Improved Low Reflection Transition From Microstrip Line to Empty Substrate-Integrated Waveguide

Abstract

Substrate integrated waveguides (SIW) maintain the advantages of planar circuits (low loss, low profile, easy manufacturing, integration in a planar circuit board), and improve quality factor of filter resonators. Empty substrate integrated waveguides substantially reduce the insertion losses because waves propagate through air instead of through a lossy dielectric. The first empty substrate integrated waveguide (ESIW) used a simple tapering transition that can not be used for thin substrates. A new transition has recently been proposed which includes a taper also in the microstrip line, not only inside the ESIW, and so it can be used for all substrates, although measured return losses are only 13 dB. In this work the cited transition is improved by placing via holes that prevent undesired radiation, as well as two holes that help to ensure good accuracy in the mechanization of the input iris, thus allowing very good return losses (over 20 dB) in the measured results. A design procedure, that allows the successful design of the proposed new transition, is also provided. A back to back configuration of the improved new transition has been successfully manufactured and measured.

Compact Multilayer Filter in Empty Substrate Integrated Waveguide With Transmission Zeros

“…The filter manufacture has been done layer by layer. The first layer is the bottom cover, the next corresponds to the input and output lines including the microstrip-to-ESIW transitions (which allow the connection between the filter and the vector network analyzer (VNA) -Anritsu MS4644- [22]), the third layer matches with the first resonator and the corresponding piece of the multilayer transition; and so on, until reaching the top cover that encloses the ESIW (see Fig. 10).…”

Review of Substrate Integrated Waveguide Circuits for Beam-Forming Networks Working in X-Band

“…Moreover, the authors did not specify how the sandwich of layers was glued. Also, many transitions between planar waveguides (i.e., microstrips or coplanar waveguides) and empty SIW have been designed [76][77][78][79][80][81].…”

Highly Reliable and Repeatable Soldering Technique for Assembling Empty Substrate Integrated Waveguide Devices

“…In order to feed this filter with planar lines, the transition of section III of [8] has been used. The simulated results for this filter, including the transitions to microstrip feeding lines, can be seen in Fig.…”