When discussing wiring-related technologies, two issues will be discussed: What if management cannot use a double-layer board or a ground plane, but still needs to reduce the noise in the circuit? And how to design the circuit to meet the ground plane requirements? Generally speaking, the solution is to tell management that a ground plane is necessary if reliable circuit performance is to be achieved. The main reason for using a ground plane is that the ground impedance is low and it can reduce EMI to a certain extent. But if cost constraints prevent users from achieving what they need, some suggestions provided in this article, such as star networks and correct current return paths, can also slightly reduce circuit noise.