Design and Analysis of Radar Absorbers using Smith Chart

In stealth applications, absorbers are specially designed structures to reduce the reflections of incident electromagnetic waves. In this paper, a Smith chart approach is detailed which enables the designer to visualize the layer-to-layer admittance and matching performance of the absorber. A conventional single-layer Salisbury screen and multi-layer Jaumann absorbers are designed and their performance is analyzed with the Smith chart. The parameters affecting the absorbers' performance are analyzed with the Smith chart and possible enhancement methods are discussed. The Jaumann absorbers with 2 to 8 layers are designed, and the impact of the layers on bandwidth enhancement is discussed. The mathematical calculations involved in the absorber design are detailed, and the calculated Smith chart results are verified with the EM solver simulated results.