Title :
A fractional-N frequency synthesizer with a wide-band small gain-Fluctuation VCO for mobile DTV applications
Author :
Ahn, Tae-won ; Moon, Je-cheol ; Moon, Yong
Author_Institution :
Dongyang Tech. Coll., Seoul
Abstract :
A fully integrated Sigma-Delta fractional-N frequency synthesizer featuring wide-band and small VCO-gain (KVCO) fluctuation is presented. To cover wide-band frequency operation for mobile DTV applications, 6-bit switched-capacitor bank LC VCO is used, and for small KVCO fluctuation, four self-controlled varactor blocks are added to conventional capacitor bank scheme. The integrated VCO tuning range is as wide as 890 MHz (65%) from 910 MHz to 1.8 GHz, which can cover all the desired frequencies for the DVB-H/ISDB-T/T-DMB receiver and achieves 52% smaller KVCO fluctuation than that of a conventional design.
Keywords :
capacitor storage; capacitor switching; digital television; frequency synthesizers; mobile television; voltage-controlled oscillators; fractional-n frequency synthesizer; gain-fluctuation VCO; mobile DTV; self-controlled varactor; switched-capacitor bank; wide-band frequency operation; Capacitors; Delta-sigma modulation; Digital TV; Digital video broadcasting; Fluctuations; Frequency synthesizers; Tuning; Varactors; Voltage-controlled oscillators; Wideband;
Conference_Titel :
ASIC, 2007. ASICON '07. 7th International Conference on
Conference_Location :
Guilin
Print_ISBN :
978-1-4244-1132-0
Electronic_ISBN :
978-1-4244-1132-0
DOI :
10.1109/ICASIC.2007.4415627
