random number block in Simulink

how i can set the frequency of the random number? and what is the equation and calculation that used in the block ?

example if i want to 5uvrms with frequency 100 hz how i can set it in the block ?

Answer 1

[Pramil]

Hello Anas,

In Simulink, the "Random Number" block generates random numbers with a specified mean and variance. However, if you want to generate a random signal with a specific frequency, like "5 µV" RMS at "100 Hz", you need to use a combination of blocks to achieve this, as the "Random Number" block itself does not directly support frequency settings. You can know more about the block here:

https://www.mathworks.com/help/releases/R2024a/simulink/slref/randomnumber.html

Here's how you can set it up:

• Add a "Random Number" block from the Simulink library. Set the "mean" to "0" (since you want an RMS value) and set the "variance" to achieve the desired RMS value, since RMS = √(Variance), set "Variance" to "(5e-6)^2".
• To focus the random signal around "100 Hz", add a "Bandpass Filter". You can refer the following documentation to know how you can create the "Bandpass Filter": https://www.mathworks.com/discovery/bandpass-filter.html

Hope it helps.