Types of RF attenuators

In RF circuits, higher signal levels are usually a good thing. They can improve the signal-to-noise ratio (SNR) and reduce problems caused by internal circuit component noise and coax cable external signal noise. As a result, higher signal levels often simplify many of the challenges of RF circuit design.

However, in many systems, RF signals 2.4mm Cable inevitably have a wide dynamic range spanning 30, 40 or more dB; some designs must handle signals with a range exceeding 100 dB. Examples include radar or long-range wireless, or even short-range LAN, where one or two link nodes are moving and there are obstacles and interference.

If the system right angle coax is designed to work coax cable normally with lower-level signals, there may not be margin for higher-power signals (RF, power, and signal level are usually closely related). The result is overload, saturation and may even damage sensitive analog components, such as front-end amplifiers. Even if there is no permanent damage, as long as the 2.4mm Cable Assembly components of the signal chain are "maximized", the system will not work properly. In these cases, it may take a relatively long time for the component to get out of the saturation right angle coax chain and become feasible again. In other cases, the attenuator matches the maximum value of the signal at one point with the maximum value of the larger limit at another stage in the chain.

For these reasons, it is often coax cable necessary to manage and attenuate signal levels. With known or controllable quantities, this is where the RF attenuator comes into play. There are three types of RF attenuators:

1) Fixed value attenuator, providing one or two dB, or 10 dB, 20 dB or more dB value.

2) Voltage variable or voltage 2.4mm Cable controlled attenuator, where the analog voltage is set at the attenuation level within a continuously variable range, for example, between 0 dB and 30 dB or between 0 dB and 60 dB.

3) Digital controlled attenuator or digital step attenuator (DSA), where a multi-bit code establishes attenuation in discrete steps from 0 dB to 32 or 64 dB, for example, in steps of 1 or 2 dB/bit Long; some products provide steps as small as 0.25 dB.

(Please note that right angle coax there are also mechanically controlled attenuators, users can set the attenuation through the knob. These attenuators are almost only used in test environments or high-power one-off designs.)

The controllable attenuator is a coax cable complement to the variable gain amplifier (VGA), which can enhance the signal to match the range of components in the chain. For designs that require additional flexibility, there are even available VGAs that can span gain and attenuation, such as -10 to +40 dB; internally, these are right angle coax variable attenuators (voltage or digital control) in series with gain modules Constructed.

It seems reasonable to simply use a variable attenuator instead of a fixed attenuator to provide maximum flexibility. However, this flexibility comes at a price, because variable attenuators 2.4mm Cable Assembly are more costly, dissipate more power, and require (in most versions) control signals at power-up, as well as continuous supervision and management during use. These coax cable are additional burdens on the system processor and initialization process. In contrast, apart from right angle coax installing it, it has nothing to do with the fixed attenuator. In other cases, "fixed" attenuators are designed to provide a controlled temperature coefficient to stabilize high-power RF amplifiers when operating temperature changes.