Distortion in a waveform or Distortion in a communication sign and distortion occurs during transmission of a waveform :

Distortion in a waveform or Distortion in a communication sign.

•    Distortion in a waveform.

                    or 

•   Distortion in a communication sign.

The Distortions may be introduced in a waveform or a communication signal when ,they are

transmitted from one point to other point through a transmission channel. The transmission

channel consists of various electronic components like amplifier, heterodyning element etc. The

different types of distortions ,that occur during transmission of an input signal like waveform or

communication signal are,

1. Linear distortions:

(i) Amplitude distortion

(ii) Phase or delay distortion

2. Non-linear distortions:

(i) Harmonic distortion

(ii) Inter modulation distortion.


In details explain as per following ,

l. Linear Distortions:

(i) Amplitude Distortion

When different frequency components of the input signal are amplified or attenuated by different

amounts, The output signal consists of distortions, known as amplitude distortions (i.e.,)

amplitude distortion occurs When the amplification or attenuation of the signal is not constant

over the useful range of frequencies.

(ii) Phase or Delay Distortion

If the phase of the output signal is different from the phase of input signal then such distortion is

known as phase distortion. Phase distortion leads to delay in the transmission of the signal.

Hence, it is known as delay distortion. If different amounts of phase shifts occur at different

frequencies of an output signal then it becomes necessary to compensate for such phase

distortions. Whereas if same amount of phase shift occurs at all frequencies then such phase

distortion can be ignored.

The phase distortion arises due to the presence of energy storage elements in the transmitting

circuit (i.e. reactive elements such as capacitor and inductor).

2. Nonlinear Distortions:

The non-linear distortions in the signal arise due to non-linear characteristics of the electronic

components like amplifiers, etc. The two types of non-linear distortions are,

(i) Harmonic Distortion

The non-linear characteristics of an electronic circuit give rise to harmonics in the output signal.

These harmonics produce distortions in the output signal. The distortions caused due to

harmonics are known as harmonic distortions. Harmonic components occur at frequencies 2f1,

3f1, 4f1……………. (where. f1= Fundamental frequency of signal).

(ii) Inter modulation Distortion

When two signals of different frequencies (f1 and f2) are mixed together (i.e.…..heterodyned) the

resultant signal will be a sum or difference of the actual frequencies of the signal i.e. f1± f2, 2f1 ±

f2.....etc. Thus, when the signals are heterodyned additional frequency components are generated

which are undesirable and which lead to distortions in the signal. The distortion caused by

heterodyning of different frequency signals is known as inter modulation distortion.

• distortion occurs during transmission of a waveform :

Distortion refers to the deviation in any parameter (like amplitude, frequency. shape) of a signal

from that of an ideal signal. The non-linear characteristics of the elements of an electronic circuit

give rise to harmonics in the output signal which in turn causes distortion of the output signal.

The distortion caused due to harmonics is known as harmonic distortion.

The different types of harmonic distortions caused by an electronic circuit (for example,

electronic amplifier are as per follows,

(i) Amplitude distortion.

(ii) Frequency distortion.

(iii) Phase distortion

(iv) Crossover distortion

(v) Inter modulation distortion.

(i) Amplitude Distortion:

When the amplitude of the output signal is not a linear function of the amplitude and input

signal is distorted under specific conditions then such type of distortion are known as

amplitude distortion. Amplitude distortion occurs when the amplifier gives rise to harmonics

of the fundamental frequency of the input signal.

(ii) Frequency distortion:

Frequency distortion of a signal takes place when the signal is amplified by different

amounts at different frequencies. This is caused mainly due to the combination of active devices

and components in an amplifier.

as Example, the non uniform frequency response of RC-coupled cascade amplifier refers to

frequency distortion

(iii) Phase Distortion: 
It is different from the phase of the input signal then such distortion is

known as phase distortion.

If different amounts of phase shifts occur at different frequencies of an output signal than

it becomes necessary to compensate for such phase distortions. While if same amount of phase

shift occurs at all frequencies then such phase distortion cannot be ignored .the phase distortion

arises due to presence of storage elements in the circuit

(iv)Crossover Distortion:

The improper biasing voltages of the electromagnetic components of an amplifier (as

example push-pull amplifier give rise to crossover distortion)

(v) Inter modulation Distortion:

When two signals of different frequencies are mixed together (i.e., heterodyned) the

resultant signal will be a sum or difference of the actual frequencies of the signals. Thus, when

the signals are heterodyned, additional frequencies are generated which are undesirable and

thereby leads to distortion. The distortion caused by heterodyning of frequencies is known as

inter modulation distortion.

The various distortions in the signal can be analyzed using a distortion analyzer 
we can give example as,harmonic distortion analyzer.