High Dielectric Constant and Low Dielectric Loss PPS/Ca_0.5Sr_0.5TiO₃ Composite Materials as BeiDou Antenna for Navigation Satellite Application

This study developed PPS/Ca_0.5Sr_0.5TiO₃ 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.