Direct Synthesis of Waveguide Filters considering unsymmetrical Filter Losses

Filters which are designed exclusively with regard to their geometrical proportions, i.e. neglecting losses, show an ideal transmission behaviour /1/. In contrast to this, measurements of real filters, owing to losses, indicate not only an increase in passband attenuation but also an unsymmetrical distribution of the losses over the bandwidth. Therefore, a method was developed which not only allows to calculate the losses but also to redesign the geometry for the used waveguide material. Such filters represent an optimum for a given window type. Even more symmetrical filters become possible by using both, inductive and capacitive windows in one single "hybrid" filter.