High-Gain Grating Antenna With Surface Wave Launcher Array

In this letter, a high-gain grating antenna operated at 11.5 GHz is presented. Planar surface wave launcher (SWL) array is adopted to feed the grating antenna. Compared with spherical-like waves generated by single SWL structure, SWL array generates planar-like waves, which can concentrate the energy. With SWL array as the launcher, metallic straight strips are employed to achieve leaky-wave radiation. By using the theory of miniaturization of grating, the length of strips is optimized. The peak gain of main beam is as high as 20.3 dBi. Theoretical and optimization process is given to explain the principle. An example is fabricated and measured. A good agreement between simulated and measured results evidently validates the proposed grating antenna.