Coupling characteristics between leaky coaxial cables with and without obstacle

The coupling characteristics between two leaky coaxial cables (LCXs) with transverse slots are analyzed by employing an equivalent method and superposition principle. In the method, two cables are used as transceiver, and the coupling characteristics are studied by analyzing the received signals in two ports of the receiving cable when the structure parameters and frequency change. It is found that the received signals are the same as the transmitted signal, only with a time delay and attenuation in amplitude. When there is an obstacle between the cables, the received signals regularly change with the location of the obstacle. Based on the analysis, a location detection method which is valuable to the design of intrusion detection system is discussed.