Spectral domain: A numerical ray launching method for curved structures

In this paper, the numerical method created and validated for propagation modeling within waveguides, cavities, or structures with dielectric or conducting curved interfaces, is presented, revalidated for new applications (cylindrical waveguides, parabolic antennas and S-cavities). This method is called shooting Spectral Rays and Tracking (SRT) and it is based on the discretization of the plane wave spectrum of the source fields, truncated by the guide or cavity aperture (without any approximation, neither far field nor asymptotic). From this decomposition, fields at any observation point in the cavities or waveguides are expressed as a discrete sum of all contributions from ray tubes tracked within the propagation environment. The proposed method appears to be appealing in terms of numerical efficiency and precision compared to other ray based methods used in similar contexts or a reference solutions, in order to validate asymptotic methods such as Gaussian beam launching.