Title :
A Fast fc Automatic Tuning Circuit with Wide Tuning Range for WCDMA Direct Conversion Receiver Systems
Author :
Watanabe, Osamu ; Ito, Rui ; Saigusa, Shigehito ; Arai, Tadashi ; Itakura, Tetsuro
Author_Institution :
Corporate Res. & Dev. Center, Toshiba Corp., Kawasaki
Abstract :
A fast fc automatic tuning circuit suitable for WCDMA systems is proposed. The circuit employs master-slave architecture using digitally controlled Gm-C filter for avoiding long transient response. The tuning feedback loop contains a 2-bit up-down counter ADC for fast tuning operation. Furthermore, to avoid degradation of fc tuning accuracy due to reference feedthrough, an analog loop filter with notch located near reference frequency is used. The fast f c automatic tuning circuit is fabricated in a SiGe BiCMOS process. The tuning time within 200mus is achieved for 35 chips from 2 lots and the standard deviation of 25.5 kHz is obtained for the average fc of 2.12 MHz
Keywords :
BiCMOS integrated circuits; Ge-Si alloys; analogue-digital conversion; circuit tuning; code division multiple access; filters; integrated circuit design; radio receivers; 2.12 MHz; 200 mus; 25.5 kHz; ADC; BiCMOS process; Gm-C filter; SiGe; WCDMA systems; analog loop filter; automatic tuning circuit; direct conversion receiver systems; fc tuning; master-slave architecture; transient response; tuning feedback loop; Automatic control; Circuit optimization; Counting circuits; Digital control; Digital filters; Feedback loop; Master-slave; Multiaccess communication; Transient response; Tuning;
Conference_Titel :
Solid-State Circuits Conference, 2006. ESSCIRC 2006. Proceedings of the 32nd European
Conference_Location :
Montreux
Print_ISBN :
1-4244-0303-0
DOI :
10.1109/ESSCIR.2006.307599
