The principle and classification of attenuator are briefly i

[IC trading network attenuator] An attenuator is an electronic component that provides attenuation and is widely used in electronic equipment.

 

 

 

Its main uses are: (1) to adjust the size of the signal in the circuit; (2) In the comparative method measurement circuit, it can be used to directly read the attenuation value of the measured network; (3) Improve impedance matching, if some circuits require a relatively stable load impedance, an attenuator can be inserted between this circuit and the actual load impedance to buffer the impedance change.

 

How it Works:

 

An attenuator is a circuit used to introduce a predetermined attenuation within a specified frequency range. It is generally indicated by the number of decibels introduced and the number of ohms of the characteristic impedance. Attenuators are widely used in cable TV systems to meet the level requirements of multiple ports

 

. Such as amplifier input, output level control, branch attenuation control. Attenuators Passive attenuators and active attenuators two types. The active attenuator is combined with other thermal elements to form a variable attenuator, which is used in an amplifier for automatic gain or slope control circuits. Passive attenuators have fixed attenuators and adjustable attenuators.

 

Basic composition:

 

The basic material of RF/microwave power attenuator is resistive material. The usual resistance is a basic form of attenuator, and the resulting resistance attenuator network is a lumped parameter attenuator. The corresponding frequency attenuator is formed by placing the resistance material into the RF/microwave circuit structure of different bands through a certain process. If it is a high-power attenuator, the volume must be increased, and the key is the heat dissipation design.

 

High power attenuator

 

With the development of modern electronic technology, rapid adjustment attenuators are used in many occasions. This kind of attenuator is usually implemented in two ways, one is a semiconductor low-power fast-tuning attenuator, such as a PIN tube or FET monolithic integrated attenuator; The second is the resistance attenuation network controlled by switches, which can be electronic switches or RF relays.

 

 

High power attenuator

 

Technical indicators:

 

1. Working frequency band

 

The working frequency band of the attenuator refers to the use of the attenuator within a given frequency range, so that the attenuator can reach the index value. Since the RF/microwave structure is related to frequency, components in different frequency bands have different structures and cannot be universal. The working frequency band of modern coaxial structure attenuators is quite wide, which should be paid attention to in design or use.

 

2. Attenuation quantity

 

3. Power capacity

 

4. Return loss

 

5. Power coefficient

 

Type:

 

Displacement type optical attenuator

 

When the two sections of optical fiber are connected, a fairly high alignment accuracy must be achieved in order to enable the optical signal to be transmitted with less loss. Conversely, if the alignment accuracy of the fiber is properly adjusted, its attenuation can be controlled. Displacement optical attenuator is based on this principle: deliberately let the fiber in the docking, there is a certain dislocation, so that the light energy loss, so as to achieve the purpose of controlling the attenuation amount.

 

Displacement type optical attenuators are divided into two types: transverse displacement type optical attenuators and axial displacement type optical attenuators. Lateral displacement optical attenuator is a more traditional method, because the lateral displacement parameters are in the order of magnitude in the micron level, so generally do not need to make variable attenuator, only used in the production of fixed attenuator, and the use of welding or bonding method, so far there is still a large market, its advantage is that the return loss is high, generally greater than 60dB. In the process design of the axial displacement optical attenuator, as long as the two optical fibers are separated by a certain distance for alignment, the purpose of attenuation can be realized. This principle is mainly used in the production of fixed optical attenuators and some small variable optical attenuators.

 

Thin film type optical attenuator

 

This attenuator is made by using the principle that the intensity of light reflected on the surface of the metal film is related to the thickness of the film.

 

Attenuator plate type optical attenuator

 

The attenuator directly fixed the attenuator with absorption characteristics on the end face of the optical fiber or in the optical path to achieve the purpose of attenuating the optical signal, this method can be used not only to make a fixed optical attenuator, but also to make a variable optical attenuator.

 

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