CN219302644U - Radio frequency system and magnetic resonance system - Google Patents
Radio frequency system and magnetic resonance system Download PDFInfo
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- CN219302644U CN219302644U CN202121603791.9U CN202121603791U CN219302644U CN 219302644 U CN219302644 U CN 219302644U CN 202121603791 U CN202121603791 U CN 202121603791U CN 219302644 U CN219302644 U CN 219302644U
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Abstract
The application relates to a radio frequency system and a magnetic resonance system, wherein the radio frequency system comprises a radio frequency power amplifier, an output stabilizing device and a radio frequency coil, the radio frequency power amplifier is connected with the output stabilizing device and the radio frequency coil, and a radio frequency input signal is compensated by the output stabilizing device and is amplified by the radio frequency power amplifier and then sent out by the radio frequency coil; the output stabilizing device is connected with the radio frequency power amplifier and comprises a gain compensation module; the gain compensation module is used for compensating the radio frequency input signal according to the compensation parameters and a preset compensation rule; the compensation parameters include at least one of a supply voltage, a junction temperature, and a power of the radio frequency power amplifier. According to the method and the device, the fluctuation of the output power of the radio frequency power amplifier is compensated, the defect of the traditional open loop compensation is overcome, the output of the radio frequency power amplifier under different working conditions can be stable, and the compensation effect is improved.
Description
Technical Field
The present application relates to the field of magnetic resonance technology, and in particular, to a radio frequency system and a magnetic resonance system.
Background
In a magnetic resonance system, a radio frequency power amplifier is an integral part. The magnetic resonance system has higher performance requirements on the radio frequency power amplifier, and the radio frequency power amplifier is required to amplify and output radio frequency pulses emitted by the magnetic resonance spectrometer to the emitting coil to excite the experimental sample, so that the radio frequency power amplifier is required to ensure stable gain to achieve good imaging effect. However, the rf power amplifier has a nonlinear characteristic, and when the rf power amplifier operates in a saturation region or a cut-off region, nonlinear distortion of the pulse signal is caused. The distortion comprises in-band amplitude and phase distortion and out-of-band spectrum spreading, and interferes with signal transmission of adjacent channels, so that imaging of a magnetic resonance system finally causes artifacts and distortion, and the picture quality is reduced, and the disease diagnosis and scientific research are interfered.
In the existing radio frequency power amplifier stabilization scheme: one is a feedback method that directly suppresses an input signal by using an output signal, or an indirect negative feedback method that compares an output signal with an input signal by an indirect connection. The other is predistortion technology, the basic idea is to insert a predistorter with the curve characteristic being reciprocal to the curve characteristic of the radio frequency power amplifier in front of the radio frequency power amplifier to carry out nonlinear correction, and the radio frequency power amplifier linearization is realized by the cascade use of the predistorter and the radio frequency power amplifier. However, these schemes do not consider the fluctuation of the gain of the power amplifier caused by the change of the power supply voltage, the temperature and humidity and other related factors when the power amplifier works, and do not consider the influence of the power amplifier on the compensation result when the gain compensation is performed according to the related factors, so that the compensation effect is not ideal.
Disclosure of Invention
The embodiment of the application provides a radio frequency system and a magnetic resonance system, which at least solve the problem of non-ideal output compensation effect of a radio frequency power amplifier in the related technology.
In a first aspect, an embodiment of the present application provides a radio frequency system, which is characterized by including a radio frequency power amplifier, an output stabilizer, and a radio frequency coil, where the radio frequency power amplifier is connected to the output stabilizer and the radio frequency coil, and a radio frequency input signal is compensated by the output stabilizer and amplified by the radio frequency power amplifier and then sent out by the radio frequency coil; the output stabilizing device is connected with the radio frequency power amplifier and comprises a gain compensation module; the gain compensation module is used for compensating the radio frequency input signal according to the compensation parameters and a preset compensation rule; the compensation parameters comprise at least one of supply voltage, junction temperature and power of the radio frequency power amplifier;
in some embodiments, the output stabilization apparatus further comprises a nonlinear correction module for nonlinear correction of the radio frequency input signal.
In some embodiments, the compensation rule is a mapping relationship between different supply voltages, different junction temperatures, different output powers and corresponding gain compensation amounts; the gain compensation amount is the difference between the gain of the power amplifier and the expected gain.
