CMOS 2nd Order Gm-C Intermediate Frequency Band Pass Filters for Wireless Systems

Abstract

In this paper the design and implementation of CMOS Gm-C 2nd order band pass filters operating at center frequency 45 MHz with a bandwidth of 3 MHz and Quality factor (Q) of 15 are presented. The Band Pass Filter (BPF) is a Biquad structure with Operational Transconductance Amplifier (OTA) as the basic building block and is implemented in Cadence Analog Design Environment using CMOS 0.18 μm technology. The performance of the BPF designed with different OTA’s are compared in terms of Q, voltage gain, IIP3, 1-dB compression and noise parameters. These filters can be operated at center frequency of 45 MHz under 1.8 V power supply. The filters are suitable for intermediate frequency (IF) range in the transmitter of most of the wireless systems operating at 900 MHz and 2.4 GHz.