5.4.3 Types offilters Many methods can be adopted in filter design to raise the filter order. four basic designing methods Butterworth, Chebyshev, Bessel, Cauer or elliptical filters With the increase in filter order the transition band become steeper, the attenuation increases thus the filtering effect strengthened Theoretically, it is possible to cascade several RC networks to enhance filter order and to accelerate the attenuation In practice, loading effect between different cascaded stages must be considered. To solve the loading effect, a better way is to use operational amplifiers to construct active filters5.4.3 Types of filters • Many methods can be adopted in filter design to raise the filter order. four basic designing methods: Butterworth, Chebyshev, Bessel, Cauer or elliptical filters. With the increase in filter order, the transition band become steeper, the attenuation increases, thus the filtering effect strengthened. • Theoretically, it is possible to cascade several RC networks to enhance filter order and to accelerate the attenuation. In practice, loading effect between different cascaded stages must be considered. To solve the loading effect, a better way is to use operational amplifiers to construct active filters