The microwave dielectric properties of (I -x)CaTiO3-xSm(Mg1/2Tit,2)O3(0.1 <-x< 1.0) have been investigated. The
system forms a solid solution throughout the entire compositional range. The dielectric constant decreases from 86 to 25 as x
varies from 0.1 to 1.0. The Qxf varies non-linearly and increases for composition with x> 0.6. The nonmonotonic variation
with composition x is more pronounced in Tt than in er. The microwave dielectric properties indicate the possibility of a phase
transformation for x between 0.4 and 0.5
Bijumon, P V; Dr.Sebastian, M T; Mohanan, P(Regional Research Laboratory (CSIR), August , 2005)
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Abstract:
This thesis presents the microwave dielectric properties of two novel dielectric
resonator materials with the composition Ca(Ca1/4Nb2/4Ti1/4)O3 and Ca(Ca1/4Ta2/4Ti1/4)O3
ceramics and their application in the fabrication of wideband antennas. The microwave
dielectric properties of the ceramics were tailored by several techniques such as doping,
glass addition and solid solution formations in the complex perovskite A and B-sites with
suitable substitutions. Among the wide variety of DRs developed, ceramic resonators
with optimum properties were identified to fabricate broadband dielectric resonator
loaded microstrip patch antennas. Furthermore, wideband, high permittivity dielectric
resonator antennas were fabricated and explored the possibility of tuning their
characteristics by modifying the feed line geometries.