How to select Continuously Variable Attenuators
Continously Variable attenuators, like the name suggests are attenuators whose attenuation can be changed by varying the voltage or current to the device. These are used in application where it is required to continuously vary the signal level.
The key specifications to look for in an rf and microwave attenuator are:
Frequency (MHz): This is the frequency range over which the attenuator can operate with while providing a constant level of attenuation with minimal reflections.
Attenuation (dB): This is the ratio of the output and input power levels.
Power (W): The level of power that an attenuator can handle is the amount of power the device can dissipate while maintaining the signal integrity i.e the Attenuation level with minimal reflections.
Impedance (Ohms): The impedance of an attenuator must match the circuit/system it is connected to; this will minimize any reflection within the circuit/system. Usually the impedance is 50 Ohms or 75 Ohms.