Leaky properties of microstrip above a perforated ground plane

A leaky line is proposed. The leaky line emits leaky wave by feeding the bound mode that is not supposed to leak. The proposed guiding structure consists of a microstrip above a perforated ground plane with etched holes positioned anti-symmetrically. A prototype is built and tested to verify the concept. The two-port scattering parameters of the leaky line employing the well-known full-wave integral equation method agree well with the measured data. The investigation of RPA (relative power absorbed) and G/sub A,max/ (maximum available power gain) of the prototype points to a substantial excitation of the EH/sub 1/ leaky mode, over 50% leakage of input energy for the 72 mm long prototype at 6.5 GHz.