scholarly journals HIGH-FREQUENCY SCATTERING FROM A COATED CYLINDER

1964 ◽  
Vol 42 (11) ◽  
pp. 2121-2128 ◽  
Author(s):  
P. L. E. Uslenghi
Keyword(s):  
Electromagnetic Wave ◽  
Scattered Field ◽  
High Frequency ◽  
Plane Electromagnetic Wave ◽  
Normal Incidence ◽  
Index Of Refraction ◽  
Wave Incident ◽  
Complex Index ◽  
Coated Cylinder ◽  
Complex Index Of Refraction

The scattered field produced by a plane electromagnetic wave incident on an infinitely long imperfectly conducting cylinder coated with a layer of material with complex index of refraction is considered. The geometric optics and the creeping wave contributions to the backscattered field are obtained, for normal incidence and small wavelengths.

INVESTIGATION OF COMPLEX INDEX OF REFRACTION OF GALLIUM NITRIDE GaN

2018 ◽  
Vol 14 (2) ◽  
pp. 29-39
Author(s):  
J O AKINLAMI ◽  
I O OLATEJU
Keyword(s):  
Dielectric Constant ◽  
Gallium Nitride ◽  
Photon Energy ◽  
High Frequency ◽  
Index Of Refraction ◽  
Complex Dielectric Constant ◽  
Complex Index ◽  
Maximum Value ◽  
Cell Arrays ◽  
Complex Index Of Refraction

An understanding of the complex index of refraction of Gallium Nitride (GaN) is important because of the increasing application of GaN in many high frequency, optical and electronics devices. Complex index of refraction of Gallium Nitride (GaN)have been investigated theoretically by means of Kramers and Kronig method in the photon energy range 2.0 – 10.0eV. We obtained refractive index which has a maximum value of 2.89 at photon energy 7.0eV, the extinction coefficient which has a maximum value of 1.17 at photon energy 7.0eV, the dielectric constant, the real part of the complex dielectric constant has a maximum value of 7.0 at photon energy 7.0eV and the imaginary part of the complex dielectric constant has a maximum value of 6.79 at photon energy 7.0eV, the transmittance which has a maximum value of 0.18 at photon energy 7.0eV, the absorption coefficient which has a maximum value of 86.18 at photon energy 7.0eV. The values obtained for complex index of refraction ofGaN are essentially important for emerging GaN applications such ashigh-power and high-frequency devices, solar cell arrays for satellites, communications and optoelectronics devices.

Optical properties of amorphous hydrogenated carbon films: A spectroscopic ellipsometry study

1987 ◽  
Vol 2 (5) ◽  
pp. 645-647 ◽  
Author(s):  
Shuhan Lin ◽  
Shuguang Chen
Keyword(s):  
Optical Properties ◽  
Spectroscopic Ellipsometry ◽  
Carbon Films ◽  
Index Of Refraction ◽  
The Real ◽  
Complex Index ◽  
Tentative Explanation ◽  
Amorphous Hydrogenated Carbon ◽  
Ellipsometry Data ◽  
Complex Index Of Refraction

Optical properties of plasma-deposited amorphous hydrogenated carbon films were studied by spectroscopic ellipsometry. From the ellipsometry data, the real and imaginary parts, n and k, of the complex index of refraction of the film have been deduced for photon energies between 2.0 and 4.0 eV for as-grown as well as for thermally annealed films. Here n and k showed considerable variation with subsequent annealing, even under 400°C. A tentative explanation of the results is proposed.

scholarly journals OPERATOR METHOD IN THE PROBLEM OF A PLANE ELECTROMAGNETIC WAVE DIFFRACTION BY AN ANNULAR SLOT IN THE PLANE OR BY A RING

2021 ◽  
Vol 26 (4) ◽  
pp. 350-357
Author(s):  
M. E. Kaliberda ◽  
◽  
L. M. Lytvynenko ◽  
S. A. Pogarsky ◽  
◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Circular Hole ◽  
Wave Diffraction ◽  
Scattered Field ◽  
Plane Electromagnetic Wave ◽  
Operator Method ◽  
Fredholm Integral Equations ◽  
Fourier Amplitude ◽  
Annular Slot ◽  
Electromagnetic Wave Diffraction

Purpose: The problem of a plane electromagnetic wave diffraction by an annular slot in the perfectly conducting zero thickness plane is considered. As a dual problem, the problem of diffraction by a perfectly conducting zero thickness ring is also considered. The paper aims at developing the operator method for the axially symmetric structures placed in free space. Design/methodology/approach: The problem is considered in the spectral domain. The scattered field is expressed in terms of unknown Fourier amplitudes (spectral functions). The annular slot is given as a unity of two simple discontinuities, namely of a disk and a circular hole in the plane, which interact with each other. The Fourier amplitude of the scattered field is sought as a sum of two amplitudes, the Fourier amplitude of the field of currents on the disk and Fourier amplitude of the field of currents on the perfectly conducting plane with circular hole. The operator equations are written for these amplitudes, which take into account the electromagnetic coupling of the disk and the hole in the plane. The equations use the reflection operators of a single isolated disk and a single hole in the plane. They are supposed to be known and can be obtained for example by the method of moments.The reflection operators can have singularities. After transformations, the equations are obtained, which are equivalent to the Fredholm integral equations of second kind and they can be solved numerically. Findings: The operator equations relative to the Fourier amplitudes of the field scattered by the discussed structure are obtained. The far zone scattered field for an annular slot and a ring for different values of parameters are studied. Conclusions: The rigorous solution of the problem of the electromagnetic wave diffraction by an annular slot in the plane and by a circular ring is obtained. The problem is reduced to the Fredholm integral equations of second kind. The far field distribution for different parameters is studied. The developed approach is an effective instrument for a number of problems of antenna technique to be solved. Key words: circular hole; disk; annular slot; ring; operator method; diffraction

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