Ultra-wide transmission band frequency-selective rasorber using 2.5-D miniaturized structures

Abstract

In this paper, a miniaturized frequency-selective rasorber (FSR) with an ultra-wide transmission band (| S21 | <1 dB) is presented. The FSR is made up of a lossless multi-layer cascaded frequency-selective surface (FSS) with a 2.5-D lossy layer above, separated by an air gap. Modified metallic Jerusalem crosses loaded with lumped resistors serve as the unit cell of the lossy layer. An equivalent parallel LC circuit with high inductance and extremely low parasitic capacitance is introduced by zigzag strips and vias, which broaden the transmission band significantly. The equivalent circuit model (ECM) is constructed to provide further insight into the structure. Simulation results show that the proposed FSR exhibits an ultra-wide transmission band of 1-dB from 6.20 to 17.97 GHz (97.4%) with a minimum insertion loss of 0.074 dB. Meanwhile, an 80% absorption band covering 2.58-4.13 GHz is achieved below the passband. For demonstration, an experimental prototype of the 2.5-D FSR is fabricated and measured, and the simulated and measured results are reasonably consistent.

Multi-characteristic Integrated Ultra-wideband Frequency Selective Rasorber

“…The relative bandwidths of these 2D FSRs can reach about 30% with broad absorption. To further expand the passband bandwidth, a 2.5D ATA FSR with a relative bandwidth (−1 dB passband) of 40.5% is proposed, but the two absorption bands are narrow [35,36]. In addition, some researchers have introduced 3D FSRs based on parallel waveguides and planar slot lines to obtain better performance, achieving a relative bandwidth of 40% of −1 dB passband and two wide absorption bands [37][38][39].…”

Intelligent electromagnetic mapping via physics driven and neural networks on frequency selective surfaces

“…To uncover the EM mappings between various structures and beam properties in an intuitive and simple way, Marcuvitz [34] proposed the classical equivalent circuit model (C-ECM), in which the structures with infinite length were intuitively regarded as cascades of lumped elements. Since then, the theory of equivalent circuit models (ECMs) has been extensively optimized and introduced into analyzing complex structures [9,[35][36][37][38][39][40][41][42][43][44][45]. Unlike the C-ECM, later models concentrated on finite length structures, which were still based on the C-ECM but beyond the application scope.…”