E-plane waveguide filters with partially filled dielectrics for wide bandwidth

A partially dielectric-filled waveguide bifurcation structure is proposed t o realize wideband bandpass filters. By using modal expansion and matching the tangential fields at the discontinuity, a variational expression for th e input admittance is obtained. The Ritz method is used to form a group of linear equations from which the actual admittance can be obtained; then the equivalent-circuit parameters of the discontinuity are achieved. It is con firmed that the structure is capable of realizing wideband filters. A numer ical analysis of a filter example is conducted to justify the validity. (C) 2001 John Wiley & Sons, Inc.