A Critical Review of Interconnect Options for SIW Technologies

Despite extensive research on integrating Substrate Integrated Waveguide (SIW) technologies with conventional transmission technologies such as Microstrip Transmission Line (MSTL), Co-planar Waveguide (CPW), Rectangular Waveguide (RWG), and Coaxial lines, a comprehensive evaluation and design framework has yet to be explored. This review addresses this critical gap by providing a detailed examination of recent advancements in interconnect technologies at millimeter-wave (mmWave) frequencies. The paper identifies unresolved challenges and introduces a Figure-of-Merit (FoM) for the first time designed to evaluate and decide the state-of-the-art in interconnect technologies. Furthermore, it proposes a novel design flow that aids interconnect designers by integrating reported advances into a well-defined process. As such, the study provides a basis for further developments, leveraging existing and SIW technologies to ease mmWave system development, along with a commercial perspective.