Fundamental Limitations for Antenna Radiation Efficiency

Shahpari, Morteza; Thiel, David V.

doi:10.1109/tap.2018.2836447

Cited by 42 publications

(38 citation statements)

References 41 publications

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“…It can be seen that the efficiency of the proposed antenna satisfies the general bound for a conductivity greater than 10 6 S/m, below which the results start to deviate similar to results presented in [7]. The efficiency of the proposed antenna indicates a very low reduction in efficiency due to the presence of the dielectric.…”

Section: Manufacturing and Resultssupporting

confidence: 67%

“…The complex manufacturing and the presence of a dielectric necessitates the investigation of the radiation efficiency of the proposed antenna which provides a simple feasibility check of the proposed antenna. The radiation efficiency of the proposed antenna has been compared to the theoretical bound [7]. The proposed antenna displays a theoretical efficiency of better than 98%.…”

Section: Introductionmentioning

confidence: 99%

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A Compact Dielectric-Filled Slotted Cavity Mimo Antenna

Sheel¹,

Coetzee²

2018

PIER Letters

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Abstract-This paper presents a compact slotted MIMO cube antenna operating at 5.8 GHz, consisting of three orthogonal slots, each with a distinct main direction of radiation. Each slot produces linear polarization enabling the structure to radiate three orthogonal polarizations. This provides spatial diversity which helps mitigating the effects of multipath propagation and enhances the diversity gain. The cube is filled with a dielectric with a relative permittivity, ε r thus reducing the minimum dimension of the cube by a factor of 1/ √ ε r . The antenna has a return loss of 20 dB and a coupling of less than −26 dB between the ports. This paper describes the principle operation as well as the design and manufacturing process of the proposed antenna.

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Section: Manufacturing and Resultssupporting

confidence: 67%

Section: Introductionmentioning

confidence: 99%

A Compact Dielectric-Filled Slotted Cavity Mimo Antenna

Sheel¹,

Coetzee²

2018

PIER Letters

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“…Expressing unknown currents in a finite dimensional basis, the finite dimensional matrix operators governing quantities of interest may be readily calculated using the tools developed for solving integral equation problems [23], i.e., using the method of moments [24]. Problems in antenna theory solved in this way include maximization of directive gain [25,26,27], maximization of radiation efficiency [28,26,29], minimization of Q-factor (analogous to maximizing bandwidth) [30,31], and the trade-off between these parameters [32,27].…”

Section: Introductionmentioning

confidence: 99%

Upper bounds on absorption and scattering

et al. 2020

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C Radiation modes 30 D Material models 33Abstract A general framework for determining fundamental bounds in nanophotonics is introduced in this paper. The theory is based on convex optimization of dual problems constructed from operators generated by electromagnetic integral equations. The optimized variable is a contrast current defined within a prescribed region of a given material constitutive relations. Two power conservation constraints analogous to the optical theorem are utilized to tighten the bounds and to prescribe either losses or material properties. Thanks to the utilization of matrix rank-1 updates, modal decompositions, and model order reduction techniques, the optimization procedure is computationally efficient even for complicated scenarios. No dual gaps are observed. The method is well-suited to accommodate material anisotropy and inhomogeneity. To demonstrate the validity of the method, bounds on scattering, absorption, and extinction cross sections are derived first and evaluated for several canonical regions. The tightness of the bounds is verified by comparison to optimized spherical nanoparticles and shells. The next metric investigated is bi-directional scattering studied closely on a particular example of an electrically thin slab. Finally, the bounds are established for Purcell's factor and local field enhancement where a dimer is used as a practical example.

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“…The radiation efficiency enhancement due to copper electroplating can be explained as follows. It is well known that a highly conductive surface provides a high radiation efficiency . The conductivity of copper (5.8 × 10 7 S/m) is more than graphite (1 × 10 5 S/m) material.…”

Section: Resultsmentioning

confidence: 99%

“…However, the graphite might lead to a reduction in conductivity, which impacts radiation efficiency and absorption cross section of the antennas . But, by using a conductive coating, the radiation efficiency can be significantly improved . The modern communication systems desire high data rate and reliability with improved system capacity, which can be achieved by using a multi‐port antenna configuration.…”

Section: Introductionmentioning

confidence: 99%

Carbon fiber‐based deca‐port multiple‐input‐multiple‐output antenna with pattern diversity and high inter‐element isolation

Mishra

Das

Pattnaik

et al. 2020

Int J RF Microw Comput Aided Eng

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In this article, a deca-port carbon fiber-based multiple-input-multiple-output (MIMO) antenna with pattern diversity is presented. The radiating elements of the proposed antenna consist of low cost, light weight, environmental friendly graphite material. The 10 radiating elements of the MIMO antenna are arranged in a group of two (termed as sub-MIMO structure), in a cubical manner to cover all the propagating directions. Furthermore, the two carbon fiber-based radiating elements of the sub-MIMO structure are placed in an orthogonal arrangement to generate different radiation patterns. The antenna exhibits high inter-element isolation and low envelope correlation coefficient due to orthogonal placement of the radiating elements. The antenna is fabricated and the measured results confirm that the proposed MIMO/diversity antenna may be useful for vehicle-to-network applications. The MIMO performance parameters such as diversity gain, total active reflection coefficient, mean effective gain, channel capacity loss are evaluated and found within suitable limits. The three-dimensional pattern diversity helps to communicate in all directions.

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Fundamental Limitations for Antenna Radiation Efficiency

Cited by 42 publications

References 41 publications

A Compact Dielectric-Filled Slotted Cavity Mimo Antenna

A Compact Dielectric-Filled Slotted Cavity Mimo Antenna

Upper bounds on absorption and scattering

Carbon fiber‐based deca‐port multiple‐input‐multiple‐output antenna with pattern diversity and high inter‐element isolation

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