nRF21540 connectivity range

[Hiihtaja]

Hello !

Do you have any evaluation results for nRF21540 DK in case of real connectivity range ? Just some typical digits what can be seen easily.

I have own radio and can send BLE radio (2M - 125K) compatible frames ( 32 - 255 bytes ) long and direct visibility ( and good weather ).

FEM output power +20dBM and internal antennas in use.

By the way, what is difference between internal antennas ? Are they completely equal ? Can you recommend low cost external antennas what can be used with this board ?

What connectivity range I should expect in best case ?

Regards,

Eugene

[Bendik Heiskel]

Hi Eugene,

We have a blog post about range testing comparing the nRF21540DK to the nRF52840DK:

https://devzone.nordicsemi.com/nordic/nordic-blog/b/blog/posts/testing-max-range-with-ble-with-nrf21540dks-and-nrf52840-dks

By the way, what is difference between internal antennas ? Are they completely equal ?

The two antennas on the DK are equal.

Can you recommend low cost external antennas what can be used with this board ?

Any antenna designed for the 2.4GHz band can be used.

To attach it to the DK a cable that converts the SWF connector on the DK to SMA is needed. Such a cable is available from Murata, the part number is: MXHS83QE3000

 

Best regards,

Bendik

[Hiihtaja]

Hi Bendik !

About blog.

I think in case of advertising to one direction and connected role, actual frame size is quite small.

32 bytes or even less ? But if we move to full frames e.g 255 bytes, range can be even less.

Is this so ? Shorter frames spread longer. 

For what frame size all of those digits are ?

Regards.

Eugene

[Bendik Heiskel]

Hi Eugene,

For the case of the advertising/scanning the maximum packet length is 32 bytes. For the connected case the packet length used during the range testing was 156 bytes.

When the packets are longer there will be a higher likelihood of bit errors which will results with more dropped packet, this will limit the maximum range for both connected and advertising/scanning states.

 

Best regards,

Bendik