A novel periodic microstrip leaky-wave antenna with backward to forward scanning

A novel structure of printed periodic leaky-wave antenna is proposed in this article with the goal to provide a constant frequency scanning of the antenna beam from backward to forward, including the broadside. A new method based on the matching of a unit cell and the characteristic impedance of the transmission line has been proposed to systematically remove the open stop band. This method has been effectively implemented on a unit cell and a periodic leaky-wave antenna has been designed. Using the proposed technic the open stop band is completely removed and a relatively constant gain is achieved over the desired frequency band.