On the design of a reject band filter for antennas mutual coupling reduction

Abstract

In this article, a novel concept for mutual coupling reduction between antenna elements is proposed at 2.45 GHz for Wi‐Fi applications. A reject band filter (RBF) is used in order to reduce the mutual coupling between two monopoles for multi‐input multi‐output (MIMO) systems. The proposed RBF inclusions are developed to have zero refractive index response over a specific frequency band. The inclusions considered here are composed of open‐loop resonators; each one with the same iteration level of Minkowski‐like pre‐fractal structures coupled with an open‐stub transmission line to increase the band selectivity. The inclusions are inserted between λ/2‐spaced monopole elements at 2.45 GHz. A significant mutual coupling reduction is realized by incorporating only two RBF cells. Such effective response is attributed to the electromagnetic wave cloaking at 2.45 GHz using the developed RBF inclusions. An extensive theoretical study using both numerical and analytical methods is invoked to obtain the best performance of the proposed MIMO antenna structure. Finally, the experimental and numerical results are agreed excellently.

Hilbert metamaterial printed antenna based on organic substrates for energy harvesting

“…However, mixing the nanoscale structures with organic materials was investigated in [4][5][6] to create dielectric substrates in the microwave bands. On the other hand, the introduction of fractal geometries to print antennas was recently realised by using right and/or left inclusions to add extra size reduction with enhanced performances [7][8][9][10][11][12][13][14][15][16][17]. For example, in [7,8], space filling fractal geometries were introduced to miniaturise the antenna size for high compacted portable modern devices.…”

Novel miniaturized folded UWB microstrip antenna‐based metamaterial for RF energy harvesting

“…It is found a significant change in the evaluated results in comparison to the presented results in Figure . Such change is attributed to the addition of the EBG structure, which is added extra capacitive effects …”

“…Nevertheless, the antenna bandwidth between 4 and 14 GHz is affected severely with changing gp l due to the effects of capacitive coupling effects of the EBG structure with the ground plane. This capacitive coupling increases as much as the ground plane becomes very close from the EBG to equate the inductive component of the feed line structure. Therefore, the proposed location at gp l =8 mm is found to be exactly the same length of the transmission line.…”

“…Such change is attributed to the addition of the EBG structure, which is added extra capacitive effects. 3…”

“…For example, frequency selective surfaces were applied to miniaturize the antenna size and enhance the radiation properties . Electromagnetic band gap (EBG) structure‐based metal patches or etched patterns from ground planes were proposed to provide forbidden propagation bands. While, metamaterials (MTMs) possess several attractive features such as surface wave reduction and unique stopbands .…”