LTE Cat 4 Cell Modem Card

Ok guys, My name is Tim and I would like to introduce myself. I am an engineer with over 20 years experience in making innovative designs from military vehicle modifications to commercial tools. After seeing Framework for the first time I have fallen in love with their vision and want to help see their concept get off the ground. To that idea I decided to do what I do best…

Design Something.

So I present my first design for framework. The Cat 4 LTE modem.

There were a few design challenges with this one, including:

  • Finding a modem module to fit in the housing
  • Specifying available components
  • Getting an antenna connection

Now there is no way we can fit the antenna in this module as well for sizing as well as I don’t have the facilities to test antenna efficiency. But I have provided 2 MMCX connectors for a primary and a diversity antenna(optional).

The main features of this module are:

  • Using a Nano Sim Card
  • Fully fits within the expansion card dimensions (*mostly, the antenna connectors required an extra 0.5mm length, I swear you won’t see it :wink: )
  • Transmit LED Between the antenna connectors
  • Cat4 Speeds (150 Mbit/s downlink — 50 Mbit/s uplink)

Verizon support:

  • LTE bands B2, B4, and B13
  • UMTS bands B2 and B5

AT&T Support

  • LTE bands B2, B4, B5, and B17
  • UMTS bands B2 and B5

The goal of this module is to provide a fully contained modem within the outline of the expansion module. Things like faster connections/Integrated antenna/other provider support will require a larger module.

When fully inserted the SIM card is hidden below the rail of the card.

  • {Image of the card fully inserted ISO View - not included due to new user restrictions}
  • {Image of the card fully inserted Front View Wireframe - not included due to new user restrictions}

PCB Views:

  • {Image of the PCB Top Side - not included due to new user restrictions}
  • {Image of the PCB bottom Side - not included due to new user restrictions}

I am working on getting quotes and other required information to apply for the Developer program. I am also looking for ideas for my next card development. Please provide some feedback and let me know what else you guys would like me to work on.

@Framework I have ordered a card sample to look at your production assembly methods, I saw that it shipped and am looking forward to disassembling it. but this module has a tight fit, I am looking for tips on how to add the “lid” to this with how thin it needs to be over the module. I will include this in my Developer Program application but figured I would ping you here, too.

Project Status:

  • 100/100 Schematic
  • 100/100 Layout
  • 25/100 Documentation
  • 0/100 Prototype construction
  • 0/100 Prototype Testing
  • 0/100 First Run order

Very nice! I hope you succeed and get the Developer Program rolling.

There are several topics on here with various requests/ideas for cards.

For some real… challenges, look at the “Niche Expansion Cards” topic.


That is excellent work!

Shame the LTE bands are so incredibly restricted. Not a single one my provider uses :pensive:


Great job! I can’t wait to see how the final product performs! I will buy this.


If this becomes real, holy shit it will be cool


If this product becomes a real thing I’d happily buy it. I need an always connected device!


I would buy as well, but what I was thinking is that the internal wifi module be swapped for LTE and the user could then install a WIFI dongle into the expansion bays. That way we get to use the laptop’s internal antennas.


@Shawn_Lewis The internal antennas don’t work for cellular frequencies.

At least that’s what nrp said I think


Yes please. Looking forward to that first run order.

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This is awesome! On the lid, it’s not strictly necessary. If you just want to prevent people from poking stuff that is in there, you could use a 0.1mm mylar sticker similar to what we have on parts of the Mainboard.


That’s so cool! :heart_eyes:

A question though (from a noob), you are saying that you need an external antenna. Why is that important? I mean, in a smartphone there is a 4G LTE antenna embedded in a quite small space :slight_smile: - So I was naively thinking before reading this post that something similar could be achieved for this expansion card.


Hell, they even embed all that stuff into watches too (which is mind blowing in it’s own right).


You don’t get as good a signal on an Apple Watch as you do an iPhone. Plus, it doesn’t need to support streaming video or anything like that. The most it ever needs to do is stream audio, but the bulk of the time it’s just enough of a connection for notifications and the odd siri request.


This is so cool. Makes me love the Framework even more. I’ll buy it for sure.

And it’s not just getting LTE support, it’s that the modem is removable–so perfect for privacy.

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want this, need this.

how about antennas in an external flat body that slimmly attach to the side and plug into the card?

like a thin gauge wire in a harder material painted gray

snap into the adapter and flush with the body

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I would buy this in a heartbeat.


Along that line, an antenna plate that folds up flat to the module when it is not inserted, eliminate the connectors.

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This Is what I’m talking about. THAT’S so cool!!! If framework don’t make 'em DIY stuff.


This is awesome dude! Great work!

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