A Highly linear CMOS Gm-C Low Pass Filter for Mobile Communication

A 2nd order low pass Butterworth filter has been designed for direct conversion receiver. Direct conversion receivers require only low pass filtering in the analogue baseband. This architecture has been applied for multi-mode transceiver. Low-pass filters are an essential part of the analogue baseband circuit of modern communication receivers, because of the ability to re-configure the bandwidth, gain or linearity in order to fulfill the requirements of different standards subjecting to wireless standards. Highly linear and wide tunable OTA based Butterworth filter has been simulated in CMOS 90nm Technology. Up to 625 MHz filter has a good linearity at supply voltage 1.2 V. The circuit shows a single OTA with common mode feedback has been prepared in microwind3.1 with 90nm CMOS Technology.