Noise by the Numbers

Broadcasted on 8/18/2010

Noise by the Numbers - Bob Muro

Bob Muro
Wireless Telecom Group

This webinar is perfect for those looking to learn the basics about noise and what you can do with it. The main areas covered will include:

  • What can I do with noise?
  • How is noise created?
  • What types of noise can Noisecom provide?
  • What do I need to know before purchasing a noise solution?
  • Helpful formulas for specific noise parameters

Learn how noise is created, the different types and how to control it. Bob will show how to define your noise requirements so you can identify the specific form factor, including diodes, modules and instruments that provide the best solution for your application. 

Webinar Q&A

Below are questions we received during the webinar. If you have any additional questions, email us.

Electrons in resistors move randomly with temperature. Why should I use noise diodes and not a simple attenuator?

Because a simple attenuator at room temperature does not have enough power (Excess Noise Ratio) to be measured by any available instrument and a reversed biased diode circuit can generate sufficient power.

Is an FM modulated signal for altering serial receiver clocks not better suited than noise? With FM I can set exact limits and cover the whole frequency range.

Yes, and FM is currently used by Digital engineers to enhance Random jitter, or white noise in combination. The FM modulated signal is referred to as deterministic jitter in the Total Jitter model defined by PCI sig.

“White noise” is flat, but Gaussian distribution is not. Could you elaborate why “white” noise should be “Gaussian”?

Flat white noise is measured in the frequency domain, and a Gaussian amplitude is measured in the time domain. These are two independent domains, but they are related when speaking about AWGN. A continuous flat white noise band with uniform spectral density usually has a Gaussian amplitude distribution in the time domain provided the amplification chain is not saturated.

You offer digital and analog noise generators. Is the digital one not more flexible and better suited for many applications?

Yes the digital generator is more flexible, but better for some applications, typically with narrow band requirements and high power.

What noise source ENR value is correct for a 16 dB noise figure device under test

  1. Standard Rule: if the expected noise figure is ≤ 15 dB, the source ENR  value should be low,  ≤7dB; this is to improve return loss.
  2. If the expected noise figure is ≥ 15db, then the noise source ENR value ≤ 15 dB over the band.