Physical Bounds and Radiation Modes for MIMO Antennas

Ehrenborg, Casimir; Gustafsson, Mats

doi:10.1109/tap.2020.2972398

Cited by 13 publications

(8 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On the other hand, always two of these three power quantities can be orthogonalized. These formulations, where one of the power-related operators is dropped out, produce solutions that cannot be considered as CMs, but that could be useful in various situations [21].…”

Section: Discussionmentioning

confidence: 99%

Orthogonality Properties of Characteristic Modes for Lossy Structures

Kuosmanen

Ylä‐Oijala

Holopainen

et al. 2022

IEEE Trans. Antennas Propagat.

View full text Add to dashboard Cite

Orthogonality of the characteristic modes with respect to the weight operator of the generalized eigenvalue equation, and in the far field, is investigated in the case of lossy conducting and dielectric objects. Linking the weight operator to radiated power is shown to provide orthogonal far fields in the lossless case. In the lossy case, both the orthogonality of the characteristic far fields and the weight operator orthogonality of the modal currents are satisfied with respect to the Hermitian inner products only for sufficiently symmetric geometries, such as a sphere. For irregular lossy shapes, independently of the symmetry of the formulation, the far-field orthogonality can be obtained only with respect to the symmetric (non-Hermitian) product. The weight operator orthogonality can be satisfied with (complex) symmetric formulations, but again only with respect to the symmetric product. Since the symmetric products are not related to any physical power quantity, the modes do not form a (radiated) power orthogonal set in the lossy case. Hence, for lossy structures CMs do not satisfy their classical definition and they need to be redefined.

show abstract

Section: Discussionmentioning

confidence: 99%

Orthogonality Properties of Characteristic Modes for Lossy Structures

Kuosmanen

Ylä‐Oijala

Holopainen

et al. 2022

IEEE Trans. Antennas Propagat.

View full text Add to dashboard Cite

show abstract

“…YPICALLY, for antenna design, it is promising to maximize the channel capacity via a multiple-inputmultiple-output (MIMO) system to approach the limit of channel capacity during propagation. Thus, Under the demand for high accuracy and low latency nowadays, the basic research on efficient characterization of MIMO systems is very important [1]. On this basis, we can carry out further work such as the optimization solutions for the power and phase allocation of antenna units.…”

Section: Introductionmentioning

confidence: 99%

An Electromagnetic Information Theory Based Model for Efficient Characterization of MIMO Systems in Complex Space

et al. 2023

IEEE Trans. Antennas Propagat.

View full text Add to dashboard Cite

It is the pursuit of a multiple-input-multiple-output (MIMO) system to approach and even break the limit of channel capacity. However, it is always a big challenge to efficiently characterize the MIMO systems in complex space and get better propagation performance than the conventional MIMO systems considering only free space, which is important for guiding the power and phase allocation of antenna units. In this manuscript, an Electromagnetic-Information-Theory (EMIT) based model is developed for efficient characterization of MIMO systems in complex space. The group-T-matrix-based multiple scattering fast algorithm, the mode-decomposition-based characterization method, and their joint theoretical framework in complex space are discussed. Firstly, key informatics parameters in free electromagnetic space based on a dyadic Green's function are derived. Next, a novel group-T-matrix-based multiple scattering fast algorithm is developed to describe a representative inhomogeneous electromagnetic space. All the analytical results are validated by simulations. In addition, the complete form of the EMIT-based model is proposed to derive the informatics parameters frequently used in electromagnetic propagation, through integrating the mode analysis method with the dyadic Green's function matrix. Finally, as a proof-or-concept, microwave anechoic chamber measurements of a cylindrical array is performed, demonstrating the effectiveness of the EMIT-based model. Meanwhile, a case of image transmission with limited power is presented to illustrate how to use this EMIT-based model to guide the power and phase allocation of antenna units for real MIMO applications.

show abstract

“…A more general computational framework is proposed in Refs. [27][28][29] which bounds the total information capacity of a communicating domain by optimizing over freely varying currents in a larger bounding domain. This approach, however, forcefully restricts the optimization space of the free-varying currents to bound the information capacity of a MIMO system that only has access to N number of communication channels [29].…”

Section: Introductionmentioning

confidence: 99%

“…[27][28][29] which bounds the total information capacity of a communicating domain by optimizing over freely varying currents in a larger bounding domain. This approach, however, forcefully restricts the optimization space of the free-varying currents to bound the information capacity of a MIMO system that only has access to N number of communication channels [29]. Such restrictions yield an optimization space, represented by the span of the first N optimal communication channels of the bounding domain, that does not encompass all possible current distributions of any Nchannel MIMO system.…”

Section: Introductionmentioning

confidence: 99%

Bounds on the Coupling Strengths of Communication Channels and Their Information Capacities

Kuang¹,

Miller²,

Miller³

2022

Preprint

View full text Add to dashboard Cite

The concept of optimal communication channels shapes our understanding of wave-based communication. Its analysis, however, always pertains to specific communication-domain geometries, without a general theory of scaling laws or fundamental limits. In this article, we derive shapeindependent bounds on the coupling strengths and information capacities of optimal communication channels for any two domains that can be separated by a spherical surface. Previous computational experiments have always observed rapid, exponential decay of coupling strengths, but our bounds predict a much slower, sub-exponential optimal decay, and specific source/receiver distributions that can achieve such performance. Our bounds show that domain sizes and configurations, and not domain shapes, are the keys to maximizing the number of non-trivial communication channels and total information capacities. Applicable to general wireless and optical communication systems, our bounds reveal fundamental limits to what is possible through engineering the communication domains of electromagnetic waves.

show abstract

Physical Bounds and Radiation Modes for MIMO Antennas

Cited by 13 publications

References 21 publications

Orthogonality Properties of Characteristic Modes for Lossy Structures

Orthogonality Properties of Characteristic Modes for Lossy Structures

An Electromagnetic Information Theory Based Model for Efficient Characterization of MIMO Systems in Complex Space

Bounds on the Coupling Strengths of Communication Channels and Their Information Capacities

Contact Info

Product

Resources

About