Title :
A 4th-order active-Gm-RC low-pass filter with RC time constant auto-tuning for reconfigurable wireless receivers
Author :
Liu Junbo ; Fan Xiangning ; Bao Kuan
Author_Institution :
Sch. of Inf. Sci. & Eng., Southeast Univ., Nanjing, China
fDate :
Oct. 29 2012-Nov. 1 2012
Abstract :
Based on 0.18μm RF CMOS process, a 4th-order Butterworth low-pass filter (LPF) used in reconfigurable wireless receivers (for WCDMA and GPS/Galileo) is presented in this paper. The LPF adopts active-Gm-RC structure, and can satisfy both WCDMA and GPS/Galileo requirements, which maximizes hardware reuse. A RC time constant auto-tuning circuit is applied to improve the accuracy of bandwidth. The chip area occupies 0.78mm2. The LPF is measured on wafer. With 1.8V power supply, the core circuit of the LPF consumes 1mW and 1.6 mW for WCDMA and GPS/Galileo respectively. The out of band attenuation rate is about -78dB/10 octave. The measured 1dB compression point is severally -3.0dBm and -5.1dBm.
Keywords :
Butterworth filters; CMOS analogue integrated circuits; Global Positioning System; circuit tuning; code division multiple access; low-pass filters; radio receivers; 4th-order Butterworth active-Gm-RC low-pass filter; GPS-Galileo requirement; LPF; RC time constant autotuning circuit; RF CMOS process; WCDMA requirement; power 1 mW; power 1.6 mW; reconfigurable wireless receivers; size 0.18 mum; voltage 1.8 V; Filtering theory; Global Positioning System; Low pass filters; Multiaccess communication; Spread spectrum communication; Switches; Tuning;
Conference_Titel :
Solid-State and Integrated Circuit Technology (ICSICT), 2012 IEEE 11th International Conference on
Conference_Location :
Xi´an
Print_ISBN :
978-1-4673-2474-8
DOI :
10.1109/ICSICT.2012.6467693
