This article explains what are analog and digital signals along with their differences. Also, find out the uses, advantages, and disadvantages of both.
We exist in an analog world. It has an abundant variety of colors, paints, voice tones, types of smells, etc. These are infinite in numbers. All these are Analog signals. And the similarity among all of these analog signals is their endless possibilities.
But, unlike analog signals, Digital signals and objects distinct or finite in quantity, meaning there is a limited set of values about their existence. They generally have a set of only two possible values, instead of having infinite possibilities.
When a person is from an electronics background, it means that he has to deal with both analog and digital signals. The electronics projects have to interact with the real, Analog world in some ways, but most of the microprocessors, computers, and logic units are entirely digital components. Analog signals and digital signals are like different electronic languages. Generally, some of the electronic components we use are bi-lingual, whereas some can understand only one of the two.
Analog and digital signals are widely used to send information, generally with the help of electric signals. In digital technology, translation of information is in the form of binary format (either 0 or 1), and the same information is translated into electric pulses of fluctuating amplitude in analog technology.
In this article, we’ll cover the overview of both digital and analog signals, including applications in real life of each. We will also have an in-depth view of the difference between the two.
Signal – What it is?
In signal processing, a signal can be defined as any function that transmits information about any phenomenon. In electronics and telecommunications, it refers to voltage, current or electromagnetic wave varying with the time that carries information.
Any quality (physical quantity) that shows signs of variation in space or time can be used as a signal to transmit messages between observers. The IEEE Transactions on Signal Processing defines signal as “a signal can be audio, video, speech, image, sonar and radar-related, and so on.” The signal was later defined as, “Anything that is only a function of space, such as an image, is excluded from the category of signals.” At the same time, it is worth noting that a signal may or may not contain any message.
According to a different feature of values, signals can be classified as Analog signals and Digital signals.
By definition, “Analog signal is any continuous signal for which the time-varying feature (variable) of the signal is a representation of some other time wearing quantity, that is, analogous to another time wearing a signal.” To quote an example, in an analog audio signal, the instantaneous voltage of the signal fluctuates in harmony with the pressure of the sound waves.
By looking at the graph of a signal, it is easy to identify whether the signal is analog or digital. In the case of an Analog signal, the graph is generally smooth and continuous and very much similar to the sine graph. As we can see in a continuous graph, the range is specified for maximum and minimum values. However, it is to one who has to keep in mind that there is still an infinite number of possible values within that particular range.
Uses of Analog systems
Almost all types of measurements use specialized Analog signal Processing. For example, the electric field meters, precision micro voltmeters, Analog watches thermometer, capacitance, etc. They are also used to broadcast radio frequency and widely used in mobile applications too.
Advantages of the Analog system
- one of the significant benefits of the Analog signal is that it can store up an infinite amount of data.
- As compared to digital signals, the density of messages is much higher.
- It is effortless to understand the use of Analog signals as compared to digital signals.
- The Analog system and their use is very less expensive as compared to the digital system.
- The accuracy of the Analog system is also more than the digital system.
Disadvantages of Analog system
- one of the significant drawbacks in the Analog signal is that along with the transmission of messages; it carries a lot of unwanted noise, which is transmitted during recording.
- While transferring data at long distances, there is a high chance of having unwanted disturbances.
- If the operator of an Analog system takes months to upgrade the order to the digital interface, it is not possible.
By definition, “a digital signal is a signal that is being used to represent as a series of discrete values, at any given time it can only take on one of a finite number of values.” The fact that the digital signal can only take a finite number of values is the fundamental difference between the digital signal and The Analog signal. The digital signals can only have a limited number of values, whereas the Analog signals have an almost infinite number of values.
In most of the digital circuits of the systems, the signals can have only two possible values, and they are also called binary signals or logic signals. The digital signals are represented by two voltage pants, one band which is near a reference value (generally 0), and the other band lies near the supply voltage. This is similar to the values, ‘0’ and ‘1’ or ‘false’ and ‘true’ of the Boolean domain. This means that at any particular time, a digital signal can represent only one binary digit.
One significant advantage of digital signals is that they are immune to outside noise and electronic noise, provided that it is not very loud and does not affect the digital circuits. In the case of the Analog signal, the noise can always degrade the transmission quality.
Uses of digital system
Nowadays, the digital system is used almost everywhere. Thermometer use, photocopies, landline telephones, audiotape recorders, television, computers, laptops, mobile phones, wristwatches, wall clocks, are all becoming digital nowadays. It increases the accuracy of the message as well as makes it easy to read.
Advantages of Digital system or signals
- Because of the digital nature, the signals in the digital systems can travel significantly faster over digital lines as compared to the Analog signals
- As compared to Analog signals, digital signals can transfer more data.
- The digital systems are less expensive, more reliable, easy to manipulate, and more flexible as compared to the Analog system.
- A digital system can be made compatible with other digital systems to which is not possible in the Analog system.
Disadvantages of digital system or signals
- Higher bandwidth in the case of digital signal transmission is essential.
- the systems and processing of the signals are more complicated as compared to the Analog system
- There is always a very big chance of sampling errors in case of digital system
- In order to detect the digital signals, the communications system of the digital systems needs to be appropriately synchronized.
Difference between Analog signals and Digital signals
|Analog Signal||Digital Signal|
|The analog signal is a continuous signal that helps to measure physical quantities.||Digital signals are time separated signals, and they are generated with the help of digital modulation.|
|The analog signals can be denoted with the sine curves.
||The digital signals can be denoted with the square curves.
|It can use a continuous range of values that facilitate you to understand or send information.||The Digital signal uses distinct 0 and 1 to represent information.|
|Temperature sensors, Resistive touch screen, FM radio signals, Light sensor, Photocells are examples of Analog signals.
||Computers, Laptops, Pen drive, CDs, DVDs are some examples of Digital signal.
|The bandwidth of the analog signal is low.||The bandwidth of digital signal bandwidth is high.|
|Noise can easily damage the analog signals during transmission, as well as the write/read cycle.||Digital signals are immune to deterioration during the transmission process and write/read cycle.|
|Analog hardware can never offer flexible execution.||Digital hardware offers flexibility in execution.|
|Analog signals are preferable for audio and video transmission.||Digital signals are preferable for Computing and digital electronics.|
|Analog instruments generally have a scale, which is situated at the lower end and gives significant observational errors.||Digital instruments do not give any kind of observational errors.|
|Analog signals have no fixed range.||Digital signals have a finite range, that is, 0 and 1.|
|The analog systems record waveforms as it is.||The digital systems collect analog waveforms into a limited set of numbers and then record them.|
|The analog systems can store data in the form of wave signals.||The digital systems can store data in the form of a binary bit.|
|As compared to digital signals, analog signals are generally very cheap.||As compared to analog signals, digital signals are costly.|
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