New Space Leaky Wave Spectrum Components on the Slotline

Surface and space leakage of power deteriorates the operation of circuits. On the other hand space leaky waves enable the design of specific radiators. In this paper we therefore investigate the potential of the slotline to radiate into space. We confirm the findings of earlier studies and extend them to higher order modes. Leakage into the third and fifth higher order space leaky waves of the second class, with odd symmetry of the electric field within the slot, and leakage into the second higher order space leaky waves of first and also second class, with even symmetry of the electric field within the slot, are interesting new findings. We also present the measured and calculated radiation patterns of a slotline antenna operating with the first higher order space leaky wave of the first class.