A New Realization of Dual Mode Dielectric Resonator Filters

A new realization of dual hybrid mode dielectric resonator band pass filters is presented. All the coupling elements in this realization are tunable, and no iris or coupling holes are needed to achieve coupling among resonators. As a result the new structure is easier to tune and considerably less expensive to manufacture, since expensively machined iris with tight tolerance are eliminated. Measured results from an experimental 4-pole elliptic function filter realized in the new structure agreed closely with theory.