Abstract: The three dimensional pattern function with dual polarization smart antenna array of base station is struc tured according to specifications on the broadcast beam pattern. Thus, the sector power ratios (SPR) and gains with antenna array of base station are calculated when different the half power beam width (BW) in azimuth direction, the front to back ratios (FBR), electrical and mechanical down tilt in pitch direction within the working frequency bands . The results indica ted that, BW and FBR of base station antenna pattern are major causes of an effect on SPR. SPR with mechanical down tilt of the antenna has an advantage over electrical down tilt of that.