Dielectric Resonator Antennas with Frequency Stability Under Severe Temperature Variations Based on Li2MgTi3O8 Ceramic Matrix Added with Bi2O3

摘要

This paper presents the application of the Li2MgTi3O8 (LMT) ceramic matrix added with small quantities (0 wt.%, 1 wt.%, 3 wt.%, and 5 wt.%) of Bi2O3 for building and studying dielectric resonator antennas (DRA) to operate in microwave frequency bands. A low-cost procedure of manufacturing was applied to produce a material with good dielectric characteristics such as near zero temperature coefficient of resonant frequency (iota(f)) in - 8.37 ppm.degrees C-1 for LMT added with 3 wt.% Bi2O3, relative permittivity (epsilon(r)) varying approximately between 19 and 24 and loss tangent (tan delta) varying between 5.41 x 10(-4) and 1.42 x 10(-3). Antenna prototypes and computational models were built for each compound, showing excellent agreement between measurements and simulations. All prototypes and simulated models have bandwidths (BW) wider than 100 MHz with resonant frequencies near 3.5 GHz. The gains and radiation efficiencies of the simulated antennas remained above 6.3 dBi and 98%, respectively.