PRINCIPLES OF APPLICATION OF ULTRATHIN COATINGS FOR SHIELDING ELECTROMAGNETIC RADIATION OF MAN-MADE ORIGIN
Abstract
Purpose. To develop the principles of using ultrathin metallized coatings for shielding electromagnetic radiation of technogenic origin.
Methods. Theoretical justification of obtaining ultrathin metal coatings for optimal shielding of electromagnetic fields of ultrahigh and higher frequencies. Empirical confirmation that sputtering a thin metal layer on glass provides protection from the effects of electromagnetic radiation and does not significantly reduce the penetration of daylight.
Results. It was established that the reflection coefficient for coatings up to 10 nm thick can provide reflection coefficients of electromagnetic waves up to 25 dB. Calculation relations are provided for determining the conductivity of a metal film, which is significantly different from the bulk conductivity and determines the value of the shielding coefficient. The dependences of the reflection coefficients of sputtering in common metals on the film thickness are provided. The effect of achieving a maximum reflection coefficient at a certain film thickness is established. It is calculated to show what happens when the film thickness is equal to the skin layer thickness for a given radiation frequency. This makes it possible to optimize the thickness of the metal coating both from the point of view of electromagnetic safety and based on lighting needs.
Novelty. Based on calculations, it was established that a stable value of the reflection coefficient of electromagnetic waves is achieved at a certain frequency of the electromagnetic field, provided that the film thickness reaches the thickness of the skin layer in the metal.
Practical significance. It was established that in the ultrahigh and ultrahigh frequency ranges, the reflection coefficient of electromagnetic waves for a fixed film thickness practically does not depend on the radiation frequency. To increase the shielding efficiency of glass with metal coating, it is desirable to ground the metallized layer.
