Behavioral modeling of tubular wave coupler

In this work, a behavioral model of tubular wave couplers (TWC), whose use was recently included into automotive Standards for immunity verification of wiring harnesses in the frequency range from 400 MHz to 3 GHz, was derived. The model is based on scattering parameter measurements with the TWC mounted onto the calibration structure provided by the manufacturer, and the spurious effects related to such a fixture have been modeled and de-embedded from the measurement data. The proposed behavioral model allows physical insight into the TWC behavior (e.g., device directivity), and represents an important step for possible correlation of the TWC method with radiated susceptibility test procedures foreseen by the Standards.