A low-noise widely tunable Gm-C filter with frequency calibration

• Published in: Journal of semiconductors 2016-09, Vol.37 (9), p.88-95
• Main Author: 王彧 刘静 闫娜 闵昊
• Format: Article
• Language: English
• Subjects: 低噪声技术; 低通滤波器; 信道选择; 宽带可调谐; 截止频率; 无线接收器; 转基因细胞; 频率校准
• ISSN: 1674-4926
• DOI: 10.1088/1674-4926/37/9/095002

A fourth-order Gm-C Chebyshev low-pass filter is presented as channel selection filter for reconfigurable multi-mode wireless receivers. Low-noise technologies are proposed in optimizing the noise characteristics of both the Gm cells and the filter topology. A frequency tuning strategy is used by tuning both the transconductance of the Gm cells and the capacitance of the capacitor banks. To achieve accurate cut-off frequencies, an on-chip calibration circuit is presented to compensate for the frequency inaccuracy introduced by process variation. The filter is fabricated in a 0.13 m CMOS process. It exhibits a wide programmable bandwidth from 322.5 k Hz to20 MHz. Measured results show that the filter has low input referred noise of 5.9 n V/（Hz）~（1/2） and high out-of-band IIP3 of 16.2 d Bm. It consumes 4.2 and 9.5 m W from a 1 V power supply at its lowest and highest cut-off frequencies respectively.