Planar balun and multi-layer circuit board

Patent metadata

Field	Value
Publication number	US-10594290-B2
Application number	US-201715851037-A
Country	US
Kind code	B2
Filing date	Dec 21, 2017
Priority date	Dec 30, 2016
Publication date	Mar 17, 2020
Grant date	Mar 17, 2020

Abstract

The present invention provides a planar balun and a multi-layer circuit board. The planar balun formed on the multi-layer circuit board comprises: a first winding with at least one turn, which is formed in a first conductive layer, and has a first lead and a second lead serving as a first balanced end and a second balanced end of the balun respectively; a second winding with at least one turn, which is formed in a second conductive layer separated from the first conductive layer by at least a first insulating layer, and has a third lead and a fourth lead, wherein the third lead is connected to a ground potential, and the fourth lead serves as an unbalanced end of the balun; and a first balancing capacitor, which is connected between a selected portion near a center of the first winding and the ground potential.

First claim

What is claimed is:

1. A planar balun formed on a multi-layer circuit board, comprising:
a first winding with at least one turn, which is formed in a first conductive layer, and has a first lead and a second lead serving as a first balanced end and a second balanced end of the balun respectively;
a first peripheral grounding pad formed at a periphery of the first winding, the first peripheral grounding pad matching an outer contour of the first winding;
a second winding with at least one turn, which is formed in a second conductive layer separated from the first conductive layer by at least a first insulating layer, and has a third lead and a fourth lead, wherein the third lead is connected to a ground potential, and the fourth lead serves as an unbalanced end of the balun;
a second peripheral grounding pad formed at a periphery of the second winding, the second peripheral grounding pad matching an outer contour of the second winding; and
a first balancing capacitor, which is connected between a selected portion near a center of the first winding and the ground potential.

2. The planar balun of claim 1 , wherein the selected portion is determined from a plurality of candidate portions near the center of the first winding according to an operational frequency of the balun.

3. The planar balun of claim 1 , further comprising:
a first regulating capacitor, which is connected between a portion near the first lead of the first winding and the ground potential; and
a second regulating capacitor, which is connected between a portion near the second lead of the first winding and the ground potential.

4. The planar balun of claim 1 , further comprising a first tuning capacitor, which is connected between the first lead and the second lead.

5. The planar balun of claim 1 , further comprising a second tuning capacitor, which is connected between the fourth lead and the ground potential.

6. The planar balun of claim 1 , wherein the first winding and the second winding are formed at corresponding positions of the first conductive layer and the second conductive layer, and overlapped with each other.

7. The planar balun of claim 1 , wherein the first lead and the second lead are oriented in a first direction, and the fourth lead is oriented in a second direction which is opposite to the first direction.

8. The planar balun of claim 1 , further comprising a metal ground serving as the ground potential, which is formed in a third conductive layer separated from the second conductive layer by at least a second insulating layer.

9. The planar balun of claim 1 , further comprising a metal ground serving as the ground potential, which is formed in a third conductive layer separated from the first conductive layer by at least a second insulating layer.

10. The planar balun of claim 8 , wherein a coverage area of the metal ground is greater than or equal to respective coverage areas of the first winding and the second winding.

11. The planar balun of claim 1 , wherein the first winding is a single-turn winding.

12. The planar balun of claim 11 , wherein the second winding is a multi-turn winding, with a terminal of the innermost turn of the second winding being connected to the third lead, and a terminal of the outermost turn of the second winding being connected to the fourth lead.

13. The planar balun of claim 12 , wherein the first balancing capacitor is connected between a selected portion near an inner center of the single-turn winding and the ground potential, and there is a center tap at an outer center of the single-turn winding, the center tap being connected to the ground potential via the second balancing capacitor.

Assignees

• Gen Electric

Inventors

• Liu Yu
• Yang Dongliang
• Xie Xin
• Xing Haoyang
• Wang Kai
• Xiao Chunlai

Classifications

• H01F27/40

  Structural association with built-in electric component, e.g. fuse · CPC title

• H01F17/0033

  with the coil helically wound around a magnetic core · CPC title

• H03F3/30 Primary

  Single-ended push-pull {[SEPP]} amplifiers {(single-ended sense amplifiers G11C7/067)}; Phase-splitters therefor · CPC title

• H01F27/29

  Terminals; Tapping arrangements {for signal inductances} · CPC title

• H01F2027/2809

  on stacked layers · CPC title