Design of an Ultra-Thin Magnetic-Type Radar Absorber Embedded With FSS

In this letter, the design of an ultra-thin magnetic-type radar absorber (RA) having good absorbing performance at low frequency is demonstrated. A 2-mm-thick RA with an operating bandwidth of 1.5-2.2 GHz is obtained on the basis of polymer composites filled with carbonyl iron and Co(2)Z ferrite. The use of frequency selective surfaces (FSSs) results in a significant increase of operating bandwidth of the RA. By selecting the unit dimensions of FSS and its location in RA, a maximal operating bandwidth can be obtained. Experimental results are presented and compared to numerical simulations, and they demonstrated that the RA embedded with FSS has a significantly increased bandwidth of 1.19-2.89 and 1.08-3.02 GHz for the single-layer or double-layer case.