ATTENUATOR

An attenuator is an electronic device that reduces the amplitude or power of a signal without appreciably distorting its waveform.
An attenuator is effectively the opposite of an amplifier, though the two work by different methods. While an amplifier provides gain, an attenuator provides loss, or gain less than 1.
Attenuators are usually passive devices made from simple voltage divider networks. Switching between different resistances forms adjustable stepped attenuators and continuously adjustable ones using potentiometers.
Fixed attenuators in circuits are used to lower voltage, dissipate power, and to improve impedance matching
Basic circuits used in attenuators are pi pads (π-type) and T pads.

                                                                        fig 1 π-type unbalanced attenuator circuit

                                                                         fig 2 T-type unbalanced attenuator circuit

                                                                        fig 3 π-type balanced attenuator circuit

                                                                       fig 4 T-type balanced attenuator circuit