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singh Community Member Offline Posts: 57	average noise power Dec 23^rd, 2011, 10:38am i have a transfer function which is multiplied with noise voltage density transfer function (flicker+white noise curve) and i get resulting data from that. So in order to calculate avergae noise power, do i need to take Root mean square of all the values or root sum square of all the values? Please help me on this
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raja.cedt Senior Fellow Offline Posts: 1516 Germany	Re: average noise power Reply #1 - Dec 23^rd, 2011, 11:34am hello, finally you have to find rms value of the output. but already you have output psd, so just find sum and take square root. thanks, raj.
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singh

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Posts: 57

Re: average noise power
Reply #2 - Dec 23^rd, 2011, 12:48pm

raja.cedt wrote on Dec 23^rd, 2011, 11:34am:

hello,
finally you have to find rms value of the output. but already you have output psd, so just find sum and take square root.

thanks,
raj.

thanks

for noise voltage density i use
eVN2 = eFN2/freq + eWN2;
eVN = sqrt(eVN2)

suppose my transfer function
save_tf_values(j) = variable1;
save_output_noise(j) = variable1 * eVN;

these eVN values i multiply with my transfer function for each frequency and get data.. eVN is not squared.. so i think i need i need to take rms as shown below?
rms = sqrt(mean(save_output_noise.^2))

please suggest whether this correct?

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raja.cedt Senior Fellow Offline Posts: 1516 Germany	Re: average noise power Reply #3 - Dec 23^rd, 2011, 2:14pm yes, sounds correct. But why u r doing this.
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singh Community Member Offline Posts: 57	Re: average noise power Reply #4 - Dec 26^th, 2011, 1:04pm i have two different transfer functions and i want to see which one has more noise power.. thanx for ur suggestions
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aaron_do Senior Fellow Offline Posts: 1398	Re: average noise power Reply #5 - Dec 26^th, 2011, 5:23pm Hi, not sure if I'm missing something here, but why did you divide EFN2 by freq? thanks, Aaron
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singh Community Member Offline Posts: 57	Re: average noise power Reply #6 - Dec 27^th, 2011, 2:33am aaron_do wrote on Dec 26^th, 2011, 5:23pm: Hi, not sure if I'm missing something here, but why did you divide EFN2 by freq? thanks, Aaron efn is flicker noise voltage at 1Hz and the flicker noise gives 1/freq behaviour ... i just took general formula to calculate total noise due to flicker and white noise
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HdrChopper Community Fellow Offline Posts: 493	Re: average noise power Reply #7 - Dec 30^th, 2011, 4:10am If intereseted in average noise power, you need to integrate the resulting noise psd at the output. Best Tosei
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