P⁵⁺‐ Enhanced Novel Samarium Niobate Ultralow‐Loss Microwave Ceramics as Dielectric Resonator for X‐Band Antenna Applications

Abstract High efficiency, high frequency, high selectivity characteristics and low latency of dielectric resonator antennas (DRA) for high frequency are challenges which must be addressed simultaneously in 5G communication. To overcome these difficulties, new Sm(Nb_1−xP_x)O₄ (SNP@x, 0.1 ≤ x ≤ 0.4) ceramics are prepared and demonstrated that P⁵⁺ effectively enhances microwave dielectric properties. Reduction of permittivity (ɛ_r) was co‐dominated by the ionic polarizability of P⁵⁺ and the secondary phase SmPO₄ with low ɛ_r. Quality factor (Q × f) was governed by two factors. Firstly, the secondary phase curbs micro‐crack generation and propagation, thwarts electron migrationand diminishes leakage conduction loss. Secondly, the increased binding energy of P 2p enhances the electron binding by the nucleus, reduces the mechanism. High frequency selectivity (Q × f = 93,900 GHz) was obtained in Sm(Nb_0.7P_0.3)O₄ (SNP@0.3) ceramic. Additionally, a cylindrical dielectric resonator antenna (CDRA) operating in the X‐band was designed and fabricated using ultra‐low SNP@0.3 ceramic and a Rogers substrate, achieved a high gain (4.8 – 6.0 dBi) and efficiency (>90%) in the bandwidth region (10.903 – 11.482 GHz), improving the transmission and communication quality in communication system. This work expedites the evolution of dielectric ceramic and dielectric resonator antennas in high‐frequency communications.