P2 antenna performance when pcb up-side-down


for various reasons we like to mount the pcb with the p2 upside down in the housing. is the radiation pattern of the wifi antenna known? especially how well it will do through the pcb (no copper) on which it the p2 is mounted?


The trace antenna performance will be affected being upside down, depending on various factors. For example, both the P2 module board and your board will attenuate the signal if the Wi-FI AP is above the unit.

If you have to put the module upside-down you may want to consider using an external antenna. It will work upside-down, but probably not optimally.

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Is “upside down” mounting it on the backside of the PCB with the antenna pointing upwards, or is it mounting the module on the front of the PCB with the antenna pointing downwards?

yes, antenna pointing downwards (al components on one side of pcb and pcb up-side-down in housing)

do you know if there are any radiation patterns measured?

There is no publicly available radiation pattern diagram for the P2 trace antenna at this time.

In two previous designs (wall mounted) with other wifi modules in similar format to P2, mounted upside down worked really well.

The antenna was sticking outside the PCB, and with space between the antenna and bottom of the housing of 25mm. In case the device was placed standing on a surface.

Radiation pattern in the “sideways plane” have been an optimal direction on wifi modules I used in the past.

I have also placed the module sideways in a design revision, and the direction directly opposite the antenna was somewhat degraded.

You said you do not have components or traces in the antenna area of your board already, but have you considered having your board routed to just remove that portion of your PCB? You will still have some fridge effects but it will reduce problems.

yes, we will remove as much pcb under the antenna as possible. depends a bit on our pcb-a recommendation on what they can still reliably solder

with the p1 we are using this external antenna: 2jf0202p

how would you rate the new p2 antenna against this one? (i know it is now an easy question)

our plan so far is to keep using the same external antenna but also test the p2 antenna (p2 on bottum of pcb but cut out underneath p2 antenna)