Dual-polarized absorptive frequency selective reflector with reconfigurable absorption intensity and tunable reflection band

Abstract One absorptive frequency selective reflector (AFSR) for dual-polarization and wideband, is proposed and characterized by tunable reflection notch and reconfigurable absorption intensity. By placing a lossy frequency-selective surface (FSS) with four PIN diodes above the metal plane, a wideband absorptive structure with reconfigurable absorption intensity is constructed, and the capacitance of the varactor diode within the lossless layer can be efficiently modulated through an external voltage, enabling rapid and dynamic tuning of the notch frequency. The mechanisms of reconfigurable absorption and adjustable notch are revealed by investigating on the equivalent circuit models and surface currents. The measured experiment results show that the AFSR presents tunable notch band from 4.85 to 7.52 GHz, strong absorption band from 4.31 to 6.88 GHz and 7.96 to 11.28 GHz. By varying resistance of the loaded PIN diodes, the reflectivity within the absorption band can be dynamically tuned, ranging from approximately 0 dB to -10 dB. It offers significant insights for the design of antenna reflector systems aimed at reducing radar cross-section (RCS) out of band.