Empirical formulas for propagation constant calculation of leaky circular waveguide

The approach for analyzing the propagation constant of leaky circular waveguide with periodic slots is given in this paper, which is different from that of the traditional closed waveguide. The relationships between the waveguide parameters and the normalized propagation constant of the leaky circular waveguide are analyzed. Based on the analysis, empirical formulas for propagation constant calculation of leaky circular waveguide can be derived via curve-fitting method using the data obtained from numerical method, which are very valuable for the investigation on the cut-off wavelength and the spatial harmonics of leaky circular waveguide.