Amplifier - Types, Parameters, and Applications

This article discusses the different types of amplifiers, including A.F, R.F, I.F, and operational amplifiers. It also covers amplifier parameters such as gain, frequency response, bandwidth, input impedance, and output impedance. Additionally, the article highlights the various applications of amplifiers, including inverting amplifiers, instrumental amplifiers, voltage followers, non-inverting amplifiers, and summing amplifiers.

Running Head: AMPLIFIER
Amplifier
Student’s Name
Institution

AMPLIFIER
Introduction
An amplifier is an electronic device that is used in increasing the signal power which is the
time-varying current or voltage. In doing so, the amplitude of the signal’s waveform
increases without a change in other waveform parameters such as wave-shape and frequency.
Amplifiers are the widely and commonly applied circuits in performing various functions in
electronics and electronic systems. The symbol used to generally display an amplifier is
shown below. This symbol provides no detail of the described amplifier type, but the signal
flow is assumed to be directed from left going right of the diagram (Gerhard, 2018).
Types of amplifiers
A way of describing an amplifier is by the kind of the signal amplification is performed.
These types of signal amplification are numerous hence some of the amplifiers include;
A.F Amplifiers
Audio frequency amplifiers are applied in signal amplification to an approximate range of
20Hz- 20kHz that people can hear. Some audio Hi-Fi amplifiers exceed an average range of
100kHz while a number of audio amplifiers may limit the high frequency to about 15kHz or
lower (Mladen & Saurabh, 2017).
R.F Amplifiers
These are tuned amplifiers whereby the operational frequency is regulated using a tuned
circuit. Depending on the function of the amplifier, the circuit may be non-adjustable or
adjustable.

AMPLIFIER
I.F Amplifiers
These are tuned amplifiers applied in radar, radio and televisions the main purpose is for
producing many voltage amplification signals of television, radio and radar. The vide
information transmitted through the signal is first separated from the signal of the radio.
Operational amplifiers
These are developed circuits for the original computers that were analogue and were applied
for mathematical operations which include subtraction and addition. In the modern days, they
are applied widely in forms of integrated circuit available in packages of double or single
amplifiers (Bumman, 2018).
Amplifier parameters
Gain
It is the ratio of the amplitude of output signal to the amplitude of input signal, the symbol
being ‘’A’’.
Av (voltage gain) = output voltage amplitude ÷ input voltage amplitude.
Ai (current gain) = output current amplitude ÷ input current amplitude
Ap (power gain) = output power signal ÷ input power signal

AMPLIFIER
(Bumman, 2018)
Frequency response
Frequency bands that produce enough amplification leaving behind frequencies that are
below and above the band where amplification is lower.
Bandwidth
It is a frequency band that makes the amplifier possess a useful gain
Input impedance
Impedance in this context is the resistance to the flow of AC current. Amplifiers have input
impedances which are the resultant impedances between the input terminals.
Output impedance
This is an apparent impedance that can be shown by the reduction of signal voltage from the
amplifier’s output terminals after current exits these terminals (Andrei, Nathan, & Marc,
2011).
Applications
Generally, op-amps are the latest mainly used amplifiers. The applications of these amplifiers
have been influential in many fields. These fields include (Mladen & Saurabh, 2017);
 Inverting amplifiers
 Instrumental amplifiers
 Voltage followers
 Non-inverting amplifiers
 Summing amplifiers

AMPLIFIER
References
Andrei, G., Nathan, O., & Marc, F. (2011). Switchmode RF Power Amplifiers. Baqal:
Newnes.
Bumman, K. (2018). Doherty Power Amplifiers: From Fundamentals to Advanced Design
Methods. Fujairah: Elsevier Science.
Gerhard, K. (2018). Applications of Lock-In Amplifiers in Optics. Dubai: SPIE Press.
Mladen, B., & Saurabh, S. (2017). Millimeter-Wave Low Noise Amplifiers. Kawr Fakkān:
Springer.