Tuneable spiral shape multilayer microwave absorber

Microwave absorber is a material that attenuates energy in the electromagnetic wave. To cover a wideband of frequencies, a thick microwave absorber is needed. In this project, the effect of spiral shape on the microwave has been studied. A spiral shape which act as absorbent layer on the microwave absorber can give good absorption performance. The absorbent layer is made up from mixture of carbon black and paint. The absorption performance of the microwave absorber was measured using free space arch reflectivity method in the range between 8 GHz to 12 GHz. From the result, it can be said spiral shape of microwave absorber can enhance the absorption performance. Absorber with loop non painted shows the best absorption performance with its maximum absorption is -3.6 dB. The smaller size of loop gives the best absorption performance with average absorption of -3.4 dB.