This paper presents the processing, modelling and results of a resonant element made from ultra high permittivity dielectric material shaped into a helix. The ceramic helix was made from bulk barium strontium titanate and was produced by viscous plastic processing (VPP). A 1.2 turn and 1.75 turn helix was produced and measured to validate the electromagnetic modelling results. Some of the helices studied in this work are very compact. An optimised device may possess moderate Q factors, due to the low filling factors. The dielectric loss and permittivity of the bulk barium strontium titanate were also measured at microwave frequencies. The quality factors achieved in this paper with dielectric helical resonators, made from barium strontium titanate, are the highest so far attained.

This paper introduces the use of Viscous Plastic Processing (VPP) for the production of microwave ferrite materials and components. Conventional ceramic processing methods produce bulk ferrite materials restricted to relatively simple shapes and that can possess significant micro-structural defects resulting in poor mechanical properties. Using VPP the microstructures and physical strength of ferrite materials can be substantially enhanced and entirely new and unique device geometries produced, such as those based on ferrite helices. Ferrite Materials produced by VPP, such as lithium based ferrites, will be compared to those produced by standard methods of production such as powder pressing.