The 0.61CaTiO3-0.39LaAlO3 (CTLA) ceramics are widely used in relay station, aerospace and radar systems for their superior properties: remarkable quality factor and excellent thermal stability. However, some deficiencies remain, such as low permittivity and excessively high sintering temperature, which limit their development in microwave communication. Herein, we introduce CaV2O6 to the CTLA ceramics to solve these problems and systematically investigate its effects on sintering temperature, phase constitution, microstructure and microwave dielectric properties. The CTLA ceramics added with 0–2.0 wt% CaV2O6 were prepared by the traditional solid-state reaction procedure. The XRD patterns indicated that the pure phase Ca0.61La0.39Al0.39Ti0.61O3 (PDF #52-1773) was obtained from all samples, which revealed that the CaV2O6 was dissolved into CTLA lattice to form a solid solution. As the CaV2O6 content increased, the strongest X-ray diffraction peaks gradually shifted toward low angles, which manifested the increase of cell volume of the solid solution. When the additive amount was 1.0 wt%, the CaV2O6 could high-effectively lower the sintering temperature from 1450 ℃ to 1290 ℃ and obviously promote the growth of grains. Meanwhile, the εr slightly increased, the Q×f significantly improved and the τf favorably decreased to closer to zero, then the prominent microwave dielectric performance was exhibited, with εr = 40.6, Q×f = 48,800 GHz (at 4.5 GHz), and τf = 0.78 ppm/℃. Such CTLA ceramics are expected to promote the development of high-performance and temperature-stable microwave components.

In this paper, a single-fed wideband circularly polarized dielectric resonator antenna (DRA) is proposed. The antenna consists of a substrate, a cylindrical dielectric resonator, and four curved parasitic metal blocks that are rotated and placed around the dielectric resonator. The GND of the substrate is etched with an inverse f-shaped slot. The orthogonal working mode of the DRA is excited by the inverse f-shaped slot coupled to the microstrip, thereby obtaining circularly polarized radiation. The impedance bandwidth and axial ratio bandwidth of the antenna are improved by optimizing the structure of the inverse f-shaped slot and the shape and size of curved parasitic metal blocks, and finally, a circularly polarized dielectric resonator antenna with significant bandwidth advantages is obtained. The antenna is simulated, fabricated, and measured. The measured results show that the proposed circularly polarized DRA has an impedance bandwidth of 58.5% (2.61–4.77 GHz) and an axial bandwidth of 55.2% (2.75–4.85 GHz) and finally achieves an effective axial bandwidth of 53.7% (2.75–4.77 GHz), the peak gain of 6.84 dBi, and average efficiency of 90.78%, with excellent overall performance.