Wideband multilayer transmission line transformer

Patent metadata

Field	Value
Publication number	US-9627738-B2
Application number	US-201213351062-A
Country	US
Kind code	B2
Filing date	Jan 16, 2012
Priority date	Jan 16, 2012
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

Abstract

Embodiments of the invention include transmission line transformers. According to one aspect, a multilayer transmission line transformer (TLT) includes a first set of two conductors forming a first clockwise spiral. The TLT includes a second set of two conductors forming a second counterclockwise spiral that is substantially coaxial with the first spiral. The first and second spirals are arranged to cause a substantial cancellation of common mode currents in the first and second sets of conductors during operation of the TLT.

First claim

What is claimed is:

1. A multilayer transmission line transformer, comprising:
a first set of two conductors having no intervening conductor there between, the first set of two conductors forming a first clockwise inward spiral, the first set of two conductors forming a first transformer; and
a second set of two conductors having no intervening conductor there between, the second set of two conductors forming a second counterclockwise inward spiral, the second set of two conductors forming a second transformer, the second counterclockwise inward spiral being substantially coaxial with the first clockwise inward spiral; and
the first and second inward spirals having no intervening conductor there between so that the combination of the first clockwise inward spirals and the second counterclockwise inward spirals being substantially coaxial cause a substantial cancellation of common mode currents in the first and second sets of conductors during operation without substantially suppressing differential mode currents.

2. The transformer of claim 1 , wherein the two conductors of the first set of conductors are substantially physically parallel.

3. The transformer of claim 1 , wherein the first set of conductors forms a Guanella transformer.

4. The transformer of claim 1 , wherein the first set of conductors forms a Ruthroff transformer.

5. A transformer, comprising:
a first conductor in a first plane, the first conductor forming a first clockwise inward spiral;
a second conductor, proximal the first conductor, the second conductor forming a second clockwise inward spiral substantially coaxial with the first clockwise inward spiral, the first and second conductors forming a first transformer, there being no intervening conductor between the first and second conductors;
a third conductor, the third conductor forming a third counterclockwise inward spiral substantially coaxial with the first spiral, the third conductor provided in a second plane that is substantially parallel to the first plane; and
a fourth conductor proximal the third conductor, the fourth conductor forming a fourth counterclockwise inward spiral substantially coaxial with the third counterclockwise inward spiral, the third and fourth conductors forming a second transformer, there being no intervening conductor between the third and fourth conductors; and
the first and second transformers having no intervening conductor there between so that the orientation of the clockwise and counterclockwise inward spirals being substantially coaxial cause a substantial cancellation of common mode currents of the first and second transformers during operation without substantially suppressing differential mode currents.

6. The transformer of claim 5 , wherein the first and second conductors are substantially physically parallel to each other, and wherein the third and fourth conductors are substantially physically parallel to each other.

7. The transformer of claim 5 , wherein the first and second conductors form inductors having a first pair of mutually coupled inductive reactances.

8. The transformer of claim 7 , wherein the second and third conductors form inductors having a second pair of mutually coupled inductive reactances.

9. The transformer of claim 8 , wherein the first and second pair of inductive reactances cause the substantial cancellation of common mode currents through the first and second conductors.

10. A dual transformer, comprising:
a first clockwise inward spiral conductor forming a first inductor having a first inductive reactance;
a second clockwise inward spiral conductor forming a second inductor having a second inductive reactance mutually coupled to the first inductive reactance, to form a first transformer, there being no intervening conductor between the first and second clockwise inward spiral conductors;
a third counterclockwise inward spiral conductor forming a third inductor having a third inductive reactance, the third inductive reactance electrically in parallel with the first inductive reactance; and
a fourth clockwise inward spiral conductor forming a fourth inductor having a fourth inductive reactance electrically in parallel with the second inductive reactance, the fourth inductive reactance mutually coupled to the third inductive reactance, to form a second transformer, there being no intervening conductor between the third and fourth counterclockwise inward spiral conductors; and
the first input port connected to the third input port, the second input port connected to the first output port, and the fourth input port connected to the third output port; and
the first and second transformers having no intervening conductor there between so that the orientation of the clockwise and counterclockwise inward spirals being substantially coaxial cause a substantial cancellation of common mode currents of the first and second transformers during operation without substantially suppressing differential mode currents.

11. The transformer of claim 1 , wherein a separation between the first set of two conductors and the second set of two conductors is greater than a separation between the two conductors forming one of the first and second sets.

12. The transformer of claim 1 , wherein the first set of two conductors and the second set of two conductors are disposed between ground planes.

13. The transformer of claim 12 , wherein a separation between a ground plane and a nearest one of the first and second set of conductors is greater than a separation of conductors in the nearest set.

14. The transformer of claim 5 , wherein a separation between the second conductor and the third conductor is greater than a separation between the first conductor and the second conductor.

Assignees

• Wyville Mark William
• ERICSSON TELEFON AB L M (publ)

Inventors

• Wyville Mark William

Classifications

• H01P5/10

  for coupling balanced lines or devices with unbalanced lines or devices · CPC title

• H03H7/42

  Networks for transforming balanced signals into unbalanced signals and vice versa, e.g. baluns · CPC title

• H03H7/422

  comprising distributed impedance elements together with lumped impedance elements · CPC title

• Y10T29/4902

  Electromagnet, transformer or inductor · CPC title

• H01F19/04 Primary

  Transformers or mutual inductances suitable for handling frequencies considerably beyond the audio range (resonant circuits H03H) · CPC title