Two different coupling circuits, capacitive and inductive, are introduced. These coupling circuits are analyzed by laboratory measurements. The measurements of the load impedance of coupling circuits are realized. The general discontinuity in communication path is presented in form of coupling circuit. The influence of position of coupling circuit and number of branches on transfer function is also demonstrated. In addition, the simple model of coupling circuit was designed and the effect of discontinuity and impedance mismatch will be shown on the multipath model.