Definition of High Power RF Attenuator

1. What is an RF attenuator?

In the radio frequency circuit, the main function of the attenuator is to provide a higher capacitance level, thereby maintaining the signal-to-noise ratio (SNR), reducing the problems caused by internal circuit component noise and external signal noise.

In the entire RF test system, the radio frequency attenuator is an indispensable part. HBTE is an expert on RF solutions and the OTA system. If you want to know more about the attenuator, contact us now.

2. What is the high power RF attenuator?

Different from other radio frequency measurement devices, high power RF attenuator is designed for the range of RF signals that are considered high-power at a given maximum frequency. Whether it is regarded as high power or not usually depends on the application and operating frequency range. Powers of several hundred kilowatts to several megahertz and several hundred watts to several kilowatts can be regarded as high-power RF attenuators. In the millimetre wave spectrum of about 18GHz, ten watts of power can also be regarded as high power. This difference is partly due to the increase in RF loss with frequency and the reduced geometric size of transmission lines and other components to increase performance at higher frequencies.

The small size and spacing between conductors and dielectrics in high-frequency devices limit the power handling capabilities of transmission lines, components, and devices at higher frequencies. For example, the spacing and size of high-frequency coaxial transmission lines must be kept smaller than the spacing and size of a specific center conductor and outer conductor to prevent the development of undesired transmission modes, otherwise, the use efficiency of the generally expected transverse electromagnetic (TEM) mode will be reduced.

Therefore, high-power RF attenuators are designed to handle power levels close to the peak capacity at a given frequency, while exhibiting a fixed attenuation over the entire frequency band. The design of this type of RF attenuator (that is, maintaining a flat attenuation in a wide frequency range from DC to tens of megahertz) is not easy and sometimes involves multiple challenging design requirements. One of the main requirements of a high-power RF attenuator is to minimize the VSWR of the port to prevent accidental reflections, otherwise, components that are sensitive to the upcoming high-signal energy may be damaged.