5G NR promises improved data rate, decreased latency and better communication quality. To compensate the increased free-space-path-loss, an area-efficient design is necessary for large array size. This paper presents a 28-GHz 4H+4V bi-directional beamformer chip supporting DP-MIMO in 65nm CMOS. The proposed neutralized bi-directional amplifier significantly reduces the required on-chip area. With the bi-directional vector summing phase shifter, -50° to +50° beam steering angle can be realized. 1-m OTA measurement are conducted under 5G modulation standard.