We can see Figure 5. Picture of the embedded antenna system and 3D antenna heat maps
in Cisco Aironet Series 2800/3800 Access Point Deployment Guide; <https://www.cisco.com/c/en/us/td/docs/wireless/controller/technotes/8-3/b_cisco_aironet_series_2800_3800_access_point_deployment_guide/b_cisco_aironet_series_2800_3800_access_point_deployment_guide_chapter_01001.html>.
I understand that AP2800i and AP3800i have 4 antennas of 2.4/5GHz Dual Band for Macro-Cell.
I understand that AP2800i and AP3800i have 4 antennas of 5GHz Band for Micro-Cell.