Reduction of conducted electromagnetic interference by using filters

Electromagnetic interference (EMI) is described as the unwanted noise created by electromagnetic (EM) waves. EMI is divided into two forms, that is, conducted and radiated. There exists Common mode (CM) and differential mode (DM) noise in the conducted EMI. Hence, All the electronic wireless equipment must provide the EMI filters (EMIF) to filter the CM and DM noise components within the circuits. In this paper, an inductor filter, choke filter (IF and CF) and Pi-Filter (PF) are designed to eliminate conducted EMI. This system is named as EMIF-CM-DM (i.e., EMI filter for avoiding the common mode and differential mode noise). The IF and CF has low ripple factor at heavy load currents and very good load regulation, respectively. Pi-Filter also gives low ripple factor and high output voltage. This EMIF-CM-DM system improved the CM and DM noise voltages and insertion loss (IL).