Response of Ag thick film microstrip straight resonator to perturbation of bulk and thick film Ni_(1-x)Cu_x_Mn_2O_4 (0 ≤ x ≤ 1) ceramics

摘要

Purpose - The purpose of this paper is to describe the use of copper-substituted nickel manganite thick film and bulk ceramic superstrate on Ag thick film microstrip straight resonator (MSR), to modify its response and measure complex permittivity as a function of copper. Design/methodology/approach The glass frit free (fritless) copper-substituted nickel manganite thick films were formulated on alumina substrate by screen printing technique from the powder synthesized by oxalic precursor method. A comparison has been made between the X band response of Ag thick film MSR due to perturbation of bulk and thick film Ni_(1-x)Cu_x_Mn_2O_4 (0 ≤ x ≤ 1) ceramic. The shift has been used to measure the permittivity of the ceramic. The dielectric constants obtained by superstrate technique on Ag thick film microstrip component are comparable to those obtained from theoretical calculations. Findings - The resonance frequency of MSR shifts towards lower frequency due to the presence of Ni_(1-x)Cu_x_Mn_2O_4 (0 ≤ x ≤ 1) ceramic as superstrate. The dielectric constant of bulk and thick film match well with the theoretical values. The dielectric constant increases with copper concentration and shows reduction of power gain of MSR. The peak output (power gain) of MSR due to thick film Ni_(1-x)Cu_x_Mn_2O_4 increases by 10.19 per cent with decrease in bandwidth and increase in the quality factor with copper concentration. Originality/value - The ,uperstrate on Ag thick film straight resonator is an efficient tool capable of detecting the composition-dependent changes in microwave properties of ceramic thick films. These Ni_(1-x)Cu_x_Mn_2O_4 ceramic being thermistor materials apart from modifying the response can also be used as power sensors providing cost-effective miniaturization.