The state-of-the-art terahertz systems employ conventional, bulky, optical system design approach that lags the miniaturization, high-density integration, and mobility of the terahertz imaging systems. On the other hand, the motivation for miniaturization of the terahertz systems using integrated circuits (ICs) is limited by the conventional terahertz waveguide performance that requires utilization of a novel waveguiding technology. The spoof surface plasmon polariton (SSPP) waveguide (WG) measurements have recently been reached the record low insertion loss per unit length performance among all planar terahertz WGs at 0.3 THz suggesting tremendous potential for demonstration of high-performance terahertz ICs. Nevertheless, the real potential of the terahertz imaging systems requires demonstration of an imaging system that can provide high-resolution feature extraction of the targets covered by obstacles at real-terahertz frequencies. We present the design and simulation of 135° spoof surface plasmon polariton (SSPP) bending circuits at 1 THz that are one of the most fundamental building blocks in novel IC technologies that will enable development of high-performance, high-resolution terahertz imaging systems along with the investigation of the coupling mechanism of the SSPP waves through non-aligned waveguide geometries that is mandatory for implementing standalone terahertz ICs.
The terahertz imaging systems bring the advantage of both optical and microwave frequency spectrums, thanks to the invasion capability of the terahertz waves through different media providing high-resolution imaging at real terahertz frequencies such as 1 THz. Nevertheless, the state-of-the-art terahertz technologies employ bulky optical system design approach. In consequence, the state-of-the-art terahertz systems are not suitable for high mobility terahertz imaging applications. On the other hand, the state-of-the-art terahertz integrated circuits (TICs) suffer from high attenuation due to conventional terahertz waveguides, and hence, a novel high-performance terahertz waveguide is needed. In this paper, we present the investigation of loss performance of spoof surface plasmon polariton (SSPP) waveguides (WGs) that operate at 1 THz, which will enable the demonstration of compact and high-performance TICs. We present a relationship between the corrugation dimensions, radiation, and metallic losses and guided wavenumber for the first time. The proposed SSPP WGs are able to transmit the terahertz wave in expense of an insertion loss of -4.93 dB through 250 µm at 1 THz.
