Designing band-pass filters with optimal redundancy parameters

In this paper a procedure is proposed for designing band-pass filters based on insertion of ideal transformers with optimal transformation ratio t. Also, an efficient numerically based procedure is given for getting optimal transformation ratio t in closed form. In this way obtained parameter t provides minimal ratio between maximum and minimum values of reactive elements in the transformed network. These networks with a minimum spread of element values are very suitable for realization of filters with transmission lines