Signal Bandwidth & Transmission Medium

Signal Bandwidth refers to the difference between the frequencies of the upper band and the lower band in the continuous band frequency.

For example, if the amplifier has a bandwidth of 2800 Hz, the amplifier can amplify the signal well (without any distortion between 300Hz to 3100Hz).

In communication systems, the signal transmission channels can be various, such as voice, music, image or computer data. Each of these has a specific frequency range called the signal bandwidth.

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Bandwidth

The majority of signals are delivered using electromagnetic or radio waves. The signal power is overlaid on a carrier signal or alters its frequency to carry the data from the transmitter to the recipient. It is demodulated and transformed back to the original signal.

Every signal is produced from a huge range of signals of various frequencies, and each signal is different in its structure. This brings us to the techniques used in the signal recognition process. This is when the term “bandwidth” enters the picture. A modulated radio-frequency bandwidth of the signal is the frequency range inhabited by the signal, commonly expressed in hertz (cycles per second) or as a percentage of the radio frequency.

The difference between the upper and lower frequencies of a signal created is known as the signal’s Bandwidth. Signal Bandwidth (B) is equal to the change between the higher or upper frequency (fH) and the lower frequency (fL). It is measured in Hertz (Hz), the frequency unit.

Regardless of where it is in the frequency range, a band of a certain width can possess a unique maximum quantity of information. The fundamental constraint, which is not depending on the carrier frequency, is unaffected by modifying the band at a high frequency.

There are no channels on all frequencies, nor are there channels on any frequency range, yet each channel has its distinct frequency, similar to an ID.

There are bandwidths of signals of all kinds in the optical and audio spectrums and far beyond.

The human ear’s hearing bandwidth is 20 Hz to 20,000 Hz. Infrasonic noises are below 20Hz, and ultrasound sounds are beyond 20000 Hz. Ultrasonic sounds are audible to dogs. Blue whales, on the other hand, can make infrasonic sounds. So let us look at some uses of different signals at different bandwidths.

There are different kinds of bandwidths of signals in the optical and audio spectrums and far beyond.

Smaller frequencies are utilised for long-distance communication because they can travel without distortion across vast distances. Larger frequencies convey more data and have more power, but they are ineffective and cannot be transferred over long distances.

The frequency range section containing the majority of the signal energy is known as essential Bandwidth. The Bandwidth of a device, circuit, or component is fractionally divided by its central frequency.

The fractional Bandwidth is 50% if the Bandwidth is 4 MHz and the centre frequency is 8 MHz.

The average power of the sent signal is known as the transmitted power. The input (message) signal’s channel bandwidth refers to the range of major frequency components available for transmission.

BANDWIDTH OF TRANSMISSION MEDIUM 

Similar to message signals, many types of transmission media give different bandwidths. The most widely used transmission media is free area and fibre optic cable. The coaxial cable is a widely used wire medium, providing a bandwidth of about 750 MHz. Such cables typically operate below 18 GHz. Frequent communication using radio waves occurs at a very wide range of frequencies: from a few hundred kHz to a few GHz. These are subdivided and assigned to different services. 

Solids

Solid materials are often used as means of transmission. For example, sound can travel through metal in the form of vibrations. That is why we hear a distant train as we place our ears on a railroad track or hear noises from another room as we place our ears against a wall. Fibre optic cables, glass, metals are all solid transmission mediums.

Liquid

The liquid can be easily used as a transmission device for any wave. How does water boil, and if not, conduction currents are added when burning a bakery or container? Light can also pass through liquid; the reason we can see fish in an aquarium or pond.

Gas

Gases are a very effective means of transmission. You can always hear your friends calling you from a distance when they shout. The use of free cell phones without any cable connection is only possible due to air as a transmission point.

Vacuum

We know that the waves can travel in space as light and heat from the sun reach the earth’s surface through space. Any transmission method has a certain bandwidth limit as a signal that can be built with multiple frequencies and thus have a specific bandwidth. 

Conclusion :

Thus, Bandwidth plays a vital role in determining signal quality while reflecting the scope of the appropriate signal performance.

Signal Bandwidth also indicates the amount of data that can be transferred over a given period. In addition to Bandwidth, additional data can be transferred. 

The bandwidth of signals has a different meaning in different contexts, referring to the frequency range the signal can work best in the communication system. In contrast, the Computer system refers to the amount of data transmitted. Bandwidth plays a vital role in communication systems, both wired and wireless.