Radio frequency switching circuit and control method thereof, radio frequency transceiver link and magnetic resonance device

Abstract

The present invention relates to a radio frequency switching circuit and a control method thereof, a radio frequency transceiver link and a magnetic resonance device. The radio frequency switching circuit includes an electrically connected switch control bridge circuit and a diode. The switch control bridge circuit includes at least one power device, and the diode is arranged on the radio frequency link; wherein, by controlling the opening and closing of at least one power device, at least one discharge loop is formed in the switch control bridge circuit. The present invention uses a bridge circuit to construct a switch control bridge circuit, and by opening and closing the power device therein, different discharge loops are formed in the switch control bridge circuit. When the diode switches state, the discharge loop is used to reduce the inherent recovery time, so as to achieve the purpose of quickly switching different radio frequency links and improve the switch switching rate.

Description

Technical Field

[0001] The present invention relates to the field of radio frequency technology, and in particular to a radio frequency switching circuit and a control method thereof, a radio frequency transceiver link and a magnetic resonance device. Background Art

[0002] In magnetic resonance imaging equipment, the RF system is a functional unit that implements RF excitation and receives and processes RF signals. The RF system includes an RF transmission link and an RF reception link. Under the action of the timing controller, the RF transmission link generates various RF pulses that meet the sequence requirements. Under the action of the timing controller, the RF reception link receives the magnetic resonance signals generated by the human body.

[0003] In current magnetic resonance systems, the RF transceiver link needs to be switched by controlling the conduction or cutoff of the diode. Due to the inherent recovery time in the state switching process of the diode, there will be a delay in the switching of the RF transceiver link. However, for some switches, the broadband RF transceiver link often has a high switching rate requirement, which needs to reach the level of several microseconds, but the existing solutions cannot meet this requirement. Summary of the invention

[0004] In view of this, it is necessary to provide a radio frequency switching circuit and a control method thereof, a radio frequency transceiver link and a magnetic resonance device to overcome the problem in the prior art that the inherent recovery time of the diode is likely to interfere with the switching rate of the radio frequency link.

[0005] In order to solve the above technical problems, the present invention provides a radio frequency switching circuit, including an electrically connected switch-controlled bridge circuit and a diode, wherein the switch-controlled bridge circuit includes at least one power device, and the diode is arranged on the radio frequency link; wherein, by controlling the opening and closing of the at least one power device, at least one discharge loop is formed in the switch-controlled bridge circuit.

[0006] Furthermore, the switch-controlled bridge circuit adopts a full-bridge circuit structure, including a first rectifier circuit, a second rectifier circuit and a shunt branch, wherein the first rectifier circuit is electrically connected to the anode of the diode, the second rectifier circuit is electrically connected to the cathode of the diode, and the shunt branch is connected in parallel at both ends of the diode.

[0007] Furthermore, the first rectifier circuit includes a first inductor and a first capacitor electrically connected, a first resistor and a first power device connected in series, and a second power device electrically connected to the first power device.

[0008] Furthermore, the second rectifier circuit includes a second inductor and a second capacitor which are electrically connected, and a third power device and a fourth power device which are electrically connected.

[0009] Furthermore, the shunt branch includes the fifth power device and the second resistor electrically connected in sequence, wherein: one end of the fifth power device away from the second resistor is electrically connected to the anode of the diode, and one end of the second resistor away from the fifth power device is electrically connected to the cathode of the diode.

[0010] The present invention also provides a radio frequency transceiver link, comprising the radio frequency switching circuit as described above, at least one radio frequency receiving link and / or at least one radio frequency transmitting link, wherein the diodes in the radio frequency switching circuit are respectively arranged on at least one radio frequency receiving link and / or at least one radio frequency transmitting link.

[0011] The present invention also provides a control method for a radio frequency switching circuit. Based on the radio frequency switching circuit as described above, the control method includes:

[0012] Get the set sending and receiving status;

[0013] According to the set transceiver state, determining a radio frequency link formed between corresponding transceivers when the set transceiver state is reached;

[0014] According to the formed RF link, the opening and closing of at least one power device corresponding to each diode is controlled to form at least one discharge loop in the switch control bridge circuit, thereby reducing the inherent recovery time when the conduction state of each diode is switched, so as to speed up the switching rate of the formed RF link.

[0015] Furthermore, the control of the opening and closing of at least one power device corresponding to each diode according to the formed radio frequency link to form at least one discharge loop in the switch control bridge circuit includes:

[0016] According to the diodes that need to be turned on in the formed radio frequency link, the corresponding switch controls the opening and closing of at least one power device in the bridge circuit, so that the diodes that need to be turned on are forward-conducted and the other diodes are reverse-cut off.

[0017] Further, the at least one power device includes a first power device to a fifth power device, and the control of the opening and closing of at least one power device in the corresponding transceiver circuit so that the diode that needs to be turned on is turned on and the other diodes are turned off includes:

[0018] When the diode needs to be forward-conducted, the first power device and the fourth power device are controlled to be turned on, and after the forward conduction is completed, the second power device, the fourth power device and the fifth power device are controlled to be turned on;

[0019] When the diode needs to be reverse cutoff, the second power device and the third power device are controlled to be turned on, and after the reverse cutoff is completed, the second power device, the fourth power device and the fifth power device are controlled to be turned on.

[0020] The present invention also provides a magnetic resonance device, comprising:

[0021] a scanner for generating magnetic resonance radio frequency signals;

[0022] at least one radio frequency transmission link, used for processing the magnetic resonance radio frequency signal and transmitting the magnetic resonance radio frequency signal;

[0023] at least one radio frequency receiving link, used to receive the magnetic resonance radio frequency signal and convert the magnetic resonance radio frequency signal into a digital signal;

[0024] And, according to the RF switching circuit and processor as described above, the diodes in the RF switching circuit are respectively arranged on at least one RF receiving link and / or at least one RF transmitting link, and the processor is used to execute the control method of the RF switching circuit as described above on the RF switching circuit.

