Study of Cutoff Frequencies of Open or Closed Periodic Waveguides by Conformal Mapping

Abstract

Using the studies realized by Meinke [1], Tisher and Yee [2] and Laura [3] to determine by conformal mapping the cutoff frequencies for TM or TE waves in waveguides of very general cross-section, we show that it is possible to generalize it to periodic waveguides with EH waves [4]. For rectangular overdimensioned waveguides with sinusoidal or rectangular corrugations, the comparison of the theoretical and experimental results is satisfactory when corrugations are relatively large compared with wavelength.