Evaluating Channel Sounding with Multiple Antennas on nRF54L15DK

[Hay]

I want to evaluate Bluetooth LE Channel Sounding on the nRF54L15, using multiple antennas. The nRF54L15DK only has one antenna, so if I use it as both initiator and reflector, I only get one antenna path. Channel Sounding supports up to four paths by spec and Nordic appears to have the software support in place, so I’d like to try more.

In theory, I could connect an external board with an RF switch and multiple antennas to the DK via the SWF connector and GPIOs. I haven’t found an off-the-shelf board like this. It doesn’t seem too complicated to design - as I understand the main goal is simply to place typical BLE antennas to maximize polarization diversity?

What I have found are external antenna array boards aimed at Direction Finding. These have more antennas than needed/possible with channel sounding, but I wonder if it still could make sense to use such a board for channel sounding evaluation by just using a subset (selection as to maximize polarization diversity) of the antennas?

Or what's the easiest way to evaluate Channel Sounding with multiple antennas?

[Ressa]

Hi,

There is a guideline how to evaluate channel sounding with multiple antennas (LE Channel Sounding).  As you mentioned, nRF54L15DK only has one antenna, so you need to have external hardware extension board to support multiple antennas. By using RF switch and controlling that with GPIOs you can have the setup in place. Just make sure the RF switches switching time should be less than 6 us to comply with channel sounding timing requirements. Please check the shared link for more details.

You can have multiple antennas that are combined together (using power combiner or other techniques) without having a switch to select one antenna at each time, and you probably will have some improvement as you will have some gain from space/polarization diversity, but that is not the exact purpose of channel sounding multiple antenna mechanism.

Best regards,
Ressa