Rational approximation of irrational functions by linear fractional transformations
Omar Wing, Yao‐Lin Jiang, Qingjian Yu · IEEE Transactions on Circuits and Systems I Fundamental Theory and Applications · 1998
The cascaded two-port circuit theory is generalized and applied to the approximation of the square root of a rational function by a function in the form of a chain of linear fractional transformations. We prove the convergence of the approximation, and derive an explicit expression of the relative error in terms of the two-port parameters and the order of approximation. Examples are given.