Bandstop Filter in Nonradiative Dielectric Waveguide Using Rectangular Resonators

A bandstop filter realized by means of rectangular resonators coupled to the centre dielectric strip of a Nonradiative Dielectric (NRD) waveguide is described. This filter has the advantage that it is simple to manufacture, making use of a centre dielectric of standard cross section. The design procedure is similar to the conventional stripline design procedure, with the stubs replaced by "stubs" of dielectric, or resonators. The properties of the stubs are obtained through measurement.