Braca
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Hello,
When measuring noise I notice a disagreement between the noise levels displayed in the RTA upper right and Distortion panels.
Referring to the attachment, I'm measuring thermal noise of a 50 ohm resistor, amplified by an LNA with a gain of 60dB and a flat noise floor at 0.39nV/rtHz RTI.
The noise floor I expect to see is 0.98uV which is only slightly higher than the value of 0.96 that I see in REW, i.e. a very good result.
Integrating the former vallue over a BW of 44kHz and taking into account the LNA gain I get 206uV, and expect to see 202uV in REW.
Combining the two noise values from the upper right panel in RTA I get 205uV, which is again very good.
However, in the Distortion panel, RTA displays a noise value of 123uV, which I can not explain to myself.
Thank you for a great software!
Kind regards,
Braca
When measuring noise I notice a disagreement between the noise levels displayed in the RTA upper right and Distortion panels.
Referring to the attachment, I'm measuring thermal noise of a 50 ohm resistor, amplified by an LNA with a gain of 60dB and a flat noise floor at 0.39nV/rtHz RTI.
The noise floor I expect to see is 0.98uV which is only slightly higher than the value of 0.96 that I see in REW, i.e. a very good result.
Integrating the former vallue over a BW of 44kHz and taking into account the LNA gain I get 206uV, and expect to see 202uV in REW.
Combining the two noise values from the upper right panel in RTA I get 205uV, which is again very good.
However, in the Distortion panel, RTA displays a noise value of 123uV, which I can not explain to myself.
Thank you for a great software!
Kind regards,
Braca
