Radio Absorbing Structure Based on Arrays of Resistive Squares
- PDF / 663,900 Bytes
- 5 Pages / 612 x 792 pts (letter) Page_size
- 93 Downloads / 176 Views
TRODYNAMICS AND WAVE PROPAGATION
Radio Absorbing Structure Based on Arrays of Resistive Squares V. I. Ponomarenkoa, * and I. M. Lagunova aVernadsky
Crimean Federal University, Simferopol, 295007 Russia *e-mail: [email protected]
Received April 24, 2019; revised April 24, 2019; accepted July 8, 2019
Abstract—A periodic structure consisting of plane arrays of resistive squares located in a dielectric layer on a metal mirror is considered. On the basis of the solution of the problem of diffraction of a normally incident electromagnetic wave by this structure, the optimal structure parameters that provide for the minimal reflection coefficient in a given wavelength range are calculated. It is shown that, when the number of arrays is up to three, the approximate calculation of the reflection coefficient of a fine-meshed structure can be performed using the method, in which the arrays are matched with films that have the effective surface resistance calculated on the basis of the solution of the quasi-static problem. It is also shown that the optimized investigated structure has the reflection level that is lower than the reflection level of the optimized known structure based on resistive films. DOI: 10.1134/S1064226920070098
1. FORMULATION OF THE PROBLEM An electromagnetic wave absorber (EWA) based on solid resistive films separated by nondispersive dielectric layers as the similar EWA based on conducting grids is considered. When the number of films (grids) between layers is given, the above EWAs have the level of the reflection coefficient (RC) in the working frequency range. This level is as smaller as the thickness of the structure with respect to the maximal wavelength is larger, which is typical for nonmagnetic EWAs [1, 2]. The decrease of the reflection level without increasing the thickness of EWAs or, which is interconnected, the decrease of the thickness without increasing the reflection [3—5] is actual. This is evident for application of EWAs in the microwave technology. In this work, we investigate the possibility to decrease the reflection level of the EWA containing many films by means of its fragmentation, exactly, by dividing the films into square elements separated by gaps. The efficiency of fragmentation for a EWA with one film is shown in [6—8]. The investigated structure shown in Fig. 1 consists of N plane arrays of resistive squares having surface resistances ρi and sides 2si , i = 1,2,… , N . The period of the structure is 2b . The arrays are in the dielectric layer having relative permittivity ε and separate it into layers of thicknesses {di }. The structure is on a metal mirror lying in the plane z = d . The plane electromagnetic wave depending on time according the law exp ( −i ω t ) is polarized along the x axis and is incident on the structure normally from the region of the free space z < 0 .
Along with the structure shown in Fig. 1, we investigate also the structure, in which neighboring arrays are shifted with respect to each other along axes x and y by the half of the period. 2. DIFFRA
Data Loading...
