High Dielectric Constant and Low Dielectric Loss PPS/Ca _0.5 Sr _0.5 TiO ₃ Composite Materials as BeiDou Antenna for Navigation Satellite Application

ABSTRACT This study developed PPS/Ca _0.5 Sr _0.5 TiO ₃ composites via twin‐screw melt extrusion and hot‐pressing to meet the demanding requirements of BeiDou antenna substrates. With an increased filler ratio of up to 40 vol.%, the composite demonstrated a significantly enhanced dielectric constant (13.45) while maintaining a low dielectric loss (10 ⁻³ level). Thermal properties were also substantially improved, with thermal conductivity reaching 0.649 W·m ⁻¹ ·K ⁻¹ (a 280% increase) and thermal expansion decreasing to 28.26 ppm/°C. To validate these material advantages, a BeiDou antenna was fabricated using the 40 vol.% substrate. The antenna achieved a 57.2 MHz dual‐resonance bandwidth (1.592 and 1.616 GHz) with gains of 4.2 and 4.3 dBi and over 80% radiation efficiency. Ultimately, the high‐permittivity substrate enabled significant antenna miniaturization compared to traditional designs, while preserving stable circular polarization and excellent radiation performance, demonstrating its viability for satellite communications.