Broadband and High-Gain Embedded Probe-Fed Low-Profile High-Order-Mode Antennas
Wenyu Zhao, Xiuping Li, Zhi Ning Chen, Zihang Qi
Abstract
In this communication, a low-profile high-order-mode (HOM) antenna fed by an embedded L-shaped probe is proposed for high gain and broadband operation. Mode distribution in this low-profile cavity is studied. Three feeding structures, including substrate-integrated waveguide (SIW), probe, and embedded probe, are discussed thoroughly regarding their effect on the HOM cavity. The quasi-metasurfaces (MTS) are introduced to suppress the performance deterioration of the proposed antenna. The mode <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$TE_{810} $ </tex-math></inline-formula> is excited over a wide bandwidth for improved radiation. The study shows that the proposed metasurface antenna achieves a gain of 12 dBi and a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$|S_{11}|\leqslant - 10$ </tex-math></inline-formula> dB bandwidth of 35.8% (4.7–6.75 GHz) with an area of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.14\times 1.14\,\, \lambda _{0}^{2}$ </tex-math></inline-formula> , where <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$ \lambda _{0}$ </tex-math></inline-formula> is the free-space wavelength at the center frequency of 5.72 GHz. In particular, the proposed HOM-fed antenna features a very low profile of 0.045 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$ \lambda _{0}$ </tex-math></inline-formula> .