Dual-polarized Frequency-selective Rasorbers with Two Transmission Bands

In this paper, two frequency-selective rasorbers (FSRs) with a wide low-reflection band and two transmission bands are proposed. The FSRs are composed of a similar lossy resistive sheet (LRS) and different lossless frequency selective surfaces (FSSs) separated by air spacer. The LRS is composed of a resistor-loaded four-arm copper strip and a ring-shaped spiral interdigital structure in the center. The design is polarization-insensitive due to the symmetrical structure. The dual-band FSSs by etching two slots with different shapes and dimensions in a metallic plane. One of the two FSRs is with the passbands working at 6.6 GHz and 12 GHz. The passbands of another FSR are working at 2.1 GHz and 8 GHz. Both FSRs are with wideband -10 dB low-reflection performance, which cover the C and X bands. One of the FSRs is fabricated and measured. Moreover, the efficient and instructive design strategy of FSRs is summarized. The proposed designs provide alternatives for the stealth applications of satellites with two antennas.