A Compact Multi-Frequency Broadband Dual-Antenna System with Mutual Coupling Reduction for Wi-Fi 6E Application

In this letter, a compact multi-frequency broadband dual-antenna system with mutual coupling reduction for Wi-Fi 6E application is proposed. The dual-antenna system consists of two identical IFA antennas and the minimum distance of two antennas is only 2 mm, yet the antenna system occupied a small size of 6.5 × 41 mm ² (about 0.05 λ _min × 0.32 λ _min , λ _min is the wavelength at the lowest frequency). A decoupling inductor is induced between two open ends of two antennas for lower band decoupling, while a modified decoupling branch and a modified neutralization line are introduced between two antennas for upper wide band decoupling. After adopting the three decoupling techniques, the dual-antenna system obtains remarkable isolation with | S ₂₁ | > 22dB in all desired bands of WLAN 2.4GHz/5GHz (2.4-2.484 GHz, 5.15-5.35 GHz, 5.725-5.825 GHz) and Wi-Fi 6E (5.925-7.125 GHz). These presented decoupling techniques are compact and low-cost and can be used for those designs of multi-frequency broadband dual-antenna systems without adding extra size.