Magnetostatic band suppression at microwave frequency in triple-layered garnet films

Preliminary results are presented on magnetostatic wave suppression in a triple-layered garnet structure where a low-loss pure YIG film is sandwiched between two Ca-doped YIG layers acting as signal absorbers in two well defined field (or frequency) ranges. In this way, all magnetostatic modes except one can be suppressed or strongly attenuated. The approach proposed here is particularly promising in the field of narrowband filters and high-Q resonators, or whenever tight control of the spurious signal rejection in wideband devices is required.