Net gain (telecommunications)

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In telecommunications, net gain is the overall gain of a transmission circuit. Net gain is measured by applying a test signal at an appropriate power level at the input port of a circuit and measuring the power delivered at the output port. The net gain in dB is calculated by taking 10 times the common logarithm of the ratio of the output power to the input power.

The net gain expressed in dB may be positive or negative. If the net gain expressed in dB is negative, it is also called the net loss. If the net gain is expressed as a ratio, and the ratio is less than unity, a net loss is indicated.

The test signal must be chosen so that its power level is within the usual operating range of the circuit being tested.

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<span class="mw-page-title-main">Amplifier</span> Electronic device/component that increases the strength of a signal

An amplifier, electronic amplifier or (informally) amp is an electronic device that can increase the magnitude of a signal. It is a two-port electronic circuit that uses electric power from a power supply to increase the amplitude of a signal applied to its input terminals, producing a proportionally greater amplitude signal at its output. The amount of amplification provided by an amplifier is measured by its gain: the ratio of output voltage, current, or power to input. An amplifier is defined as a circuit that has a power gain greater than one.

<span class="mw-page-title-main">Operational amplifier</span> High-gain voltage amplifier with a differential input

An operational amplifier is a DC-coupled electronic voltage amplifier with a differential input, a (usually) single-ended output, and an extremely high gain. Its name comes from its original use of performing mathematical operations in analog computers.

<span class="mw-page-title-main">Emphasis (telecommunications)</span> Process for reducing noise

In signal processing, pre-emphasis is a technique to protect against anticipated noise and loss. The idea is to boost the frequency range that is most susceptible to noise and loss beforehand, so that after a noisy and lossy process more information can be recovered from that frequency range. Removal of the distortion caused by pre-emphasis is called de-emphasis, making the output accurately reproduce the original input.

<span class="mw-page-title-main">Loop gain</span> Sum of the gain around a feedback loop

In electronics and control system theory, loop gain is the sum of the gain, expressed as a ratio or in decibels, around a feedback loop. Feedback loops are widely used in electronics in amplifiers and oscillators, and more generally in both electronic and nonelectronic industrial control systems to control industrial plant and equipment. The concept is also used in biology. In a feedback loop, the output of a device, process or plant is sampled and applied to alter the input, to better control the output. The loop gain, along with the related concept of loop phase shift, determines the behavior of the device, and particularly whether the output is stable, or unstable, which can result in oscillation. The importance of loop gain as a parameter for characterizing electronic feedback amplifiers was first recognized by Heinrich Barkhausen in 1921, and was developed further by Hendrik Wade Bode and Harry Nyquist at Bell Labs in the 1930s.

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<span class="mw-page-title-main">Gain (electronics)</span> Ability of a circuit to increase the power or amplitude of a signal

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<span class="mw-page-title-main">Negative-feedback amplifier</span> Type of electronic amplifier

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<span class="mw-page-title-main">Differential amplifier</span> Electrical circuit component which amplifies the difference of two analog signals

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<span class="mw-page-title-main">Attenuator (electronics)</span> Type of electronic component

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<span class="mw-page-title-main">Power dividers and directional couplers</span> Radio technology devices

Power dividers and directional couplers are passive devices used mostly in the field of radio technology. They couple a defined amount of the electromagnetic power in a transmission line to a port enabling the signal to be used in another circuit. An essential feature of directional couplers is that they only couple power flowing in one direction. Power entering the output port is coupled to the isolated port but not to the coupled port. A directional coupler designed to split power equally between two ports is called a hybrid coupler.

In electronic systems, power supply rejection ratio (PSRR), also supply-voltage rejection ratio, is a term widely used to describe the capability of an electronic circuit to suppress any power supply variations to its output signal.

<span class="mw-page-title-main">Audio analyzer</span> Test and measurement instrument

An audio analyzer is a test and measurement instrument used to objectively quantify the audio performance of electronic and electro-acoustical devices. Audio quality metrics cover a wide variety of parameters, including level, gain, noise, harmonic and intermodulation distortion, frequency response, relative phase of signals, interchannel crosstalk, and more. In addition, many manufacturers have requirements for behavior and connectivity of audio devices that require specific tests and confirmations.

An RF chain is a cascade of electronic components and sub-units which may include amplifiers, filters, mixers, attenuators and detectors. It can take many forms, for example, as a wide-band receiver-detector for electronic warfare (EW) applications, as a tunable narrow-band receiver for communications purposes, as a repeater in signal distribution systems, or as an amplifier and up-converters for a transmitter-driver. In this article, the term RF covers the frequency range "Medium Frequencies" up to "Microwave Frequencies", i.e. from 100 kHz to 20 GHz.

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