Abstract: A chassis shielding effectiveness evaluation system includes a chassis having a chassis ground. A board is located in the chassis and includes a board ground layer. A signal generator includes at least one ground member coupled to the chassis ground and a signal member coupled to the board ground layer. The signal generator is operable to send a signal through the signal member to the board ground layer.

Abstract: A chassis shielding effectiveness evaluation system includes a chassis having a chassis ground. A board is located in the chassis and includes a board ground layer. A signal generator includes at least one ground member coupled to the chassis ground and a signal member coupled to the board ground layer. The signal generator is operable to send a signal through the signal member to the board ground layer.

Abstract: A method for preparing a printed circuit board and an apparatus are provided to decrease losses associated with high speed signal propagation. The printed circuit board has at least two conductive layers separated by an dielectric layer formed of a dielectric material. A conductive path is formed in one of the conductive layers for propagation of the high speed signal. At least a portion of the dielectric layer is removed on both sides of and adjacent to the conductive path. The removed portion extends in the dielectric layer between the conductive layers from one to the other and includes a hole shaped portion and a trough shaped portion. The removed portion does not extend beyond the dielectric layer.

Abstract: A method for preparing a printed circuit board and an apparatus are provided to decrease losses associated with high speed signal propagation. The printed circuit board has at least two conductive layers separated by an dielectric layer formed of a dielectric material. A conductive path is formed in one of the conductive layers for propagation of the high speed signal. At least a portion of the dielectric layer is removed on both sides of and adjacent to the conductive path. The removed portion extends in the dielectric layer between the conductive layers from one to the other and includes a hole shaped portion and a trough shaped portion. The removed portion does not extend beyond the dielectric layer.

Abstract: An air duct is provided for ventilating an electronic device having a processor. The air duct comprises one or more walls that have an irregular surface and that further have a layer of conductive material applied to the irregular surface. Further embodiments of the invention include electronic device enclosures and electronic devices having an air duct featuring an irregular interior surface and having conductive material applied to the irregular surface.

Abstract: An air duct is provided for ventilating an electronic device having a processor. The air duct comprises one or more walls that have an irregular surface and that further have a layer of conductive material applied to the irregular surface. Further embodiments of the invention include electronic device enclosures and electronic devices having an air duct featuring an irregular interior surface and having conductive material applied to the irregular surface.

Abstract: A system and method incorporate one or more magnets affixed in proximity to a ground plane of a printed circuit board such that the magnetic flux of the magnet is operable to perturb current flow through the ground plane, resulting in a reduction in electromagnetic emissions. The invention is implemented with various types of magnets in different embodiments, including rare-earth magnets, AlNiCo magnets, Neodymium magnets, and flat-sheet magnets. A digital electronic device consistent with the present invention incorporates one or more magnets in proximity to a ground plane of a circuit board within the device, such devices including computers, set-top boxes, and personal digital assistants in various embodiments.