Ultrawideband lightweight absorber based on composite strategy with active control of absorption in the UHF band

Abstract

In this paper, a composite strategy has been developed to achieve continuous absorption coverage from the ultrahigh-frequency (UHF) band up to the Ku band. Based on this strategy, an ultrawideband (UWB) lightweight composite metamaterial absorber is fabricated and measured. The composite absorber comprises two cascaded parts operating in separated frequency bands. First, we design a polarization-insensitive tunable absorber in the UHF band based on the equivalent circuit model (ECM). The measured results indicate that the tunable UHF absorber obtains a tunable -10 dB reflection coefficient from 0.88 to 1.48 GHz. Furthermore, a lightweight 3D absorber is applied to cascade with the tunable UHF absorber to constitute a UWB composite absorber. The composite absorber achieves an ultrawideband absorption ranging from 0.78 to 18 GHz with a reflection coefficient below -10 dB. The overall composite structure is extremely lightweight with a surface density below 0.2897 g/cm2. This composite absorber also exhibits good angular stability, low profile, and polarization insensitiveness. We think this work is of great application potential for military and civilian applications.

A bifunctional metamaterial with broadband properties of absorption and linear-to-linear polarization conversion

“…This remarkable flexibility unlocks the creation of metamaterials with a vast array of functionalities. Consequently, metamaterials find extensive practical applications in areas such as absorbers [9,10], polarization converters [11,12], reflectors [13], etc. * Author to whom any correspondence should be addressed.…”

Microwave meta‐absorber by using Smith Chart

“…Later, the EM absorber based on metasurfaces has been adopted to achieve RCS reduction since it has the unique ability to manipulate the amplitude, phase, and polarization properties of the EM wave 2,3 . Due to the advantage of compact size, low cost, and easy manufacture, various types of metasurfaces absorber (meta‐absorber) have been proposed frequencies 4–8 …”