Ast Research, Inc.

Edward D Suski

David J Silva

Glenn G Miner

Jozef B Baran

A shielded flexible cable includes a first shielding grid having conductive elements formed as squares. A second shielding grid is also formed as squares. The two shielding grids are positioned with respect to each other so that the vertices of the squares of the two grids are respectively offset from each other in each of two directions by one-half the diagonal distance between the vertices of the squares. Electrical signal conductors are positioned between the two grids along lines extending between the vertices of the squares to maintain a controlled impedance of the signal lines. A circuit board includes a reference plane configured as a grid having conductive elements formed as squares. Electrical signal conductors are positioned in a plane adjacent said grid. The decreased percent copper used to construct the grid increases the characteristic impedance of the signal conductors without increasing the thickness of the circuit board, without decreasing the width or thickness of the conductors and without using nonhomogeneous or nonstandard dielectrics. The circuit board provides the use of an increased range of impedance in signal conductors that permits the transfer of signals without degradation of the signal quality or loss of signal density, while providing an acceptable shielding capability.

Technique for increasing the range of impedances for circuit board

A circuit board includes a plurality of signal conductors and a grid. The grid has a pattern of conductive material which forms cell structures oriented along a first axis. The grid pattern is configured so that when the signal conductors are oriented parallel to a first axis they overlay a substantially constant area of the conductive material regardless of where the signal conductors are positioned. The capacitance of the signal conductors is thereby controlled so that the impedances of the signal conductors can be maintained at a high level.

Bidirectional non-solid impedance controlled reference plane requiring

A flexible circuit connector is formed from a flexible printed circuit comprising a plurality of embedded electrically conductive lines partially exposed at a first end of the flexible printed circuit by bending or folding the flexible printed circuit to enable said first end to mate with a board mounted connector, thereby eliminating the need for a mating connector. When the flexible circuit connector is properly inserted into the board mounted connector, the mating of said plurality of exposed electrically conductive lines of said flexible circuit connector with a plurality of metal contacts on the board mounted connector provides an electrical interface between the flexible printed circuit and the board mounted circuit, as well as the boards on which the flexible printed circuit and board mounted connector are attached.

Flexible circuit connector

A notebook computer or other electronic device has a flexible cable interconnecting electronic circuitry in a base with electronic circuitry in a cover. A flexible potentiometer is coupled to said flexible cable in a location which bends when said cover is opened and closed with respect to the base. The resistance of the flexible potentiometer has a first value when the cover is closed and has a second value when the cover is open. A detection circuit is responsive to the resistance of the flexible potentiometer and generates an output signal which indicates whether the cover is open or closed.

Flexible printed circuit sleep switch for electronic device

A termination circuit for RGB signal lines provides a high frequency termination impedance that matches the impedance of a monitor cable and monitor termination, without adversely affecting the monitor-sense circuitry of an ASIC that generates the RGB video signals. When used with a VGA ASIC designed to work with 150 .OMEGA. pull-down sense resistors on the RGB lines, the circuit provides the proper 75 .OMEGA. AC termination impedance required for VGA lines while producing the 150 .OMEGA. DC termination required for proper monitor sense operation.

Termination circuit for RGB lines

Solder pad for printed circuit boards

An apparatus and method for recovering power dissipated by a semiconductor integrated circuit includes a thermoelectric generator which converts the heat generated by the integrated circuit into electrical energy. The electrical energy is used to drive a fan or other airflow generating device to cause heated air to be moved away from the integrated circuit and cooler air to be drawn to the integrated circuit to absorb further heat from the integrated circuit. In the described embodiment, the thermoelectric generator is a Peltier cooler positioned between the integrated circuit and a heatsink. The Peltier cooler is operated in the Seebeck mode to generate power in response to the temperature differential between the integrated circuit and the heatsink. The fan is positioned proximate to the heatsink to cause air flow over the heatsink thereby reducing the temperature of the heatsink and thus reducing the temperature of the integrated circuit by causing more heat to be transferred from the integrated circuit to the heatsink.

Method and apparatus for recovering power from semiconductor circuit

An improved omni-directional non-occluding solder pad design for printed circuit boards comprising a plurality of spokes radiating outward from a through-hole on the printed circuit board, with a ring concentric to the through-hole that intersects each of the plurality of spokes at approximately a perpendicular angle. The ringed-spoke configuration eliminates the need to ensure proper orientation of the solder pad on the printed circuit board prior to a wave soldering process since the symmetrical ringed-spoke design is omni-directional. The concentric ring structure provides an additional contact area of solder between the printed circuit board and a computer chassis. This additional contact area of solder ensures that there is a sufficient electrical connection between the printed circuit board and the computer chassis such that when the printed circuit board is mounted to the computer chassis, a proper grounding connection is provided.

A method for defining traces on a multi-layer circuit board suppresses electro-magnetic emissions radiated from the traces. The defined traces carry a differential signal. Layers of signal and return trace pairs are formed. Each succeeding layer of traces is spaced above and follows the traces below, with the succeeding signal trace positioned above the preceding return trace and the succeeding return trace positioned above the preceding signal trace. All of the signal traces are conductively connected and all of the return traces are conductively connected. The symmetry of the arrangement causes the electro-magnetic fields generated by the conductors (traces) to cancel at any appreciable distance. Additionally, varying combinations of layers and/or varying parameters such as dimension, spacing and dielectric material, results in a desired impedance for matching to external cabling and the like.

Apparatus and method to reduce electromagnetic emissions in a

A shielded flexible cable includes a first shielding grid having conductive elements formed as squares. A second shielding grid is also formed as squares. The two shielding grids are positioned with respect to each other so that the vertices of the squares of the two grids are respectively offset from each other in each of two directions by one-half the diagonal distance between the vertices of the squares. Electrical signal conductors are positioned between the two grids along lines extending between the vertices of the squares to maintain a controlled impedance of the signal lines.

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Lake Forest, CA, United States of America

Edward D Suski