An attenuator is an electronic device that helps by reducing the power of a signal but without any distortion of the waveforms. As the name suggests, it attenuates the signal.
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Variable attenuator
Variable rf attenuators are used for applications where there is a necessity to continuously vary the level of a signal. These are used for the exact opposite purpose of fixed attenuators. It is basically a circuit that helps to reduce the input signal’s strength either continuously or step by step but without any appreciable signal distortion. They are used where variation in attenuation level is required. This is attained by variation in input voltage that goes through the control line.
Variable Attenuators vary the analog voltage on the input control line to allow a continuous level change as required at a given point. Variable attenuators use some form of voltage control known to act on variable elements such as PIN diode, which in turn work with other electronic-based components to enable continuous variable attenuation.
Understanding where is variable attenuator used
To know the answer to what variable attenuators are used for, let’s first see what attenuators are used for. An attenuator is a passive two-post electronic device that is used to control the signal strength by reducing it to the required level without causing any disturbance in the waveform.
Attenuators are used to weaker, stronger signals in radio, communication, and transmission applications. Volume control is made by using resistive attenuators at broadcasting locations and for matching the circuits with different resistive impedances.
In the case of variable attenuators, these resistors are replaced with MOSFETs or PIN diodes (solid state elements) that allows controlling the voltage and thereby enabling RF resistance to vary almost continuously.
Thus it is possible to vary a specific attenuation with greater resolution. Variable attenuators permit varying attenuation levels by adjusting the input voltage in the control line. This is done by controlling the amount of voltage or current that passes by the FET or diode.
Pin diode attenuator gives attenuation ranging from 20 dB and can be used in 50 ohm systems. These types of attenuators can be both manually and electronically controlled. Variable attenuators are easy on installation and use and are used to dial down the signal.
Some instances of variable attenuator usage:
1. Electronically controllable variable attenuator is helpful in controlling microwave power using a Pin diode.
2. The electronically controlled variable attenuators that are available in current-controlled and voltage-controlled versions are used in many tests, systems, and lab applications.
3. To generate the required levels of signals, a variable control radio frequency attenuator is used.
4. Variable attenuators are suitable for operations where too much precision is not required, and there is the presence of analog electricity.
The most crucial thing that you need to figure out before zeroing on the type of attenuator that is required is to calculate the required frequency range. Thus, it is on the same observation that the variable attenuator use of decided upon. The main point is that variable attenuators are used for non-constant systems.
