5G iPhone Teardown: What’s Apple’s Next Step?

Article By : Don Scansen

An iPhone teardown: There is no better entertainment than speculating about Apple's next step in its silicon development in order differentiate its iPhones from others...

For reasons from economic to the technological to even the political, the 5G rollout is a big milestone for 2020. Considering many other events of this forgettable (hopefully soon) year, I could even call it a feel-good story. And it is an opportunity for those who cover technology because new generations of cell phone infrastructure and devices are on a decade-long introduction cycle. It won’t be new for long, and there are things to think about early in the cycle before the technology matures.

Speaking of maturing, though, the sign that 5G is really here was that Apple finally has a phone for this new generation of mobile connection. Apple is known for setting many trends but sometimes likes to take a wait-and-see approach (think OLED, wireless charging etc.).

Mobile phones — especially flagship brands — depend on the latest components from the chip manufacturers. Apple has famously brought a great deal of chip design in-house, but didn’t quite get the job done for 5G. Rather, it depends on some of the usual suspects. Or should I say the usual suspect — Qualcomm.

Prior to the launch of their A-series processors, Apple was completely outsourcing the job to chip vendors. At some point, the applications processor became their own design. But they continued to rely on off-the-shelf components for a host of other devices. The most significant piece of non-memory silicon is the baseband processor. Historically, Qualcomm had the iPhone modem socket, but eventually, Apple moved to the Intel baseband and RF transceiver designs for the iPhone 8. Although the deal had not yet been finalized, Apple’s acquisition of the Intel smartphone chipset group was well underway by the time the iPhone 11 launched (2017).

Modem-transceiver questions
The switch to Intel may have been an opportunity to collaborate on design and perhaps with an eye to bringing some of the RF chain under the Apple umbrella. Having presumably worked closely with the Intel baseband unit (the baseband business was acquired from Infineon) for several generations, Apple made the decision to bring that in-house as well by acquiring it.

But getting 5G into the product lineup needed to happen on a different timeline than internal development that was going on. The iPhone 12 models have now switched back to Qualcomm. The iPhone 12 contains the SDR865 and SDX55 modem-transceiver combination which is the most advanced on the market.

Click the image above to enlarge. Apple iPhone 12 main circuit board (source: iFixit)

Now, we know that Apple is probably developing a modem-transceiver to go with its A-series processor for some future iPhone generation.

But who else is in the game?

Apple’s main competition is Samsung, which was actually a chip company before it got into the smartphone game, rather than the other way around. And yes, Samsung has a broad portfolio of 5G-related RF products for both sides of the 5G system, handset and base station.

Can we assume Samsung is using their own chipset in their latest phones?

Nope.

Qualcomm is there as well. According to iFixit again, the Galaxy S20 Ultra has the Qualcomm modem and transceiver combination as well as a Snapdragon 865 processor (Samsung’s own Exynos processors are used in some markets).

Is Qualcomm going to own 5G? At least for now, it seems that way.

In addition to Samsung, the other 5G modem vendors that have announced are Huawei and MediaTek. Although it is possible that Samsung will deploy its own branded modem for phones, there is a very good chance that Qualcomm will remain the winner as Samsung shows no favoritism to their semiconductor group. We will have to wait and see.

Samsung’s RF component division will probably be counting on internal sales to its small cell base station products much more than for the smartphone.

MediaTek has been making major inroads into the cellphone space for a while. The MediaTek applications processors will certainly find their way into more modestly priced 5G handsets as the technology filters down to the people that don’t treat phones as a luxury item. I expect the lower end phones will use the new MediaTek chipset including the Helio M70 modem.

Although I don’t have any direct knowledge of Huawei’s skill set for baseband and beyond in the RF signal chain, its modems may beat the others to market considering the restrictions on US chip technology supplies to China. What choice will it have?

Qualcomm’s current dominance in the 5G market is telling and it makes me wonder how long it might stay that way. But perhaps a more interesting part of the 5G rollout is the hardware beyond the transceiver. As the Qualcomm CEO noted at last year’s Electronics Resurgence Initiative Summit plenary, the RF guys are “back in charge” because physics is starting to have more impact than coding and other digital domain issues. Where does that take us?

Antenna questions
Beam-forming antennas are a good place to start.

