Frequency selective surface based radio frequency absorber at 90GHz of operational frequency

Frequency ranging from 0.3GHz to 300GHz in Electromagnetic (EM) waves are known as Microwaves, for these wave the wavelengths use to be of the order of 1m to 1mm. These waves obeys all the laws of optics like reflection, absorption and refraction depending upon the boundary conditions of two mediums. Most of the time it is needed to absorb the EM waves to avoid the reflections in the DUT test zones. As per the available literature, EM wave absorbers can be designed & developed either using dielectric materials like carbon impregnated foam or using frequency selective surfaces (FSS). Foam based absorbers works on the principal of absorbing the incident EM wave and converting these EM energy into heat. Absorbers can provide two different type of losses i.e. electric loss and magnetic loss. Type of loss provided by absorbers depends upon the dielectric properties whether it is complex permittivity or complex permeability. Compact size of the absorbers can be achieved by using material with high value of permeability which can be achieved from ferrite or magnetic absorbers, but it can be achieved after pledging notable amount of time and resources A frequency-selective surface (FSS) is any papery, unvaried surface designed to follow the laws of optics to EM waves depending upon frequency, polarization, and angle of incidence. FSS resonating unvaried periodic array which depends upon the polarization, Angle of incidence and frequency of EM wave.In past decennium, a notable number of works and studies has been performed to work out the development of FSS surfaces. This area is still active to develop the structure that can control the indenting EM waves and provide a good amount of absorption to them.This paper presents a proof of concept demonstrating the efficient designing technique with minimum time and fabrication complexity & challenges. This concept shows the model produces a simple structure and provide around 90% RF Absorption at 90GHz of operational frequency.