Electromagnetic bandgap (EBG) structures can help in the reduction of mutual coupling by their capabilities of suppressing surface wave's propagation in a specific frequency range. In this work, a dual-layer EBG structure, which had a lower resonant frequency than the single-layer one, is proposed in order to reduce the mutual coupling between <svg style="vertical-align:-0.0pt;width:12.225px;" id="M1" height="10.325" version="1.1" viewBox="0 0 12.225 10.325" width="12.225"  xmlns="http://www.w3.org/2000/svg">
	<g transform="matrix(1.25,0,0,-1.25,0,10.325)">
		<g transform="translate(72,-63.74)">
			<text transform="matrix(1,0,0,-1,-71.95,63.79)">
				<tspan style="font-size: 12.50px; " x="0" y="0">𝐸</tspan>
			</text>

		</g>
	</g>
</svg>-plane coupled microstrip antenna array. As this EBG structure significantly made the series capacitance between neighbor cells larger, a drastic reduction of the unit cell size was achieved. The simulated and experimental results show that the proposed structure has a significant 19&#x2009;dB mutual coupling reduction.

A. Azarbar

J. Ghalibafan

A Compact Low-Permittivity Dual-Layer EBG Structure for Mutual Coupling Reduction

A new technique that combines adaptive power allocation and iterative detection based on singular value decomposition (SVD) is introduced for the modified Turbo-BLAST system with imperfect channel state information (I-CSI). At the transmitter, in order to maximize the capacity performance, the MIMO channel is decomposed into several parallel eigen subchannels by SVD, and then proper power based on the water-filling principle is allocated to every subchannel subject to the total transmit power constraint. At the receiver, the modified MMSE detector taking the CSI imperfection into account is used to remove the coantenna interference, and then the turbo idea is employed for iterative detection to lower the system BER. As a result, the BER performance is effectively enhanced. Numerical results show that the introduced SVD-aided adaptive power allocation method is valid to improve not only the capacity but also the BER performance in the presence of channel state information imperfection, while the iterative detector can further lower the BER results.

Xiaomin Chen

Xiangbin Yu

Dazhuan Xu

SVD-Aided Power Allocation and Iterative Detection Scheme for Turbo-BLAST System with Imperfect Channel State Information

The radiation properties of an axially slotted elliptic antenna coated with magnetic metamaterials are investigated. The fields inside and outside the dielectric coating are expressed in terms of the Mathieu functions. The boundary conditions at various surfaces are enforced using the orthogonality property of angular Mathieu functions. Numerical results are presented graphically for the radiation pattern, aperture conductance, and antenna gain for the TM case. It was found that a slotted antenna coated with magnetic metamaterials has more gain as well as lower side lobes compared to one coated with conventional dielectric or nonmagnetic metamaterials.

A. K. Hamid

Elliptic Cylinder with Slotted Antenna Coated with Magnetic Metamaterials

This paper describes a broadband printed cross-dipole element with four polarization reconfigurations (BPCDE_PR). The BPCDE_PR can configure two linear and two circular polarizations in the operating band of 1.7–2.5 GHz. To implement the broadband polarization reconfigurations, switched network type broadband phase shifters are proposed and designed. The fabricated BPCDE_PR prototype with switched network including broadband phase shifters shows good electrical performances and the desired polarization reconfigurable functions in the operating band.

Soon-Young Eom

Ic-Pyo Hong

Jong-Myeon Kim

Broadband Printed Cross-Dipole Element with Four Polarization Reconfigurations for Mobile Base Station Array Antenna Applications

The channel capacity of MIMO system increases as a function of antenna pairs between transmitter and receiver but it suffers from multiple expensive RF chains. To reduce cost of RF chains, antenna selection (AS) method can offer a good tradeoff between expense and performance. For a transmitting AS system, channel state information (CSI) feedback is required to choose the best subset of available antennas. However, the delay and error in feedback channel are the most dominant factors to degrade performances. In this paper, the concept of AS method using reciprocal CSI instead of feedback channel is proposed. The capacity performance of proposed system is investigated by own developing Testbed. The obtained results indicate that the reciprocity technique offers a capacity close to a system with perfect CSI and gains a higher capacity than a system without AS method. This benefit is from 0.9 to 2.2 bps/Hz at SNR 10 dB.

Peerapong Uthansakul

Nattaphat Promsuwanna

Monthippa Uthansakul

Performance of Antenna Selection in MIMO System Using Channel Reciprocity with Measured Data

Diversified deformations on reflection-style optical antennas caused by processing technique and complex outer-space environment in free-space laser communications are modeled by wavelet analysis. Influence due to the deformations on received power is studied by distortion attenuation factor based on the model. Theoretical and numerical analysis shows that distortion attenuation factor increases with shift factor of the model, decreases with dilation factor of the model, and decreases with irregular fluctuations with wavelet coefficient of the model. To the special case that the deformation can be well approximated to a constant, distortion attenuation factor varies periodically with the linear increase of the deformation coefficient. A reference for the requirement on the precision of optical antenna is proposed, and a method to reduce the effect of deformation is recommended. It is hoped that the study can be used in the design of free space laser communication systems.

Wanqing Xie

Liying Tan

Jing Ma

Yang Liu

Received Power Attenuation Analysis Based on Wavelet for
Reflection-Style Optical Antenna Deformations in Free-Space Laser Communications

Two efficient probe-compensated near-field-far-field transformations with spherical scanning for antennas having two dimensions very different from the third one are here developed. They rely on the nonredundant sampling representations of the electromagnetic fields and on the optimal sampling interpolation expansions, and use effective antenna modellings. In particular, an antenna with a predominant dimension is no longer considered as enclosed in a sphere but in a cylinder ended in two half spheres, whereas a surface formed by two circular &#x201c;bowls&#x201d; with the same aperture diameter but different lateral bends is adopted to shape an antenna with two predominant dimensions. These modellings are able to fit very well a lot of antennas by properly setting their geometric parameters. It is so possible to remarkably lower the number of data to be acquired, thus significantly reducing the measurement time. Numerical tests assessing the accuracy and the robustness of the techniques are reported.

Francesco D&#39;Agostino

Flaminio Ferrara

Claudio Gennarelli

Rocco Guerriero

Massimo Migliozzi

Effective Antenna Modellings for NF-FF Transformations
with Spherical Scanning Using the Minimum Number of Data

About this journal

<p><em>International Journal of Antennas and Propagation </em>publishes research on the design, analysis, and applications of antennas, along with studies related to the propagation of electromagnetic waves through space, air, and other media.</p>


Journal profile

Meet the editorial board

<p>Chief Editor, Professor Koziel, engages in research focused on surrogate-based modeling and optimization including space mapping technology for engineering design at Reykjavik University.</p>


Editor spotlight

Submit to Special Issue

We currently have a number of Special Issues open for submission. Special Issues highlight emerging areas of research within a field, or provide a venue for a deeper investigation into an existing research area.

Special Issues

Author guidelines

Editorial board

Databases and indexing

International Journal of Antennas and Propagation - Table of contents 2011

International Journal of Antennas and Propagation | Hindawi

title

International Journal of Antennas and Propagation publishes research on the design, analysis, and applications of antennas, along with studies related to the propagation of electromagnetic waves through space, air, and other media.

description

International Journal of Antennas and Propagation

https://images.hindawi.com/journals/ijap/ijap.banner.jpg

International Journal of Antennas and Propagation