[0025] Compared with the prior art, the beneficial effects of the present invention include:

[0026] In the RF switching circuit, the on or off state of the diode in the transceiver circuit is switched to form different RF links between the transceiver ends. Under specific application requirements, an RF link is formed between the preset transceiver ends to achieve conversion of different transceiver states. At the same time, the switch is used to control the opening and closing of multiple power devices in the bridge circuit. In the process of switching the diode on or off, different discharge loops are constructed. The circuit structure of the discharge loop consumes charge, reduces the inherent recovery time of the diode, and accelerates its switching rate, thereby effectively improving the switching rate of different RF links.

[0027] In the control method of the radio frequency switching circuit, first, the set transceiver state is effectively acquired; then, according to the set transceiver state, the preset transceiver end is determined; finally, corresponding to different set transceiver states, the radio frequency link that needs to be formed by the preset transceiver end is determined, in which the opening and closing of the power device in the transceiver circuit corresponding to each diode is controlled, and when the diode switches to the on or off state, different discharge loops are constructed to speed up its switching rate, and under different combinations of diode on or off states, the radio frequency link corresponding to the set transceiver state is formed, thereby reducing the influence of the inherent recovery time when the diode switches, and speeding up the efficiency of the radio frequency link switching.

[0028] In the magnetic resonance equipment, the processor is used to execute relevant control methods on the radio frequency switching circuit, effectively controlling the opening and closing of the power device and accelerating the switching of the diode's on and off state, thereby speeding up the switching efficiency of the radio frequency link and ensuring the rapidity of the magnetic resonance equipment switching between different receiving and transmitting states.

[0029] In summary, the present invention utilizes a bridge circuit to construct a switch-controlled bridge circuit, and forms different discharge loops in the switch-controlled bridge circuit by opening and closing the power devices therein. When the diode switches state, the discharge loop is utilized to reduce its inherent recovery time, thereby achieving the purpose of quickly switching different RF links and effectively improving the switch switching rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic structural diagram of an embodiment of a radio frequency switching circuit provided by the present invention;

[0031] Figure 2 A schematic diagram of the structure of an embodiment of a switch-controlled bridge circuit provided by the present invention;

[0032] Figure 3 A schematic diagram of the specific structure of an embodiment of a switch-controlled bridge circuit provided by the present invention;

[0033] Figure 4 A schematic structural diagram of an embodiment of a forward-conducting diode provided by the present invention;

[0034] Figure 5 A schematic diagram of the specific structure of an embodiment of a diode reverse recovery discharge provided by the present invention;

[0035] Figure 6 A schematic diagram of the specific structure of an embodiment of the reverse cutoff provided by the present invention;

[0036] Figure 7 A schematic diagram of the specific structure of an embodiment of a diode forward recovery discharge provided by the present invention;

[0037] Figure 8 A schematic diagram of the structure of an embodiment of a radio frequency transceiver link provided by the present invention;

[0038] Fig. 9 A schematic diagram of a specific structure of an embodiment of a radio frequency transceiver link provided by the present invention

[0039] Fig.10 A schematic structural diagram of an embodiment of a driving rear-stage transmitting coil provided by the present invention;

[0040] Fig.11 A schematic flow chart of an embodiment of a control method for a radio frequency switching circuit provided by the present invention;

[0041] Fig.12 A schematic structural diagram of an embodiment of a control device for a radio frequency switching circuit provided by the present invention. DETAILED DESCRIPTION

[0042] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0043] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0044] In the description of the present invention, reference to an "embodiment" means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive of other embodiments. It is explicitly and implicitly understood by those skilled in the art that the described embodiments may be combined with other embodiments.

[0045] The present invention provides a radio frequency switching circuit and a control method thereof, a radio frequency transceiver link and a magnetic resonance device. The multiple power devices in the bridge circuit are controlled by switches to control the conduction of diodes between different transceiver ends, thereby improving the switching rate of the diode state and forming different radio frequency links between different transceiver ends, thereby providing a new idea for further improving the rapidity of the radio frequency link switching switch.

[0046] Before describing the specific embodiments, the technical terms involved are explained as follows:

[0047] Magnetic resonance equipment: usually includes a magnetic resonance frame, in which there is a main magnet, which can be composed of superconducting coils and is used to generate a main magnetic field; during magnetic resonance imaging, the imaging object will be carried by the bed, and as the bed moves, the imaging object will be moved into an area where the magnetic field distribution of the main magnetic field is relatively uniform. The pulse control unit in the magnetic resonance equipment controls the radio frequency pulse generating unit to generate radio frequency pulses. The imaging object will generate corresponding magnetic resonance signals by resonance according to radio frequency excitation, which can be collected by a radio frequency body coil or a local coil, and the image will be reconstructed according to the magnetic resonance signal to form a magnetic resonance image;

[0048] RF transceiver link: collects the frequency signals corresponding to the nuclides of interest in specific applications for analysis. The results of the analysis can provide important data support for the clinical, preclinical, and cutting-edge scientific research results of experts in specific fields; including the transmitting link and the receiving link; in the transmitting link, the RF pulse is amplified by the RF power amplifier, passes through the switch control unit, and is finally emitted by the RF body coil or local coil to perform RF excitation on the imaging object; similarly, in the receiving link, after passing through the switch control unit, the RF body coil or local coil performs the acquisition, that is, the RF receiving coil performs the acquisition;

[0049] Multi-core transmission / reception state: when the load of the RF link is a multi-core coil and the RF link is a transmission link, it is a multi-core transmission state; when the load of the RF link is a multi-core coil and the RF link is a reception link, it is a multi-core reception state; multi-core transmission means that the frequencies transmitted in different time periods are different (such as 20MHz in the first time period t1, 40Mhz in the second time period t2, 60MHz in the third time period t3, etc.), and the common narrowband (such as 60MHz±1MHz) RF switch cannot be compatible with so many frequencies, so a multi-core transmission switch is required;

[0050] Based on the above technical terminology explanation, in the prior art, the self-transmission and self-reception of multi-core RF coils require the control of broadband RF switches to form different RF transceiver links, and multiple RF transmission links or RF receiving links also require RF switches to control on and off. The control of the switches is achieved by controlling the conversion of the on-state and off-state of the diode, but the inherent recovery characteristics of the diode require a certain amount of time to discharge, which affects the switching rate of the switch.

