Investigation of Spectral Characteristics for Microstructured Quasi-Optical Bandpass Subteraherz Filters

The electrodynamic features of quasi-optical bandpass filters based on multilayer microstructured frequency selective surfaces intended for effective spectral selection of subteraherz electromagnetic radiation are considered. As an optimal solution, the multiplex filters are highlighted wherein tripole-slot self-bearing copper microstructures free from dielectric substrates are employed. The results of the experimental development for such filters are presented by the example of structures with resonant transmission at the frequencies of 0.6 and 1 THz, and the details of testing their spectral performance in the range of 0.1-1.5 THz using a BWO spectroscopy technique are described. Good agreement between the experimental data and the results of theoretical predictions is demonstrated.