Two coaxial lines cross-coupled to a rectangular waveguide

The boundary-value problem of two coaxial lines cross-coupled to a rectangular waveguide is solved. The techniques of Fourier transform, mode matching, image method and superposition are used to obtain an analytic solution. Residue calculus and Poisson´s summation formula are employed to transform the solution into a fast convergent series that is numerically efficient. Computations are performed to verify the validity of the series solution.