Circularly Polarized Double-walled SIW Fractal Slot and Hexagonal Ring Slot Antenna Array for X-band Satellite Applications

Abstract

This paper presents a circularly polarized double wall substrate integrated waveguide (SIW) fractal slot antenna array designed for X-band satellite applications. The proposed antenna demonstrates a reflection coefficient, covering the frequency range from 7.3 GHz to 8.5 GHz. The antenna is circularly polarized with a 3-dB axial ratio bandwidth ranging from 7.88 GHz to 8.58 GHz. The antenna array exhibits a gain variation between 11 dBi and 12.51 dBi. Moreover, the proposed design achieves an efficiency of 89%. With overall dimensions of 177 mm × 48.8 mm × 3.175 mm (4.8λ0 × 1.32λ0 × 0.086λ0), the antenna array is compact and suitable for satellites with limited surface area. This compact form factor facilitates seamless integration into satellite systems without compromising performance. The proposed antenna is suitable to be employed for the satellite X-band telemetry application extending from 7.9 GHz to 8.4 GHz. A prototype of the proposed antenna has been fabricated and then measured using Vector Network Analyzer (VNA) and anechoic chamber. The proposed antenna's measurement results match the simulated results.