A Quick Look at Qualcomm’s 5G Smartphone Reference Design

One of the exciting things on display at Qualcomm's Snapdragon tech summit was their 5G reference smartphone design – the one that gets handed around to the smartphone vendors so they can initiate their own designs. Reference platforms are usually base and ‘generally good’ all-around designs that OEMs can take as a starting point, and so Qualcomm had to address one of the main issues with 5G with its QRD: size. Thanks to the extra 5G modem and the many antennas required for mmWave frequencies, 5G requires a good deal more hardware than current 4G phones. Qualcomm's reference design, in turn, is of reasonable dimensions, and not completely out of place amongst the larger modern smartphones of today.

The 5G Qualcomm Reference Design (QRD)

The unit on display was essentially a phone with the rear panel removed and replaced with a acrylic cover, and then the whole device was in a acrylic box. Unfortunately this means that it was somewhat difficult to see inside, but we can take a look.

From side to side, the device was only slightly bigger than some of the larger smartphones we see on the market today. That edge to edge space in the bottom half is taken up mostly by battery, which is an odd shape because that Qualcomm 5G Snapdragon logo is actually taking up some z-height in the device in that area. The main part is in the top half however.

In yellow I have labelled the three mmWave QTM052 antennas in the unit. If you remember back to when Qualcomm announced these, they were mentioned as small, but it wasn’t until I saw one in person that I realised how small. Nonetheless, in order to make this device mmWave capable, there needs to be three and they have all been installed width-ways into the edge of the device. This means the device is actually around 9mm thick altogether, slightly larger than the flagships we see today,

This shot shows it a little better, with a QTM052 in the background.

It’s worth pointing out that each of these three antennas is connected via cables to access points on the PCB: four per antenna. The others area harder to see, but the antenna on the left has the connections here exposed. This is suitable for a reference design, whereas a modern flagship will be able to put the connections in a more integrated design to save on volume.

On the right hand side here, we can see the two-module camera solution. Ttechnically the S855 only supports two cameras, but that can be expanded by muxing or using different sensors and software tricks to make it work. To the right and below the caera module is where we see what looks like the SIM tray holders. That is surprising given the volume rockers nearby. There are a couple more jumper points to the left of the tray, but these are unconnected. This could be for a fourth mmWave antenna (the Moto mod has four, for example) when the device is put together, though at least the last time Qualcomm was talking about the QTM052, they indicated that they were expecting smartphones to only use three such antennas.

Thankfully this device was USB Type-C. But here you can see the thickness of the reference design again.

What I’ve marked here in yellow is a rigid metallic beam that seems to go across most of the top half of the device (and around the edge of the battery). Normally I would call this a stiffener, although it could also be to aid cooling. It looks quite sizable.

It’s hard to tell what is under the rest of the unit. We can assume that the pink foamy area (it’s definitely a foam) is covering something vital, as well as that big 5G sticker.

Qualcomm usually gives a small number of select journalists and analysts some time with the QRD before the first devices are launched to allow us to gauge what Qualcomm expects performance to be. Hopefully we will get our hands on one to test shortly.