[0051] In modern pulse circuits, transistors or diodes are widely used as switches, or logic integrated circuits mainly composed of them are used. The diode used as a switch mainly utilizes its on (very small resistance) and off (very large resistance) characteristics, that is, the switching effect of the diode on forward and reverse currents. The difference between a diode and a general switch is that the "on" and "off" are determined by the polarity of the applied voltage, and there is a small voltage drop in the "on" state and a small current in the "off" state. When the voltage changes from forward to reverse, the current does not reach the preset state immediately, but for a period of time, the reverse current is always large, and the diode is not turned off. After a period of time, the reverse current gradually decreases, and after a period of time, the current of the diode reaches the preset state. This is actually caused by the charge storage effect. The inherent recovery time is the time required for the stored charge to be exhausted, and the time from the change to the preset state is called the inherent recovery time.

[0052] Among them, the inherent recovery time includes forward recovery time and reverse recovery time. When the switch changes from the on state to the off state, the diode or rectifier needs to release the stored charge before the diode blocks the reverse current. This discharge time is called the reverse recovery time, during which the current flows through the diode in the reverse direction. That is, the time from when the forward conduction current is 0 to when it enters the completely off state; conversely, it is the forward recovery time.

[0053] Therefore, in view of the above problems, the technical solution of the present invention provides a radio frequency switching circuit and a control method thereof, a radio frequency transceiver link and a magnetic resonance device, which are described in detail below:

[0054] The embodiment of the present invention provides a radio frequency switching circuit, combined with Figure 1 Come and see, Figure 1 This is a schematic diagram of the structure of an embodiment of a radio frequency switching circuit provided by the present invention. The radio frequency switching circuit 1 includes an electrically connected switch control bridge circuit 101 and a diode D. The switch control bridge circuit 101 includes at least one power device, and the diode D is arranged on the radio frequency link; wherein, by controlling the opening and closing of at least one power device, at least one discharge loop is formed in the switch control bridge circuit 101.

[0055] In an embodiment of the present invention, in a radio frequency switching circuit, the on or off state of a diode in a transceiver circuit is changed to form different radio frequency links between the transceiver and the receiver, thereby realizing the conversion of different transceiver states. At the same time, a switch is used to control the opening and closing of multiple power devices in a bridge circuit. In the process of switching the diode on or off, different discharge loops are constructed. The charge is consumed through the circuit structure of the discharge loop, thereby avoiding the inherent recovery time of the diode and accelerating its switching rate, thereby effectively improving the switching rate of different radio frequency links.

[0056] It should be noted that the diode itself has a forward recovery time and a reverse recovery time, that is, an inherent recovery time, which will affect the switching rate of the circuit. Therefore, the present invention constructs a discharge loop to avoid the inherent recovery time of the diode. In addition, there is a large LC filter circuit on the DC path in a general RF switching circuit, which will affect the discharge time of the charge. Constructing a discharge loop can also consume the charge and speed up its switching rate.

[0057] As a preferred embodiment, the one or more power devices are all GaN power devices.

[0058] It should be noted that RF switches require broadband RF switches. Broadband RF switches are generally divided into two categories: integrated devices and discrete devices. Among them, integrated devices have a faster speed, but are still at the us level, and are expensive, and the overall compatible transmission power is low; while discrete devices have a lower speed, a relatively complex circuit, and occupy a larger PCB area. Existing solutions use switching devices such as MOSFET, solid-state relays, and IGBTs to switch forward current and reverse high voltage. These devices generally have a low switching speed, and the instantaneous charge shock of switching is large, which brings a large dynamic power consumption to the entire circuit, and also has high requirements for the driving capability of negative high voltage.

[0059] In the embodiment of the present invention, in order to solve the problem that the existing switching devices cannot meet the increasingly faster switching requirements of magnetic resonance, GaN power devices are used. Since there is no PN junction, there is no body diode, and thus there is no reverse recovery problem, which can greatly improve the switching rate. On the one hand, the switching efficiency of GaN power devices is much higher than that of MOSFET transistors and IGBT transistors, so the volume can be made very small, effectively reducing the size of the control unit; on the other hand, GaN power devices have no reverse recovery time, which can further avoid reverse recovery time and improve the switching efficiency.

[0060] As a preferred embodiment, Figure 2 Come and see, Figure 2 This is a structural schematic diagram of an embodiment of a switch-controlled bridge circuit provided by the present invention. The switch-controlled bridge circuit 101 adopts a full-bridge circuit structure, including a first rectifier circuit 201, a second rectifier circuit 202 and a shunt branch 203, wherein the first rectifier circuit 201 is electrically connected to the anode of the diode D, the second rectifier circuit 202 is electrically connected to the cathode of the diode D, and the shunt branch 203 is connected in parallel at both ends of the diode D.

[0061] In an embodiment of the present invention, a full-bridge circuit structure is adopted, and a circuit structure formed by a first rectifier circuit, a second rectifier circuit and a shunt branch is utilized. The shunt branch is used at both ends of the diode, and the electrical signal transmission between the three is utilized to trigger the conduction of the diode, and the corresponding control switching timing is performed. At the same time, a circuit structure formed by the first rectifier circuit, the second rectifier circuit and the shunt branch is utilized to increase a discharge loop. When the state of the control diode is changed, the charge generated by it is consumed faster, the forward recovery time or reverse recovery time is reduced, and the switching rate is accelerated.

[0062] As a preferred embodiment, Figure 3 Come and see, Figure 3A schematic diagram of a specific structure of an embodiment of a switch-controlled bridge circuit provided by the present invention, wherein the power devices include a first power device Q1 to a second power device Q2, and the first rectifier circuit 201 includes a first inductor L1 and a first capacitor C1 electrically connected in sequence, a first resistor R1 and the first power device Q1 connected in series, and a second power device Q2 electrically connected to the first power device Q1, wherein:

[0063] One end of the first resistor R1 away from the first power device Q1 is connected to the first preset voltage V1, one end of the second power device Q2 away from the first power device Q1 is grounded, one end of the first inductor L1 close to the first capacitor C1 is electrically connected to the first power device Q1 and the second power device Q2 at the same time, one end of the first inductor L1 away from the first capacitor C1 is electrically connected to the anode of the diode D, and one end of the first capacitor C1 away from the first inductor L1 is grounded.

