Investigation on the Ohmic Conductor Losses in Substrate-integrated Waveguide and Equivalent Rectangular Waveguide

The substrate-integrated waveguide (SIW) is an artificial waveguide structure that is fabricated in planar dielectric substrate with periodic metallic cylinders, and can be analyzed as an equivalent rectangular waveguide (RW). In this letter, the formula of the conductor loss in SIW has been derived from the conductor loss formula of conventional RW. In addition, the equality condition at which the conductor losses in SIW and RW are exactly equal has been found. The conductor losses in SIW and RW have been investigated and compared, good agreement has been observed between the theoretical calculations and HFSS numerical simulations.