Square Patch-Based Dielectric Microwave Absorber

Abstract

Abstract-The work presents a simple and novel design approach to extend the bandwidth of existing Dielectric Material Based Microwave Absorber (DMBMA). The design comprises planar square patches of DMBMA placed periodically on a metalbacked FR4 sheet. For demonstration purpose, the DMBMA is synthesized by adding conducting carbon fillers in polyurethane matrix, and its electromagnetic parameters are measured in X-band. A single reflection null is observed in DMBMA owing to λ/4 resonance. In comparison, the bandwidth of 8 GHz (10-18 GHz) is achieved for −10 dB reflection for square patch based DMBMA. The thickness of proposed absorber is 2.75 mm. An additional resonant mode is observed due to capacitive coupling between the square patches. The enhanced bandwidth is attributed to the overlapping of λ/4 resonance and induced coupling mode. A good agreement between the simulated and measured data is observed.

Design and Characterization of Square Patch Salisbury Screen Microwave Absorber

“…The patches are placed manually on a metal sheet with the periodicity of 12 mm, by epoxy based adhesive. The performance of absorber is measured in an anechoic chamber using VNA and a pair of horn antennas [7]. The good degree of correlation is observed between the simulated and measured data ( Fig.…”

“…3(b) and 3(c) for TE and TM modes, respectively. The orientation of the absorber under TE and TM modes for different angle of incidence is discussed in [7]. The performance of the absorber under TE and TM modes is stable up to an angle of incidence 30 • and normal incidence respectively.…”

“…5(c)). The absorber efficiently reduces the reflection in comparison to metal for every aspect angle [7]. The reduced reflection is attributed to absorption of the incident wave by the absorber.…”

“…The reported literature suggests that by introducing additional resonance modes lead to the bandwidth improvement viz. square patch based absorber and SSMA with wire metamaterial [7,8].…”