Before revision: This results in The difference equation (using the Direct Form I) is General second-order biquad transformation A similar process can be used for a general second-order filter with the given transfer function This results in a discrete-time digital biquad filter with coefficients expressed in terms of the coefficients of the original continuous time filter: Again, the constant term in the denominator is generally normalized to 1 before deriving the corresponding difference equation.
After revision: This results in The difference equation (using the Direct form I) is General second-order biquad transformation A similar process can be used for a general second-order filter with the given transfer function This results in a discrete-time digital biquad filter with coefficients expressed in terms of the coefficients of the original continuous time filter: Again, the constant term in the denominator is generally normalized to 1 before deriving the corresponding difference equation.