Lightweight, Ultra‐Wideband, and Polarization‐Insensitive Metamaterial Absorber Using a Multilayer Dielectric Structure for C‐ and X‐Band Applications

Abstract

The design of a lightweight and ultra‐wideband absorber for C and X bands is still a challenge as the dimension of the absorber is relatively large in such a relatively low‐frequency band. Herein, an ultra‐wideband and lightweight metamaterial absorber (MMA) is presented for C‐ and X‐band applications. The unit cell of the proposed MMA consists of four copper sectors loaded by lumped resistors and a continuous copper ground plane, which is printed on two FR‐4 substrates. Furthermore, an airgap separating the FR‐4 layers is used as the active substrate medium of the MMA to achieve both ultra‐wideband absorption spectra and lightweight design. The MMA is investigated by simulation and measurement, showing that a good agreement is achieved. The result indicates that the absorptivity of the MMA under both transverse electric (TE) and transverse magnetic (TM) polarizations is greater than 90% in a wide range from 3.7 to 13.6 GHz for all polarization angles. Compared to other reported broadband absorbers, the proposed MMA shows an ultra‐wide absorption bandwidth and a lightweight design, which demonstrates a great potential for C‐and X‐band applications.

Ultra-Wideband and Lightweight Electromagnetic Polarization Converter Based on Multiresonant Metasurface

“…The effects of the air-gap thickness on the performance of the proposed polarization converter can be explained by the transmission line theory. The equivalent circuit of a unit cell of proposed structure can be illustrated in [32]. The admittance of metallic resonant patch and the admittance of the FR4 dielectric slabs and the airgap are connected in parallel to form the input admittance of the proposed structure.…”

“…To meet the lightweight requirement, the thickness of FR-4 substrates are fixed to 0.8 mm. As a result, the resonant frequencies can be adjusted using the thickness of the airgap (k) [32]. Furthermore, an optimized airgap thickness can be found to create the resonances that give the largest impedance matching and yield the widest broadband characteristic.…”

Design of wideband metamaterial absorber using circuit theory for X‐band applications

“…The small thickness of MMAs makes them suitable for lightweight applications. Moreover, the fabrication costs are significantly low for MMAs [26][27][28][29].…”

A Simple Design of Water-based Broadband Metamaterial Absorber for THz Applications

“…However, designing the broadband absorber remains a challenging issue, especially in the THz region [12]. Therefore, many different methods have proposed to broaden the bandwidth of absorbers, such as using multi-resonators in a unit cell [4], vertical stacking metal-dielectric multi-layers [13,14], and lumped elements [15,16] or using graphene [17][18][19], or vanadium dioxide [20][21][22], and MoS 2 [23].…”