Susquehanna said Monday that Apple will launch its first 5G iPhones in September, but a faster version may not come before next January.

"The delay in the launch, according to our checks, stems from Apple's decision to in-source Antenna-in-Package (AiP) modules instead of purchasing from a 3rd party," Susquehanna said in a note. The note said the faster mmWave 5G iPhone models probably won't come before December.

There are several types of 5G networks, which can make things a bit confusing.

For example, T-Mobile recently rolled out its nationwide 600MHz 5G network, but it's only marginally faster than 4G LTE. Another 5G technology called mmWave is about 10 times faster than 4G LTE and offered by T-Mobile, AT&T and Verizon, but those networks aren't widely available and can't cover large areas or penetrate walls and buildings. People who want the faster speeds need to be standing very close to a cell tower that offers the mmWave support right now.

It's likely Apple will announce all of its new iPhones in September as it traditionally does, but the iPhones with 5G mmWave support may launch a couple of months later. Apple did this when it announced the iPhone 8 and iPhone X in September 2017 and released the iPhone X two months later.

Susquehanna said the slower 5G iPhones will have LCD screens while the mmWave iPhones will have better OLED screens, like the screens in today's iPhone 11 Pro. This means the successor to the iPhone 11 may only support slower but more widespread 5G networks while the more premium successors to the iPhone 11 Pro and iPhone 11 Pro Max will also support faster but less widespread mmWave networks.

There currently aren't any phones available that support all of the 5G technologies and mmWave is still only available in select areas.

So, there's no rush for Apple to get these models out or for consumers to buy a 5G phone just yet. Still, Samsung is expected to announce the Galaxy S11 on Feb. 11, which may be the first to support all of the new 5G networks. If it does, Samsung could have a leg up on Apple for almost a year.

Apple was not immediately available to comment.