A Wideband Gain‐Enhanced Compact Antenna Employing a Metasurface Reflector for Sub‐6 Ghz and C‐Band Wireless Applications

ABSTRACT A compact wideband monopole antenna integrated with a metasurface reflector is proposed for Sub‐6 GHz and C‐band wireless applications. The proposed antenna consists of a 20 × 20 × 1.6 mm 3 (0.23 λ × 0.23 λ × 0.018 λ) radiating element backed by an 84 × 84 × 10 mm 3 (0.97 λ × 0.97 λ × 0.12 λ) metasurface reflector composed of a 7 × 7 array of concentric circular‐ring unit cells. The metasurface reflector exhibits a near‐zero reflection phase around 5.94 GHz, providing artificial magnetic conductor (AMC)‐like characteristics that enable constructive interference between the directly radiated and reflected electromagnetic waves, thereby enhancing the antenna gain while maintaining a wide impedance bandwidth. By optimizing the antenna–reflector separation to 10 mm, the proposed antenna achieves a measured impedance bandwidth of 3.46–8.41 GHz (83.6%) and a peak realized gain of 6.38 dBi at 5.94 GHz, corresponding to a gain enhancement of approximately 5.57 dB compared with the standalone antenna. The proposed design provides an excellent trade‐off among compact size, wide impedance bandwidth, gain enhancement, and fabrication simplicity while employing a simple, low‐cost single‐layer FR4‐based metasurface reflector. Owing to its compact configuration, wide operating bandwidth, and enhanced radiation performance, the proposed antenna is a promising candidate for Sub‐6 GHz and C‐band wireless communication applications.