Below is an image of the different connector types typically used in UHF RFID.
Here is a listing of Impinj products and the connectors used on each of them:
Speedway Revolution RFID reader- RP-TNC Female (requires RP-TNC Male connector on cable). The 'RP' stands for 'Reverse Polarity', note that the RP-TNC female actually has a center pin. RP-TNC is also sometimes referred to as simply R-TNC.
The Impinj Speedway Antenna Hub, Mini-Guardrail antenna, Threshold antenna and MatchBox antenna all have SMA Female connectors (require SMA Male connectors on cable).
The Far-Field (patch) antenna and the Brickyard antenna have a 2m pigtail with a RP-TNC Maleconnector, these will mate directly to the Speedway Revolution reader. If using an extender cable, you will need one with RP-TNC Female on one end and RP-TNC Male on the other end.
Click here for an overview of Impinj antenna offerings including links to data sheets.
Some UHF RFID antennas use N Type connectors, usually N Type Female. To connect these antennas to the Speedway Revolution reader, you would need an N Type connector of opposite sex on one end of the cable and a RP-TNC Male on the other end. If connecting to the Speedway Antenna Hub, then the other end would need to be SMA Male (instead of RP-TNC Male).