Proper transfer function

In control theory and signal processing, a **proper transfer function** is a type of transfer function that has certain mathematical properties. A transfer function \( H(s) \) is expressed as the ratio of two polynomials in the Laplace variable \( s \): \[ H(s) = \frac{N(s)}{D(s)} \] where: - \( N(s) \) is the numerator polynomial, - \( D(s) \) is the denominator polynomial.