An efficient boundary-integral-equation technique for accurate analysis of leakage and coupling effects in arbitrary transmission lines

Design of modern radio-frequency and microwave devices and their integration with other subsystems requires a deeper knowledge of the coupling and leakage mechanisms in transmission lines and printed circuits: in many cases, crosstalk can be understood and effectively counteracted by resorting to the notion of leaky-wave excitation. This work presents a numerical technique based on boundary integral equations for the analysis of arbitrarily-shaped guiding structures: unlike other full- wave numerical approaches (finite elements, finite differences, etc.), the proposed method allows searching for complex eigensolutions such as leaky waves as well. On the other hand, the approach can be applied to the vast majority of guiding structures, without suffering the limitations of most of the "ad hoc" semi-analytical techniques (transverse resonance, spectral domain approach, etc.) commonly used for investigating leaky-wave solutions. Various examples are provided to show the attractive computational features of the present implementation.