A 28-MHz wideband switched-capacitor bandpass filter with transmission zeros for high attenuation

A 28-MHz wideband switched-capacitor (SC) bandpass filter employs an N-path technique and implements transmission zeros in the transfer function to achieve high attenuation. A modified SC biquadratic filter architecture is proposed to achieve high-speed operation. Implemented in a 0.35-/spl mu/m CMOS process, the bandpass filter operates at 28-MHz center frequency with a 3.84-MHz bandwidth and adjacent-channel attenuation of more than 35 dB. At 3-V supply, the filter measures a dynamic range of 37 dB at the 1% THD3 point while dissipating 19.6-mW per pole and occupying a chip area of 1.65 mm/sup 2/.