In some of these embodiments, the mapping relationship is a gain compensation table between compensation parameters and corresponding gain compensation amounts.
In some embodiments, the mapping relationship is a functional relationship between the compensation parameter obtained by the data fitting mode and the corresponding gain compensation amount.
In some of these embodiments, the gain compensation module further comprises: the signal acquisition module is connected with the radio frequency power amplifier and the compensation amount acquisition module;
the signal acquisition module is used for acquiring the compensation parameters of the radio frequency power amplifier and outputting the compensation parameters to the compensation quantity acquisition module;
the compensation amount acquisition module is used for obtaining the gain compensation amount of the radio frequency power amplifier based on the compensation parameters of the radio frequency power amplifier and the preset compensation rule.
In some of these embodiments, the signal acquisition module comprises: the device comprises a temperature acquisition module, a power supply voltage acquisition module and a power acquisition module;
the power supply voltage acquisition module is used for acquiring the power supply voltage of the radio frequency power amplifier;
the temperature acquisition module is used for acquiring the junction temperature of the radio frequency power amplifier;
the power acquisition module is used for acquiring the power of the radio frequency power amplifier.
In some embodiments, the junction temperature of the radio frequency power amplifier is the sum of the ambient temperature and the power amplifier junction temperature rise.
In some embodiments, the junction temperature rise of the power amplifier is calculated based on the loss power and the equivalent thermal resistance of the radio frequency power amplifier.
In a second aspect, embodiments of the present application provide a magnetic resonance system comprising a radio frequency system as described in the second aspect above.
Compared with the related art, the output stabilizing device of the radio frequency power amplifier provided by the embodiment of the application is provided with the gain compensation module and the nonlinear correction module, the gain compensation module is additionally arranged on the basis of the traditional scheme of nonlinear correction of radio frequency input signals, the fluctuation of the output power of the radio frequency power amplifier caused by the fluctuation of at least one relevant factor in temperature change, power supply voltage and power is compensated, the defect of traditional open loop compensation is overcome, the output of the radio frequency power amplifier under different working conditions can be stabilized, and the compensation effect is improved.
The details of one or more embodiments of the application are set forth in the accompanying drawings and the description below to provide a more thorough understanding of the other features, objects, and advantages of the application.
Drawings
The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application and do not constitute an undue limitation to the application. In the drawings:
fig. 1 is a schematic structural diagram of an output stabilization device of a radio frequency power amplifier according to one embodiment of the present application;
FIG. 2 is a schematic diagram of a matching structure of an output stabilization device and a power amplifier according to one embodiment of the present disclosure;
FIG. 3 is a graph of the transmission characteristics of a MOSFET in one embodiment of the present application;
FIG. 4 is a graph of the gain of a radio frequency power amplifier in one embodiment of the present application;
fig. 5 is a schematic structural diagram of an output stabilization device of a radio frequency power amplifier according to another embodiment of the present application;
fig. 6 is a schematic structural diagram of a radio frequency system according to an embodiment of the present application.
Description of the drawings: 1. an output stabilization device; 11. a gain compensation module; 111. a signal acquisition module; 112. the compensation quantity acquisition module; 12. a nonlinear correction module; 2. a radio frequency power amplifier; 3. a radio frequency coil.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described and illustrated below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the present application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden on the person of ordinary skill in the art based on the embodiments provided herein, are intended to be within the scope of the present application.
It is apparent that the drawings in the following description are only some examples or embodiments of the present application, and it is possible for those of ordinary skill in the art to apply the present application to other similar situations according to these drawings without inventive effort. Moreover, it should be appreciated that while such a development effort might be complex and lengthy, it would nevertheless be a routine undertaking of design, fabrication, or manufacture for those of ordinary skill having the benefit of this disclosure, and thus should not be construed as having the benefit of this disclosure.
Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is to be expressly and implicitly understood by those of ordinary skill in the art that the embodiments described herein can be combined with other embodiments without conflict.
