Metamaterial assisted antenna array for reduction of sidelobe level

In this paper, a novel design of metamaterial is reported for realizing low sidelobe level (SLL) in the antenna array. This metamaterial is divided into some rows which are composed of periodic annular slots with different transmission controlled by its dimension. The transmission distribution of all the rows can be designed as Taylor amplitude distribution (TAD), by properly adjusting the dimension of annular slots. To prove the validity of this metamaterial, it is located above the traditional linear array with uniform amplitude and phase as surperstrate. The simulation result shows that the employment of metamaterial can effectively reduce the SLL of the antenna array from -13.4dB to -23.6dB at 10.284GHz, which is very close to the designed SLL of -26dB. This approach has some potential application in the antenna arrays, avoiding complicated design of unequal feeding network.