Artificial Dielectric Resonators for Miniaturized Filters

This paper discusses about miniaturization of microwave resonators based on the artificial dielectric concept. Very high effective permittivity will contribute to reduce the dimension of resonators significantly, though the unloaded Q is deteriorated. Its recovery should be possible by controlling the thickness of metal strips.Another feature of artificial dielectrics, easy control of anisotropy and inhomogeneity, will improve the spurious property of the resonator. Artificial dielectric is suitable to be implemented in the LTCC technology. Some examples were described, though there is more room for improvement of spurious and loss property. The concept of artificial dielectrics is related to that of coupled resonators. Control of mutual coupling between resonators creates a new type of resonator. The improvement of loss property is a key issue for the application of artificial dielectrics, and it is now being studied by our group. The same thing is also true for metamaterials, as long as the unit particles are made of metal strips.