A novel transition for a Half-Mode substrate integrated waveguide leaky wave antenna

A novel transition structure of the half mode substrate integrated leaky wave antenna has been proposed in this paper. The transition structure can efficiently convert the input power to the leaky mode to enhance the efficiency of the leaky wave antenna and avoid possible reflection at the terminal of the leaky wave antenna. Moreover, a modified method of complex propagation constants extraction for leaky wave antenna is also presented in this paper, which gives accurate prediction on the radiation performance of the leaky wave antenna. Measured and simulated results indicate that the proposed transition structure makes the side lobe of the half mode substrate integrated leaky wave antenna smaller.