AC coupled termination of a printed circuit board power plane in its characteristic impedance

Abstract

High speed power supply transients are suppressed in a system having fast edges and where a radial transmission line exists between the power supply and ground planes, by terminating the edges of the PCB in it characteristic impedance. In practice, this means approximating a continuous construct with many spaced instances of a discrete resistance. The dissipative terminations themselves are resistive, and if placed directly between the power supply and ground would needlessly dissipate a great deal of DC power. To prevent that they are AC coupled with a high quality coupling capacitor of sufficient capacitance to allow the resulting impedance to appear predominately resistive at and above the lowest frequency of interest, say, 100 MHz. Because of the confused nature of the reflection that may be generated at arbitrary locations within the interior of the PCB, there may well be "hot spots" within that interior that would benefit from the placement of a selected AC coupled load at or near such a spot.

Dependencies are inferred from the claim text.