Why BANDWIDTH is important in ELECTRONICS.

In electronics, Bandwidth is used to measure electronic communication. It is defined as the width of the range of the frequencies that an electronic signal uses. Bandwidth is expressed in terms of the difference between the signal having highest-frequency and the signal having the lowest-frequency. In computer networks, bandwidth is often used as a term for the data transfer rate. More easily, the amount of data that is carried or passed from one point to another in a network, in a given time period (usually a second).

Usage:

Bandwidth is often applied to the electromagnetic spectrum (e.g., radio waves, light waves and X-rays). Such waves are vibrations (oscillations) of electric and magnetic fields. To use a radio example, the lowest United States AM radio channel covers the band of frequencies from 535,000 Hz to 545,000 Hz. It therefore has a bandwidth of 10,000 Hz (545,000 - 535,000). All United States AM radio broadcasting stations have this bandwidth (though the location of each band is distinct). The lowest United States FM radiochannel (on the other hand) covers the band from 88,000,000 Hz (88 MHz) to 88,200,000 Hz (88.2 MHz). It therefore has a bandwidth of 200,000 Hz. (Notice that the width of an FM band is 20 times the width of an AM band.)

The term "bandwidth" has been misused in the field of digital data communication. It is often incorrectly used to mean "data carrying capacity". However, there is no such thing as "digital bandwidth". The proper term for the data carrying capacity of a communication channel is channel capacity.

It is true that, in general, the channel capacity of a system increases with the bandwidth used for communication. However, many other effects are also important. Therefore, in many (if not most) real systems, the channel capacity is not easily related to the channel bandwidth.

Broadband:

Sometimes, the word "broadband" is used to mean "high-speed", especially in for high speed internet connections. "Broadband" means "wide band", and suggests high-speed. However, the term is not clear; "high-speed" is more clear. Typically, a dial-up telephone connection is thought to be low-speed, at less than 56,000 bit/s (bits per second). High-speed is usually 200,000 bit/s or faster. DSL (Digital Subscriber Line) or Cable modem connections are usually high-speed.

Controlling Bandwidth

Any amplifier should ideally have a bandwidth suited to the range of frequencies it is intended to amplify, too narrow a bandwidth will result in the loss of some signal frequencies, too wide a bandwidth will allow the introduction of unwanted signals, in the case of an audio amplifier for example these would include low frequency hum and perhaps mechanical noise, and at high frequencies, audible hiss.