Transparent conformal metasurface absorber for ultrawideband radar cross section reduction

Abstract

Flexible metasurface based absorbers have gained significant importance in recent years due to their possible use in non-planar radar stealth applications, however, their narrow bandwidth and insensitivity to incidence angles limit their potential use. In this work, we present an ultrawideband and angular insensitive metasurface absorber based on indium tin oxide (ITO), polyethyleneterephthalate (PET), and polyvinyl chloride (PVC), that is both transparent and flexible. Broad-spectrum absorption can be maximized by using ITO with modest sheet resistance upon interaction with electromagnetic (EM) waves. To further validate the absorption performance, the RCS characteristics are investigated. The results indicate that over 10 dB RCS reduction is realized across an ultra-wide frequency range of 13.30– 39.76 GHz, with relative bandwidth up to 100% for planar metasurface under linearly (LP) and circularly (CP) polarized incidence EM waves. Furthermore, the RCS reduction performance of a metasurface is well maintained in the abovementioned frequency band when it is bent with various bending angles. The proposed metasurface is a promising contender for practical applications in microwave stealth technology due to its additional advantages of visible transparency, mechanical flexibility, low profile, outstanding angle stability, and polarization insensitivity.