A novel pseudo differential transconductor for IEEE 802.11 WLANs

A novel pseudo differential transconductor for multi-mode analog baseband channel selection filter is presented. The highly linear transconductor is designed based on the dynamic source degeneration and predistortion cancellation technique. Meanwhile, wide tuning range is achieved with the current division technique. An LC ladder third-order Butterworth low-pass filter implemented with transconductors and capacitors was fabricated by TSMC 0.18-μm CMOS process. The results show that the filter can operate with the cutoff frequency ranging from 4 to 20 MHz. The tuning range is wide enough for the specifications of IEEE 802.11a/b/g/n Wireless LANs under the consideration of low power consumption and linearity requirement. The maximum power consumption is 3.61 mA at the cutoff frequency of 20 MHz.