Nonconventional Transmission Zeros in Distributed Rectangular Structures

A lossless distributed rectangular structure, composed of a dielectric layer interposed between two perfectly conductive metallic layers, is considered. This structure is endowed with two ports, whose positions and widths are variable and is connected to the environment through uniform transmission lines. A procedure is exposed to obtain the impedance matrix at the terminals of the transmission lines. The existence of transmission zeros and of filtering properties is demonstrated.