Design and Analysis of a Carbonyl Iron Powder/Epoxy Composite-Based Ultra-Wideband Multi-Pyramidal Magnetic Absorber Using an Equivalent Circuit Model

This paper presents a CIP/epoxy composite based ultra-wide band electromagnetic multipyramidal absorber. The constituent parameters of the CIP/epoxy composite is experimentally extracted using a waveguide measurement setup. This raw data is then quantified using a least-square fit polynomial based curve fitting technique to facilitate its use in the design and the analysis of the pyramidal absorber. Four asymmetrical truncated pyramids supported by a grounded base constitute the absorber unit cell. The absorption bandwidth of the design ranges from 3.21 GHz to 40 GHz (FBW of 170.3%, S - band to V - band) and stable absorption characteristics under oblique incidences is observed up to 35°. To enhance the understanding of its operational principles, an equivalent circuit model (ECM) based on planar multi-layer structure incorporating both synthetic capacitance and inductance models is proposed. Validation of the proposed absorber is done by measuring the performance of its prototype.