3-D radial loading of cylindrical cavities with multiple rectangular waveguides

Summary form only given. An analytical method for calculating the natural modes of a cylindrical (or coaxial) cavity loaded by radially directed rectangular waveguides has been developed. In order to avoid the limitations of lumped circuit parameter models, the electromagnetic fields in the cavity and waveguide regions are written as a doubly infinite series of their natural harmonics. The fields are matched across the cavity-waveguide interface, and a harmonic decomposition of the cavity electric fields is carried out by analytically integrating around the interior surface of the cylinder and waveguide entrance. A similar integration is performed with respect to the magnetic field components over the curved cavity-waveguide boundary surface using the waveguide harmonics. The coefficients of the cylindrical (Bessel function) terms are algebraically eliminated, and a linear system of equations containing the waveguide expansion coefficients (only) is obtained