Wideband equivalent-circuit model analysis, realization and time-domain spectroscopy characterization of terahertz periodic metamaterial devices

In my PhD thesis, I have thoroughly researched THz periodic metamaterial devices by dealing with all the phases of their development: electromagnetic analysis, design, fabrication, characterization, and data post-processing. Initially, for the analysis and design phases, I have adopted an analytical/numerical perspective for the retrieval of the devised circuit topologies. In particular, I have developed and applied equivalent circuit models and parametric macromodels for the physical investigation and optimization of the devices; these methods have been validated by proving their efficiency and effectiveness through the comparison with finite-element method based simulations. Also, they guarantee a wider range of applications in terms of frequency spectra, complexity of geometrical shapes, and material characteristics. For the realization phase, I have used a heuristic procedure of micro-fabrication and after evaluating possible non-idealities, I have made tolerance studies in order to obtain a stable electromagnetic performance. For the characterization of the flexible devices, I have used custom THz-TDS setups for both reflection and transmission-modes; the resulting configurations have proved to be compact and interesting also for further integration in embedded measurement systems. For the data analysis phase, I have post-processed the acquired measurements by implementing retrieval procedures of the constitutive parameters of the samples. Other than topics specifically related to the THz field, I have developed some models of analytical/numerical character for the study of scatterers with discontinuous impedance boundary conditions.