Flexible broadband terahertz absorbers for RCS reduction on conformal surfaces

Flexible broadband terahertz absorbers (FBTAs) have attracted great attention in recent years due to their promising potential for nonplanar objects, however, these applications are limited by rigorous requirements for being insensitive to arbitrary incident angles. Herein, we have proposed an ameliorated angular insensitivity method by integrating the appropriate amount and type of building absorbers into a hybrid flexible array according to spatial distributions and surface curvatures. Based on the integrable strategy, we have successfully designed three types of FBTAs with diverse robustness and insensitivity for wide incident angles. The radar cross section (RCS) reductions for these FBTAs are theoretically investigated to further validate their absorption performance. Additionally, the equivalent circuit theory is employed to reveal the underlying physical mechanism of the bandwidth expansion. It can be deduced that our proposed strategy would be beneficial to broaden the bandwidth and enhance the angular independence of flexible absorbers and provide several promising prospects in the development of emerging functional THz technologies.