scholarly journals Effects of Curved Wavefronts on Conductor-Backed Reflection-Only Free-Space Material Characterization Techniques

2015 ◽  
Vol 2015 ◽  
pp. 1-9
Author(s):  
Raenita A. Fenner ◽  
Edward J. Rothwell
Keyword(s):  
Plane Wave ◽  
Magnetic Permeability ◽  
Free Space ◽  
Material Characterization ◽  
Plane Waves ◽  
Characterization Methods ◽  
Radar Absorbing Material ◽  
Absorbing Material ◽  
Space Material ◽  
The Impact

A true plane wave is often not physically realizable in a laboratory environment. Therefore, wavefront curvature introduces a form of systematic error into Free-space material characterization methods. Free-space material characterization is important to the determination of the electric permittivity and magnetic permeability of conductor-backed and in situ materials. This paper performs an error analysis of the impact on wavefront curvature on a Free-space method called the two-thickness method. This paper compares the extracted electric and magnetic permeability computed with a plane wave versus a line source for a low-loss dielectric and magnetic radar absorbing material. These steps are conducted for TE and TM plane waves and electric and magnetic line sources.

Free space material characterization of carbon nanotube thin films at sub-terahertz frequencies

2016 ◽  
Vol 30 (5) ◽  
pp. 589-598
Author(s):  
Sujitha Puthukodan ◽  
Ehsan Dadrasnia ◽  
Vinod V. K. Thalakkatukalathil ◽  
Horacio Lamela Rivera ◽  
Guillaume Ducournau ◽  
...  
Keyword(s):  
Thin Films ◽  
Carbon Nanotube ◽  
Free Space ◽  
Material Characterization ◽  
Terahertz Frequencies ◽  
Space Material

Reflection of spherical seismic waves in elastic layered media

Geophysics ◽  
1983 ◽  
Vol 48 (6) ◽  
pp. 655-664 ◽  
Author(s):  
Paul M. Krail ◽  
Henry Brysk
Keyword(s):  
Plane Wave ◽  
Seismic Waves ◽  
Plane Waves ◽  
Spherical Wave ◽  
Bright Spot ◽  
Angle Of Incidence ◽  
Complicated Manner ◽  
Plane Wave Incident ◽  
Wave Limit ◽  
The Impact

The solution of the elastic wave equation for a plane wave incident on a plane interface has been known since the turn of the century. For reflections from reasonably shallow beds, however, it is necessary to treat the incident wave as spherical rather than plane. The formalism for expressing spherical wavefronts as contour integrals over plane waves goes back to Sommerfeld (1909) and Weyl (1919). Brekhovskikh (1960) performed a steepest descent evaluation of the integrals to attain analytic results in the acoustic case. We have extended his approach to elastic waves to obtain spherical‐wave Zoeppritz coefficients. We illustrate the impact of the curvature correction parametrically (as the velocity and density contrasts and Poisson’s ratios are varied). In particular, we examine conditions appropriate to “bright spot” analysis; expectedly, the situation becomes less simple than in the plane‐wave limit. The curvature‐corrected Zoeppritz coefficients vary more strongly (and in a more complicated manner) with the angle of incidence than do the original ones. The determination of material properties (velocities and densities) from the reflection coefficients is feasible in principle, with exacting prestack processing and interpretation. For orientation, we outline the procedure for the simple case of a separated single source and detector pair over a multilayered horizontal earth.

Electromagnetic waves

2018 ◽  
Author(s):  
Nathalie Deruelle ◽  
Jean-Philippe Uzan
Keyword(s):  
Plane Wave ◽  
Electromagnetic Waves ◽  
Maxwell Equations ◽  
Plane Waves ◽  
Geometrical Optics ◽  
Particle Detection ◽  
Spatial Coordinates ◽  
A Charge

This chapter examines solutions to the Maxwell equations in a vacuum: monochromatic plane waves and their polarizations, plane waves, and the motion of a charge in the field of a wave (which is the principle upon which particle detection is based). A plane wave is a solution of the vacuum Maxwell equations which depends on only one of the Cartesian spatial coordinates. The monochromatic plane waves form a basis (in the sense of distributions, because they are not square-integrable) in which any solution of the vacuum Maxwell equations can be expanded. The chapter concludes by giving the conditions for the geometrical optics limit. It also establishes the connection between electromagnetic waves and the kinematic description of light discussed in Book 1.

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