Source: wikibot/proper-transfer-function
= Proper transfer function
{wiki=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.