Web Hosting News

Please rate this article

(No Ratings Yet)

 Loading ...

As we all know, noise always disturbs the streamlined order of the environment making things little bit messy. Whenever we think of noise, what first comes to our mind is audible noise. But there are so many “noises” around us that becomes subject to various fields of professions. In this brief article, we are trying to elaborate on Electronic Noise which is not a familiar area for an ordinary reader.

In electronic science, electronic noise is described as an unwanted signal characteristic of all electronic circuits. Depending on the design and the components of the circuit, the noise put out by the electronic device can vary greatly. Various effects and phenomena within circuits cause this noise. Let’s have a look at few types of noises that can be found in all electronic devices.

Shot noise

The main culprit for this type of noise is the electrons. When electrons flow through the conductors of the circuit, the density of electron flow may fluctuate randomly due to various factors. This very fluctuation of electric current causes shot noise. Therefore, the strength of the noise increases with the average magnitude of the electric current. But when it comes to higher magnitude currents, noise produced is far less than the current itself and therefore the disturbance is somewhat negligible. But noise really matters in small magnitude signals such as low voltage circuits where the gap between the current and the noise is very less. In these cases, specific noise reduction methods should be executed.

Burst noise

If you are familiar with audio recording for some reason, this type of noise may have been encountered by you. Have you heard a background noise in your audio recording which is similar to popcorn sound? Aha… that’s what we are talking about. This usually happens in step-like transition of electronic current. Usually this noise appears in semiconductors.

Flicker noise

Unlike most other types of noises, flicker noise is generated only by direct current (DC). This occurs in almost all the electronic devices, and results from a variety of effects, such as impurities in conductive channel, noise in transistors due to base current etc. Carbon composition resistors contain a lot of flicker noise and in contrast, wire-wound resisters have the least amount.

Thermal noise

This is the most popular and known type of noise of electronic devices. You may not be able to find an electronic item with no thermal noise at all, as thermal noise appears regardless of the voltage level of the circuit. When electrons travel through the conductors of the circuit, they crash in to conductor’s atoms and generate some kind of heat although it is not measurable in most of the cases. You should be able to hear thermal noise of your home theater system if you increase the volume without playing anything. Since this thermal noise is negligible and there exists mechanisms to eliminate it to a higher degree, we are not bothered about it in our day-to-day life. But when it comes to radio telescopes, they are ultra sensitive to their own thermal noise so their circuits are covered in liquid nitrogen to minimize the heat generation.