Analytical expressions for reflection coefficients of artificially soft and hard surfaces: dielectric slab loaded with a periodic array of strips over a ground plane

1995 ◽  
Vol 142 (2) ◽  
pp. 145 ◽  
Author(s):  
Shuguang Chen
Author(s):  
N.B. Chertova ◽  
◽  
Yu.V. Grinyaev ◽  

The stress-strain state on the interface of the elastic solids is investigated. The studied interface presents a contact layer which is characterized by dimension and the set of physics mechanical parameters. The models of layered and block medium are used for the description this boundary. In the framework of these models the problem of elastic wave propagation through the interface is considered. Analytical expressions for the refraction and reflection coefficients allowing us to determine the strains on the interface and strains distribution in the contact layer are found. Corresponding strains amplitudes depending on the layer thickness are calculated at the different elastic parameters of contacting solids and boundary. The strain laws on the interface which is described by the layered and block medium models are analyzed. The regions of equivalent use these models are determined in the case of strain analysis on the boundary and the strain distribution in the contact layer.


2015 ◽  
Vol 13 ◽  
pp. 161-168 ◽  
Author(s):  
R. Rambousky ◽  
J. Nitsch ◽  
S. Tkachenko

Abstract. By applying the Transmission-Line Super Theory (TLST) to a practical transmission-line configuration (two risers and a horizontal part of the line parallel to the ground plane) it is elaborated under which physical and geometrical conditions the horizontal part of the transmission-line can be represented by a classical telegrapher equation with a sufficiently accurate description of the physical properties of the line. The risers together with the part of the horizontal line close to them are treated as separate lines using the TLST. Novel frequency and local dependent reflection coefficients are introduced to take into account the action of the bends and their radiation. They can be derived from the matrizant elements of the TLST solution. It is shown that the solution of the resulting network and the TLST solution of the entire line agree for certain line configurations. The physical and geometrical parameters for these corresponding configurations are determined in this paper.


2020 ◽  
Vol 20 (4) ◽  
pp. 320-326 ◽  
Author(s):  
Kyeong-Sik Min

This paper proposes a multiband cross-shaped inverse triangular notch antenna on a circular ground plane for a radio shadow zone mobile communication design for a broadband repeater antenna in the firefighting band for in-building mobile communication. To arrive at the broad and multi-bandwidth reflection coefficients, methods are considered for optimizing the cross-shaped notch antenna with an inverse triangular structure and the circular ground plane. The measured reflection coefficients are observed −10 dB lower in the firefighting band (440–450 MHz) and the mobile repeater band (890–2,450 MHz), and they agree well with those obtained through simulation. The desired omni-directional patterns are obtained in the firefighting band, even though the radiation patterns in the Wi-Fi band have directivity from 10° to 15° and from −10° to −50°. The measured radiation patterns and gains also agree well with the predictions.


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