[0064] In an embodiment of the present invention, through the electrical connection structure between the first resistor, the first power device, the second power device, the first inductor and the first capacitor, a turn-on voltage or a turn-off voltage is effectively applied to the diode, causing it to be turned on or off, and the circuit devices in the above-mentioned first rectifier circuit are used to construct a discharge loop related to the two ends of the diode, causing it to quickly consume charge, thereby achieving the purpose of reducing its inherent recovery time and increasing the switching rate.

[0065] As a more specific embodiment, the source of the first power device Q1 is electrically connected to the drain of the second power device Q2, the drain of the first power device Q1 is electrically connected to the first resistor R1, and the source of the second power device Q2 is grounded. In the embodiment of the present invention, the connection structure of the first power device Q1 and the second power device Q2 effectively utilizes the characteristics of the field effect transistors thereof to realize the conduction control of the circuit and construct a corresponding discharge loop. It should be noted that, in combination with Figure 3 Let's take the first power device Q1 as an example (other power devices are consistent with the first power device Q1), the source is marked as the S pole, the drain is marked as the D pole, and the gate is marked as the G pole.

[0066] As a preferred embodiment, still combined with Figure 3 From the perspective of FIG. 1 , the power devices include a third power device Q3 to a fourth power device Q4, and the second rectifier circuit 202 includes a second inductor L2 and a second capacitor C2 electrically connected in sequence, and a third power device Q3 and a fourth power device Q4 electrically connected in sequence, wherein:

[0067] One end of the third power device Q3 away from the fourth power device Q4 is connected to the second preset voltage V2, one end of the fourth power device Q4 away from the third power device Q3 is grounded, one end of the second inductor L2 close to the second capacitor C2 is electrically connected to the third power device Q3 and the fourth power device Q4 at the same time, one end of the second inductor L2 away from the second capacitor C2 is electrically connected to the cathode of the diode D, and one end of the second capacitor C2 away from the second inductor L2 is grounded.

[0068] In an embodiment of the present invention, through the electrical connection structure between the third power device, the fourth power device, the second inductor and the second capacitor, a turn-on voltage or a turn-off voltage is effectively applied to the diode, causing it to be turned on or off, and the circuit devices in the above-mentioned second rectifier circuit are used in conjunction with the circuit devices in the first rectifier circuit to construct a discharge loop related to both ends of the diode, causing it to quickly consume charge, thereby achieving the purpose of reducing its inherent recovery time and increasing the switching rate.

[0069] As a more specific embodiment, the source of the third power device Q3 is electrically connected to the drain of the fourth power device Q4, the drain of the third power device Q3 is connected to the second preset voltage, and the source of the fourth power device Q4 is grounded. In the embodiment of the present invention, through the connection structure of the third power device Q3 and the fourth power device Q4, the characteristics of the field effect tube thereof are effectively utilized to realize the conduction control of the circuit and construct a corresponding discharge loop.

[0070] As a specific embodiment, the first preset voltage V1 is +5 V, and the second preset voltage V2 is +200 V. In the embodiment of the present invention, a small forward voltage and a high reverse voltage are applied to both ends of the diode to effectively turn the diode on or off.

[0071] It should be noted that by applying a small forward voltage to the diode, such as the first preset voltage (corresponding to a current of, for example, 100mA), the diode is turned on (after being turned on, the diode is equivalent to a low impedance such as 0.1Ω relative to the RF signal), and then applying a high reverse voltage, such as the second preset voltage, to cut off the diode (when cut off, the diode is equivalent to a high impedance such as 1MΩ relative to the RF signal). The voltage value is related to the input power, such as 1kW roughly corresponds to about 250V.

[0072] As a preferred embodiment, still combined with Figure 3 In the embodiment, the power device includes a fifth power device Q5, and the shunt branch includes the fifth power device Q5 and a second resistor R2 electrically connected in sequence, wherein: one end of the fifth power device Q5 away from the second resistor R2 is electrically connected to the anode of the diode D, and one end of the second resistor R2 away from the fifth power device Q5 is electrically connected to the cathode of the diode D.

[0073] In an embodiment of the present invention, the first rectifier circuit and the second rectifier circuit are electrically connected by utilizing a parallel structure of shunt branches at both ends of the diode, so as to effectively construct multiple discharge loops at both ends of the diode, and the resistance value of the second resistor can be utilized to accelerate the discharge and speed up the switching rate.

[0074] As a more specific embodiment, the source of the fifth power device Q5 is electrically connected to the anode of the diode D, and the drain of the fifth power device Q5 is electrically connected to the second resistor R. In the embodiment of the present invention, the conduction control of the circuit is realized by the characteristics of the field effect transistor of the fifth power device Q5, and the corresponding discharge loop is constructed.

[0075] It should be noted that the discharge time is mainly determined by the equivalent resistance of the second resistor R2 and the first inductor L1 and the second inductor L2. Because the amount of charge accumulated in a single cycle is fixed, the charge must be converted into heat for consumption through these resistors. The larger the relative resistance, the faster the charge is released, but too large a resistance will also reduce the current in the discharge circuit.

[0076] In a specific embodiment of the present invention, still combined with Figure 3 From the perspective of FIG. 1 , the anode of the diode D1 is electrically connected to the receiving end RFIN through the third capacitor C3, and the cathode of the diode D1 is electrically connected to the transmitting end RFOUT through the fourth capacitor C4. When the diode D1 is turned on, the RF link is directly connected from RFIN to RFOUT1, forming a transmitting state.

