Critical evaluation of additively manufactured electrical ceramics for dielectric resonator applications

Abstract

Dielectric resonators (DRs) are ceramic components used primarily in wireless communication devices for their high relative permittivities and low loss properties, with much room for improvement aimed at maximizing their electrical properties. Additive manufacturing (AM) of ceramic materials opens the door for new methods of fabrication of these DRs to produce functionally graded permittivities. An extrusion-based ceramic AM technique has been employed to print structures with graded permittivity and custom geometries. Through a series of rheological studies, shear thinning ceramic suspensions of titanium dioxide and barium titanate have been developed to demonstrate this technique and improve the ability to print such structures. Co-sintering studies were performed to ensure that these materials are compatible during densification and sintering, with validation through microstructural characterization, to verify that the essential material properties meet the requirements of these DR devices. Graded permittivity parts have the ability to enable new electrical properties of DRs, which can be used as a host of new opportunities in the field of microwave dielectrics, such as DR oscillators and DR antennas.