UHF ground interconnects
AssigneeLockheed Martin Corporation
InventorPeter A. Miller
Life of this patent
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Abstract
A via on a printed circuit board having a circuit has a first interconnect and a second interconnect located about at least a portion of the first interconnect. The second interconnect connects to ground of the circuit and is coaxial and substantially concentric with the first interconnect and inductively coupled with the first interconnect. A method of electrically interconnecting at a via multiple layers on a printed circuit board to provide a common ground plane for a circuit is also provided. A high speed interconnection can be attained by allowing the ground return path for a circuit carried on multiple layers of a multilayer printed circuit board to remain coupled to the signal, thereby lowering ground inductance and maintaining signal integrity, even at UHF, while minimizing costs.
Claims10
A via for use in a multilayer printed circuit board having a circuit, the printed circuit board including a first plurality of conductive layers and a second plurality of conductive layers, the first and second plurality of conductive layers being interleaved in a first direction which extends parallel to an axis of the via, the via comprising:
- a first interconnect located about the axis of the via and electrically connecting the first plurality of interleaved conductive layers to a signal net of the circuit;
- and
- a second interconnect having a portion located about the first interconnect for electrically connecting the second plurality of interleaved conductive layers to a ground plane of the circuit,
- wherein the second interconnect is coaxial with the first interconnect and is inductively coupled with the first interconnect.
A multilayer printed circuit board having a circuit, the multilayer circuit board comprising:
- a first plurality of conductive layers;
- a second plurality of conductive layers, the first and second plurality of conductive layers being interleaved in a first direction which extends parallel to an axis of the via;
- and
- a via including a first interconnect, the first interconnect located about the axis of the via and electrically connecting the first plurality of interleaved conductive layers to a signal net of the circuit, and a second interconnect, the second interconnect located about at least a portion of the first interconnect and electrically connecting the second plurality of interleaved conductive layers to a ground plane of the circuit,
- wherein the second interconnect is coaxial with the first interconnect along its length in the first direction and is inductively coupled with the first interconnect.
Dependencies are inferred from the claim text.