Modified Adaptive Prototype Inclusive of the External Couplings for the Design of Coaxial Filters

The filter prototype of side-coupled coaxial filters, which we recently proposed, has been modified to suit an arrangement in which the coupling apertures are placed on the side opposite the coaxial end gaps. In this situation, the modified prototype fits the physical counterpart better, resulting in a further design simplification. In addition, the feeds have also been modeled and included into the prototype, thus enhancing the correspondence between the prototype and physical structure. A practical design, concerning a WIMAX application, shows the reliability of this solution.