There are characteristics of digital/analog signal mixed

multi power

multi ground wire

having too much components and so a high density

etc. with subscriber circuit board

which will bring about interference. Proper and rational distribution and wiring plans an important role in restraining interference. By analyzing several typical interference phenomenon and causatiou that causing it

a series of means to control the interference effectively is raised here. Finally

it indicates the problems to which one should pay more attention when designing power and ground wire in Subscriber Circuit Board.