It looks like the first 5G iPhone will be available in 2020. As regular readers of this site will know, we're expecting a handful of 5G handsets to debut in 2019 but it doesn't look like the iPhone 11 will be one of them.
The iPhone XIS (11S) or iPhone 12? Now that's a different matter.
Apple and Qualcomm's long-running legal disputes have resulted in Apple switching to Intel's modem hardware inside the iPhone (or at least moving that way, it's unclear if all new iPhones use Intel).
According to Fast Company, Apple will use Intel’s 8161 5G modem in 2020. Fast Company's source alleges that there have been some issues around heat in early testing of Intel 5G 8060 chips (and there have been other related rumours before) but it's common knowledge that the first 5G modem chips will likely have an impact on heat and battery consumption, although we'll have to wait until we can use a device on a 5G network to see how this plays out.
Intel is likely to ship 5G modem chips slightly after Qualcomm; Intel says its chips will "ship in commercial customer devices in mid-2019".
That means those modem chips will have only just shipped by the time the iPhone 11 debuts - and with 5G networks still in their infancy in 2019, it's not surprising that Apple will wait another year.
Qualcomm is expected to have more to say at its tech summit next month - we're expecting the successor platform to the Qualcomm Snapdragon 845 which will debut alongside the already-announced X50 5G modem.
The Samsung Galaxy S10 - or at least a version of it - will have 5G, while OnePlus has also stated it will release a 5G handset in 2019 - probably due to its relationship with Qualcomm. We're expecting the OnePlus 7 to be with us relatively early next year.