A compact and ultra‐wideband three‐element quasi‐Yagi MIMO antenna system for wireless applications

Abstract

In this article, a new configuration of a compact planar three‐element multiple‐input‐multiple‐output (MIMO) antenna system is proposed based on quasi‐Yagi elements. A simple yet novel monopole driven three elements quasi‐Yagi antenna (QYA) is designed to obtain a directional pattern over an ultra‐wide bandwidth with a simple and compact configuration. The proposed single QYA contains the semi‐elliptical driven monopole, the flared truncated ground plane reflector, a single elongated elliptical director and a simple microstrip feedline. The simulated and measured results showed that the proposed MIMO antenna system operates in an ultra‐wide frequency range, starting from 1.53 to 6 GHz (118.7%, for |S11| < −10 dB), which covers several wireless communication bands. It has a compact total electrical area of 0.21λ02 (λ0 is the highest operating wavelength) and a minimum isolation of 17 dB between its ports with a common ground plane without any complex decoupling structure. For each element, the measured peak gain and simulated total efficiency variations are between 3.3‐5.6 dBi and 77.6%–89%, respectively. There is good agreement between simulated and measured results. Furthermore, the calculated envelope correlation coefficient of < 0.006, channel capacity loss of < 0.2 bit/s/Hz, and stable total active reflection coefficient resonance are obtained over entire operating bandwidth, which conforms satisfactory MIMO/pattern diversity performance for wireless access‐point applications.

A wideband MIMO antenna with high isolation for 5G application

“…[1][2][3] In order to cover more frequency bands and apply in more scenes, it is crucial to design wideband MIMO antennas. [4][5][6] Keeping each unit of the MIMO antenna independent from each other is the key to ensure the antenna perform well, which means the mutual coupling between the radiation ports should be low enough. Many methods are proposed to improve the isolation between antenna elements, including etching defected ground structure (DGS), [7][8][9] adding electromagnetic band gap (EBG) structure, [10][11][12] adding parasitic elements, [13][14][15] adding metamaterial and metasurface to reduce the mutual couplings, [16][17][18] diversity technique, and so on.…”