High Efficiency Dielectric Periodic Leaky Wave Antenna in the Transverse Radiation Mode

Leaky wave antennas are widely used due to their relatively simple design, small cross-sectional dimensions, and high efficiency. In one-sided mode dielectric periodic leaky wave antennas, which convert the slow surface wave of a dielectric waveguide into a spatial radiated wave by means of a periodic grating, are used in oblique radiation mode. At the same time, the transverse radiation mode is preferable in some cases. However, the implementation of this mode is associated with a catastrophic deterioration in emissivity due to Bragg diffraction. The paper discusses the ways to eliminate the normal effect. In relation to an antenna with a radiating aperture in the form of a planar dielectric waveguide loaded with a periodic comb grating, a method is implemented for introducing an additional groove within a period at a distance of a quarter of the wavelength from the main groove. It is established that when an additional groove within the period occurs, and it is equivalent in size to the main groove, the increase in the emissivity of the antenna is not so significant. There are two options proposed for increasing the efficiency of the antenna with a modified aperture. The first one is optimizing the position of the additional groove relative to the main groove, and the second one is selecting the depth of the additional groove. It is established that the increment in the emissivity and radiation efficiency of the leaky wave antenna when optimizing the depth of additional grooves is higher than in the case of selecting the distance between the additional and main grooves. The results are obtained based on the electrodynamic simulation, implemented following the widely recognized author's projection model.