A method for the direct synthesis of cascaded quintuplets

A new lowpass prototype configuration for a cascaded quintuplet is presented. The cascaded quintuplet is a cross-coupled filter structure that is used in microwave filter topologies to realize three finite frequency transmission zeros. The lowpass prototype can be converted into the cascaded quintuplet format using a series of equivalent circuit transformations. The method permits the direct synthesis of an arbitrary number of in-line cascaded quintuplets from the filter impedance function.