A THIN AND BROADBAND MICROWAVE ABSORBER BASED ON MAGNETIC SHEETS AND RESISTIVE FSS

Abstract

To achieve broadband microwave absorption, a three-layer structure is designed and manufactured. It involves a resistive frequency selective surface (FSS) sandwiched between two layers of magnetic sheets. The measurement results reveal that this structure exhibits −13 dB reflectivity in the frequency range of 7.9-18 GHz while the thickness is only 1.7 mm. The reflectivity bandwidth at the level of −10 dB is 11.4 GHz which is much wider than that of magnetic sheets with non-resistive FSS or the magnetic sheets without FSS. The effect of resistive FSS on the performance of the multilayered absorber is discussed in detail. It is concluded that an embedded resistive double loops FSS can result in a secondary resonance peak which obviously broadens the reflectivity bandwidth of the magnetic sheets.