As millimeter-wave(mm-wave) band is attracted for 5G. and autonomous driving technology, mm-wave band has become a commercial interest. In mm-wave radar applications, the suppression of the side lobe level has to he considered thoroughly. This paper proposes an array antenna structure that reduces the side lobe level by arranging the equal power divider in series from the uniform distribution structure. The beam patterns of the proposed 1x8 array antenna completely suppress the first side lobe. The level difference between a peak gain and side lobe level was 18.4dB. The proposed method provides an array antenna with low side lobe level for mm-wave radar applications such as motion sensing and security.