[0077] Combine the following Figures 4 to 7 Come and see, Figure 4 A schematic diagram of the structure of an embodiment of a forward conducting diode provided by the present invention, Figure 5 A schematic diagram of the specific structure of an embodiment of a diode reverse recovery discharge provided by the present invention, Figure 6 A schematic diagram of the specific structure of an embodiment of the reverse cutoff provided by the present invention, Figure 7 The specific structural diagram of an embodiment of the forward recovery discharge of a diode provided by the present invention is used to illustrate the principle of forming different discharge loops of the radio frequency switching circuit to speed up the switching rate of the switch, and the control timing is described as follows:

[0078] by Figure 4 For example, the first power device Q1 and the fourth power device Q4 are controlled to be turned on, and other power devices are turned off, so that the diode D1 is forward-conducted, wherein a small forward voltage (first preset voltage) is applied to the diode D1 to cause it to be forward-conducted;

[0079] by Figure 5For example, after the forward conduction of the diode D1 ends, the second power device Q2, the fourth power device Q4, and the fifth power device Q5 are controlled to be turned on, and the first power device Q1 and the third power device Q3 are turned off. At this time, due to the existence of the first inductor L1 and the second inductor L2, the instantaneous current direction remains unchanged, forming two discharge loops as follows:

[0080] 1. The charge passes through the fifth power device Q5, the second resistor R2, the second inductor L2, the fourth power device Q4, GND, the second power device Q2, and the first inductor L1 in sequence;

[0081] 2. The charge passes through the anode of the diode D1, the fifth power device Q5, the second resistor R2, and the cathode of the diode D1 in sequence;

[0082] It should be noted that after the diode D1 is forward-conducted, the fourth power device Q4, GND, and the second power device Q2 are quickly consumed via the second resistor R2; at the same time, due to the parasitic capacitance effect of the diode D1, the anode is positive, and the positive charge is consumed via the fifth power device Q5 and the second resistor R2. The current directions of the two discharge paths are consistent, and both are discharged by the second resistor R2. The resistance value of the second resistor R2 can be adjusted to accelerate the discharge time;

[0083] by Figure 6 For example, the second power device Q2 and the third power device Q3 are controlled to be turned on, and other power devices are turned off, so that the diode D1 is reversed, wherein a reverse high voltage (a second preset voltage) is applied to the diode D1 to cause it to be reversely cut off;

[0084] by Figure 7 For example, after the diode D1 is reversely cut off, the second power device Q2, the fourth power device Q4, and the fifth power device Q5 are controlled to be turned on, and the first power device Q1 and the third power device Q3 are turned off. At this time, due to the existence of the first inductor L1 and the second inductor L2, the instantaneous current direction remains unchanged, forming two discharge loops as follows:

[0085] 1. The charge passes through the fifth power device Q5, the first inductor L1, the second power device Q2, GND, the fourth power device Q4, the second inductor L2, and the second resistor R2 in sequence;

[0086] 2. The charge passes through the cathode of the diode D1, the second resistor R2, and the anode of the fifth power device Q5 diode D1 in sequence;

[0087] It should be noted that after the reverse cutoff of the diode D1 is completed, the second power device Q2, the fourth power device Q4, and the fifth power device Q5 are turned on, and the first power device Q1 and the third power device Q3 are turned off. At this time, the charges stored in the first inductor L1, the second inductor L2, and the diode D1 are released through two paths to complete rapid discharge.

[0088] It needs to be further explained that, when the diode D1 is electrically connected to the first receiving end RFIN and the first transmitting end RFOUT1 respectively through the third capacitor C3 and the fourth capacitor C4, when the diode D1 is turned on (through the first power device Q1 and the fourth power device Q4 being turned on), a radio frequency link is formed between the first receiving end RFIN and the first transmitting end RFOUT1; and when there is no need to form a radio frequency link between the first receiving end RFIN and the first transmitting end RFOUT1, when the diode D1 is switched from on to off, it is necessary to control the second power device Q2, the fourth power device Q4, and the fifth power device Q5 to be turned on, and the first power device Q1 and the third power device Q3 to be turned off after the forward conduction of the diode D1 ends, so as to construct two discharge loops and reduce their inherent recovery time, and then control the second power device Q2 and the third power device Q3 to be turned on, and other power devices to be turned off, so as to reverse the diode D1, thereby increasing the switching rate and improving the rapidity of switching the radio frequency link.

[0089] The embodiment of the present invention also provides a radio frequency transceiver link, combined with Figure 8 Come and see, Figure 8 A schematic structural diagram of an embodiment of a radio frequency transceiver link provided by the present invention includes the radio frequency switching circuit 1 as described above, at least one radio frequency receiving link and / or at least one radio frequency transmitting link, and the diode D in the radio frequency switching circuit 1 is respectively arranged on at least one radio frequency receiving link and / or at least one radio frequency transmitting link.

[0090] In an embodiment of the present invention, a radio frequency switching circuit is provided on the radio frequency link, and the on or off state of the diode in the radio frequency switching circuit is switched, so that different radio frequency links are formed between the receiving end and the transmitting end. Under specific application requirements, a radio frequency link is formed between preset transceiver ends to realize the conversion of different transceiver states. At the same time, a switch is used to control the opening and closing of multiple power devices in the bridge circuit. In the process of switching the diode on or off, different discharge loops are constructed. The circuit structure of the discharge loop consumes charge, reduces the inherent recovery time of the diode, and accelerates its switching rate, thereby effectively improving the switching rate of different radio frequency links.

[0091] As a preferred embodiment, at least one radio frequency receiving link or at least one radio frequency transmitting link comprises a receiving end and a transmitting end, and at least one diode D is arranged between the receiving end and the transmitting end.

[0092] In the embodiment of the present invention, the on / off between the receiving end and the transmitting end is effectively controlled by turning on or off the diode.

[0093] As a preferred embodiment, two ends of the diode are electrically connected to a receiving end / a transmitting end / one end of another diode through a capacitor.

[0094] In an embodiment of the present invention, both ends of a diode are electrically connected to a transmitting end, or a receiving end, or one end of another diode through a capacitor, and each diode has a corresponding switch control bridge circuit loaded at both ends. In an embodiment of the present invention, a radio frequency link formed by multiple diodes being turned on is formed through the electrical connection relationship between the diodes and the electrical connection structure between the diodes and the transmitting end or the receiving end, so as to achieve the purpose of switching different radio frequency links. It can be understood that the aforementioned transceiver includes a transmitting end and a receiving end.

[0095] As a preferred embodiment, Fig. 9 Come and see, Fig. 9 A schematic diagram of a specific structure of an embodiment of a radio frequency transceiver link provided by the present invention, wherein the radio frequency receiving link includes a multi-core receiving link, and at least one radio frequency transmitting link includes a multi-core transmitting link and a hydrogen core transmitting link, wherein:

[0096] A first diode D1 and a fourth diode D4 are provided between the receiving end and the transmitting end of the multi-core transmitting link;

[0097] A third diode D3 is provided between the receiving end and the transmitting end of the multi-core receiving link;

[0098] A second diode D2 is provided between the receiving end and the transmitting end of the hydrogen nucleus transmitting link.

