I'm planning to design a board with both GSM and GPS/Glonass functionality so I picked Simcom's SIM5360 module which seems right for me. It has three antennas, one for GSM, one for GPS/Glonass and the other is marked as diversity antenna. Now I looked inside its documents but they never explained what is a diversity antenna and is it necessary to use it. Can I just leave it unconnected?
Because having 3 antennas would make my design very complicated to use in a special environment I'm planning to use and it would make a lot of extra connections and it's just not practical. Why would there be a need for diversity antenna when there are already two other antennas?