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Model noise using current or voltage noise source in RF systems

  • Noise block

RF Blockset / Circuit Envelope / Sources


Use the Noise block to model noise as a ideal current or voltage source for blocks. When you use a Noise to simulate noise in an RF model, also select the Simulate noise check box in the Configuration block. Otherwise, the model simulates without noise. The Noise block does not depend on the Temperature parameter in the Configuration.

Noise block mask icons are dynamic and show the current type of source. This table shows you how the icons on this block vary based on the type of source you set on the Source type parameter on the block.

Source type: Ideal voltageSource type: Ideal current

Sinusoid block icon with Source type is set to Ideal voltage.

Sinusoid block icon with Source type is set to Ideal current.


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Noise type, specified as Ideal voltage or Ideal current.

Noise distribution type, specified as White, Piece-wise linear, or Colored.

Single-sided noise power spectral distribution (PSD), specified as:

  • White, spectral density is a single non-negative value. The power value of the noise depends on the bandwidth of the carrier and the bandwidth depends on the time step. This is an uncorrelated noise source.

  • Piece-wise linear, spectral density is a vector of values [pi]. For each carrier, the noise source behaves like a white uncorrelated noise. The power of the noise source is carrier-dependent.

  • Colored, depends on both carrier and bandwidth. This is a correlated noise source.

When Source type is set to:

  • Ideal voltage, spectral density units are V2/Hz.

  • Ideal Current, spectral density units are A2/Hz.

Frequencies for piece-wise linear noise distribution, specified as vector of non-negative frequencies.

Select this option to internally ground and hide the negative terminals. To expose the negative terminals, clear the option. By exposing these terminals, you can connect them to other parts of your model.

By default, this option is selected.

Version History

Introduced in R2010b

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