[0099] In the embodiment of the present invention, multiple radio frequency links are provided and the on / off of the diodes is utilized to trigger the on / off of the related radio frequency links, thereby realizing the conversion of different radio frequency receiving states or radio frequency transmitting states.

[0100] Combine the following Fig. 9 From the perspective of FIG. 1 , a specific embodiment is used to illustrate the principle of the RF switching circuit for multi-core self-transmission and self-reception switching, as follows:

[0101] When there are a first receiving terminal RFIN, a second receiving terminal RX, a first transmitting terminal RFOUT1, and a second transmitting terminal RFOUT2, the first receiving terminal RFIN is electrically connected to the first transmitting terminal RFOUT1 through a first diode D1 and a fourth diode D4, the first receiving terminal RFIN is electrically connected to the second transmitting terminal RFOUT2 through a second diode D2, the second receiving terminal RX is electrically connected to the second transmitting terminal RFOUT2 through a third diode D3, and the first diode D1 to the fourth diode D4 are all correspondingly provided with a switch-controlled bridge circuit (the ellipsis is the switch-controlled bridge circuit corresponding to the diode, which is loaded at both ends of the corresponding diode), wherein:

[0102] When the first diode D1 and the fourth diode D4 are turned on, and the second diode D2 and the third diode D3 are turned off, the RF link is directly connected from the first receiving end RFIN to the first transmitting end RFOUT1, and the load is the multi-core coil. At this time, it is in the multi-core transmitting state;

[0103] When the third diode D3 is turned on, and the first diode D1, the second diode D2, and the fourth diode D4 are turned off, the RF link is from the first transmitting end RFOUT1 to the second receiving end RX, and the RF signal returned from the multi-core coil is sent to the acquisition system. At this time, it is in the multi-core receiving state;

[0104] When the second diode D2 is turned on, and the first diode D1, the fourth diode D4, and the third diode D3 are all turned off, the RF link is from the first receiving end RFIN to the second transmitting end RFOUT2, and the back end can be connected to the hydrogen nucleus transmitting coil. This is the state where the multi-nucleus transmission is converted to the hydrogen nucleus transmission state;

[0105] It should be noted that multi-core transmission refers to different frequencies transmitted in different time periods (such as t1 is 20MHz, t2 is 40Mhz, t3 is 60MHz, etc.). Common narrow-band (such as 60MHz±1MHz) RF switches cannot be compatible with so many frequencies, so multi-core transmission switches are needed;

[0106] It is further explained that in the multi-core self-transmitting and self-receiving coil unit, the switching of the TX / RX link is completed by the switching circuit. Taking the fourth diode D4 and the third diode D3 as an example, the fourth diode D4 is turned on and the third diode D3 is turned off, which is the transmitting state; the fourth diode D4 is turned off and the third diode D3 is turned on, which is the receiving state;

[0107] At the same time, the transmission link can also be selected by controlling the first diode D1 and the second diode D2. For example, the first diode D1 controls the multi-core transmission link; the second diode D2 can be selected as the 1H core transmission channel, etc. (the rear stage can be connected to a 3dB bridge to output an orthogonally coupled RF signal to drive the rear stage transmission coil).

[0108] It should be noted that, combined with Fig.10 Come and see, Fig.10 This is a schematic diagram of the structure of an embodiment of the driving rear-stage transmitting coil provided by the present invention. Port 1 is the input port, ports 2 and 3 are the output ports, and port 4 is the isolation port, connected to 50Ω. The circuit function is to generate radio frequency signals with equal power and 90° phase difference, from Fig. 9 It can be known that it is directly related to the wavelength (ie frequency) of the input signal and can only be applied to RF transmission under narrowband. Therefore, it is only used under hydrogen nucleus transmission to output orthogonally coupled RF signals to drive the subsequent transmitting coil.

[0109] The embodiment of the present invention provides a control method for a radio frequency switching circuit. Based on the control method for a radio frequency switching circuit as described above, combined with Fig.11 Come and see, Fig.11 A flow chart of an embodiment of a control method of a radio frequency switching circuit provided by the present invention includes steps S1101 to S1102, wherein:

[0110] In step S1101, the set sending and receiving state is obtained;

[0111] In step S1102, according to the set transceiver state, a radio frequency link formed between corresponding transceivers when the set transceiver state is reached is determined;

[0112] In step S1103, according to the formed RF link, the opening and closing of at least one power device corresponding to each diode is controlled to form at least one discharge loop in the switch-controlled bridge circuit, thereby reducing the inherent recovery time when the conduction state of each diode is switched, so as to speed up the switching rate of the formed RF link.

[0113] In an embodiment of the present invention, first, the set transceiver state is effectively acquired; then, corresponding to different set transceiver states, the opening and closing of the power device in the transceiver circuit corresponding to each diode is controlled, and when the diode switches to the on or off state, different discharge loops are constructed to speed up its switching rate, and under different combinations of diode on or off states, a radio frequency link of the set transceiver state is formed, thereby reducing the impact of the inherent recovery time when the diode is switched, and speeding up the efficiency of the radio frequency link switching.

[0114] As a preferred embodiment, the above step S1102 includes:

[0115] According to the diodes that need to be turned on on the formed radio frequency link, the corresponding switch controls the opening and closing of at least one power device in the bridge circuit, so that the diodes that need to be turned on are forward-conducted and the other diodes are reverse-cut off.

[0116] In an embodiment of the present invention, according to the set transceiver state, the corresponding RF link to be formed is determined, the diode that needs to be turned on to form the RF link is determined, and the switch loaded at both ends of the diode controls the opening and closing of the power device in the bridge circuit to cause the diode to be turned on or off, and during the switching process, the discharge circuit constructed by the power device is used to speed up its switching rate.

