Dielectric Constant Measurement Using Metallized Slot Substrate Integrated Waveguide at PCB Process

Traditional via wall substrate integrated waveguide (SIW) can be realized in PCB process. As it does not have continuous side walls, its equivalent width is required to extract substrate εr from measured β. This paper presents a metalized slot SIW (MS-SIW) that can be realized by PCB process and has continuous side walls. Continuous side walls allow the use of close form equation to extract substrate εr from measured β. Fabrication flow and circuit design for transmission line method to extract ε_r using MS-SIW is presented for 30GHz ~ 65GHz. Comparison with microstrip strip line method shows less than 2% difference in extracted dielectric constant.