Direct coupling configuration between TE/sub 01 delta / dielectric resonator modes: application to the design of an elliptic microwave filter

A technique for realizing direct coupling between dielectric-resonator dipolar modes is presented. This novel geometric configuration eliminates the need for the transmission lines, metallic screws, or irises generally used in microwave filters to obtain negative coupling coefficients. An experimental four-pole elliptic filter has been constructed to verify the theory.<
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