Variational Analysis of Folded Substrate-Integrated Waveguides

An accurate numerical solution describing the propagation behavior of two types of folded substrate-integrated waveguide (FSIW) is demonstrated in this letter. The computation is based on a variational method which can be carried out efficiently by solving the stationary equation corresponding to each type of FSIW. The approach can be extended to solve various folded structures, i.e., with different gap positions, where the layers are made of substrates with different thicknesses and material properties.