A Gm-C continuous-time anti-alias filter for UWB analog front-end

A proposed constant drain-source transconductor topology is designed to keep linearity at high frequency. By using the proposed operational transconductance amplifier as a building block, a fourth-order low-pass filter is realized. The filter was fabricated in 0.18 μm CMOS technology and feathers a 250 MHz cutoff frequency. The measured IM3 performance is ?36 dB at 0.6 Vpp input swing and the power consumption is 22 mW.