[0117] Specifically, still combined with Fig. 9 From the perspective of the transmission and reception states, the set transmission and reception states include multi-core transmission states, multi-core reception states, and hydrogen nucleus transmission states. According to different set transmission and reception states, the diodes that need to be turned on and the diodes that need to be turned off are determined, and the corresponding switches control the opening and closing of the power devices in the bridge circuit to switch the states of the corresponding diodes. Among them, the diodes that need to be turned on or off corresponding to the multi-core transmission state, multi-core reception state, and hydrogen nucleus transmission state refer to the above description and will not be repeated here.

[0118] As a preferred embodiment, the above control of the opening and closing of at least one power device in the corresponding transceiver circuit so that the diode that needs to be turned on is turned on and the other diodes are turned off includes:

[0119] When the diode D needs to be forward-conducted, the first power device Q1 and the fourth power device Q4 are controlled to be turned on, and after the forward conduction is completed, the second power device Q2, the fourth power device Q4 and the fifth power device Q5 are controlled to be turned on;

[0120] When the diode D needs to be reversely cut off, the second power device Q2 and the third power device Q3 are controlled to be turned on, and after the reverse cut off is completed, the second power device Q2, the fourth power device Q4 and the fifth power device Q5 are controlled to be turned on.

[0121] In the embodiment of the present invention, the on and off of the relevant power devices are used to cause the diode to be turned on or off. At the same time, the on and off timing of the relevant power devices is used to construct different discharge loops during the switching state to accelerate the switching rate.

[0122] The following is a specific application example. Fig. 9 The technical solution of the present invention is more clearly described as follows:

[0123] The first step is to obtain the set receiving and transmitting state as a multi-core transmitting state; it should be noted that this can be set by the relevant user according to the actual scanning requirements;

[0124] In the second step, when the multi-core transmission state is reached, it is determined that the corresponding RF link is directly connected from the first receiving end RFIN to the first transmitting end RFOUT1, then the first diode D1 and the fourth diode D4 between the first receiving end RFIN and the first transmitting end RFOUT1 need to be turned on, and the other diodes (the second diode D2 and the third diode D3) need to be turned off.

[0125] Among them, for the first diode D1 and the fourth diode D4, the corresponding switches loaded at both ends control the power devices in the bridge circuit to make them conduct. Taking the first diode D1 as an example, the first power device Q1 and the fourth power device Q4 are controlled to be conducted, and other power devices are turned off, so that the diode D1 is forward-conducted; if the original state of the first diode D1 is reverse cut-off, then at the end of its reverse cut-off, the second power device Q2, the fourth power device Q4, and the fifth power device Q5 are controlled to be conducted, and the first power device Q1 and the third power device Q3 are turned off, and then the first power device Q1 and the fourth power device Q4 are controlled to be conducted, and other power devices are turned off, so as to reduce their inherent recovery time and speed up the switching state rate, thereby ensuring the switching rate of the entire RF link;

[0126] Among them, for the second diode D2 and the third diode D3, the corresponding switches loaded at both ends control the power devices in the bridge circuit to turn them off. The switching timing and switching principle of the specific turn-off process are similar to those of the turn-on process, see the above description, and will not be repeated here.

[0127] An embodiment of the present invention further provides a magnetic resonance device, comprising:

[0128] A scanner, used for generating a main magnetic field and capable of exciting nuclear spins of multiple specific nuclides of a detection object in the main magnetic field to generate magnetic resonance radio frequency signals;

[0129] At least one radio frequency transmission link, including a broadband radio frequency power amplifier, a driving circuit module, a transmission filter module, a first firmware and a digital-to-analog converter, to process the magnetic resonance radio frequency signal and transmit the magnetic resonance radio frequency signal;

[0130] at least one radio frequency receiving link, including a secondary amplifier, a second firmware, a receiving filter module and an analog-to-digital converter, to receive the magnetic resonance radio frequency signal and convert the magnetic resonance radio frequency signal into a digital signal;

[0131] And, according to the RF switching circuit and processor as described above, the diode (D) in the RF switching circuit is set on at least one RF receiving link and / or at least one RF transmitting link, and the processor is used to execute the control method of the RF switching circuit as described above on the RF switching circuit.

[0132] The more specific implementation methods of each unit of the magnetic resonance device can refer to the description of the above-mentioned radio frequency switching circuit and its control method, and have similar beneficial effects, which will not be repeated here.

[0133] The embodiment of the present invention also provides a control device for a radio frequency switching circuit, Fig.12 Come and see, Fig.12 This is a schematic diagram of the structure of an embodiment of a control device for a radio frequency switching circuit provided by the present invention. The control device 1200 for a radio frequency switching circuit includes:

[0134] The acquisition unit 1201 is used to acquire the set sending and receiving state;

[0135] The processing unit 1202 is used to determine, according to the set transceiver state, a radio frequency link formed between corresponding transceivers when the set transceiver state is reached;

[0136] The control unit 1203 is used to control the opening and closing of at least one power device corresponding to each diode according to the formed RF link, form at least one discharge loop in the switch control bridge circuit, reduce the inherent recovery time when the conduction state of each diode is switched, so as to speed up the switching rate of the formed RF link.

[0137] The more specific implementation of each unit of the control device of the radio frequency switching circuit can refer to the description of the control method of the radio frequency switching circuit, and has similar beneficial effects, which will not be repeated here.

[0138] An embodiment of the present invention further provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the control method of the radio frequency switching circuit as described above is implemented.

[0139] Generally speaking, the computer instructions for implementing the method of the present invention can be carried by any combination of one or more computer-readable storage media. Non-transitory computer-readable storage media can include any computer-readable media except for the signal itself that is temporarily propagating.

[0140] Computer-readable storage media can be, for example, but not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or devices, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection with one or more conductors, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this document, a computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, device, or device.

[0141] Computer program code for performing the operation of the present invention can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages, such as Java, Smalltalk, C++, and conventional procedural programming languages, such as "C" language or similar programming languages, in particular, Python language suitable for neural network computing and platform frameworks based on TensorFlow, PyTorch, etc. can be used. The program code can be executed entirely on the user's computer, partially on the user's computer, as an independent software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computer (for example, using an Internet service provider to connect through the Internet).

[0142] An embodiment of the present invention further provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the control method of the radio frequency switching circuit as described above is implemented.

