What is a 2.92mm Attenuator used for?

A 2.92mm 50 Ohm Fixed Attenuator is a fixed coaxial attenuator that uses the 2.92 mm coaxial connector standard as the port for the attenuator. A coaxial attenuator can either be a fixed, programmable, or variable attenuator, where each presents different benefits for certain applications. Fixed coaxial attenuators tend to be more compact and can also double as coaxial adapters with different coaxial type and gender options . 50 Ohm fixed coaxial attenuators, such as 2.92 mm attenuators, are used in attenuation applications from 0 to 40 GHz, which is the single-mode frequency limit for the 2.92 coaxial connector standard.

The configuration of 2.92 mm fixed coaxial attenuators is likely a Pi or Pi pad type, which is a wideband resistive attenuator which allows for good impedance matching to 50 Ohms. This type of attenuator configuration also enables the manufacture of compact coaxial attenuators with attenuation levels  from 1 dB to 30 dB. At higher attenuation levels, the attenuator is absorbing a greater amount of energy than at lower attenuation levels, which accounts for the power rating capability of the 2.92 mm attenuators. These attenuators have two different input power ratings, continuous wave (CW) and peak. Where continuous wave applies to signals with or near 100% duty cycle and peak input power applies to low duty cycle (~1.25%) with a certain pulse length rating, such as 5 us.

Given the wide frequency range of 2.92 mm fixed coaxial attenuators, the VSWR, attenuation accuracy, and power ratings will likely vary over frequency. Generally, the VSWR and attenuation accuracy are less at higher frequencies than lower frequencies. Typically, a data sheet will present the VSWR and attenuation accuracy as a function of frequency range, and the worst-case performance is generally the highest frequency of operation of the attenuator.

2.92 mm fixed coaxial attenuators are commonly used in wireless test systems for the latest 5G and future 6G cellular technologies, as well as military/defense, aerospace, space, and radar applications. The frequency range of 2.92 mm coaxial attenuators covers the IEEE HF, VHF, UHF, L, S, C, X, Ku, K, and Ka frequency bands. However, given the relative cost, power handling, and availability of 2.92 mm coaxial attenuators, it is likely that these connectors are most viable from 18 GHz to 40 GHz applications or for wideband applications that need the entire range of operation of the attenuator, such as with 40 GHz vector network analyzers or spectrum analyzers.