Frequency control of a resonant radio absorber with a free space

Numerical calculations of the matching of a resonant radio absorber (RA) have confirmed that the ideal matching of such an RA with free space can be realized using practically any dielectrics with losses at any desired frequency. The conditions are considered that provide the widest matching band of the RA, and it is shown that the ratio of the bandwidth to the RA thickness (bandwidth to thickness ratio) is about 3.7, i.e., more than for the usual single-layer Dallenbach RA (about 3.2).Kotelnikov Institute of Radio Engineering and Electronics (Fryazino Branch), Russian Academy of Sciences; Tomas Bata University in Zlin (Czech Republic) [FW 010100327]Russian Academy of Sciences, РА