Microwave studies by perturbation of Ag thick film microstrip ring resonator using superstrate of bismuth strontium manganites

Abstract

Purpose -The purpose of this paper was to determine the complex permittivity of bismuth strontium manganites (Bi 12 x Sr x MnO 3 ) in the 8-12 GHz range by using perturbation of Ag thick film microstrip ring resonator (MSRR) due to superstrate of both bulk and thick film. Design/methodology/approach -The BSM ceramics were synthesized by simple low cost solid state reaction method and their fritless thick films were fabricated by screen printing technique on alumina substrate. A comparison has been made between the X band response of Ag thick film microstrip ring resonator due to perturbation of bulk and thick film Bi 12 x Sr x MnO 3 ceramic. Findings -The bulk and thick film superstrate decreases the resonance frequency of MSRR. In this technique even minor change in the properties of superstrate material changes the MSRR response. Variation of strontium content also influences microwave conductivity and penetration depth of bulk and thick films. Originality/value -The microwave complex permittivity decreases with increase in Sr content in bismuth manganite and it is higher for bulk as compared to its thick films. The superstrate on Ag thick film microstrip ring resonator is an efficient tool capable of detecting the composition dependent changes in microwave properties of ceramic bulk and thick films.