How to reduce common mode radiation?

Common mode radiation is due to the voltage drop in the ground circuit (as shown in the figure below). Some parts have high potential common mode voltage. When the external cable is connected to these parts, common mode current will be generated under the excitation of common mode voltage, which becomes the antenna of radiant electric field. This is mostly due to the voltage drop in the grounding system. Common mode radiation usually determines the radiation performance of the product. So, how to reduce common mode radiation?

(1) Minimize the source voltage (ground potential) that excites the antenna;

(2) Provide high common mode impedance in series with the cable, that is, increase the common mode choke;

(3) Bypass the common mode current to the ground;

(4) Reduce the length of cable;

(5) Cable shielding layer and shielding shell shall be terminated at 360°.