Radiation Pattern and Aperture Admittance of Dielectric Filled Waveguides with Rectangular Cross Section using the Mode Matching Technique

A formulation for determining the aperture admittance and radiation patterns of dielectric filled waveguides with rectangular cross-section is presented. A variational expression for the aperture admittance is developed using the reaction concept of Rumsey, including higher order excitations. The radiated fields are computed using the Chu formulation. It is found that the higher order excitations, if included, slightly affect the aperture admittance but permit a more accurate determination of the radiation fields especially near 90°. The agreement between experiment and theory demonstrates the accuracy of the model presented.