Matching Network Placement and Routing-BLE Antenna Routing

RE: Matching Network Placement and Routing-BLE Antenna Routing

Afzal — Wed, 29 Mar 2023 06:59:23 GMT

Thank you so much, Jonathan.

Thanks & Regard
Syed Afzal

Hardware Design Engineer
Atlanta Systems Pvt. Ltd
M-135 2nd Floor, Connaught Place
New Delhi-110001

Mob- +917503601370 | http://www.atlantasys.com

RE: Matching Network Placement and Routing-BLE Antenna Routing

JONATHAN LL — Tue, 28 Mar 2023 12:26:33 GMT

[quote user="Afzal"]Please also confirm that the recommended image as shown is based on nrf52832. Right![/quote]

Correct, but there is some modifications, removed some components on other pins for less visual clutter. We do have some guides on HW design here here https://devzone.nordicsemi.com/guides/short-range-guides/b/hardware-and-layout/posts/nrf52832-specific-pcb-guidelines and here https://devzone.nordicsemi.com/guides/short-range-guides/b/hardware-and-layout/posts/general-pcb-design-guidelines-for-nrf52.

[quote user="Afzal"] clarify my point for C3 we have to provide the ground plane clearance or not as shown in the image below-[/quote]

There are two reasons to why the layout is at it is. Firstly it serves as the matching to get to 50 Ohms, and secondly it serves as a filter for harmonics. So the specific layout helps suppress the unwanted harmonics.

So we highly recommend that you include the keep out zone/ground plane cleared area on the top layer for best performance.

[quote user="Afzal"]Also please clear one more query related to nRF52833. We have to do the same procedure in clearance for the nRF52833[/quote]

Yes, also follow the layout example we have here for best performance.

[quote user="Afzal"]After L2 we have to add a Pi network and maintain a 50-ohm impedance. Right![/quote]

The Pi network is just an example of what can be used for properly matching the antenna. A T or some other network is also perfectly fine, and if you are using a specific antenna that has some recommendations in terms of matching components then use that. But we see that in most cases the typical Pi network placed close to the antenna works great.

PS:
We do schematic and hardware reviews so if you want to have your design review we can do that, all you need to do is create a new Devzone ticket either private or public and name it HW review.

RE: Matching Network Placement and Routing-BLE Antenna Routing

Afzal — Tue, 28 Mar 2023 09:31:07 GMT

Hey Jonathan,

Thanks for your response.

Please also confirm that the recommended image as shown is based on nrf52832. Right!

->I will remember it for further Design but also clarify my point for C3 we have to provide the ground plane clearance or not as shown in the image below-

-> Also please clear one more query related to nRF52833. We have to do the same procedure in clearance for the nRF52833

After L2 we have to add a Pi network and maintain a 50-ohm impedance. Right!

Thanks & Regard
Syed Afzal

Hardware Design Engineer
Atlanta Systems Pvt. Ltd
M-135 2nd Floor, Connaught Place
New Delhi-110001

Mob- +917503601370 | http://www.atlantasys.com

RE: Matching Network Placement and Routing-BLE Antenna Routing

JONATHAN LL — Tue, 28 Mar 2023 09:15:47 GMT

Hi,

The ANT pin is not 50Ohm so looking from L1 and in to the ANT pin we don't need it to be 50 Ohm's. But out from the L1 and towards the antenna then the transmission line should maintain 50 Ohm's.

Illustration:

Regards,
Jonathan