PA/LNA Question.

[Hirls]

Hi everyone, I'm notice that there a way to increase the range of Bluetooth mesh network by using the LN/PNA module.

I'm currently want to have this module implement on my nRF52832 DK(Client).

I'm wonder what is the FEMs, how i get that module and are there any alternative of that module.

Regards,

Hirls

[Hieu]

Hi Hirls,

Front end modules (FEMs) are modules that improve the performance of radio and thus give you better range.
We have some overview of them in our product page here: Range extenders.
Arrow also has a nice description here: RF Front End IC | RF Front End Module | Arrow.com.

Nordic also has a FEM product, which is the nRF21540, and a Development Bundle with a nRF21540 Evaluation Kit (EK) and a nRF21540 Development Kit.
The nRF21540 EK is a shield that can be easily fit on top of your nRF52 DK, which serves your interest very well.
The nRF21540 DK is a development kit with a nRF52840 connected to a nRF21540.

I notice that your screenshot comes from the nRF5 SDK for Mesh documentation. Which SDK are you using? The nRF21540 is far better supported in the nRF Connect SDK than the nRF5 SDK for Mesh.

An alternative to using FEM is using an external antenna with high gain and tune it properly.

Best regards,

Hieu

[Hirls]

I notice that your screenshot comes from the nRF5 SDK for Mesh documentation. Which SDK are you using? The nRF21540 is far better supported in the nRF Connect SDK than the nRF5 SDK for Mesh.

Yes, I'm using the nRF5 SDK v17.0.2.

An alternative to using FEM is using an external antenna with high gain and tune it properly.

I see this as a better solution for me right now because in my country don't see any shop provide this.

So do I have to tune the antenna myself or there anything that I can look into like some antenna that already tuned.

My application right now is there like 11 servers on an open field (football field) and 1 client listen to the status message of all the servers. I want my client to be better at received those messages. All of my servers (nRF52840) are set to 8 dBm in Tx power and cannot attach any type of external antenna because it is a wearable device. In short, I just want my client to be better at receiving.

Regards,

Hirls

[Hieu]

Hirls said:

So do I have to tune the antenna myself or there anything that I can look into like some antenna that already tuned.

If you are using the nRF52 DK, there is a connector on the board for external antenna. It is intended to be used for measurement purpose, and thus is not very user friendly when it comes to a field setup like yours (refer to more discussion in this case).

The receptacle connector on the DK is MM8130-2600RB8. It is compatible with the adapter cable MXHS83QE3000, from which you can connect with various standard antenna.

Please note that when use with the correct mating connector from Murata, the connection will also disconnect the PCB antenna and make sure all the radio activity is through the external antenna. This cannot be guaranteed when using a different brand.

If you are using your own custom PCB, then the antenna will have to be tuned, whether it is a PCB antenna, or external, or a chip antenna. We do offer antenna tuning assistance, so you can open a different ticket for that.

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Hirls said:

I see this as a better solution for me right now because in my country don't see any shop provide this.

If you cannot purchase the nRF21540 DB, you can still use other FEMs. The support for FEMs in the nRF5 SDK is not very strong, but simpler FEMs controllable by GPIO can be used.

Best regards,

Hieu