Design of Flexible Metamaterial Absorber for Broadband Microwave Applications

This paper presents a broadband flexible metamaterial absorber (MMA) for X- and Ku-band microwave applications. The unit cell resonator consists of a periodic array of sectional square and sectional circular loops with 8 identical lumped resistor chips. The unit cell is numerically investigated. The simulation results show that the proposed structure achieves a broadband absorption over the ultra-wide frequency region covering X- and Ku-bands, from 7.45 GHz to 18.8 GHz, with an absorptivity of above 90%. The angular response of the unit cell is also investigated. The proposed absorber shows wide-incidence angle and polarization-independent absorption spectra up to 45° for TE and TM polarizations. The unit cell is electrically thin, which is only 2.85 mm. Therefore, the proposed metamaterial absorber can be used as a flexible broadband absorption platform in various practical applications.