Modifications of planar leaky wave antenna arrays

Two new modifications of planar center-fed leaky-wave antenna arrays are presented. The antenna arrays consist of a printed one-dimensional periodic metal strip grating on a grounded dielectric waveguide and designed for broadside radiation. The first new model has a single-layer structure with an excitation device for the planar dielectric waveguide, represented by coaxial-fed comb line. The second new model also has a single-layer structure with the excitation device, represented by a waveguide-fed linear substrate integrated slotted waveguide array. The investigated examples of the antennas exhibit low return loss at frequencies of broadside radiation. The radiation efficiency of the antennas exceeds 50 % at frequencies up to 60-80 GHz, while the antenna gain is 27-30 dBi.