Please answer the below discussion question in detail. Not less than 2 paragraph. 1. Class C amplifiers are biased so that conduction occurs for much less than 180º. These amplifiers are more efficient than either class A or class AB, but they produce an output waveform which is severely distorted. Why use them with such a distortion? Could you describe important applications where class C amplifiers play an important roll. Solution AMPLIFICATION SYSTEM Generally an important role of an amplification system final output is to ensure a low output resistance so that the output signal may be delivered to a low resistance load without loss of gain. However, it is still of paramount importance that LINEARITY must be preserved i.e, signal distortion must be kept to an absolute minimum. Another output stage requirement is that it delivers the required power to the load efficientlyi.e EFFICIENCY. This means that the power dissipated in output stage transistors must be kept to an absolute minimum, both to ensure maximum power delivered to the load and, probably more importantly, to ensure that the transistor temperature remain below specified levels Amplifiers are classified according to the characteristics of the collector (output) current waveform with an applied input. They are Class A, Class B, Class AB and Class C. CLASS A Class A operation may be implemented with a single transistor to produce complete waveform.The transistor of a Class A amplifier conducts for the entire cycle of the input signal . The transistor of a Class A amplifier conducts for the entire cycle of the input signal . The only requirement is that ICQ be greater than the amplitude of the signal current to avoid nonlinear distortion. Since we know that the maximum power dissipated by the transistor is equal to ICQ*VCEQ. therefore for better linearuty class A requires high ICQ which leads to high power disipiation (ICQ*VCEQ). Class A configuration offers the better linearity (smaller distortion), but has pretty lousy efficiency (power dissipiation) CLASS B Class B operation uses two transistor to produce complete waveform Class B stage does well with efficiency, but has rotten linearity CLASS AB: Class AB operation still uses two transistor amplifiers, one for the positive going portion of the input and one for the negative going input, but the bias of the individual transistors is between the extremes of Class A and Class B. The Q-point remains in the linear region of the characteristic curves, which avoids the nonlinear distortion of the cutoff region; Each transistor conducts for an interval slightly longer than a half-cycle. From the above two points the Class AB configuration is a compromise – the efficiency of the Class A and the linearity of the Class B stage have been significantly (although not perfectly) improved. CLASS C: The transistor in a Class C stage is biased such that it conducts for an interval of less than a half- cycle of the input. The result is a waveform .

1. Please answer the below discussion question in detail. Not less than 2 paragraph.
1. Class C amplifiers are biased so that conduction occurs for much less than 180º. These
amplifiers are more efficient than either class A or class AB, but they produce an output
waveform which is severely distorted.
Why use them with such a distortion? Could you describe important applications where class C
amplifiers play an important roll.
Solution
AMPLIFICATION SYSTEM
Generally an important role of an amplification system final output is to ensure a low output
resistance so that the output signal may be delivered to a low resistance load without loss of gain.
However, it is still of paramount importance that LINEARITY must be preserved i.e, signal
distortion must be kept to an absolute minimum.
Another output stage requirement is that it delivers the required power to the load efficientlyi.e
EFFICIENCY. This means that the power dissipated in output stage transistors must be kept to
an absolute minimum, both to ensure maximum power delivered to the load and, probably more
importantly, to ensure that the transistor temperature remain below specified levels
Amplifiers are classified according to the characteristics of the collector (output) current
waveform with an applied input. They are Class A, Class B, Class AB and Class C.
CLASS A
Class A operation may be implemented with a single transistor to produce complete
waveform.The transistor of a Class A amplifier conducts for the entire cycle of the input signal .
The transistor of a Class A amplifier conducts for the entire cycle of the input signal . The only
requirement is that ICQ be greater than the amplitude of the signal current to avoid nonlinear
distortion. Since we know that the maximum power dissipated by the transistor is equal to
ICQ*VCEQ.
therefore for better linearuty class A requires high ICQ which leads to high power disipiation
(ICQ*VCEQ).
Class A configuration offers the better linearity (smaller distortion), but has pretty lousy
efficiency (power dissipiation)
CLASS B
Class B operation uses two transistor to produce complete waveform
Class B stage does well with efficiency, but has rotten linearity
CLASS AB:

2. Class AB operation still uses two transistor amplifiers, one for the positive going portion of the
input and one for the negative going input, but the bias of the individual transistors is between
the extremes of Class A and Class B.
The Q-point remains in the linear region of the characteristic curves, which avoids the nonlinear
distortion of the cutoff region;
Each transistor conducts for an interval slightly longer than a half-cycle.
From the above two points the Class AB configuration is a compromise – the efficiency of the
Class A and the linearity of the Class B stage have been significantly (although not perfectly)
improved.
CLASS C:
The transistor in a Class C stage is biased such that it conducts for an interval of less than a half-
cycle of the input. The result is a waveform that pulsates periodically with the period of the input
signal.
If the input is a sinusoid, the output is a series of “blips” that contain the frequency of the input
as the fundamental, plus higher frequency harmonics.
The output may then be passed through an LC (inductor-capacitor) circuit tuned to the frequency
of the input sinusoid. This tuned circuit acts as a bandpass filter and yields a sinusoid at the
output that is approximately the same frequency as the input (the narrower the passband, the
closer the approximation.i.e LINEARITY in the output is preserved using LC circuit
and at the same time EFFICIENY also good
therefoere CLASS C amplifiers are used prior than CLASS A,AB
ADVANTAGES
High efficiency.
Excellent in RF applications.
Lowest physical size for a given power output.
APPLICATIONS OF CLASS C AMPLIFIERS:
(i) These are usually employed in RF (radio-frequency) power amplification and are capable of
providing large amounts of power.
(ii) RF oscillators.
(iii) RF amplifier.
(iii) FM transmitters.
(iv)Booster amplifiers.
(v)High frequency repeaters
(vi) Tuned amplifiers etc.