Difference between Hirose U.FL and IPEX connectors
Short answer: It's a brand thing.
Long answer: All refer to micro RF coaxial connectors for 0-6Ghz applications based on the Hirose U.FL-series design.
U.FL = U.FL series from Hirose Electric Group
IPEX = MHF series from I-PEX Connectors
Ya got me on IPAX...
IPX = IPX series from LightHorse Technologies
AMC = Amphenol Micro Coaxial connector series from Amphenol RF
MHF = MHF series from I-PEX Connectors
UMCC = Ultraminiature Coax Connector and Cable Assembly Style A Series from Tyco Electronics
All claim 100% compatibility with Hirose u.fl
Yes, IPEX is a line/type of connectors made by LTI (LightHorse Technologies Inc). As @Passerby pointed out, IPEX mhf connector is the equivalent of Hiroshi U.fl (according to this website they are 100% compatible: http://www.wellshow.com/rf-connectors/mini-connector/ipex-mhf-connector/)