Novel Temperature‐Stable (1‐ <i>x</i> )Ba ₃ V ₂ P ₃ O ₁₅ ‐ <i>x</i> BaV ₂ O ₆ Composite Ceramics with Ultralow Sintering Temperature and Low Dielectric Loss for Dielectric Resonator Antenna Applications

Abstract The phase composition, crystal structures, dielectric properties, and thermal characteristics of novel (1‐ x )Ba 3 V 2 P 3 O 15 ‐ x BaV 2 O 6 (0 ≤ x ≤ 1) composite ceramics are systematically investigated. The composite ceramics are rationally designed by combining novel Ba 3 V 2 P 3 O 15 ceramics with BaV 2 O 6 ceramics, enabling the regulation of microwave dielectric properties. Experimental results demonstrate that pure‐phase Ba 3 V 2 P 3 O 15 ceramics sintered at 720 °C for 2 h exhibit outstanding microwave dielectric properties: permittivity ( ε r ) = 7.5, quality factor ( Q × f ) = 25 920 GHz (at 12.22 GHz), and temperature coefficient of resonant frequency ( τ f ) = −38 ppm °C −1 . Notably, 0.2Ba 3 V 2 P 3 O 15 ‐0.8BaV 2 O 6 ceramics sintered at 580 °C for 2 h achieve excellent microwave dielectric properties: ε r = 10.0, Q × f = 21 600 GHz (at 10.92 GHz), and τ f = +3.5 ppm °C −1 . Additionally, 0.2Ba 3 V 2 P 3 O 15 ‐0.8BaV 2 O 6 ceramics exhibit superior terahertz dielectric performance, highlighting significant potential for terahertz applications. Furthermore, 0.2Ba 3 V 2 P 3 O 15 ‐0.8BaV 2 O 6 ceramics show favorable compatibility with Al electrodes, demonstrating significant potential for ultralow temperature co‐fired ceramic (ULTCC) application. A cylindrical dielectric resonator antenna (DRA) element is designed using 0.2Ba 3 V 2 P 3 O 15 ‐0.8BaV 2 O 6 ceramics, exhibiting a high radiation efficiency of 88.7% and a peak realized gain of 5.56 dBi. Both simulated and measured performances of the DRA are exceptional, indicating its promising applicability in 5.8 GHz Wi‐Fi communication systems.