Towards an Advanced Analysis of Smooth Circular Horns Using Transformation Optics and Hierarchical Model Reduction

We present an advanced analysis framework for waveguide devices with circular ports, applied here to the preliminary study of circular horns with smooth walls and axial symmetry. The method combines transformation optics with hierarchical model reduction, providing an efficient and accurate approach to device characterization. Radiation at the horn aperture is modeled through mode matching by terminating the output port with a cylindrical load of twice the horn aperture radius. Future developments will incorporate a perfectly matched layer around this cylinder to more accurately capture free-space impedance loading. The proposed framework offers a fast and reliable design tool for horn antennas with linear and nonlinear smooth tapers.