Propagation of a radio wave pulse in cold plasma

2007 ◽  
Vol 7 (1) ◽  
Author(s):  
G. M. Strelkov
Keyword(s):  
Radio Wave ◽  
Cold Plasma ◽  
Wave Pulse

Further Comparisons of Meteorological Soundings by Radio Waves With Radiosonde Data†

1941 ◽  
Vol 22 (2) ◽  
pp. 53-61 ◽  
Author(s):  
Albert W. Friend
Keyword(s):  
Reflection Coefficient ◽  
Radio Wave ◽  
Continuous Recording ◽  
Radiosonde Data ◽  
Radio Waves ◽  
Wave Pulse ◽  
Continuous Pulse

Summary Radio wave pulse echoes can be utilized for continuous recording of all meteorological discontinuities to the base of the stratosphere. Both operations and preliminary theory show that extremely weak reflections are superimposed upon a continuous pulse reflection background up to the base of the stratosphere. This allows observation of almost infinitesimal reflection variations as humps on the general reflection background of reflection coefficient about 10−6 to 10−7 (when 123 meter waves are used). New equipment to replace this now obsolete station awaits utilization.

Evaluation of the accuracy of reconstruction of the electrophysical and geometric parameters of multilayer dielectric coatings by the multi-frequency radio wave method of a slow surface electromagnetic waves

2020 ◽  
pp. 51-58
Author(s):  
Aleksandr I. Kazmin ◽  
Pavel A. Fedjunin
Keyword(s):  
Radio Wave ◽  
Noise Level ◽  
Electromagnetic Waves ◽  
Dielectric Materials ◽  
Geometric Parameters ◽  
Experimental Investigations ◽  
Wave Method ◽  
Dielectric Coatings ◽  
Surface Electromagnetic Waves ◽  
Multilayer Dielectric

One of the most important diagnostic problems multilayer dielectric materials and coatings is the development of methods for quantitative interpretation of the checkout results their electrophysical and geometric parameters. The results of a study of the potential informativeness of the multi-frequency radio wave method of surface electromagnetic waves during reconstruction of the electrophysical and geometric parameters of multilayer dielectric coatings are presented. The simulation model is presented that makes it possible to evaluate of the accuracy of reconstruction of the electrophysical and geometric parameters of multilayer dielectric coatings. The model takes into account the values of the electrophysical and geometric parameters of the coating, the noise level in the measurement data and the measurement bandwidth. The results of simulation and experimental investigations of reconstruction of the structure of relative permittivitties and thicknesses of single-layer and double-layer dielectric coatings with different thicknesses, with different values of the standard deviation (RMS) of the noise level in the measured attenuation coefficients of the surface slow electromagnetic wave are presented. Coatings based on the following materials were investigated: polymethyl methacrylate, F-4D PTFE, RO3010. The accuracy of reconstruction of the electrophysical parameters of the layers decreases with an increase in the number of evaluated parameters and an increase in the noise level. The accuracy of the estimates of the electrophysical parameters of the layers also decreases with a decrease in their relative permittivity and thickness. The results of experimental studies confirm the adequacy of the developed simulation model. The presented model allows for a specific measuring complex that implements the multi-frequency radio wave method of surface electromagnetic waves, to quantify the potential possibilities for the accuracy of reconstruction of the electrophysical and geometric parameters of multilayer dielectric materials and coatings. Experimental investigations and simulation results of a multilayer dielectric coating demonstrated the theoretical capabilities gained relative error permittivity and thickness of the individual layers with relative error not greater than 10 %, with a measurement bandwidth of 1 GHz and RMS of noise level 0,003–0,004.

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