Adjustable Control: Allows the attenuation level to be changed continuously or in steps during operation. How: Uses a moving contact (wiper) on a resistive element (like a film or card) or a moving vane in a waveguide. Adjusted manually via a knob or screw. This type of component is generally used to balance signal levels in the signal chain, to extend the dynamic range of a system, to provide impedance matching, and to. An RF Attenuator is a two-port passive electronic device designed to reduce (attenuate) the power or amplitude of an RF signal. It does not distort its waveform or affect its frequency. They can adjust the signal strength by controlling the amount of attenuation, ensuring that the signal reaches the desired level for transmission in a. trength of the signal passing through it. The basic function of an RF attenuator is to.