Apple is Upgrading Its C1 Modem with Faster mmWave 5G, Kuo Reports

Highlights

• Apple is working on a refreshed C1 modem for next year to address its lack of mmWave 5G support.
• The new version will include mmWave transceivers and front-end components using a 28nm node.
• The iPhone 17 Air will use the C1 modem, while other iPhone 17 models will continue using Qualcomm’s 5G modem.
• More iPhone 18 models may adopt the upgraded C1 modem next year.

Apple recently joined the small group of companies making their own 5G modems. It introduced the Apple C1 Chip inside the iPhone 16e and while Apple highlighted its power efficiency, the modem has some key limitations. This makes Apple’s first in-house 5G modem unsuitable for higher-end iPhones. Here’s what we know.

Apple To Address C1 Chip’s Lack Of mmWave 5G

According to analyst Ming-Chi Kuo’s recent post on X (formerly Twitter), Apple is already working on a “refreshed C1” for next year, which will address its biggest drawback of lack of mmWave support.

Apple’s C1 modem process technology:
– Baseband: 4/5nm (both technologies are similar)
– Low-frequency/Sub-6 TRx (Transceivers): 7nm
– Intermediate Frequency (IF) TRx: 7nm
– PMIC: 55nm

The C1 refreshed version is under development for mass production next year, aiming to improve…

— 郭明錤 (Ming-Chi Kuo) (@mingchikuo) March 6, 2025

As of now, the C1 modem only supports sub-6GHz 5G. It features a baseband built on a 4nm or 5nm process, 7nm transceivers for low and intermediate frequencies and a 55nm Power Management Integrated Circuit (PMIC). While some expected Apple to move to a 3nm baseband in the next version, according to Kuo that’s unlikely since it wouldn’t significantly improve power efficiency.

Apple instead plans to add mmWave transceivers and front-end components using a 28nm node, allowing for much faster 5G speeds, at least in regions where mmWave is available. Kuo notes that making mmWave work isn’t difficult, but creating a modem that is both stable and power-efficient is a bigger challenge.

Kuo writes, “(improved chip) aims to improve power consumption and transmission speed and support for mmWave (including TRx and front-end components, built on a 28nm process). While supporting mmWave isn’t particularly challenging, achieving stable performance with low power consumption remains a key hurdle.”

Kuo previously reported that the iPhone 17 Air would use the C1 modem along with Apple’s in-house Wi-Fi chip. However, the rest of the iPhone 17 lineup will continue using Qualcomm’s 5G modem while switching to Apple’s Wi-Fi chip (Apple previously relied on Broadcom for this).

It’s unclear whether Apple’s existing agreements with Qualcomm or the lack of mmWave support will keep the C1 out of most iPhone 17 models. However, more iPhone 18 models could adopt the upgraded C1 modem next year. As for a next-generation Apple C2 modem, there’s no information on that yet.

FAQs

Q1. What is the major improvement planned for Apple’s C1 modem?

Answer. Apple is working on a refreshed C1 modem for next year, addressing its biggest drawback, the lack of mmWave support, allowing for faster 5G speeds.

Q2. What does the current C1 modem support, and how is the new version different?

Answer. The current C1 modem only supports sub-6GHz 5G and is built on a 4nm or 5nm process. The new version will include mmWave transceivers and front-end components using a 28nm node.

Q3. Which iPhone models will use the C1 modem?

Answer. The iPhone 17 Air will use the C1 modem, while the rest of the iPhone 17 lineup will continue using Qualcomm’s 5G modem. More iPhone 18 models could adopt the upgraded C1 modem next year.

Read More: Apple Plans to Integrate Modems into Main Chipset, But It’ll Take Years

Read More: Apple Unveils Its First In-House 5G Modem C1 Chip, Replacing Qualcomm