Barium strontium titanate dielectric helical resonators

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.