TRANSFORMER BASED LCTANK STRUCTURE

• US 20160260537A1
• Filed: 08/07/2015
• Published: 09/08/2016
• Est. Priority Date: 03/02/2015
• Status: Abandoned Application

• Current Assignee: Realtek Semiconductor Corp.
• Original Assignee: Realtek Semiconductor Corp.
• Inventors: YEN, Hsiao-Tsung, TSAI, Chih-Yu
• Application Number:
  US14/821,207
• Publication Number:
  US 20160260537A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01F 2027/2809 on stacked layers
• CPC Class Codes: H01F 27/2804 Printed windings
• CPC Class Codes: H01F 27/292 Surface mounted devices
• CPC Class Codes: H01F 41/042 by thin film techniques
• CPC Class Codes: H03B 5/1212 the amplifier comprising a pair of transistors, wherein an output terminal of each being connected to an input terminal of the other, e.g. a cross coupled pair
• CPC Class Codes: H03B 5/1228 the amplifier comprising one or more field effect transistors
• CPC Class Codes: H03B 5/124 the means comprising a voltage dependent capacitance
• CPC Class Codes: H03B 5/1296 the feedback circuit comprising a transformer

Abstract

A transformer includes a first winding and a second winding. The first winding is constructed in a preset solid region having a first level and a second level. The first winding is wound from a first end in a left side region of the first level, guided across a first center line and through a right side region of the second level, and wound in a left side region of the second level until reaches a second end in the left side region of the second level. The second winding is wound from a first end in the right side region of the second level, guided across the first center line and through the left side region of the second level, and wound in a right side region of the first level until reaches a second end in the right side region of the first level.

Claims

1. A transformer for an oscillator, comprising:

a first winding being a first planar metal winding and constructed in a preset solid region, the preset solid region comprises a first level and a second level, each of the first level and the second level includes a left side region and a right side region, wherein the first winding is wound from a first end in the left side region of the first level, guided across a first center line and through the right side region of the second level, and wound in the left side region of the second level until reaches a second end in the left side region of the second level; and

a second winding being a second planar metal winding and constructed in the preset solid region, the second winding being wound from a first end in the right side region of the second level, guided across the first center line and through the left side region of the second level, and wound in the right side region of the first level until reaches a second end in the right side region of the first level;

wherein

the first winding has a first center tap disposed along a second center line and in the right side region of the second level, and the second winding has a second center tap disposed along the second center line and in the left side region of the second level.

2. The transformer as claimed in claim 1, wherein the first end in the left side region of the first level and the first end in the right side region of the second level are coupled to a power source.

3. The transformer as claimed in claim 2, further comprising:

a variable capacitor having two terminals respectively coupled to the first center tap and the second center tap.

4. The transformer as claimed in claim 3, wherein the second end in the left side region of the second level and the second end in the right side region of the first level are coupled to a switch.

5. The transformer as claimed in claim 3, wherein the switch comprises:

a first transistor, wherein a first terminal of the first transistor is coupled to the second end in the left side region of the second level, and a second terminal of the first transistor is grounded; and

a second transistor, wherein a first terminal of the second transistor is coupled to the second end in the right side region of the first level, a second terminal of the second transistor is grounded, a control terminal of the second transistor is coupled to the first terminal of the first transistor, and a control terminal of the first transistor is coupled to the first terminal of the second transistor.

6. The transformer as claimed in claim 5, wherein the first center tap and the second center tap are coupled to a switch.

7. The transformer as claimed in claim 6, wherein the switch comprises:

a first transistor, wherein a first terminal of the first transistor is coupled to the second center tap, and a second terminal of the first transistor is grounded; and

a second transistor, wherein a first terminal of the second transistor is coupled to the first center tap, a second terminal of the second transistor is grounded, a control terminal of the second transistor is coupled to the first terminal of the first transistor, and a control terminal of the first transistor is coupled to the first terminal of the second transistor.

8. The transformer as claimed in claim 7, wherein the second end in the left side region of the second level and the second end in the right side region of the first level

9. The transformer as claimed in claim 1, wherein the first end in the left side region of the first level and the first end in the right side region of the second level are coupled to a first capacitor.

10. The transformer as claimed in claim 9, wherein the first center tap and the second center tap are coupled to a power source.

11. The transformer as claimed in claim 10, wherein the second end in the left side region of the second level and the second end in the right side region of the first level are coupled to a second capacitor.

12. The transformer as claimed in claim 1, wherein the first end in the left side region of the first level and the first end in the right side region of the second level are coupled to a switch.

13. The transformer as claimed in claim 12, wherein the switch comprises:

a first transistor, wherein a first terminal of the first transistor is coupled to the first end in the left side region of the first level, and a second terminal of the first transistor is grounded; and

a second transistor, wherein a first terminal of the second transistor is coupled to the first end in the right side region of the second level, a second terminal of the second transistor is grounded, a control terminal of the second transistor is coupled to the first terminal of the first transistor, and a control terminal of the first transistor is coupled to the first terminal of the second transistor.

14. The transformer as claimed in claim 13, wherein the first center tap and the second center tap are coupled to a power source.

15. The transformer as claimed in claim 14, wherein the second end in the left side region of the second level and the second end in the right side region of the first level are coupled to a variable capacitor.

16. A winding method for a transformer used with an oscillator, comprising the steps of:

winding a first winding in a preset solid region, wherein the preset solid region comprises a first level and a second level, each of the first level and the second level includes a left side region and a right side region, the first winding is wound from a first end in the left side region of the first level, guided across a first center line and through the right side region of the second level, and wound in the left side region of the second level until reaches a second end in the left side region of the second level;

winding a second winding in the preset solid region, wherein the second winding is wound from a first end in the right side region of the second level, guided across the first center line and through the left side region of the second level, and wound in the right side region of the first level until reaches a second end in the right side region of the first level;

providing the first winding with a first center tap disposed along a second center line and in the right side region of the second level; and

providing the second winding with a second center tap disposed along the second center line and in the left side region of the second level.

17. The method as claimed in claim 16, further comprising:

coupling the first end in the left side region of the first level and the first end in the right side region of the second level to a power source, a switch or a capacitor.

18. The method as claimed in claim 16, further comprising:

coupling the first center tap and the second center tap to a voltage source, a switch or a capacitor.

19. The method as claimed in claim 16, further comprising:

coupling the second end in the left side region of the second level and the second end in the right side region of the first level to a power source, a switch or a capacitor.