Low-Profile and Dual-Band Microstrip Patch Antenna Based on Magnetic Coupling Covering Wi-Fi 6 Bands for Mobile Terminals

The sixth generation of wireless fidelity (Wi-Fi 6) includes two unbalanced bands of 2.4 GHz to 2.5 GHz and 5.15 GHz to 5.85 GHz, making simultaneous coverage a challenge. This letter proposes a novel method of magnetic coupling and incorporating shorting vias to cover these target bands with a low profile of 1.4 mm/0.012λ<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">L</sub> and a size of 71 mm × 33 mm/0.59λ<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">L</sub> × 0.27λ<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">L</sub> (λ<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">L</sub> is the wavelength for the lowest working frequency). The design process consists of two parts: first, using the characteristic mode TM<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5,0</sub> and its parasitic mode from the half-mode patch to cover the lower band; second, utilizing the modes TM<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5,1</sub> and TM<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1.5,0</sub> along with its parasitic mode to cover the higher band. Two shorting vias on the active and parasitic patches are employed to finetune the resonant frequencies. The proposed patch antenna successfully covers the Wi-Fi 6 bands with the highest bandwidth-to-volume ratio compared to reported dual-band patch antennas, showing great potential for application in mobile terminal devices.