Single phase differential conversion circuit, balun, switch, and communication device

1. A balun, comprising:

one or more first transistors of a first conductivity type each including a first gate, a first source, and a first drain, wherein the first gate is connected to an input terminal, the first source is connected to a first voltage source, and the first drain is connected to an output node;

one or more second transistors of a second conductivity type each including a second gate, a second source, and a second drain, wherein the second gate is connected to the input terminal, the second source is connected to a second voltage source, and the second drain is connected to the output node;

a first resistor directly connected between the input terminal and the output node, wherein the output node is configured to form a junction of the first drain of the one or more first transistors and the second drain of the one or more second transistors;

a first output terminal connected to the input terminal; and

a second output terminal directly or indirectly connected to the output node.

2. A switch configured to control a balun, the switch comprising:

one or more switching transistors each including a control terminal, wherein the one or more switching transistors are configured to select at least one of one or more first transistors of a first conductivity type or one or more second transistors of a second conductivity type; and

a nonlinear circuit configured to be respectively connected to the control terminal of each of the one or more switching transistors,

wherein the balun comprises:

the one or more first transistors each including a first gate, a first source, and a first drain, wherein the first gate is connected to an input terminal, the first source is connected to a first voltage source and the first drain is connected to an output node;

the one or more second transistors each including a second gate, a second source, and a second drain, wherein the second gate is connected to the input terminal, the second source is connected to a second voltage source, and the second drain is connected to the output node;

a first resistor connected between the input terminal and the output node, wherein the output node is configured to form a junction of the first drain of the one or more first transistors and the second drain of the one or more second transistors;

a first output terminal connected to the input terminal; and

a second output terminal directly or indirectly connected to the output node.

3. The switch according to claim 2 ,

wherein the one or more switching transistors include an N-type transistor, and

impedance of the nonlinear circuit decreases with an increase in a voltage of the control terminal.

4. The switch according to claim 2 ,

wherein the one or more switching transistors include a P-type transistor, and

impedance of the nonlinear circuit increases with an increase in a voltage of the control terminal.

5. The switch according to claim 2 ,

wherein the nonlinear circuit includes a transistor.

6. The switch according to claim 5 ,

wherein the transistor includes a gate, a drain, and a source, and

one of the drain, the source, or the gate are connected to each other.

7. The switch according to claim 6 ,

wherein the transistor is a P-type transistor, and

the control terminal is connected to another of the drain or the source of the transistor.

8. The switch according to claim 6 ,

wherein the transistor is an N-type transistor, and

the control terminal is connected to one of the drain or the source of the transistor.

9. The switch according to claim 7 ,

wherein each of the one or more switching transistors is configured to be turned on and off based on a voltage applied to a terminal, among the drain and the source of the transistor of the nonlinear circuit, that is disconnected from the control terminal.

10. The switch according to claim 2 ,

wherein the control terminal of each of the one or more switching transistors is a gate of the respective one or more switching transistors.

11. The switch according to claim 2 ,

wherein the control terminal of each of the one or more switching transistors is a back gate of the respective one or more switching transistors.

12. The switch according to claim 2 ,

wherein the nonlinear circuit includes a diode.

13. The switch according to claim 2 ,

wherein the nonlinear circuit includes a variable resistance circuit configured to vary a resistance value of the non-linear circuit based on a voltage at the control terminal.