WP76xx PCB Layout TIP (Avoid routing any signals under the module)

IoT Modules
1

I’m following the 5: Routing Constraints and Recommendations section of the AirPrime WP76xx Technical Specification for the project I’m currently working on.

My PCB stackup is as follows:

TOP: Signals/Power
MID1: Ground Plane only
MID2: Signals/Ground
BOT: Signals/Ground

The WP76xx module will be placed on the TOP layer.

I would appreciate some help with the following tip:

Tip: Avoid routing any signals under the module on the application board.

I have been looking at the MangOH green reference design and I see this TIP complete ignored. You can see routing everywhere under the module. Also in my opinion routing under the module seems to be unavoidable. Also I don’t see why you can’t have traces under the module on other layers, like MID2 and BOT, given that there is a ground plane before.

Does the phrase “under the module” means the layer (TOP or BOT) where the module is placed? If that is the case, the TIP makes a lot more sense.

Your help will be greatly appreciated.

Regards,

Patricio

2

Can anybody please help me?

Thank you

3

Hi, What you understand are correct. Signals should not be routed at the top or the bottom layer to avoid radiation.