Waveguide Quadruplets With Transversal Geometry

This paper introduces a new class of waveguide quadruplets whose geometry is fully developed along the transverse direction, i.e. all resonators are arranged along the plane which is orthogonal to the waveguide direction of propagation. This unique design leads to a very short structure, as the overall length of the quadruplet filter is determined by the length of the longest resonator. In this configuration only two resonators are connected to source and load, while the other two are dangling resonators. This quadruplet configuration can generate symmetric and asymmetric 4thorder filtering functions having up to 3 transmission zeros whose location can be fully controlled by the filter structural parameters.