We give the following Guidnace:
The gain of the system antenna (i.e. the combined transmission line, connector, cable losses and radiating element gain) must not exceed the values below for mobile and fixed or mobile operating configurations:
3.67 dBi in 700 MHz, i.e. LTE FDD-12 band
4.10 dBi in 850 MHz, i.e. LTE FDD-5 band
6.74 dBi in 1700 MHz, i.e. LTE FDD-4 band
7.12 dBi in 1900 MHz, i.e. LTE FDD-2 band
Reference in user guide:
So to answer the question, any (not mono-pole) LTE antenna that has peak gain less than the above specifications for the bands used would be fine. Note, the XBee Cellular only has u.fl connectors.