Abstract
Theoretical analysis of electromagnetic fields in an annular waveguide for application in annular waveguide slot antennas (AWSA) is presented in this paper for the first time. Important aspects such as sinusoidal field distributions and single mode operation in an annular waveguide are discussed and compared with a rectangular waveguide. By using simple approximations, valuable similarity between the two cases will be established finally. The resulting field distribution will be the basis for Green's function derivation of annular waveguides and for method of moment (MoM) analysis of the AWSA.