Balun signal transformer and method of forming
View Patent ↗A balanced-unbalanced (balun) signal transformer includes an unbalanced port, a balanced port coupled to the unbalanced port, the balanced port comprising a first terminal and a second terminal, a first capacitor coupled to the first terminal, a first inductor coupled to ground and the first capacitor, a second capacitor coupled to the second terminal, and a second inductor coupled to ground and the second capacitor. The transformer may also include a third capacitor coupled to a terminal of the unbalanced port; and a third inductor coupled to the third capacitor and the third terminal.
1. A balanced-unbalanced (balun) signal transformer comprising:
an unbalanced port; a balanced port coupled to the unbalanced port, the balanced port comprising a first terminal and a second terminal; a first capacitor coupled to the first terminal; a first inductor coupled to ground and the first capacitor; a second capacitor coupled to the second terminal; a second inductor coupled to ground and the second capacitor, a third inductor, wherein the first capacitor and the second capacitor are connected to the third inductor; a fourth inductor, wherein the unbalanced port is formed by third and fourth terminals of the fourth inductor.
2. The transformer of claim 1 , wherein the unbalanced port comprises a third terminal and the transformer further comprises:
a third capacitor coupled to the third terminal; and
a third inductor coupled to the third capacitor and the third terminal.
3. The transformer of claim 1 , wherein the balanced-unbalanced signal transformer comprises a symmetric transformer.
4. The transformer of claim 1 , further comprising a substrate and wherein the transformer is implemented as an integrated circuit formed on the substrate.
5. The transformer of claim 1 , wherein the transformer is implemented with a combination of discrete passive components.
6. The transformer of claim 1 , wherein the third inductor is capable of inducing a current through the fourth inductor.
7. The transformer of claim 1 further comprising:
a first external port, wherein the first capacitor is coupled to the first external port through the first terminal; and
a second external port, wherein the second capacitor is coupled to the second external port through the second terminal.
8. The transformer of claim 7 , wherein the first external port and the second external port are coupled to a balanced device.
9. A method of forming a balanced-unbalanced (balun) signal transformer comprising: providing an unbalanced port; providing a balanced port coupled to the unbalanced port, the balanced port comprising a first terminal and a second terminal; providing a first capacitor coupled to the first terminal; providing a first inductor coupled to ground and the first capacitor; providing a second capacitor coupled to the second terminal; providing a second inductor coupled to ground and the second capacitor; and providing a third inductor, wherein the first capacitor and the second capacitor are connected to the third inductor; providing a fourth inductor, wherein the unbalanced port is formed by third and fourth terminals of the fourth inductor.
10. The method of claim 9 , further comprising:
providing a third capacitor coupled to a third terminal, wherein the unbalanced port comprises a third terminal.
11. A balanced-unbalanced (balun) signal transformer comprising:
an unbalanced port, the unbalanced port having a first terminal and a second terminal;
a balanced port coupled to the unbalanced port, the balanced port comprising a third terminal and a fourth terminal;
a first capacitor coupled to the third terminal;
a first inductor coupled to ground and the first capacitor;
a second capacitor coupled to the fourth terminal;
a second inductor coupled to ground and the second capacitor;
a third capacitor coupled to the first terminal and the second terminal; and
a third inductor coupled to the first terminal and the second terminal, wherein the third capacitor and the third inductor are coupled in parallel.
12. The transformer of claim 11 , wherein the balanced-unbalanced signal transformer comprises a symmetric transformer.
13. The transformer of claim 11 , further comprising a substrate and wherein the transformer is implemented as an integrated circuit formed on the substrate.
14. The transformer of claim 11 , wherein the transformer is implemented with a combination of discrete passive components.
15. The transformer of claim 11 , further comprising a fourth inductor, wherein the unbalanced port is formed by third and fourth terminals of the fourth inductor.
16. The transformer of claim 11 , wherein the third inductor is capable of inducing a current through the fourth inductor.
17. The transformer of claim 11 further comprising:
a first external port, wherein the first capacitor is coupled to the first external port through the first terminal; and
a second external port, wherein the second capacitor is coupled to the second external port through the second terminal.
18. The transformer of claim 17 , wherein the first external port and the second external port are coupled to a balanced device.