Can the NRF52 output an unmodulated continuous tone at a specific channel?

[ray]

Hi all,

I'm a grad student trying to innovate on the BLE concept. I require a continuous signal as a source: preferably unmodulated, but a long duty cycle could also work. Would the NRF52 (or any other Nordic bluetooth device) be able to accomplish this?

Thank you, Ray

[Øyvind Karlsen]

Hi,

Yes you can do this. I recommend using either the radio test example or alternately direct test mode. Both implement this already and can be found in the SDK under nRF5_SDK_11.0.0_89a8197\examples\peripheral\radio_test and nRF5_SDK_11.0.0_89a8197\examples\dtm\direct_test_mode.

Best regards,

Øyvind

[Øyvind Karlsen]

You could use a nRF52 for the CW source as well, anything the 8001 can do, the nRF52 can do as well. I am still not entirely sure why you want a full-duplex radio, the way I see it from the Ensworth paper there are no simultaneous receive and transmit operations. Please refer to the first image in this article, the difference in the article is that the backscatter node also alters the backscattered signal by a FET switch. I might very well be wrong here though, as I haven't had the time to properly research this topic.

It is very rare to use full-duplex as it requires expensive components in the antenna structure, ie. ensuring that the transmit does not self-interfere with the receive.

What is usually done is to time divide the transmit and receive and take turns, which is a form of half-duplex. I guess you are familiar with TDMA, this is the same thing.