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I understand some Spectrum Analyzers have an option that allows you to measure this directly, but the Spectrum Analyzer I have access to does not have this functio

Thanks

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In summary, the noise power is 1.38 x 10-20 x 293 x 106 = 4 x 10-12milliwatts per MHz = -114 dBm per MHz. The total power over a certain bandwidth can be calculated by integrating power over that bandwidth.

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I understand some Spectrum Analyzers have an option that allows you to measure this directly, but the Spectrum Analyzer I have access to does not have this functio

Thanks

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Bob S

** the noise power is kTB where k= 1.38 x 10

So noise power is 1.38 x 10

Add 3 dB noise figure to get -111 dBm per MHz

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-55.6 dBm, -55.7 dBm, -56.2 dBm, -57.2dBm, -57.8 dBm, -56.9 dBm.

I guess thr question I have is how I integrate (think that's the right term) power over that bandwidth?

Thanks

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If you back-terminate the input to the spectrum analyzer with a good matched resistor, the noise level should be in the range -114 to -111 dBm per MHz bandwidth (not per MHz resolution). See my post #2.newenglandguy said:

Bob S

Power over a frequency band refers to the amount of energy or signal present in a specific range of frequencies. This can be calculated by measuring the amplitude or intensity of the signal at each frequency within the band and summing them together.

To calculate power over a frequency band, you first need to have a frequency spectrum of the signal. This can be obtained through various methods such as Fourier transform. Then, the power at each frequency within the band is determined by squaring the amplitude or intensity value. Finally, the power values are summed together to obtain the total power over the frequency band.

Calculating power over a frequency band is commonly used in signal processing and analysis. It can help in identifying dominant frequencies in a signal, detecting noise or interference, and determining the bandwidth of a signal. It is also used in fields such as telecommunications, audio engineering, and radio astronomy.

The width of the frequency band can greatly impact the calculated power. A narrower band will result in a more precise measurement of the power at a specific frequency, while a wider band may provide a more general overview of the signal's power distribution. It is important to choose the appropriate band width based on the specific application and goals of the analysis.

Yes, power over a frequency band can be affected by external factors such as noise, interference, and filtering. These factors can alter the amplitude or intensity values of the signal at certain frequencies, therefore impacting the calculated power. It is important to consider and account for these external factors in the analysis and interpretation of the results.

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