[SOLVED] Noise and sensitivity of video detectors

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saad

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Hello everyone,
I am working on the design of a square-law video detector. I have simulated the its output noise (in units of V/√Hz). I am wondering on how do I estimate the total output noise for a given video bandwidth. I need this to get an estimate of the minimum detectable RF signal (Tangential signal sensitivity).

Saad
 

Hi Saad,

Say you have the noise voltage expressed as εn [V/√Hz].
Then the (normalized) power spectral density is εn2 [V2/Hz].
The normalized power in a bandwidth B is εn2B [V2]
The rms voltage is VEF=sqrt(εn2B)=εn√B [V]

Regards

Z
 
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saad said:
1. What is it normalized to?
2. Should it not be the integral of εn2B ?
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1) If U is a voltage, U2 is called a "normalized power" because i order to have a "true" of "physical" power it must be divided by R. The same applies to εn2B: it must be divided by a resistance in order to get the physical power spectral density (psd).

2) εn2B is already the integral of the uniform normalized psd ∫εn2df between 0 and B.
 
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