Design and simulation of a switched capacitor ladder filter in a 90nm CMOS technology for WiMAX applications

Abstract

In this paper design and simulation of a 5th order elliptic filter is presented, which its bandwidth is adjustable for WiMAX standard. This filter is realized by a switched capacitor ladder structure. Since the AC analysis of this switched capacitor filter is not possible in HSPICE, so in order to perform the AC analysis the equivalent z-domain model of the filter is also presented. This filter has 156 MHz sampling frequency and its bandwidth is adjustable as follows: 1.25, 2.5, 5, and 10 MHz. This filter has more than 80 dB attenuation at four times of the bandwidth, THD about 64 dB (@Vout =200 mVpp), SFDR more than 67 dB, and power dissipation lower than 35 mW. This filter is designed in a 90nm CMOS technology with a 0.9V supply voltage.