METHOD AND APPARATUS FOR REDUCING ELECTRICAL RESONANCES AND NOISE PROPAGATION IN POWER DISTRIBUTION CIRCUITS EMPLOYING PLANE CONDUCTORS

摘要

Electrical resonances are reduced and noise propagation is attenuated in a multi-layer construction (600) using planar power and ground planar conductors separated by insulating material by loading the power and ground planar conductors (604, 606) with a sufficient amount of capacitance, or series capacitance and resistance, at specific locations so that the planar conductors (604, 606) are electrically broken up into smaller sections which resonate at frequencies above the signal bandwidth. The propagation of injected noise is suppressed by the low-pass filter effect of the capacitive loading at the discrete locations. In accordance with one embodiment of the invention, islands (650, 652) of material with a dielectric constant higher than the dielectric constant of the overall insulator (612) are placed at regular intervals where the capacitance of each high dielectric constant island (650, 652) is comparable to, or higher than, the capacitance of the 'low' dielectric material which comprises the remainder of the insulating material (612). In accordance with a second embodiment, high dielectric constant islands are placed around power and ground vias where most of the transient charge capability is needed.