[0143] The computer-readable storage medium and electronic device provided according to the above embodiments of the present invention can be implemented with reference to the specific description of the control method of the radio frequency switching circuit as described above according to the present invention, and have similar beneficial effects as the control method of the radio frequency switching circuit as described above, which will not be repeated here.

[0144] The present invention discloses a radio frequency switching circuit and a control method thereof, a radio frequency transceiver link and a magnetic resonance device. In the radio frequency switching circuit, the on or off state of the diode in the transceiver circuit is switched, and different radio frequency links are formed between the transceiver ends to realize the conversion of different transceiver states. At the same time, the switch is used to control the opening and closing of multiple power devices in the bridge circuit. In the switching process of controlling the diode to be on or off, different discharge loops are constructed to avoid its inherent recovery time, consume its charge, and accelerate its switching rate, thereby effectively improving the switching rate of different radio frequency links. In the control method of the radio frequency switching circuit, first, the set transceiver state is effectively acquired; then, corresponding to different set transceiver states, the opening and closing of the power device in the transceiver circuit corresponding to each diode is controlled, and when the diode is switched on or off, different discharge loops are constructed to accelerate its switching rate. Under different diode on or off state combinations, a radio frequency link of the set transceiver state is formed, reducing the influence of the inherent recovery time when the diode is switched, and accelerating the efficiency of the radio frequency link switching.

[0145] The technical solution of the present invention utilizes a bridge circuit to construct a switch-controlled bridge circuit, and through the opening and closing of the power devices therein, different discharge loops are formed in the switch-controlled bridge circuit. When the diode switches state, the discharge loop is utilized to reduce its inherent recovery time, thereby achieving the purpose of quickly switching different RF links and effectively improving the switch switching rate.

[0146] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A radio frequency switching circuit, characterized in that: The invention comprises an electrically connected switch-controlled bridge circuit (101) and a diode (D), wherein the switch-controlled bridge circuit comprises at least one power device, and the diode (D) is arranged on a radio frequency link; wherein at least one discharge loop is formed in the switch-controlled bridge circuit (101) by controlling the opening and closing of the at least one power device; the switch-controlled bridge circuit (101) comprises a first rectifier circuit (201), a second rectifier circuit (202) and a shunt branch (203), wherein the first rectifier circuit (201) is electrically connected to the anode of the diode (D), the second rectifier circuit (202) is electrically connected to the cathode of the diode (D), and the shunt branch (203) is connected in parallel to both ends of the diode (D).

2. The radio frequency switching circuit according to claim 1, characterized in that: The switch control bridge circuit (101) adopts a full-bridge circuit structure.

3. The radio frequency switching circuit according to claim 2, characterized in that: The first rectifier circuit (201) comprises a first inductor (L1) and a first capacitor (C1) electrically connected, a first resistor (R1) and a first power device (Q1) connected in series, and a second power device (Q2) electrically connected to the first power device (Q1).

4. The radio frequency switching circuit according to claim 2, characterized in that: The second rectifier circuit (202) comprises a second inductor (L2) and a second capacitor (C2) which are electrically connected, and a third power device (Q3) and a fourth power device (Q4) which are electrically connected.

5. The radio frequency switching circuit according to claim 2, characterized in that: The shunt branch (203) comprises an electrically connected fifth power device (Q5) and a second resistor (R2), wherein: an end of the fifth power device (Q5) away from the second resistor (R2) is electrically connected to the anode of the diode (D), and an end of the second resistor (R2) away from the fifth power device (Q5) is electrically connected to the cathode of the diode (D).

6. A radio frequency transceiver link, characterized in that: The invention comprises a radio frequency switching circuit (1) according to any one of claims 1 to 5, at least one radio frequency receiving link and / or at least one radio frequency transmitting link, wherein a diode (D) in the radio frequency switching circuit is arranged on at least one radio frequency receiving link and / or at least one radio frequency transmitting link.

7. A control method for a radio frequency switching circuit, characterized in that: Based on the radio frequency switching circuit according to any one of claims 1 to 5, the control method includes: Get the set sending and receiving status; According to the set transceiver state, determining a radio frequency link formed between corresponding transceivers when the set transceiver state is reached; According to the formed RF link, the opening and closing of at least one power device corresponding to each diode is controlled to form at least one discharge loop in the switch control bridge circuit, thereby reducing the inherent recovery time when the conduction state of each diode is switched, so as to speed up the switching rate of the formed RF link.

8. The control method of the radio frequency switching circuit according to claim 7, characterized in that: According to the formed radio frequency link, controlling the opening and closing of at least one power device corresponding to each diode to form at least one discharge loop in the switch control bridge circuit includes: According to the diodes that need to be turned on in the formed radio frequency link, the corresponding switch controls the opening and closing of at least one power device in the bridge circuit, so that the diodes that need to be turned on are forward-conducted and the other diodes are reverse-cut off.

9. The control method of the radio frequency switching circuit according to claim 8, characterized in that: The at least one power device includes a first power device to a fifth power device, and the control of the opening and closing of at least one power device in the corresponding transceiver circuit so that the diode that needs to be turned on is turned on and the other diodes are turned off includes: When the diode needs to be forward-conducted, the first power device and the fourth power device are controlled to be turned on, and after the forward conduction is completed, the second power device, the fourth power device and the fifth power device are controlled to be turned on; When the diode needs to be reverse cutoff, the second power device and the third power device are controlled to be turned on, and after the reverse cutoff is completed, the second power device, the fourth power device and the fifth power device are controlled to be turned on.

10. A magnetic resonance device, characterized in that: include: a scanner for generating magnetic resonance radio frequency signals; at least one radio frequency transmission link, used for processing the magnetic resonance radio frequency signal and transmitting the magnetic resonance radio frequency signal; at least one radio frequency receiving link, used to receive the magnetic resonance radio frequency signal and convert the magnetic resonance radio frequency signal into a digital signal; And, according to the RF switching circuit and processor according to any one of claims 1 to 5, the diode (D) in the RF switching circuit is respectively arranged on at least one RF receiving link and / or at least one RF transmitting link, and the processor is used to execute the control method of the RF switching circuit according to any one of claims 7 to 9 on the RF switching circuit.

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