Broadband and High-Gain High-Order-Mode Fed Open-Ended Waveguide Antenna Array for Millimeter-Wave Applications
Wenyu Zhao, Xiuping Li, Zihang Qi, Hua Zhu
Abstract
In this communication, a high-order-mode (HOM)-fed open-ended rectangular waveguide antenna with high gain and broadband is proposed for fifth-generation (5G) applications. A miniaturized HOM cavity with four slots introduces hybrid modes of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$TE_{340}$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$TE_{140}$ </tex-math></inline-formula> , which act as a low loss feeding network. Furthermore, an open-ended waveguide is loaded above the HOM cavity to widen the impedance bandwidth. Compared with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$TE_{340}$ </tex-math></inline-formula> HOM, hybrid modes of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$TE_{340}$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$TE_{140}$ </tex-math></inline-formula> HOM provide more compact size and higher gain. For the proof of concept, a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$4\times $ </tex-math></inline-formula> 4 antenna array is designed and fabricated. The measured impedance bandwidth is 28.1% from 32.85 to 43.6 GHz. The measured peak gain is 21.7 dBi. Great compatibility between simulated and measured results is achieved.