Title :
A /spl Sigma/-/spl Delta/ fractional-N frequency synthesizer using a wideband integrated VCO and a fast AFC technique for GSM/GPRS/WCDMA applications
Author :
Lee, Han-il ; Cho, Je-Kwang ; Lee, Kun-Seok ; Hwang, In-Chul ; Ahn, Tae-Won ; Nah, Kyung-Suc ; Park, Byeong-Ha
Author_Institution :
Syst. LSI Div., Samsung Electron. Co. Ltd., Gyeonggi-Do, South Korea
Abstract :
A fractional-N frequency synthesizer (FNFS) in a 0.5-/spl mu/m SiGe BiCMOS technology is implemented. In order to operate wideband frequency range, a switched capacitor bank LC tank VCO and an adaptive frequency calibration (AFC) technique are used. A 3-bit 4th order /spl Sigma/-/spl Delta/ modulator is used to reduce out-of-band phase noise and to meet a frequency resolution of less than 3Hz as well as agile switching time. The experimental results show -80dBc/Hz in-band phase noise within the loop bandwidth of 25 kHz and -129dBc/Hz out-of-band phase noise at 400kHz-offset frequency. The fractional spurious is less than -70dBc/Hz at 300kHz offset frequency and the reference spur is -75dBc/Hz. The lock time is less than 150 /spl mu/s. The proposed synthesizer consumes 19.5 mA from a single 2.8-V supply voltage and meets the requirements of GSM/GPRS/WCDMA applications.
Keywords :
BiCMOS integrated circuits; cellular radio; code division multiple access; frequency synthesizers; packet radio networks; sigma-delta modulation; switched capacitor networks; voltage-controlled oscillators; /spl Sigma/-/spl Delta/ fractional-N frequency synthesizer; /spl Sigma/-/spl Delta/ modulator; 0.5 microns; 19.2 mA; 2.8 V; 25 KHz; 300 KHz; 400 KHz; BiCMOS technology; GPRS applications; GSM applications; LC tank VCO; SiGe; WCDMA applications; adaptive frequency calibration technique; agile switching time; fast AFC technique; in-band phase noise; out-of-band phase noise; switched capacitor bank; wideband frequency range; wideband integrated VCO; Automatic frequency control; Frequency synthesizers; GSM; Germanium silicon alloys; Ground penetrating radar; Multiaccess communication; Phase noise; Silicon germanium; Voltage-controlled oscillators; Wideband;
Conference_Titel :
Solid-State Circuits Conference, 2003. ESSCIRC '03. Proceedings of the 29th European
Conference_Location :
Estoril, Portugal
Print_ISBN :
0-7803-7995-0
DOI :
10.1109/ESSCIRC.2003.1257081