Unless defined otherwise, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this application belongs. Reference to "a," "an," "the," and similar terms herein do not denote a limitation of quantity, but rather denote the singular or plural. The terms "comprising," "including," "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, article, or apparatus that comprises a list of steps or modules (elements) is not limited to only those steps or elements but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus. The terms "connected," "coupled," and the like in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The term "plurality" as used herein refers to two or more. "and/or" describes an association relationship of an association object, meaning that there may be three relationships, e.g., "a and/or B" may mean: a exists alone, A and B exist together, and B exists alone. The character "/" generally indicates that the context-dependent object is an "or" relationship. The terms "first," "second," "third," and the like, as used herein, are merely distinguishing between similar objects and not representing a particular ordering of objects.
Magnetic resonance imaging (magnetic resonance, MR) is one type of tomographic imaging that uses magnetic resonance phenomena to acquire electromagnetic signals from a human body and reconstruct human body information. The magnetic resonance imaging apparatus excites hydrogen nuclei in a human body by applying radio frequency pulses of a certain specific frequency to the human body in a static magnetic field, causes the hydrogen nuclei to resonate, and absorbs energy. After stopping the radio frequency pulse, the hydrogen nucleus emits radio signal in specific frequency and releases the absorbed energy to be recorded by the receiver outside the body and processed by the electronic computer to obtain image, i.e. nuclear magnetic resonance imaging. The nuclear magnetic resonance examination thoroughly gets rid of the damage of ionizing radiation to human body, has the outstanding characteristics of multiple parameters, large information quantity, multidirectional imaging, high resolution to soft tissues and the like, and is widely applied to various fields, especially medical diagnosis.
The radio frequency coil is an important component of the magnetic resonance imaging system, and all magnetic resonance scanning examinations are completed by the radio frequency coil, and the functions of the radio frequency coil are that the radio frequency coil transmits radio frequency pulses and receives MRI signals, so that the radio frequency coil is an important link of the imaging of the MRI system. Typically, the magnetic resonance imaging system further comprises a radio frequency power amplifier 2 driving the radio frequency coils. The rf power amplifier 2 receives the pulse signal, amplifies the received pulse signal, and supplies the amplified pulse signal to the rf coil, thereby driving or controlling the rf coil to generate an rf magnetic field, thereby generating an rf excitation for imaging.
As shown in fig. 1-2, the present embodiment provides an output stabilizing device of a radio frequency power amplifier, where the output stabilizing device 1 is connected to the radio frequency power amplifier 2, and includes a gain compensation module 11. Specifically, the output stabilizing device 1 is used in cooperation with the rf power amplifier 2, the output stabilizing device 1 may be disposed on an input side of the rf power amplifier 2, and the rf input signal is compensated by the gain compensation module 11 in the output stabilizing device 1 and then output to the rf power amplifier 2. In some embodiments, the gain compensation module 11 may be, for example, a programmable gain amplifier, compensates the rf input signal according to the compensation parameter and a preset compensation rule, and feeds back the rf input signal to the signal input terminal of the rf power amplifier 2.
In some of these embodiments, the output stabilization device 1 of the radio frequency power amplifier further comprises a non-linearity correction module 12. Wherein the gain compensation module 11 is connected to the nonlinear correction module 12. In some embodiments, the gain compensation module 11 is connected to the nonlinear correction module 12 and the radio frequency power amplifier 2, respectively; in other embodiments, the nonlinear correction module 12 is connected to the gain compensation module 11 and the rf power amplifier 2, respectively, which is not specifically limited herein.
In general, to obtain high quality magnetic resonance images, magnetic resonance systems require that the radio frequency have good linearity over a large dynamic range. But the rf power amplifier 2 itself is a nonlinear device and there is a large nonlinear distortion of the output signal. In this embodiment, by providing the nonlinear correction module 12, the radio frequency input signal can be adjusted, and the adjusted signal is output to the radio frequency power amplifier 2. The nonlinear correction module 12 may be implemented by predistortion technology, feed forward method, and the like. The nonlinear correction module 12 and the radio frequency power amplifier 2 together form a linear amplification system, so that the input signal and the output signal maintain a linear relationship, and nonlinear distortion is avoided.
Because the performance requirement on the radio frequency power amplifier 2 is higher in the magnetic resonance system, the output power of the radio frequency power amplifier 2 is very high, and the instantaneous power can reach more than tens of kilowatts. A plurality of Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) are commonly used to generate high enough power by combining in series-parallel connection; secondly, the radio frequency power amplifier needs to ensure stable gain to achieve good imaging effect. Because the MOSFET itself has nonlinear gain, the gain of the power amplifier needs to be ensured to be stable through compensation.
