Coupled microstrip filters on multilayered dielectric media

Summary form only given. In this work an attempt is made to design filters with coupled microstrip lines on multilayered dielectric media. In such structures, it is possible to develop equal velocity for even and odd modes (by properly determining the geometry and the kind of dielectric substrates). We have used the insertion loss method (Chebyshev) to specify the frequency response and the electrically equivalent periodic structure of the filter. The corresponding phase velocities are defined by solving the eigenvalue equation for the propagation constant on a multiconductor line. In this step, the moment method for the evaluation of the electric field created by polarization and field charges in the structure is a useful tool. A number of geometries with equal phase velocities for even and odd mode has been determined. The frequency response of the filters designed in these structures was in good agreement with the theoretically anticipated ones and the standing wave ratio at the input of the structure was small enough