Fabrication of Wideband Low‐Profile Dielectric Patch Antennas from Temperature Stable 0.65 CaTiO3–0.35 LaAlO3 Microwave Dielectric Ceramic

Abstract In this paper, the medium dielectric constant 0.65CaTiO 3 ‐0.35LaAlO 3 (CTLA) composite microwave ceramic is employed to introduce in dielectric patch antennas (DPA). Typical, high‐performance microwave dielectric properties of ε r ≈ 44.8, Q × f ≈ 43 950 GHz@3.67 GHz and TCF ≈ 0 ppm °C –1 can be obtained by solid‐state reaction method in CTLA composite microwave ceramics sintered at 1450 °C for 2 h. Then, the CTLA composite ceramic patch fired with silver coating is mounted on the Rogers RO4003C substrate operating as a magnetic wall boundary. A simplified cavity‐like theoretical model is used to analyze the proposed DPA structure and the accuracy of this antenna model is evaluated by the theoretical results from a commercial CST Microwave Studio 2019. Based on this, the CTLA composite ceramic physical property is modified to enhance the radiation efficiency and reduce profile of the DPA. The higher‐order TM 121 mode is brought close to the dominant TM 101 mode by taking advantage of the multimode characteristics of the dielectric patch resonator and introducing a sintered silver slot in the ceramic dielectric patch. For demonstration, the proposed DPA prototype operating in the multiprobe antenna near the field measurement system is implemented and measured.