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 εr of the BaM4Si5O17 ceramics was dominated by ionic polarizability and ρrel. The Q × f values were considerably larger at BaM4Si5O17 (M = Yb and Y) ceramics with the high Utotal and low intrinsic dielectric loss. The τf values were controlled by the MO6 octahedron distortion and –VBa. 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 εr value of 9.02, a Q × f value of 60620 at 12.30 GHz, and a τf 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.