Wideband RWG-SIW Interconnection With Improved Integration for Millimeter-Wave/Terahertz Application

In this letter, wideband interconnections are proposed to connect metal rectangular waveguide (RWG) and substrate integrated waveguide (SIW) based on printed circuit board (PCB) technology. For the purpose of easy fabrications and micro-assembly processes in millimeter-wave/terahertz (MMW/THz) applications, a standard RWG is used to feed the transition without any manufactures in the metal waveguide. The wideband interconnection structure with improved impedance matching is only designed in a single-layer PCB. Particularly, the novel interconnections are realized by stepped dielectric transformers using PCB technology. These integrations have the advantages of simple structure, low fabrication cost, and easy processes. To demonstrate the scheme, two 220-GHz band interconnections are designed as examples. Back-to-back interconnections are fabricated and measured. The measured results agree well with the simulated results. It can be concluded that the measured insertion and return losses of both single interconnections are better than 0.9 and 10 dB, respectively, in the frequency range from 180 to 240 GHz (28.6%).