Leaky properties of microstrip above a perforated ground plane

Abstract

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(A,max) (maximum available power gain) of the prototype points to a substantial excitation of the EH1 leaky mode, over 50% leakage of input energy for the 72 mm long prototype at 6.5 GHz.