40MHz Gm-C filter with high linearity OTA for wireless applications

This paper presents a fourth-order linear phase low-pass filter for high speed wireless system. A high linearity operational transconductance amplifier (OTA) is proposed, where the characteristics of input attenuators and low source impedance are used to achieve high linearity. By using the proposed OTA as a building block, the fourth-order low-pass filter with the cutoff frequency of 40MHz is implemented. The filter is designed in 0.18-µm CMOS process technology and the HD3 performance is about −53.4dB. The filter works with 1.8V supply voltage and its power consumption is about 14.1mW.