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The Effect of Rotational Disorder on the Microwave Transmission of Checkerboard Metal Square Arrays.

Tremain B, Durrant CJ, Carter IE, Hibbins AP, Sambles JR - Sci Rep (2015)

Bottom Line: By applying rotational disorder to the elements comprising the arrays, with the lattice constant and element size unchanged, the electrical connectivity of the structure can be controlled whilst maintaining periodicity.When approximately half of the connections are broken, the resonant features are suppressed, with scattering loss shown to dramatically increase to as much as 40% of the incident power over a broad frequency range.The result is a thin, highly effective scatterer of microwaves.

View Article: PubMed Central - PubMed

Affiliation: School of Physics and Astronomy, University of Exeter, Exeter EX4 4QL.

ABSTRACT
The effect of rotational disorder on the microwave transmission through thin metallic checkerboard arrays has been experimentally studied. Broad resonant features below the onset of diffraction, attributed to electromagnetic radiation coupling through the structure via the evanescent fields of bound surface waves, are found to be strongly dependent on the electrical connectivity of the surface. By applying rotational disorder to the elements comprising the arrays, with the lattice constant and element size unchanged, the electrical connectivity of the structure can be controlled whilst maintaining periodicity. The results show that rotational disorder can significantly affect transmission only when it changes the structure's connectivity. When the initial structure is just above the connectivity threshold (where the metallic occupancy is 50%), increasing disorder causes the resonant features in transmission to invert as the structure switches from a predominantly connected array to a disconnected array. When approximately half of the connections are broken, the resonant features are suppressed, with scattering loss shown to dramatically increase to as much as 40% of the incident power over a broad frequency range. The result is a thin, highly effective scatterer of microwaves.

No MeSH data available.


Related in: MedlinePlus

50% metal occupancy arrays with increasing rotational randomness in square orientation defined by an increase in the standard deviation (σ) of a Gaussian distributed rotation: (a) σ = 0° (b) σ = 6° c) σ = 10° (d) random (uniform distribution corresponding to σ = 26.5°).
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f2: 50% metal occupancy arrays with increasing rotational randomness in square orientation defined by an increase in the standard deviation (σ) of a Gaussian distributed rotation: (a) σ = 0° (b) σ = 6° c) σ = 10° (d) random (uniform distribution corresponding to σ = 26.5°).

Mentions: as demonstrated in Fig. 2. The standard deviation has an upper limit of approximately 26.5° due to the fact that the rotation angle is a cyclic quantity. In addition, an array with truly ‘random’ rotations is studied by applying a uniform distribution which has the same standard deviation as this upper limit.


The Effect of Rotational Disorder on the Microwave Transmission of Checkerboard Metal Square Arrays.

Tremain B, Durrant CJ, Carter IE, Hibbins AP, Sambles JR - Sci Rep (2015)

50% metal occupancy arrays with increasing rotational randomness in square orientation defined by an increase in the standard deviation (σ) of a Gaussian distributed rotation: (a) σ = 0° (b) σ = 6° c) σ = 10° (d) random (uniform distribution corresponding to σ = 26.5°).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4645165&req=5

f2: 50% metal occupancy arrays with increasing rotational randomness in square orientation defined by an increase in the standard deviation (σ) of a Gaussian distributed rotation: (a) σ = 0° (b) σ = 6° c) σ = 10° (d) random (uniform distribution corresponding to σ = 26.5°).
Mentions: as demonstrated in Fig. 2. The standard deviation has an upper limit of approximately 26.5° due to the fact that the rotation angle is a cyclic quantity. In addition, an array with truly ‘random’ rotations is studied by applying a uniform distribution which has the same standard deviation as this upper limit.

Bottom Line: By applying rotational disorder to the elements comprising the arrays, with the lattice constant and element size unchanged, the electrical connectivity of the structure can be controlled whilst maintaining periodicity.When approximately half of the connections are broken, the resonant features are suppressed, with scattering loss shown to dramatically increase to as much as 40% of the incident power over a broad frequency range.The result is a thin, highly effective scatterer of microwaves.

View Article: PubMed Central - PubMed

Affiliation: School of Physics and Astronomy, University of Exeter, Exeter EX4 4QL.

ABSTRACT
The effect of rotational disorder on the microwave transmission through thin metallic checkerboard arrays has been experimentally studied. Broad resonant features below the onset of diffraction, attributed to electromagnetic radiation coupling through the structure via the evanescent fields of bound surface waves, are found to be strongly dependent on the electrical connectivity of the surface. By applying rotational disorder to the elements comprising the arrays, with the lattice constant and element size unchanged, the electrical connectivity of the structure can be controlled whilst maintaining periodicity. The results show that rotational disorder can significantly affect transmission only when it changes the structure's connectivity. When the initial structure is just above the connectivity threshold (where the metallic occupancy is 50%), increasing disorder causes the resonant features in transmission to invert as the structure switches from a predominantly connected array to a disconnected array. When approximately half of the connections are broken, the resonant features are suppressed, with scattering loss shown to dramatically increase to as much as 40% of the incident power over a broad frequency range. The result is a thin, highly effective scatterer of microwaves.

No MeSH data available.


Related in: MedlinePlus