With the advent of better terahertz (THz) sources and detectors in the last few decades this frequency range has increasingly been investigated to provide solutions in fields such as nondestructive evaluation, security imaging, health monitoring, biological tissues and sample inspection, and electronic circuits and systems. THz radiation holds great potential for these varied applications because it is non-ionizing, or safe for use with biological tissues, and because it offers the highest frequencies and largest bandwidth while still accommodating all electrical solutions (i.e. non-optical). One of the building blocks in using THz radiation in such applications is having a low-loss, ultra-wide bandwidth waveguide, or interconnect, with which to connect other circuits into a larger system.Current trends in data consumption are driving a need to further increase the rate and bandwidth at which common electrical devices transmit data. Many solutions have been proposed using optical and electrical interconnects to address this problem but an ideal solution has yet to be realized. This is primarily due to optical interconnects inherent latency in needing to convert between electrical and optical signals, and because electrical solutions either suffer from metal losses, crosstalk, or narrow bandwidth. In this thesis a waveguide design is proposed as a possible solution to address this need that combines the design of a traditional metal waveguide and that of a ribbon waveguide. Theoretical analysis, simulations, fabrication, and measured results are presented for waveguides of both a circular and rectangular cross-section. Theoretical expressions have been derived by hand and simulations were performed using finite element tool ANSYS Electronics Desktop HFSS to create and simulate waveguide models. Fabrication processes used here have utilized 3D printed plastics to quickly and inexpensively create prototypes, and a frequency domain THz system was used to measure devices. Results show low-loss transmission up to 0.5 THz. Applications for passive THz components, sensors, and transmission line circuits are explored. This work includes additional circuits the waveguide design can be extended to including a power splitter, band-pass and band-stop filters, and a modified version of a dielectric rod antenna. Sensor applications are shown through a probe design and demonstrating how imaging could be performed with the probe. This work has implications for future integrated circuits ability in meeting the data transmission needs of the future.
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