EMC is the abbreviation of electromagnetic compatibility, and EMC is the concept that different electronic instruments can operate in the circumstance of being close to each other without mutual interference.
Electromagnetic compatibility (EMC) is the ability of electrical equipment and systems to work normally in the electromagnetic environment through limiting the electromagnetic energy that is unexpectedly produced, transmitted, and received. This electromagnetic energy may cause unnecessary influence such as electromagnetic interference (EMI) and even physical damages onto the equipment. The goal of EMC is to properly operate different equipment in the same electromagnetic environment. It is also the name of a relative branch of the electric engineering.
EMC studies three main problems. Emission is the electromagnetic energy produced through a kind of source, and will release into the environment intentionally or unintentionally. EMC has studies unwanted emission and the solutions possibly adopted for reducing the unwanted emission. The second problem is the magnetic susceptibility, the trend that the electric equipment called the victim comes to malfunction or breakdown when suffers the harmful radiation (called radio-frequency interference, that is, FRI). Contrary to antibiotic susceptibility, immunity is the ability of equipment to normally work under the state of FRI. The principle of "hardening" the equipment is also called antibiotic susceptibility or disturbance rejection. The third study is coupling which is the mechanism that the interference produced reaches the victim.
One of the vital fields of designing circuit with good EMC functions is field of PCB designing.
Foucing on EMC, the PCB design can optimize the EMC performance of circuit boards, and help you obey some basic principles to offer good EMC performance.
Although reducing the size of PCB through using multilayers is practicable, it’s still not the best choice when designing the PCB with good EMC performance.
In order to fulfill the EMC performance, the PCB design needs to reduce coupling, which may demand the signals keep separate or add the distance among some modules. Although designing small PCB with good EMC performance, it should be very careful from the start.