Electromagnetic Simulations of Wide Angle and Polarization Insensitive Broadband Radar Absorbing Structure

Abstract

In this paper, we present the design and simulation of a wide-angle
and polarization-insensitive broadband radar absorbing structure
based on a lossy composite. The simulation was carried out in the
COMSOL Multiphysics environment and the unit-cell of the design is
composed of a three-layer structured assembly placed over a copper
ground plane. The polarization and incident angle dependency of the
designed absorber have been simulated. Also, its absorption
behaviour was theoretically evaluated to validate the simulation
result. The simulation result under normal incidence shows reflectivity
below -10dB (over 90% absorption) in a broad frequency range from
5.1–18GHz. The simulation result was correlated with the calculated
result and the results were found to be consistent with one another.
Broadband absorption performance is stable for up to 300
incident
angles in both the transverse electric (TE) and transverse magnetic
(TM) polarization and insignificantly changes at 450
. Simulated
reflectivity curves when polarization angles are varied from 00 to 600
under normal incidence are observed to overlapped, indicating that
the proposed structure absorption level is indifferent to polarization
directions. Therefore, the proposed radar absorbing structure can be
suggested for potential applications in stealth and electromagnetic
interference shielding.