Diffraction of an electromagnetic wave incident obliquely on a perforated screen

1968 ◽  
Vol 11 (12) ◽  
pp. 1074-1078 ◽  
Author(s):  
B. A. Panchenko
Keyword(s):  
Electromagnetic Wave ◽  
Wave Incident ◽  
Perforated Screen ◽  
Electromagnetic Wave Incident

Decay Instability of an Electromagnetic Wave Incident on a Weakly-Inhomogeneous Magnetised Plasma

1982 ◽  
Vol 37 (2) ◽  
pp. 97-101
Author(s):  
Bhimsen K. Shivamoggi
Keyword(s):  
Electromagnetic Wave ◽  
Pump Wave ◽  
Low Frequency ◽  
Langmuir Wave ◽  
Density Perturbation ◽  
Threshold Value ◽  
Wave Incident ◽  
Ion Acoustic Wave ◽  
Decay Instability ◽  
Electromagnetic Wave Incident

Abstract This paper considers the parametric decay of an electromagnetic wave incident on a weakly-inhomogeneous magnetised plasma into a Langmuir wave and an ion-acoustic wave. The Vlasov model is used in order to calculate the low-frequency electron-density perturbation produced by the beating of the side-band modes with the pump wave. The results show that the threshold value of the pump wave to undergo a decay instability drops in the presence of an inhomogeneity in the plasma.

Electromagnetic Properties of Bearing Cement-Based Materials

2011 ◽  
Vol 261-263 ◽  
pp. 663-668
Author(s):  
Ai Li Guo ◽  
Ri Gao ◽  
Heng Jing Ba
Keyword(s):  
Electromagnetic Wave ◽  
Electromagnetic Waves ◽  
Building Materials ◽  
Incident Angle ◽  
High Strength ◽  
Wave Incident ◽  
Electromagnetic Properties ◽  
Frequency Range ◽  
Electromagnetic Wave Incident ◽  
Cement Based Materials

For studying absorption/bearing integration of building materials, high-strength cement-based materials were prepared by using active fly ash, silica fume and quartz, etc. Electromagnetic parameters of the cement-based materials were measured through coaxial method, and then by means of these parameters, the reflectivity of electromagnetic waves of the cement-based materials were simulated under variable electromagnetic wave incident angle (θ), frequency (f) and thickness of the material(d).The reflectivity of electromagnetic waves with 8~18GHz frequency range vertically transmitting into the cement-based materials was obtained through far field radar scattered cross-section measurement, and was compared with simulated reflectance under the same incident conditions. The results show that the high-strength cement-based materials with imaginary part of dielectric constant can consume energy of the incident electromagnetic wave. Incident angle less than 15° has little effect on the reflectivity of the cement-based materials in 2~18GHz frequency range. While the thickness of the cement-based materials is 15mm or 25mm, simulation results of the reflectivity are in good agreement with measured ones. Measured absorption peak and -10dB bandwidth increase with the increasing of thickness of the cement-based materials with compressive strength of 120.7MPa. This suggests that the cement-based materials studied in this paper have the characteristics of absorption/bearing integration.

CALCULATED DIFFRACTION PATTERNS OF DIELECTRIC RODS AT CENTIMETRIC WAVELENGTHS

1954 ◽  
Vol 32 (12) ◽  
pp. 775-781 ◽  
Author(s):  
Charlotte Froese ◽  
James R. Wait
Keyword(s):  
Electromagnetic Wave ◽  
Experimental Results ◽  
Wave Incident ◽  
Infinite Length ◽  
Dielectric Cylinder ◽  
Electromagnetic Wave Incident ◽  
Diffraction Patterns ◽  
Good Agreement

Diffraction patterns are calculated for a cylindrical electromagnetic wave incident normally on a dielectric cylinder of infinite length whose diameter is comparable to the wavelength. Reasonably good agreement is obtained when the results are compared with published experimental results.

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