A research group of Takashi Kamino, a third-year student at Osaka University, devised a theory for quantifying the electromagnetic noise phenomenon that causes malfunctions and heat generation of electronic and electrical equipment, and elucidated the mechanism of its generation. , Succeeded in theoretically deriving a circuit structure that does not generate electromagnetic noise.
In an electric circuit, electromagnetic noise is generated due to electromagnetic interference with surrounding conductors (environment), but it is difficult to identify the cause, and countermeasures have been taken based on the experience and know-how of skilled engineers. With the spread of electrical equipment such as IoT in the future, elucidation of the generation mechanism of electromagnetic noise has become an important issue.
In this research, in order to describe the electromagnetic noise phenomenon, we used a three-wire circuit in which the electric circuit is represented by two conductors, which are the round-trip paths of signals, and the environment is represented by one conductor.As a result, it has become possible to formulate a normal mode that represents a signal and a common mode that represents electromagnetic interference.Furthermore, considering the connection relationship between the input and output of the three-line circuit, the equation expressing the behavior of each mode is derived.As a result, it was theoretically proved that the common mode is converted to the normal mode and electromagnetic noise is generated by the geometrical positional relationship between the circuit and the environment and the electrical connection relationship between the connected elements.
This made it possible to perform theoretical calculations under the geometrical structures of various circuits and electrical connection conditions.As a result, it turned out that the only solution to eliminate electromagnetic noise is that the circuit has a structure that is geometrically symmetric with respect to the environment, and that the circuit and the environment are electrically symmetrically connected.Furthermore, it has become possible to quantify and time-track the electromagnetic noise phenomenon, and it has become possible to intuitively understand the phenomenon.
The results of this research indicate that the cause of electromagnetic noise may be fundamentally eliminated because it is a theoretical approach rather than the conventional empirical approach.
Paper information:[Scientific Reports] Mechanism of Common-mode Noise Generation in Multi-conductor Transmission Lines
