Substrate integrated waveguide leaky-wave antenna: concept and design considerations

This paper presents a Substrate Integrated Waveguide leaky-wave antenna. The new topology makes use of one of the fundamental characteristics of this synthetic waveguide, namely, its property to generate leakage loss when the period length is sufficiently large. A design method, based on the transverse resonance technique, is presented and validated with a full-wave simulation. Inherent limitations of this structure are also exposed. We demonstrate that, in order to design efficient antennas, there is a maximum value related to the substrate permittivity. We also establish that a leaky-wave antenna cannot be designed in the upper band of a waveguide with commercially available substrates.