Design and Fabrication of a C-Band Patch Antenna with Low Loss BaM₄Si₅O₁₇ Microwave Dielectric Ceramics

Single-phase BaM₄Si₅O₁₇ (M = Yb, Er, Y, Ho) ceramics have been investigated for their crystal structures, microwave dielectric properties, flexural strength, and potential applications in dielectric antennas. Rietveld refinement and TEM analysis revealed that the BaM₄Si₅O₁₇ ceramics exhibit a monoclinic structure (space groups: P2₁/m). The ε_r of the BaM₄Si₅O₁₇ ceramics was dominated by ionic polarizability and ρ_rel. The Q × f values were considerably larger at BaM₄Si₅O₁₇ (M = Yb and Y) ceramics with the high U_total and low intrinsic dielectric loss. The τ_f values were controlled by the MO₆ octahedron distortion and ^-V_Ba. The flexural strength was mainly dominated by pores and average grain size and reached the maximum value (156 MPa) at BaY₄Si₅O₁₇ ceramic with small average gain sizes and high relative density. Additionally, a patch antenna was fabricated using high-performance BaY₄Si₅O₁₇ ceramic characterized by a ε_r value of 9.02, a Q × f value of 60620 at 12.30 GHz, and a τ_f value of -37.65 ppm/°C. This design achieved a high simulated radiation efficiency of 82.70% and a gain of 5.60 dBi at 6.97 GHz. indicating potential applications of BaY₄Si₅O₁₇ ceramic because of its low dielectric loss and high flexural strength.