Leaky-wave long slot antenna design using ridged waveguide

In this paper a long slot ridged waveguide antenna is designed and simulated. Long leaky-wave slot antennas have high sidelobes in the far field patterns leading to reduction in their performance. To obtain better performance one way is use of a ridge in the waveguide. Through this method better sidelobe level can be achieved. The proposed design consists of a nonresonant slot which is longitudinally centered on the broad wall of a rectangular waveguide. The slot has a length of 20 lambda and width of .08 lambda. With properly design of a ridge, the center-lined slot is exited and desired far field radiation pattern is achieved. The reflection coefficient of this design in about -27 dB at center frequency.