Looking for antenna/RF guidance for a custom aluminum back

goldsworthy0000

Looking for antenna/RF guidance for a custom aluminum back panel

Hi everyone!

I’m a student from India (keep in mind that I have just graduated highschool and im not an engineer) and a big Nothing/CMF enthusiast. I’m working on a personal project with my CMF Phone 1: I’d like to design and 3D-model a replacement back panel, but instead of the original plastic, I’d like to make the main part from brushed aluminum. (Because it would better for the thermals plus it would be really cool/asthetic)

The mechanical side seems fairly straightforward (yet a tall task for me as I am a car newbie), since Nothing has provided CAD resources for the CMF Phone 1. The part I’m struggling with is RF/antenna design.

I understand that a continuous metal back will interfere with the phone’s cellular, Wi-Fi/Bluetooth and GNSS antennas, and that simply guessing where the antennas are or how large an RF window should be isn’t a good idea.

I’ve looked through several CMF Phone 1 teardowns, but I haven’t been able to confidently distinguish the actual antenna elements from shields, grounding contacts and other metal components. Even asked claud and chat gpt but they just imagined their answers and weren’t all that helpful.

Could someone from Nothing/CMF, or anyone with experience working on the phone, help me with the following?

- Where exactly are the cellular, Wi-Fi/Bluetooth and GNSS antenna elements located?

- Which areas of the removable rear cover should remain RF-transparent?

- Is there a recommended minimum clearance between the antennas and conductive material such as aluminum?

- Are there recommended dimensions for antenna gaps/windows?

- Does the stock rear cover have any specific RF function or spacing that I need to reproduce?

- If possible, could someone annotate a teardown photo showing the antenna regions and the areas where I should avoid metal?

I’m not looking for proprietary information or schematics. Even a simple diagram showing the antenna locations and recommended keep-out regions would be incredibly helpful.

I’m also a student, so I don’t have access to professional RF test equipment or antenna simulation tools. I’d like to understand the design properly before spending money on machining or fabricating multiple prototypes.

I’d really appreciate any guidance from the Nothing/CMF team or anyone in the community who has worked with the CMF Phone 1’s hardware.

Thanks!