I will continue to lean heavily on the iFixit team for information on the iPhone 12. The iFixit teardown noted that the antenna module carries the brand of USI (Universal Scientific Industrial Shanghai Co., Ltd.), but my initial reaction to the photograph was that it was actually just the Qualcomm QTM525 product that appears in 5G models from Apple’s competitors. But first, a quick diversion.

iPhone 12 USI 5G Antenna Module (source: iFixit)

The iFixit comment that the iPhone 12 5G antenna was “Apple-y and shiny” caught my attention.

Shiny, yes, but this is not an Apple exclusive. The “shiny” is just the result of the metallic conformal EMI shield coating over the epoxy mold compound that appears on many other RF components in any manufacturer’s phone.

However, Apple differs in its specification for the use of this coating on the flash memory chip. One can quickly determine that the same memory component from Toshiba or Samsung will not have the shiny EMI shield in Samsung or LG models. But Apple demands it for its iPhone. Use of the EMI shield is necessitated by the many sensitive, complex radio systems crammed into a small space alongside sensitive, complex, high speed digital electronics. Apple wants to add that layer of electromagnetic interference isolation to the storage device as well. I will save speculation on that for another day.

To the iFixit team’s credit, I wasn’t standing in line or waiting around for iPhone 12 units to appear so I could launch into a livestreamed teardown providing my own real time color commentary. The pandemic means my only live audience at the moment is two unapologetically lethargic dogs.

Getting back to the antenna, the design of the module in the iPhone 12 looks identical to the Qualcomm QTM525 module that appears in other phones from LG, Samsung, and Motorola-branded Lenovo phones. The iFixit teardown shows that the iPhone 12 model is actually a USI branded component with Apple part numbering. USI typically shares the WiFi / Bluetooth module socket as a second vendor to Murata in iPhones (and other brands). Both companies do system integrations for WiFi and other wireless modules using chipsets from Cypress or Qualcomm as well as a few others.

Considering what we know about the current state of vendors for 5G, I would say that the USI antenna module for the iPhone 12 is using the two Qualcomm chips found in the QTM525 module. There appears to be a lot of commonality between the USI antenna module in the iPhone 12 and the Qualcomm version.

The Qualcomm antenna module is a critical component for 5G. MIMO (multiple input multiple output) techniques are not new with 5G, but so-called massive MIMO and beamforming are critical to this new generation. The Qualcomm antenna module enables beam forming on the user equipment side to maximize the signal strength given back to the cell tower which is also using beamforming antenna arrays. This kind of military-spawned technology deployed at the cell tower might not be that surprising, but having it in your hand seems just a little exotic. And it is a significant portion of the bill of materials. It is a relatively expensive component, and their effective deployment requires two or sometimes three units per handset.

Qualcomm QTM525 Antenna Module

The Qualcomm antenna module has a controller IC as well as an RF chip with a signal path for each of the antennas that allows the signal magnitude and phase for each antenna element to be controlled, thereby forming a controllable directed antenna propagation lobe to focus the available RF energy where the user needs it to take maximum advantage of the speeds available in the 5G technology.

The two integrated circuit die are mounted onto an organic printed wiring board with multiple antenna elements built in. These antenna-in-package (AiP) designs are quite topical. ASE does not appear to be involved in the current 5G modules but give a nice overview of their AiP offerings. The RF guys really are in charge because the limits of some of these lower-cost organic substrates for the frequency bands in use are being pushed hard.

Speaking of the substrate, the iFixit images were not quite clear enough to precisely compare the USI module’s antenna patterns with the known Qualcomm QTM525 antenna. There are four distinct elements as in the QTM525, but the patterning appears to be different. For now, this is inconclusive.

What can be precisely compared is the connector due to the clearer photograph of the encapsulated chip side of the USI module. In the iFixit image, we can see that the connector has six pins plus a ground. However, the QTM525 uses 10 connections in addition to a ground connection. This seems to represent a significant difference in connectivity, and one would expect functionality as well.

Alas, this story may end with more questions than answers.

With their internal 5G modem late to launch, getting 5G capability into the iPhone 12 meant Apple needed to use the Qualcomm X55 modem and SDR865 transceiver.

It would be logical to assume that Apple would continue its reliance on Qualcomm 5G expertise out to the edge where the signal chain meets free space at the antenna.

From what has been published, however, we must assume that Apple is doing something different at the most extreme end of the RF chain at the beamforming antenna. That’s where it gets interesting. Is Apple doing something significantly different with the antenna? It’s a critical area for ensuring handset performance in the 5G era.

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