Design of a compact dual band antenna with novel FSS for enhanced gain in X-band applications

• Designed to run at dual frequencies of 8.98 GHz and 11.2 GHz, the proposed antenna has a Framed Bilateral Oval shaped radiating patch. • At 8.98 GHz the antenna reaches a gain of 8.5 dBi from 5.8dBi due to the inclusion of frequency selective surface (FSS) under the antenna. • Equivalent circuit (EC), reflection co-efficient, surface current and radiation pattern-based study have been carried out. • Multiple antenna design was evaluated to find out the optimum design. • Both the antenna and the FSS structure uses cheap FR4 substrate material with a dielectric constant of 4.3 and a loss tangent of 0.025. • A laboratory test was conducted to evaluate the accuracy of results by comparing simulation and experimental data. • Essential for practical applications, particularly in fields like satellite communications and military radar. This paper presents the design and analysis of a compact dual band antenna featuring a novel Framed Bilateral Oval-shaped radiating patch with improved gain. The ground plane incorporates a Defected Ground Structure (DGS) with a rectangular slot at the center, measuring 20 mm × 5 mm. The antenna has a compact form factor with dimensions of 40 mm × 40 mm × 1.6 mm, making it suitable for low-profile applications. To further enhance its directivity and gain, a Hexa-Radial Star Aperture Frequency Selective Surface (FSS) is integrated underneath the antenna as a substrate. The integrated FSS-antenna system demonstrates dual-band operation, with enhanced peak gains measured at 8.5 dBi for 8.98 GHz and 6.46 dBi for 11.095 GHz. Both the antenna and the FSS structure are fabricated using cost-effective FR4 substrate material (εᵣ =4.3, tanδ=0.025). The simulated results are experimentally validated, and the findings are explored in depth. The overall dimensions of the integrated FSS-antenna structure are 60 mm × 60 mm × 23.35 mm. These findings highlight the proposed design’s potential for enhanced performance in satellite communication and military radar applications.