Fig. 3 is a transmission characteristic diagram of a MOSFET, in which the horizontal axis is input power Vgs (dBm) and the vertical axis is supply current of the MOSFET (which is non-linear in positive correlation with output power). As can be seen from the graph, at different temperatures Tj (°c), the curve relationship between the output power Id (dBm) and the input power Vgs (dBm) is different, indicating that the temperature affects the relationship between the input power and the output, i.e., affects the gain value. In addition, when the rf power amplifier 2 is used in the operating bandwidth range of the mr rf signal, the junction temperature of the power tube used in the rf power amplifier 2 is also increased, which results in a change in the gain of the rf power amplifier 2. It can also be seen from the figure that when the input power Vgs (dBm) or the output power Id (dBm) is less than a certain value, the output power and the temperature are positively correlated; above this value, the output power and temperature are inversely related, so that not only the effect of temperature but also the effect of power on gain need to be taken into account.
Fig. 4 is a graph of the gain of the rf power amplifier 2, as shown in fig. 4, with non-uniform power amplifier gain curves at different supply voltages. Therefore, in addition to factors such as temperature and power, gain fluctuation caused by supply voltage fluctuation needs to be compensated.
It can be seen that the above-mentioned various related factors also cause the gain of the power amplifier to fluctuate, and the existing nonlinear correction scheme cannot compensate the related factors, so that the output stabilizing effect is not ideal. According to the embodiment, the gain compensation module 11 configures the compensation parameters of the radio frequency power amplifier 2, and compensates and adjusts the radio frequency input signal in real time according to the compensation parameters and a preset compensation rule, so that the stabilizing effect of the radio frequency power amplifier 2 can be further improved.
In some embodiments, at least one of the supply voltage, junction temperature, and power of the radio frequency power amplifier 2 is configured with compensation parameters of the radio frequency power amplifier 2; in other embodiments, the compensation parameters may be configured in a customized manner based on operating conditions. In the compensation parameter, the supply voltage is the voltage value of the radio frequency power amplifier 2; the junction temperature is the sum of the ambient temperature and the junction temperature rise of the power amplifier; the power is the input power and the output power of the radio frequency power amplifier 2. The compensation rule may be a gain compensation table, a function or a machine learning model established according to the sample data, and the compensation rule may be configured in a self-defined manner, which is not specifically limited herein.
In summary, the output stabilizing device of the radio frequency power amplifier provided by the embodiment of the application adds the gain compensation module on the basis of the traditional scheme of carrying out nonlinear correction on the radio frequency input signal by setting the gain compensation module and the nonlinear correction module, compensates the radio frequency input signal according to the compensation parameters and the preset compensation rule, so that the fluctuation of the output power of the radio frequency power amplifier caused by the fluctuation of at least one relevant factor in temperature change, power supply voltage and power is compensated, the defect of traditional open loop compensation is overcome, the output of the radio frequency power amplifier under different working conditions can be stabilized, the fluctuation condition of the output is obviously improved, and the compensation effect is improved.
The embodiments of the present application are described and illustrated below by means of preferred embodiments.
On the basis of the above embodiments, in some of them, the compensation rule is a mapping relationship between different supply voltages, different junction temperatures, different output powers and corresponding gain compensation amounts.
Specifically, in this embodiment, firstly, relevant influencing factors that affect the output stability of the rf power amplifier and corresponding gain compensation amounts are obtained, where the relevant influencing factors include different supply voltages, different junctions and different output powers. And determining the mapping relation as a gain compensation rule by pre-establishing the mapping relation between the different related influence factors and the corresponding gain compensation amounts. The power amplifier gain is the difference between the output power and the input power of the radio frequency power amplifier; the gain compensation amount is the difference between the gain of the power amplifier and the expected gain.
In a specific embodiment, the mapping relationship may be a gain compensation table between compensation parameters and corresponding gain compensation amounts. For example, the gain curves of the radio frequency power amplifier 2 under different compensation parameters can be simulated through experiments to obtain corresponding gain compensation amounts, so that a gain compensation table between the different compensation parameters and the corresponding gain compensation amounts is established. When the gain compensation is performed on the radio frequency power amplifier 2, the gain compensation module 11 queries a pre-stored gain compensation table according to the currently acquired compensation parameter to obtain a gain compensation amount obtained by query, so that the gain compensation module 11 compensates the radio frequency input signal according to the gain compensation amount.
