Mutual impedance of two probes located in two different waveguide regions separated by a homogeneous dielectric slab: fullwave analysis

The paper presents a fullwave analysis of the mutual impedance of two probes located in the different regions I and III of an infinite rectangular waveguide that are separated by a homogeneous dielectric medium. Basic formulations of electromagnetic fields in such a waveguide and the mutual impedance of two probes are first given in terms of dyadic Green´s functions. Secondly, dyadic Green´s functions for different regions of the waveguide due to a source located in the region I are constructed and their coefficients are obtained by making use of the boundary conditions. Thirdly, the fields in the region III due to a dipole located in the region I of the waveguide are also derived. To evaluate the probe mutual impedance, the xˆxˆ-component of dyadic Green´s function for the region III due to a source in the region I is furthermore obtained. The mutual probe impedance is then integrated analytically to derive the mutual resistance and reactance of the probes. Numerical computations are made finally to show the effects of the filled medium on the mutual resistance and reactance. The results given here can be applied to the analysis of the antenna coupling in the waveguides as well as in the tunnel communications