Amplifier for reusing current by using transformer and method thereof

1. An amplifier comprising:

first and second matching networks;

first and second transistors; and

a transformer including first to third inductors,

wherein a gate and a source of the first transistor are connected to the first matching network, one end of the first inductor is connected to a drain of the first transistor, the other end of the first inductor is connected to a source of the second transistor, one end of the second inductor is connected to a gate of the second transistor, the other end of the second inductor is grounded, one end of the third inductor is connected to a drain of the second transistor, and the other end of the third inductor is connected to the second matching network.

2. The amplifier according to claim 1 , wherein the transformer comprises first to third layers, the first inductor is disposed in the first layer, the second inductor is disposed in the second layer, and the third inductor is disposed in the third layer.

3. The amplifier according to claim 1 , wherein the second inductor is disposed to surround an outer side of the first inductor, and the third inductor is disposed to surround an outer side of the second inductor.

4. The amplifier according to claim 1 , wherein the first matching network outputs an electrical signal input through an input port to the gate of the first transistor, and the first transistor outputs the electrical signal to the first inductor through the drain of the first transistor.

5. The amplifier according to claim 1 , wherein the first inductor forms a first magnetic flux in accordance with an electrical signal, the second inductor forms a second magnetic flux by the first magnetic flux, and a direction of the second magnetic flux is opposite to a direction of the first magnetic flux.

6. The amplifier according to claim 5 , wherein the second transistor forms a voltage at each of the source and the gate of the second transistor by the first magnetic flux, and a phase difference between the voltages of the source and gate of the second transistor is 180 degrees.

7. The amplifier according to claim 5 , wherein the third inductor forms a third magnetic flux by the second magnetic flux, and a direction of the third magnetic flux is equal to the direction of the second magnetic flux.

8. The amplifier according to claim 1 , wherein the first to third inductors are electromagnetically coupled.

9. A communication node comprising an antenna and an amplifier connected to the antenna,

wherein the amplifier comprises first and second matching networks; first and second transistors; and a transformer including first to third inductors, and

wherein a gate and a source of the first transistor are connected to the first matching network, one end of the first inductor is connected to a drain of the first transistor, the other end of the first inductor is connected to a source of the second transistor, one end of the second inductor is connected to a gate of the second transistor, the other end of the second inductor is grounded, one end of the third inductor is connected to a drain of the second transistor, and the other end of the third inductor is connected to the second matching network.

10. The communication node according to claim 9 , wherein the transformer comprises first to third layers, the first inductor is disposed in the first layer, the second inductor is disposed in the second layer, and the third inductor is disposed in the third layer.

11. The communication node according to claim 9 , wherein the second inductor is disposed to surround an outer side of the first inductor, and the third inductor is disposed to surround an outer side of the second inductor.

12. The communication node according to claim 9 , wherein the first matching network outputs an electrical signal input through an input port to the gate of the first transistor, and the first transistor outputs the electrical signal to the first inductor through the drain of the first transistor.

13. The communication node according to claim 9 , wherein the first inductor forms a first magnetic flux in accordance with an electrical signal, the second inductor forms a second magnetic flux by the first magnetic flux, and a direction of the second magnetic flux is opposite to a direction of the first magnetic flux.

14. The communication node according to claim 13 , wherein the second transistor forms a voltage at each of the source and the gate of the second transistor by the first magnetic flux, and a phase difference between the voltages of the source and gate of the second transistor is 180 degrees.

15. The communication node according to claim 13 , wherein the third inductor forms a third magnetic flux by the second magnetic flux, and a direction of the third magnetic flux is equal to the direction of the second magnetic flux.

16. The communication node according to claim 9 , wherein the first to third inductors are electromagnetically coupled.

17. The communication node according to claim 9 , further comprising a transmit signal processor, wherein the amplifier amplifies a transmit signal output by the transmit signal processor, and the antenna radiates the amplified transmit signal.

18. The communication node according to claim 9 , further comprising a receive signal processor, wherein the antenna receives a receive signal, the amplifier amplifies the receive signal, and the receive signal processor processes the amplified receive signal.