An X-band meta-structure absorber based on gelated deep eutectic solvent

Abstract

Herein, a meta-structure absorber (MSA) with gelated deep eutectic solvent (DES) is proposed and investigated at X-band (8.2–12.4 GHz). The ionic property of DES gel assists in enhancing absorption. The unit cell of the MSA is designed using a dumbbell-shaped resonating structure of gelated DES enclosed in a flexible silicone rubber substrate. The embedded dumbbell structure makes the MSA robust by promoting fast recovery after bending. The developed absorber is optimized for wideband absorption. The total thickness of the MSA is <3 mm. The measured results showed −40.02 dB reflection loss at 10.55 GHz with a −10 dB bandwidth of 3.34 GHz (9.06–12.4 GHz). Additionally, the proposed absorber shows polarization and incident angle insensitivity up to an angle of ±50° in both transverse electric and transverse magnetic modes. The mechanism involved in absorption is investigated through field analysis at resonating frequency. Possible application of the designed absorber in antenna isolation is studied for co-sited broadband horn antennas operating at the X-band.