Small and low-profile dielectric resonator antenna using new low loss and high permittivity ceramics

Original oxide ceramics, based on strontium and tantalum, are investigated for antenna applications. First, it concerns perovskite ceramics (Sr
2
Ta
2
O
7
)
100-x
(La
2
Ti
2
O
7
)
x
, and, secondly, the SrTa
2
O
6
composition, belonging to the tetragonal tungsten bronze (TTB) compounds. Their synthesis is conducted by a solid-state reaction route and results in dense ceramics exhibiting moderate permittivity (∼ 80) and low losses (≤ 5.10
^-3
), that have been integrated in miniature dielectric resonator antenna (DRA) prototypes. Achieved ferroelectric perovskite ceramic based antennas present measured total efficiencies of 79% and 84%, at resonant frequencies ‘F
R
’ of 5.80 GHz and 4.85 GHz, respectively, whereas the pure dielectric TTB ceramic DRA achieves an efficiency of 91% at 4.01 GHz.