Miniaturization of Microwave to Millimeter-Wave Integrated Waveguides and their Applications

• Author / Creator

  Jones, Thomas R

• The integration of waveguide technology at the planar level has been a crucial development for the successful realization of 5G, the future fifth generation cellular network. The demand for mobile networks with faster speeds, lower latencies, and denser connectivity scenarios continues to drive the development of microwave systems with increased integration without sacrificing performance. Over the last two decades, substrate integrated waveguides (SIW) have emerged as a promising technology for 5G, offering a low-cost, high performance alternative to traditional planar systems. However, the need for smaller form factors limits their application in certain situations, where their overall size becomes a challenge.
  Much progress has been made in the miniaturization of SIW, taking advantage of the unique opportunities of waveguides integrated inside a substrate, such as high aspect ratios and multilayer fabrication technologies. However, even greater miniaturizations remain both possible and essential for increased integration and performance, while reducing both the cost and size of 5G systems.
  In this thesis, a new type of miniaturized integrated waveguide platform is investigated. Through the effective combination of different SIW miniaturization techniques, the realization of several ultra-compact integrated waveguide systems are presented.
  First, the combination of ridged and half-mode SIW technologies are explored, producing broadside miniaturizations up to 75% compared to standard SIW. Furthermore, by reducing radiation losses closer to cutoff, the performance compared to half-mode SIW is also improved. Applications of the proposed technology are explored, including high density interconnects, hybrid couplers, bandpass filters, and passive non-contact sensors.
  Next, folded waveguide techniques are applied to the ridged half-mode SIW to reduce its broadside width by an additional 50%, thus resulting in a total miniaturization of 88% compared to standard SIW. Furthermore, application of the proposed technique in the design of miniaturized SIW cavity is shown to reduce the footprint up to 98%, producing transverse dimensions of approximately λ/16, while also increasing spurious-mode bandwidth more than 200%. Applications in tunable and reconfigurable bandpass and bandstop filters are then explored.
  As the need for more bandwidth pushes 5G systems up into the millimeter-wave frequency spectrum, the integration of waveguides at the wafer-level becomes increasingly important. Thus, a flexible and low-cost CMOS compatible microfabrication process is developed, and the first realization of a miniaturized monolithic wafer-level air-filled integrated waveguide platform for millimeter-wave 5G communication systems is presented. Fabricated prototypes employing ridged half-mode and folded ridged half-mode waveguide techniques are demonstrated, achieving broadside miniaturizations of 66% and 73% compared to standard rectangular waveguide, respectively. The results demonstrate the potential of the proposed miniaturized monolithic integrated waveguide platform for low-loss high-density millimeter-wave interconnects for 5G communication systems.

• Subjects / Keywords

  • Miniaturization
  • Microfabrication
  • Waveguide
  • Tunable Filter
  • Millimeter-Wave
  • Substrate Integrated Waveguide
  • Microwave
  • Reconfigurable FIlter

• Graduation date

  Fall 2019

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/r3-kj81-sf41

• License

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