A Two-Port Microstrip Antenna With High Isolation for Wi-Fi 6 and Wi-Fi 6E Applications

In this article, a two-port microstrip antenna (MSA) with high isolation is presented for simultaneously supporting wireless fidelity 6 (Wi-Fi 6) and wireless fidelity 6E (Wi-Fi 6E) applications. Due to the narrow guard band between Wi-Fi 6 (5.15-5.83 GHz) and Wi-Fi 6E (5.92-7.125 GHz), the mutual coupling near common edge frequencies cannot be sufficiently suppressed by existing filters. To mitigate the mutual coupling over the guard band of a symmetrical two-port MSA, the common-mode (CM)/differential-mode (DM) cancellation theory was utilized. Then, the operating frequencies of two ports were tuned to Wi-Fi 6 and Wi-Fi 6E bands, without deteriorating the original decoupling performance. Finally, two filters were loaded to realize high isolation over the whole working bandwidth. For the demonstration, a prototype was fabricated and measured. The measured results show that the proposed two-port MSA achieves the impedance bandwidth of 5.49-5.9 and 5.89-7.14 GHz and the isolation over 20 dB across the whole band. The results indicate that the proposed antenna is a promising candidate for Wi-Fi 6 and Wi-Fi 6E applications.