Digital metasurface for selective information distribution in the spatial domain in the THz region.

This paper presents a new, to the best of our knowledge, technique to control the flow of electron packets employing a switchable digital metasurface in the terahertz region. The proposed structure can act as a device that converts an electromagnetic (EM) wave into electron packets that can be represented in the form of digital bit sequences at the output. The top layer of the structure controls the intensity of the electron packets while the bottom layer involves the spatial distribution of the information with the help of electrical switching. The electrical switching is achieved with the application of suitable biasing across a vanadium dioxide (VO2) patch. This approach to the distribution of information helps feed the circuitry of an electronic system as per the requirement using electrical tuning, which is not possible in a conventional antenna system.

Design and mathematical analysis of a metasurface-based THz bandpass filter with an equivalent circuit model.

This paper presents successive studies of single-, double-, and triple-layered metasurface-based bandpass filters along with their equivalent circuit modeling and mathematical analyses. A triple-layered bandpass filter operating in the THz region is reported exhibiting flattop passband response while maintaining transmission of more than 95% over the entire passband starting from the design of a single-layered bandpass filter configuration. A stepwise mathematical analysis is carried out for the single-layered structure and compared with the simulation data, where the two results have been found in good agreement. Thereafter, the study is extended for double- and triple-layer bandpass filters. The triple-layered structure offers a very steep transition between passband and stopband with noise-free background, and thereby offers a potential candidate for 6G communication.