Analysis of the Dispersion Characteristics in Substrate Integrated Waveguides with Periodic Walls

Periodic structures can be used for the practical design of waveguide filters. The dispersion diagram of the unit cell provides the design guidelines to generate a finite structure with very similar pass-and stop-bands (gaps). In this work, the dispersion diagram of an Electromagnetic Band-Gap (EBG) waveguide in SIW technology with periodic waveguide walls defined by irises with either rectangular or curved profile (i.e. with straight or rounded corners) is analysed. The effect of the irises dimensions, period, and curvature radius in the dispersion diagram and thus in the frequency response of the finite-size implementation of the proposed SIWs with periodic walls is discussed. The proposed SIWs with periodic walls may be combined with additional filtering elements inside the propagation region to achieve an improved filtering response.