Study of Wideband, Wide Angle, Polarization Independent Metamaterial Hilbert Curve Absorbing Screen for Terahertz Bolometers

Abstract

A wideband, wide angle metamaterial Hilbert curve array terahertz absorbing screen is reported. The absorber consists of array of an Aluminum first order Hilbert curve array over a copper ground plane separated by dielectric spacer. 100% fractional bandwidth (-3dB absorption bandwidth) for normal incidence and more than 90% in case of oblique incidence of 45°and 60°for both TE and TM polarizations have been verified numerically. The operating bandwidth of the structure proposed here is several times of those reported to date. Peak absorption is 98% for normal incidence and more than 86% for 60°angle of incidence for either polarization. Furthermore, effects of variations in Hilbert curve dimensions, spacer thickness, spacer permittivity and ground plane conductivity are also investigated. The structure is shown to have high tolerance to variations in the aforementioned parameters.

Broadband Metamaterial Absorbers

“…[69] The nanostructures obey certain detection. [129] The structure in this reference differs from the conventional Hilbert curves, in that it uses resistive curves while in the case of traditional Hilbert curve absorbers, the material used is highly conductive. It achieves a fractional bandwidth (bandwidth of a device divided by its center frequency) of 100% for normal incidence and more than 90% in case of oblique incidence of 45° and 60° for both TE and TM polarizations.…”

Multi-band metamaterial absorber made of multi-gap SRRs structure

“…MM absorbers are available in the microwave region [7], THz region [8,9], infrared [10], and visible frequencies [11]. Now, the research into MM absorber has shown a trend into the multi-band [12,13], wide bandwidth [14,15], and tunable direction [16]. The perfect performance of a multiband MM absorber had been presented in [12], in which the structure is composed of six-closed rings distributed in two metallic layers.…”