ACTIVE FILTER AND COMMUNICATION SYSTEM

摘要

An active filter and a communication system. The active filter (1) comprises a main circuit (11) and a control circuit (12). The control circuit is used for detecting a first current (IL) output by a negative electrode of an input end of a conversion circuit (2) so as to obtain a harmonic component (ILAC) in the first current, and generating a control signal (V_GATE1-4) according to the harmonic component. The main circuit is used for generating a second current (IF) opposite to the harmonic component in phase under the control of the control signal, so that a source current (IS) formed by the first current and the second current passing through a power supply (4) is a direct current. The active filter can effectively suppress low-frequency noises.