A polarization‐insensitive ultra‐wideband absorber based on hybrid structure

Abstract

With the continuous improvement of detection technology, the survivability of targets on the battlefield is facing great challenges. Consequently, microwave absorbers with stealth characteristics are of important research value to modern military. Aim at solving the problems of narrow bandwidth or complex structure, an implementation model of ultra‐wideband (UWB) absorber based on hybrid structure is proposed. In this letter, a polarization‐insensitive ultra‐wideband absorber (PIUWA) is designed, manufactured, and characterized, which has a good absorptivity of more than 90% ranges from 4 to 24.53GHz (the fractional bandwidth [FBW] is 144%) by triggering multiple resonance peaks in the hybrid structure. In addition, the subwavelength periodicity of the PIUWA is theoretically beneficial to the angular stability under full‐wave polarizations. The operating mechanism of the PIUWA is demonstrated by the equivalent circuit model and the correctness of the design is verified by experimental measurements. This letter contributes to the approach of designing and fabricating UWB microwave absorbers with high absorptivity, good angular stability, and simpler assembly procedure.