Surface Leaky Waves and Their Measurement

A new approach to experimental identification of surface leaky waves on printed-circuit lines is presented in this paper. Active radiometry is used for field probing even in the near field zone. The measurement is adjusted into the X band. The method is demonstrated on the slotline. Consequently the line is scaled in order to investigate the 1st and 2nd leaky waves which, on a standard-sized substrate, occur in the mm-wave range only. The high rate of polarization distinctness of the probe enables us to distinguish particular field components. We present the first very promising results.