DTM Attenuation

[agm]

Hello,

I am trying to setup the DTM to evaluate our product. I am using shielded boxes and following the setup from application note 34: 

I am unfamiliar with this type of testing. Does anyone have a typical range for the attenuator? Is it around 10dB? 100dB? 

Any suggestions would be appreciated.

Thanks,

Aaron

[Andreas]

Hi,

 

It depends on the output power of the lower tester and the input power rating of the DUT, and also what you want to test. If you want to test that the radio works as it should you just need to make sure the input signal has a power that is high enough to be properly received, and low enough to not make the receiver saturate. With typical 0 dBm TX power you might want some attenuation to have some margin to the max. input signal strenght rating at  0dBm, probably at least 10 dBm. 

If you plan on testing e.g. receiver sensitivity you will need attenuation such that the incoming signal has a strength in the range of the sensitivity spec, for our devices somewhere lower than -90 dBm, depending on device, mode etc.Note that coax cables and antennas will also contribute to the total loss, so this is a test you would want to do conducted.

 

For specifications please see the PS: https://infocenter.nordicsemi.com/topic/ps_nrf52840/radio.html?cp=3_0_0_5_19_14#unique_2136654163

 

Best regards,

Andreas