Design of a two-dimensional Quasi-Yagi array antenna with low sidelobe

The paper presents the design of an end-fire array antenna with low sidelobe. The presented antenna operates on X-band consisting of 8×8 microstrip Quasi-Yagi antenna elements. In order to obtain ™21dB sidelobe level and specific half power beamwidth, particle swarm optimization (PSO) is applied to optimize the power distributions of the feeding network and the element spacing. According to the optimized power distributions, two corresponding non-isolated microstrip power dividers are designed to feed the two-dimensional array. Finally, the array is fabricated and the measure results show a maximum sidelobe level of ™18dB is achieved on the band from 8.9 to 9.6GHz with a minimum gain of 18.6dB.