Dielectric Resonator Antennas with Frequency Stability Under Severe
Temperature Variations Based on Li2MgTi3O8 Ceramic Matrix Added with
Bi2O3
JOURNAL OF ELECTRONIC MATERIALS, 47 (12):
7272-7280 (2018)DOI: 10.1007/s11664-018-6664-0
Abstract
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.