A novel high-efficiency dielectric patch antenna was fabricated using Sr 3- x Ca x V 2 O 8 ceramics. A typically temperature-stable Sr 3- x Ca x V 2 O 8 was achieved by tailoring the Ca2+ substitution to 30 mol% (x = 0.3), where well-balanced microwave dielectric properties were obtained (a near-zero value of +5.2 ppm/°C, a low ε r ∼ 13.4, and a moderate Q × f ∼ 18,500 GHz). To manifest the application potentiality in wireless communication, a patch antenna was fabricated from the x = 0.3 ceramic based on the simulated result using the CST Microwave Studio software, and it showed a high simulated radiation efficiency (99.7%) and a gain (5.35 dBi) at 3.421 GHz. All results indicate that the Sr 3- x Ca x V 2 O 8 ceramics have promising application potential for 5 G technology due to their prominent microwave dielectric properties, lightweight, and low cost. [ABSTRACT FROM AUTHOR]