[SOLVED] Noise and sensitivity of video detectors

Status
Not open for further replies.

saad

Advanced Member level 4
Joined
Jun 8, 2005
Messages
101
Helped
10
Reputation
20
Reaction score
7
Trophy points
1,298
Location
Pakistan
Activity points
2,080
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
 
Reactions: saad

    saad

    Points: 2
    Helpful Answer Positive Rating
Last edited:
Reactions: saad

    saad

    Points: 2
    Helpful Answer Positive Rating
saad said:
1. What is it normalized to?
2. Should it not be the integral of εn2B ?
Click to expand...
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.
 
Reactions: saad

    saad

    Points: 2
    Helpful Answer Positive Rating
Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…