Light-weight, high-gain antenna with broad temperature adaptability based on multifunctional 3D woven spacer Kevlar/polyimide composites

Multifunctional composites endowed with signal transmission and excellent mechanical properties show promising applications in aviation and aerospace. In this study, in combination with copper yarn, Kevlar yarn and polyimide resin, a light-weight 3D woven spacer composite antenna (3DWSCA) was developed for effective wireless signal transmitting. Based on the advanced 3D structural design, the Kevlar/Polyimide composite substrate with high specific strength (11.2 MPa/g·cm⁻³), ultra-low density (0.34 g/cm³), superb dielectric properties and small temperature coefficient of resonant frequency (TCF: -12.6 ppm/°C) was constructed. Accordingly, the 3DWSCA realized a gain value of 4.95 dB near designed frequency (2.34 GHz) with a good impedance matching (S₁₁ value < −25 dB). Moreover, the 3DWSCA demonstrated broad temperature adaptability, maintaining stable resonance frequency and radiation properties in the temperature range of −160–200 °C. With these excellent performances, 3DWSCAs can be integrated into the component structure of high-velocity aircrafts to operate in a wide range of temperature, without sacrificing their mechanical and signal transmission functions.