Periodic Metallo-Dielectric Structures: Electromagnetic Absorption and its Related Developed Temperatures.

Jean Paul Walker,Aisha S Haynes,Haim Grebel,Venkataraman Swaminathan

doi:10.3390/ma12132108

Abstract

Multi-layer, metallo-dielectric structures (screens) have long been employed as electromagnetic band filters, either in transmission or in reflection modes. Here we study the radiation energy not transmitted or reflected by these structures (trapped radiation, which is denoted—absorption). The trapped radiation leads to hot surfaces. In these bi-layer screens, the top (front) screen is made of metallic hole-array and the bottom (back) screen is made of metallic disk-array. The gap between them is filled with an array of dielectric spheres. The spheres are embedded in a dielectric host material, which is made of either a heat-insulating (air, polyimide) or heat-conducting (MgO) layer. Electromagnetic intensity trapping of 97% is obtained when a 0.15 micron gap is filled with MgO and Si spheres, which are treated as pure dielectrics (namely, with no added absorption loss). Envisioned applications are anti-fogging surfaces, electromagnetic shields, and energy harvesting structures.

Highlights

They are composed of a top metal film with a hole-array. This type of screen is known as an inductive screen; on its own, the screen serves as a transmission band filter
A disk-array screen is known as a capacitive screen; on its own it serves as a reflection band filter
Both metal screens are separated by a dielectric layer, which is embedded with dielectric colloids

Summary

Introduction

They are composed of a top (front) metal film with a hole-array. This type of screen is known as an inductive screen; on its own, the screen serves as a transmission band filter. A disk-array screen is known as a capacitive screen; on its own it serves as a reflection band filter Both metal screens are separated by a dielectric layer, which is embedded with dielectric colloids. Figure show a standalone single, micron thick copper film with circular openings airin (an inductive screen).

Monolayer

Simulations

Temperature distribution

3.3.Conclusions