A compact dual-band antenna using a gap-coupled monopole branch for Wi-Fi 6/6E/7 applications

Abstract

This paper proposes a compact multimode gap-coupled antenna for dual-band Wi-Fi 6/6E/7 applications. The proposed structure significantly improves bandwidth and efficiency while maintaining a low-profile, compact size, and planar design without the need for complex three-dimensional geometries or an external matching circuit. A distinguishing aspect of this work is the introduction of a multimode excitation mechanism enabled by a gap-coupled U-shaped resonator, which facilitates efficient mode coupling and wideband impedance matching within a compact 50 × 30 mm ground plane. Unlike previous designs that rely on multilayer stacking or metallic-frame coupling, the proposed single-layer FR-4 antenna achieves wide dual-band coverage through structural simplicity and controlled inter-branch resonance. The antenna offers dual-band operation covering the 2.4–2.5 GHz and 5.15–7.125 GHz regions, with simulated − 10 dB impedance bandwidths of 400 MHz (2.18–2.58 GHz) and 2220 MHz (5.13–7.35 GHz). Measured average total efficiencies are 70% in the lower band and 67% in the higher band, confirming stable radiation performance across the frequency ranges. Its two-dimensional radiation patterns exhibit quasi-omnidirectional characteristics suitable for mobile applications. The simple and planar configuration makes the proposed antenna a strong candidate for integration into compact wireless and IoT platforms supporting next-generation Wi-Fi 6E/7 connectivity.