Amplifier vs Repeater
Amplifier and repeater are two types of electronic circuits used in communication. Usually communication happens between two points (called sending and receiving points) through a wired, wireless or optical medium. Transmitter sends a signal containing some information and after travelling some distance, usually, a signal get weakened (attenuated) due to energy loss in the medium. Therefore, it should be improved (or amplified). Amplifier is the circuit which magnifies the weak signal to a signal with more power. Sometimes, this signal attenuation happens much before the arrival to the destination. In this case, signal is amplified and retransmitted with a power gain in one or more mid points. Those points are called repeaters. Therefore an amplifier is an essential part of a repeater.
Amplifier (also shortened as amp) is an electronic circuit that increases the power of an input signal. There are many types of amplifiers ranging from voice amplifiers to optical amplifiers at different frequencies. A transistor can be configured as a simple amplifier. The ratio between output signal power to input signal power called as the ‘gain’ of the amplifier. Gain may be any value depending on the application. Usually gain is converted into decibels (a logarithmic scale) for convenience.
Bandwidth is another important parameter for amplifiers. It is the frequency range of the signal that is amplified in expected way. 3dB bandwidth is a standard measure for amplifiers. Efficiency, linearity and slew rate are some of the other parameters to be considered when designing an amplifier circuit.
The repeater is an electronic circuit that receives a signal and retransmits the same signal with a higher power. Therefore, a repeater consists of a signal receiver, an amplifier and a transmitter. Repeaters are often used in submarine communication cables as signal would be attenuated to just a random noise when travelling such a distance. Different types of repeaters have different types of configurations depending on the transmission medium. If the medium is microwaves, repeater may consist of antennas and waveguides. If the medium is optical it may contain photo detectors and light emitters.
Difference between Amplifier and Repeater
1. Amplifier is used to magnify a signal, whereas repeater is used to receive and retransmit a signal with a power gain.
2. Repeater has an amplifier as a part of it.
3. Sometimes, amplifiers introduce some noise to the signal, whereas repeaters contain noise eliminating parts.