Characteristic impedance control structure

Patent metadata

Field	Value
Publication number	US-2026040434-A1
Application number	US-202418989160-A
Country	US
Kind code	A1
Filing date	Dec 20, 2024
Priority date	Aug 1, 2024
Publication date	Feb 5, 2026
Grant date	—

Abstract

A characteristic impedance control structure includes a first and a second transmission line, a ground pattern and a ground component. The first transmission line and the ground pattern extend along a plane. The ground pattern is spaced from the first transmission line by a first distance. The second transmission line extends along a direction and electrically connects to the first transmission line. An angle between the direction and the plane is greater than zero. The second transmission line has an outer diameter. The ground component extends along the direction and is electrically connected to the ground pattern. The ground component is next to and spaced from the second transmission line by a second distance. The ground component has a length along the direction. The first distance is less than or equal to twice the length. The second distance is less than or equal to five times the outer diameter.

First claim

What is claimed is:

1 . A characteristic impedance control structure, comprising:
a first transmission line, extending along a first plane; a first ground pattern, extending along the first plane, wherein the first ground pattern is spaced from the first transmission line by a first distance; a second transmission line, extending along a direction and electrically connected to the first transmission line, wherein a first angle between the direction and the first plane is greater than zero, and the second transmission line has an outer diameter; and a ground component, extending along the direction and electrically connected to the first ground pattern, wherein the ground component is next to and spaced from the second transmission line by a second distance, the ground component has a length along the direction, the first distance is less than or equal to twice the length, the second distance is less than or equal to five times the outer diameter.

2 . The characteristic impedance control structure according to claim 1 , further comprising a ground layer, wherein the ground layer is disposed substantially parallel to the first plane, and the ground layer is farther away from the second transmission line than the first ground pattern in the direction.

3 . The characteristic impedance control structure according to claim 1 , further comprising a ground layer and a conductive via, wherein the ground layer is disposed substantially parallel to the first plane, the second transmission line is spaced from the ground layer, the first ground pattern is farther away from the second transmission line than the ground layer in the direction, and the first transmission line is electrically connected to the second transmission line through the conductive via.

4 . The characteristic impedance control structure according to claim 1 , further comprising a third transmission line and a second ground pattern, wherein the third transmission line and the second ground pattern extend along a second plane, a second angle between the direction and the second plane is greater than zero, two ends of the second transmission line are respectively electrically connected to the first transmission line and the third transmission line, the second ground pattern is spaced from the third transmission line by a third distance, and the third distance is less than or equal to twice the length.

5 . The characteristic impedance control structure according to claim 4 , further comprising a ground layer, wherein the ground layer is disposed substantially parallel to the second plane, and the ground layer is farther away from the second transmission line than the second ground pattern in the direction.

6 . The characteristic impedance control structure according to claim 4 , further comprising a ground layer and a conductive via, wherein the ground layer is disposed substantially parallel to the second plane, the second transmission line is spaced from the ground layer, the second ground pattern is farther away from the second transmission line than the ground layer in the direction, and the third transmission line is electrically connected to the second transmission line through the conductive via.

7 . The characteristic impedance control structure according to claim 1 , wherein the ground component comprises a plurality of ground lines, and the plurality of ground lines are arranged around the second transmission line.

8 . The characteristic impedance control structure according to claim 1 , wherein the ground component comprises a ground tube, and the ground tube is disposed around the second transmission line.

9 . The characteristic impedance control structure according to claim 1 , wherein the first transmission line comprises a pair of first differential transmission lines, the second transmission line comprises a pair of second differential transmission lines, the first ground pattern is spaced from the pair of first differential transmission lines by the first distance, each of the pair of second differential transmission lines has the outer diameter, and the ground component is spaced from the pair of second differential transmission lines by the second distance.

10 . The characteristic impedance control structure according to claim 9 , further comprising a ground layer, wherein the ground layer is disposed substantially parallel to the first plane, and the ground layer is farther away from the second transmission line than the first ground pattern in the direction.

11 . The characteristic impedance control structure according to claim 9 , further comprising a ground layer and a conductive via, wherein the ground layer is disposed substantially parallel to the first plane, the second transmission line is spaced from the ground layer, the first ground pattern is farther away from the second transmission line than the ground layer in the direction, and the first transmission line is electrically connected to the second transmission line through the conductive via.

12 . The characteristic impedance control structure according to claim 9 , further comprising a third transmission line and a second ground pattern, wherein the third transmission line and the second ground pattern extend along a second plane, a second angle between the direction and the second plane is greater than zero, the third transmission line comprises a pair of third differential transmission lines, two ends of each of the pair of second differential transmission lines are respectively electrically connected to each of the pair of first differential transmission lines and each of the pair of third differential transmission lines, the second ground pattern is spaced from each of the pair of third differential transmission lines by a third distance, and the third distance is less than or equal to twice the length.

13 . The characteristic impedance control structure according to claim 12 , wherein a portion of the second ground pattern extends to where between the pair of third differential transmission lines.

14 . The characteristic impedance control structure according to claim 12 , further comprising a ground layer, wherein the ground layer is disposed substantially parallel to the second plane, and the ground layer is farther away from the second transmission line than the second ground pattern in the direction.

15 . The characteristic impedance control structure according to claim 14 , wherein the ground layer has a plurality of openings, and a plurality of projections of the pair of second differential transmission lines to the ground layer are respectively disposed overlapping with the plurality of openings.

16 . The characteristic impedance control structure according to claim 12 , further comprising a ground layer and a conductive via, wherein the ground layer is disposed substantially parallel to the second plane, the second transmission line is spaced from the ground layer, the second ground pattern is farther away from the second transmission line than the ground layer in the direction, and the third transmission line is electrically connected to the second transmission line through the conductive via.

Assignees

• Ind Tech Res Inst

Inventors

• Ding Hsiang En
• Wu Shih-Hsien

Classifications

• H05K1/0245

  Lay-out of balanced signal pairs, e.g. differential lines or twisted lines · CPC title

• H05K1/0215

  Grounding of printed circuits by connection to external grounding means · CPC title

• H05K1/0251 Primary

  related to vias or transitions between vias and transmission lines · CPC title

• H05K1/0222

  for shielding around a single via or around a group of vias, e.g. coaxial vias or vias surrounded by a grounded via fence · CPC title

• H05K1/0219

  Printed shielding conductors for shielding around or between signal conductors, e.g. coplanar or coaxial printed shielding conductors · CPC title