STUDY OF THE EFFECT OF LOOP ARRAYS ON AN ABSORBER

Abstract

Radar absorbing materials or RAM are coatings whose elecrical and magnetic properties have been altered to allow absorption of microwave energy at discrete or broad band frequencies, This type of absorber performance is limited by the intrinsic properties of the materials used and the maximum thickness permitted. In this dissertation an absorber consisting of a ferrite rubber sheet and with a thickness of 1.8 mm has been taken up for study. The absorber gave an absorption of about 10 dB from 13 to.. 18 GHz.. When a loop array of squares was incorporated with the absorber an absorption of about 13 dB was achieved from 12 to 18 GHz, But the incorporation of the double square loop array with the absorber gave an absorption of more than 10 dB from 8 to 18 GHz with peak absorption of 31 dB at 16.2 GHz. The-theoretical r.e,s ~ht_sApredieted-ar-e- compared with the experimental results and tti-e-i-r agreement confirms the correctness of theoretical as-s=umpt_i ons and r-e 1-a-t-i-o'ns---