Design of Multi-Layer Metamaterial in Terahertz Response

Abstract

The development of terahertz (THz) technology, which has the electromagnetic spectrum frequency between microwave and infra-red regions has attracted much research attention. However, due to various challenges in detection, generation and measurement of the THz waves, intense research have been carried out to enhance and tune the THz waves in order to close the ‘Terahertz gap’. One of the important ideas is to use metamaterial with Split Ring Resonators (SRR) scaled to the sub-THz wavelength size to obtain different THz resonance responses. SRRs produces the desired magnetic susceptibility (magnetic response) in various types of metamaterials. With the help of SRR, novel THz devices can be used in various applications such as THz filter. In the proposed work, SRR ring is designed & simulated using Polyethylene naphtha late (PEN) substrate which is 100 ?m in dimension. Transmission spectra responses with tunable resonances are obtained using these metamaterials. By stacking all the substrates together, a multiband THz filter at 0.3626THz is obtained. The bandwidth of this simulated filter compared to the single resonance response is 4.3 times bigger. According to the results, it shows that the SRR inside the stacked metamaterial are excited towards certain frequencies within the multiband response. Because of the stacking of more than one SRR layers there is improvement in the resonance properties. Multi-layer metamaterial provides tuning property for multiband THz devices. The above discussed structure is designed and simulated by Finite-integration time-domain using commercial software CST Microwave Studio 2014.