N- Attenuators are a type of RF (Radio Frequency) Attenuators. It is used to trim down a signal's power level by a definite amount. These circuits cut down the output signal with respect to the input and it also measures the decrease in power level in decibels (dB).
These coaxial attenuators are used in equipments which are mainly involved in following functions:
• Control of RF/microwave energy
• communication of RF/microwave energy
• Measurement of RF/microwave energy
Some of the most important features of these coaxial attenuators are
• Low standing wave ration (SWR)
• leveled frequency response and Repeatability
• frequency bandwidth
• power dissipation
These attenuators are available in different configurations based on frequency bands, attenuation values and power ratings. Like RF connectors these coaxial attenuators also include male and female genders. They may be directional or bi-directional.The basic types of N-attenuators are as follows:
• Fixed coaxial attenuators: They are usually of 50 ohms or 75 ohms. They reduce the output power level to input power level by fixed amounts over a precise bandwidth. This type of attenuator keeps the input output impedance to nominal levels.
• Continuous variable attenuators: Devices with this type of attenuators vary the attenuation between two values in a continuous manner within a specified range.
• Step attenuators: These attenuators vary the attenuation of a device by a fixed quantity at a time.
There is yet another classification of attenuators based on its power handling range:
• 2-5 watt type attenuators: These attenuators are useful in the frequency range of 0-18 GHz. Precision N connectors are used above the frequency of above 12 GHz and are usually made of stainless steel.
• 10-25 watt type attenuators: These types of attenuators are used in military and commercial applications. They are active up to a frequency of 18 GHz.
• 50 watt attenuators: They are useful in cellular, LTE and Wi-Fi system applications.
• 100-1000 watts type attenuators: These find use in the lower power levels and are usually bidirectional. Few of the attenuators in the higher power levels are unidirectional in nature.
Some of the products with the most common attenuator specifications used in the telecommunications industry are the following:• N type feed through male-to-female termination coaxial adapter
• N type male-to-female inner DC block connectors
• N type male-to-female inner/outer DC block connectors
• N type impedance matching pads
• N type male-to-female reverse polarity attenuator
• N type male-to-female, 1 dB, 100 Watts
• N type male-to-female, 17 dB, 500 Watts
• N type male-to-female, 20 dB, 1000 Watts
While one is selecting a RF coaxial attenuator for a particular type of application, one should look out for a few key parameters such as
• Connector type used in the device.
• The type of material with which the connector is made of.
• Frequency range of the application in which the attenuator will be used.
• Power CW should be checked properly because it depends on temperature.
• Directionality s another important factor.In bidirectional attenuators both sides can be used as input. But with the unidirectional ones, input and output are specifically mentions. Using them backwards can be fatal at times.
• DC handling is not intended to be its features being a restive network. So one may use attenuators with DC blocks and bias-t's.
• Contact materials should be checked. Mostly it uses brass male contact and Be-Cu female contacts.
Lovisa Alvin working as a freelance Writer as well as Blogger for more than 3 years in US. She has great interest in writing, editing and publishing.