output power question

[andrew77]

Hello,
I've tested the blade through professional equipment (spectrum analyzer, power meter and power sensor bolometric) and using osmocom-siggen I have the following questions:

The maximum output power when I generate a single frequency such as a sinusoidal CW frequency is around 20 mW @ 900 MHz, but if I generate a noise or a Gaussian noise the output power is quite lower than a single CW frequency (at the same frequency and the same Sample rate, 20 M), this power increase if I set a full band (28 MHz) but anyway this is much lower (around 0,5 mW!!)
How it is possible? How is the frequency generated in case of noise?

Regards

[robert.ghilduta]

Noise is not predictable so by definition the output of the system should be uniformly distributed between 0% and 100% (assuming white noise). This means that the average power of your noise is going to be 50% of your peak power, which is what you measured when transmitting a CW. Your VSA should still see a peak power of 20mW except it will only see it 1% of the time. This 50% reduction in average power translates to a 3dB power loss. Another issue you might be the bandwidth of your noise source. I would suggest ensuring that the 28MHz LPF is enabled, otherwise you might be feeding things into the transit PA that are way out of its bound of operation.

[mitesh]

Hello,
Currently, I am using bladeRF 2.0 micro xA9 model and I want to check transmitted noise signal power. how can I check it and how much strong noise can produce using this module?

[flamegrin]

The noise source's bandwidth can also be a problem. If the 28 MHz LPF isn't activated, you can be feeding items into the transit PA that aren't intended for that frequency range.