⑴ cable length as short as possible, so that minimal lead inductance. In low frequency circuits, because all of the circuit current flows through a common grounding impedance and grounding planes, so avoid using multi-point grounding.
B common ground should be arranged in the printed circuit board edge. Boards should be retained as much as possible on copper ground wire, can enhance the shielding ability.
C double panel can use ground surface, ground surface is designed to provide a low impedance ground.
D in multilayer printed circuit boards, you can set the ground floor, ground designed to mesh. Ground grid spacing must not be too large, since a major role is to provide signal return path to ground, if the grid spacing is too large, will form a larger signal loop area. Large loop area could lead to radiation and sensitivity problems. In addition, the signal return the actual path of the loop area is small, other ground did not work.
⑸ ground surfaces to minimize the radiation loop.