GNSS external antena for BaiCells pBS4222

Hello All!

Would you please recommend some device for using as GNSS external antena for BaiCells pBS4222?
Which interface have to be used for connection?
Which voltage level is used?
Is it possible to use GNSS as a synchronization source in FDD mode?

I tried some devices from a local market (with SMA socket) but not succeed.

Thanks in advance.