Switching power supply and magnetic resonance imaging system

1. A switching power supply, for supplying power to a radio frequency coil control device, wherein the radio frequency coil control device is used for controlling a flow direction of radio frequency power output by a radio frequency amplifier of a magnetic resonance imaging system, the switching power supply comprising:

a first power unit and a second power unit; and

an air-cored transformer, the second power unit and the first power unit being electrically coupled through the air-cored transformer, wherein

the switching power supply is configured to supply direct current power to the radio frequency coil control device and operate at a preset frequency, and frequency multiplication of the preset frequency is beyond a reception bandwidth of the magnetic resonance imaging system.

2. The switching power supply according to claim 1 , wherein the air-cored transformer comprises a non-magnetic core, a first winding, and a second winding magnetically coupled to the first winding, and the first winding and the second winding are wound on the non-magnetic core side by side.

3. The switching power supply according to claim 2 , further comprising a bypass unit, wherein the bypass unit is connected between the first winding and the second winding.

4. The switching power supply according to claim 2 , wherein the first power unit comprises:

a power amplifier, for performing power amplification on an input signal; and

a first capacitor, connected to the power amplifier and used for filtering out a direct current component in the amplified signal to output a first signal to the first winding.

5. The switching power supply according to claim 4 , wherein the input signal operates at the preset frequency.

6. The switching power supply according to claim 4 , wherein the second power unit comprises:

a second capacitor, connected to the second winding and used for filtering out a direct current component in a second signal output by the second winding; and

a rectifying unit, connected to the second capacitor and used for converting an alternating current component in the second signal into a direct current output signal.

7. The switching power supply according to claim 1 , wherein the preset frequency is 1.4 MHz.

8. A magnetic resonance imaging system, comprising:

a radio frequency coil assembly, comprising a radio frequency transmitting coil and a radio frequency receiving coil;

a radio frequency amplifier, for outputting radio frequency power to excite the radio frequency coil assembly to generate a radio frequency signal;

a radio frequency coil control device, for controlling an output flow direction of the radio frequency power to control selection of at least one of a specific type of the radio frequency transmitting coil and a specific type of the radio frequency receiving coil; and

a switching power supply configured to supply power to the radio frequency coil control device, wherein the switching power supply further comprises:

(i) a first power unit and a second power unit; and

(ii) an air-cored transformer, the second power unit and the first power unit being electrically coupled through the air-cored transformer,

wherein the switching power supply is configured to supply direct current power to the radio frequency coil control device and operate at a preset frequency, and

frequency multiplication of the preset frequency is beyond a reception bandwidth of the magnetic resonance imaging system.

9. The magnetic resonance imaging system according to claim 8 , wherein the radio frequency coil control device comprises:

a control switch, configured to control the output flow direction of the radio frequency power;

a half-bridge circuit, comprising a first switch and a second switch connected in series, wherein a connection point of the first switch and the second switch is connected to the control switch; and

a voltage conversion device, connected to a driving end of the first switch and the switching power supply, and configured to convert a first driving signal into a first control signal to control the first switch.

10. The magnetic resonance imaging system according to claim 9 , wherein the radio frequency coil control device further comprises a buffer unit that is connected to a driving end of the second switch, and configured to buffer a second driving signal to control the second switch.

11. The magnetic resonance imaging system according to claim 8 , wherein the air-cored transformer comprises a non-magnetic core, a first winding, and a second winding magnetically coupled to the first winding, and the first winding and the second winding are wound on the non-magnetic core side by side.

12. The magnetic resonance imaging system according to claim 11 , wherein the switching power supply further comprises a bypass unit, wherein the bypass unit is connected between the first winding and the second winding.

13. The magnetic resonance imaging system according to claim 11 , wherein the first power unit comprises:

a power amplifier, for performing power amplification on an input signal; and

a first capacitor, connected to the power amplifier and used for filtering out a direct current component in the amplified signal to output a first signal to the first winding.

14. The magnetic resonance imaging system according to claim 13 , wherein the input signal operates at the preset frequency.

15. The magnetic resonance imaging system according to claim 13 , wherein the second power unit comprises:

a second capacitor, connected to the second winding and used for filtering out a direct current component in a second signal output by the second winding; and

a rectifying unit, connected to the second capacitor and used for converting an alternating current component in the second signal into a direct current output signal.

16. The magnetic resonance imaging system according to claim 8 , wherein the preset frequency is 1.4 MHz.