A new design technique for non-homogeneous media filters

Artificial dielectrics with a continuous spatial variation of the electromagnetic parameters used as high-pass filters are presented. First the theoretical model for the Propagation of the TFM field inside these materials is carried out by means of the nonuniform transmission lines. Second by using a generalization of the nonuniform transmission line theory a new, reflection coefficient closed form, that can be useful both in analysis and in synthesis purposes because of its easiness, speed and accuracy, is obtained Thus, a new design technique for microwave filters using such inhomogeneous materials, based on the new reflection coefficient closed form, is proposed Finally some numerical results that show both the filtering behavior of the inhomogeneous media and the capabilities of the new synthesis method are presented.