Broadband and High-Gain Low-Profile Array Antenna Loaded With Parasitic Patches

Abstract

A 16-element array antenna, which has broad band and high gain used for WiFi-5 and WiFi-6E, is proposed in this letter. Breaking through the narrow bandwidth of traditional microstrip antennas, the structure is changed to directly stimulate the parasitic patches with the ring slit, and the appropriate gain and bandwidth are selected by adjusting the thickness of the air dielectric layer. The deformed structures of Wilkinson power divider are used in the feed network to ensure minimum feed losses. The overall measurement of the proposed antenna is 3.67 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">λ</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> × 3.67 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">λ</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> × 0.092 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">λ</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">λ</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> is the free-space wavelength at 5.5 GHz). The maximum measured gain of the antenna array is 20.58 dBi, which is almost 1 dBi less than the simulated gain. Meanwhile, the measured results show the proposed antenna has a broad bandwidth of 43.33% from 4.7 to 7.3 GHz, and the gain's fluctuation in the frequency band is less than 2.1 dBi. Compared to the simulated results, the measured results drift 300 MHz toward high frequency. According to the results, this work fully meets the application of WiFi-5 and WiFi-6E.