Analog signal

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In the context of signal theory, an analog signal is a form of signal with a continuous and uninterrupted course. An analog signal is described as a smooth function and it can be used, for example, to describe the time-continuous course of a physical variable such as sound pressure in the form of an analog audio signal . The range of values ​​of an analog signal is called the dynamic range.


Continuous and discrete signals in comparison

In electronics , analog signals are usually selected in the form of an electrical voltage , rarely also as an electrical current , to represent the physical quantity. More generally, an analog signal can also be understood as a frequency , phase position or a quantity composed of physical quantities such as brightness , temperature or various mechanical quantities . For example, a can barometer uses deformation as a result of pressure ; In the case of a record , analog sound signals can be obtained from the height differences in the individual grooves.

In contrast to a digital signal , an analog signal has a continuous and arbitrarily fine curve and can theoretically assume an infinite number of values ​​in the dynamic range. In the case of real physical quantities, however, the resolution is limited by disturbances such as noise or by distortions . Therefore, once added, interference in an analog signal cannot be undone. In the case of a digital signal, disturbances in the signal can, as long as they remain below certain limit values, be compensated for by threshold formation due to quantization , among other things .

In electronics, an electrical analog signal is converted into a digital signal that can be used in digital signal processing by means of analog-to-digital converters (ADC), while the reverse is done using digital-to-analog converters (DAU).


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