Tuned amplifier is a electronic circuit that is designed to amplify a specific frequency or a narrow band of frequencies.
Tuned amplifier use a tuned circuit, which consists of an inductor and a capacitor connected in parallel or in series, to filter the desired frequency range. The amplifier stage amplifies the filtered signal and provides the required gain.
Classification of of Tuned Amplifier
Tuned amplifiers can be classified based on different criteria, including the type of tuned circuit, the number of amplifier stages, the type of amplification, the type of coupling between stages, and the application.
1. Based on the type of tuned circuit
Tuned amplifiers can be classified into parallel tuned amplifiers and series tuned amplifiers.
Parallel Tuned Amplifiers
In parallel tuned amplifiers, the tuned circuit is connected in parallel with the load resistor.
Series Tuned Amplifiers
In series tuned amplifiers, the tuned circuit is connected in series with the load resistor. The resonant frequency of the tuned circuit determines the frequency selectivity of the amplifier.
2. Based on the number of amplifier stages
Tuned amplifiers can also be classified based on the number of amplifier stages as single tuned amplifiers, double tuned amplifiers, and triple tuned amplifiers
Single Tuned Amplifiers
Single tuned amplifiers have one tuned circuit and one amplifying stage.
Double Tuned Amplifiers
Double tuned amplifiers have two tuned circuits and two amplifying stages.
Triple Tuned Amplifiers
Triple tuned amplifiers have three tuned circuits and three amplifying stages. The number of tuned circuits and amplifying stages in a tuned amplifier determines its frequency selectivity and gain.
3. Based on the type of amplification:
Tuned amplifiers can be classified based on the type of amplification as Class A, Class B, Class AB, or Class C tuned amplifiers.
Class A Tuned Amplifiers
Class A tuned amplifiers are designed for linear amplification and have the highest fidelity, but are less efficient.
Class B Tuned Amplifiers
Class B tuned amplifiers are designed for maximum efficiency, but suffer from distortion at low signal levels.
Class AB Tuned Amplifiers
Class AB tuned amplifiers are a compromise between Class A and Class B, providing both good fidelity and efficiency.
Class C Tuned Amplifiers
Class C tuned amplifiers are used for RF power amplification and are highly efficient, but not suitable for high-fidelity applications.
4. Based on the type of coupling between stages
Tuned amplifiers can be classified based on the type of coupling between amplifier stages as transformer-coupled tuned amplifiers, RC-coupled tuned amplifiers, and direct-coupled tuned amplifiers
Transformer-coupled Tuned Amplifiers
Transformer-coupled tuned amplifiers use transformers to couple the output of one stage to the input of the next stage.
RC-coupled Tuned Amplifiers
RC-coupled tuned amplifiers use capacitors and resistors to couple the output of one stage to the input of the next stage.
Direct-coupled Tuned Amplifiers
Direct-coupled tuned amplifiers have no coupling between stages and are suitable for high-fidelity applications.
5. Based on the application
Tuned amplifiers can also be classified based on the application as RF tuned amplifiers, audio tuned amplifiers, and instrumentation tuned amplifiers.
RF Tuned Amplifiers
RF tuned amplifiers are used in radio frequency applications.
Audio Tuned Amplifiers
Audio tuned amplifiers are used in audio systems.
Instrumentation Tuned Amplifiers
Instrumentation tuned amplifiers are used in measurement and instrumentation systems, and medical tuned amplifiers are used in medical equipment.
In conclusion, the classification of tuned amplifiers helps to identify the specific type of amplifier required for a particular application. The choice of the type of tuned amplifier depends on the frequency range to be amplified, the desired gain, the level of distortion and noise that can be tolerated, and the efficiency of the amplifier.
Advantages of of Tuned Amplifier
- High selectivity
- Low noise
- High gain
- Low distortion
- Efficient
- Versatile