Graduate Thesis Or Dissertation


Design of Passive Millimeter-Wave Coaxial Components for Additive Manufacturing Public Deposited

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  • Additive manufacturing is gaining popularity in many different areas acrossengineering and science, with functional devices and systems being used for both prototyping and end-use. Steady improvement in the accuracy of 3D printing technologies has seen their increased adoption for RF applications deep into millimeter-wave frequencies. This thesis presents an overview of the current commercially available 3D printing techniques and examples of their utilization for fabrication of high-end RF components.

    Coaxial lines have seldom been considered, mainly due to the challenges associated with the physical support of the inner conductor. This work demonstrates an implementation of additive manufacturing for the fabrication of non-radiating components such is air-filled coaxial transmission lines also used as a mechanical anchor in an RF system and quadrature hybrid. Both components are designed and measured as stand-alone devices. On the system level, a coaxial anchor is integrated with a helix antenna also designed for additive manufacturing. The design feasibility is demonstrated in the direct metal laser sintering (DMLS) process for coaxial anchor, coaxial quadrature hybrid, and helical antenna integrated with the coaxial anchor for millimeter-wave frequencies 18GHz to 40GHz. Each device has a specific band inside the mentioned frequency range.

    The stereolithography (SLA) process is also used, however, mainly for proof of concept fabrication prior to the DMLS fabrication. Also, the SLA and the fused deposition modeling (FDM) are used for radome fabrication for helical antenna ii environmental protection enhancement. The environmental impact on helical antenna performances is assed with a thermal/pressure chamber developed in this thesis. The designed systems can achieve good performance across a wide, instantaneous bandwidth (air-filled coaxial anchor and helical antenna) and low levels of imbalances (coaxial quadrature hybrid). Also, the environmental impact is minimal on AUT performances.

Date Issued
  • 2022-04-19
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  • 2022-12-13
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