In another specific embodiment, the mapping relationship is a functional relationship between the compensation parameter obtained by the data fitting mode and the corresponding gain compensation amount. The corresponding gain compensation amount can be obtained by experimental simulation of gain curves of the radio frequency power amplifier 2 under different compensation parameters. Further, a functional relationship between different compensation parameters and corresponding gain compensation amounts is established through data fitting. When the gain compensation is performed on the radio frequency power amplifier 2, the gain compensation module 11 calculates according to the currently acquired compensation parameters and according to a pre-stored functional relation to obtain a corresponding gain compensation amount, so that the gain compensation module 11 compensates the radio frequency input signal according to the gain compensation amount.
Fig. 5 is a schematic structural diagram of the output stabilization device 1 of the radio frequency power amplifier 2 according to an embodiment of the present application, as shown in fig. 5, on the basis of the above embodiment, in some embodiments, the gain compensation module 11 further includes: the signal acquisition module 111 and the compensation amount acquisition module 112, wherein the signal acquisition module 111 is connected with the radio frequency power amplifier 2 and the compensation amount acquisition module 112.
In this embodiment, the signal acquisition module 111 is configured to acquire the compensation parameter of the rf power amplifier 2 and output the compensation parameter to the compensation amount acquisition module 112. Wherein, the signal acquisition module 111 includes: the device comprises a temperature acquisition module, a power supply voltage acquisition module and a power acquisition module.
The power supply voltage acquisition module is used for acquiring the power supply voltage of the radio frequency power amplifier 2. The supply voltage of the radio frequency power amplifier 2 may be obtained by sampling by means of an ADC (Analog to Digital Converter, analog-to-digital converter) as known in the art, for example. The ADC sampling method is a prior art in the field, and is not described herein in detail.
The power acquisition module is used for acquiring the power of the radio frequency power amplifier. Specifically, the power includes an input power of the power amplifier and an output power of the power amplifier. The power obtaining module may be, for example, HLW8012, or an existing power detecting module, or may be obtained by calculating a power supply voltage and a current value of a power amplifier collected by ADC sampling, which is not specifically limited in this application. And acquiring the power of the radio frequency power amplifier, further calculating to obtain the gain of the power amplifier, and calculating to obtain the corresponding compensation amount of the power amplifier according to the expected gain.
In some embodiments, the temperature acquisition module is configured to acquire an ambient temperature of the radio frequency power amplifier. The environmental temperature may be detected by a temperature and humidity sensor, for example.
In other embodiments, the junction temperature refers to the highest temperature of the actual semiconductor device in the electronic device, which is typically higher than the surface temperature of the semiconductor device. When the rf power amplifier 2 works, the junction temperature directly affects the reliability and stability of the rf power amplifier 2 and the system in which the rf power amplifier 2 is located. The temperature acquisition module is used for acquiring the junction temperature of the radio frequency power amplifier 2, and taking the junction temperature as one of the compensation parameters. Specifically, in some embodiments, the junction temperature of the rf power amplifier 2 is the sum of the ambient temperature and the power amplifier junction temperature rise, and the junction temperature of the rf power amplifier 2 may be obtained by obtaining the ambient temperature and the power amplifier junction temperature rise. The junction temperature rise of the power amplifier can be measured in real time through a temperature sensor; or can be calculated based on the loss power and equivalent thermal resistance of the radio frequency power amplifier 2. Specifically, the power amplifier power supply voltage Vin and the input current Iin which are collected at first are calculated to obtain power amplifier direct current power P, and the loss power Ploss of the power amplifier is calculated according to the power amplifier direct current power P and the power amplifier output power Pout. The specific calculation formula is as follows:
Ploss＝Vin*Iin-Pout
wherein Ploss is the loss power, w; vin is the power amplifier supply voltage, v; iin is input current, A; pout is the output power of the power amplifier, and w.
Then, the junction temperature Wen Sheng T of the power amplifier can be determined according to the power loss Ploss of the power amplifier and the equivalent thermal resistance R:
ΔT＝R*Ploss
wherein R is the equivalent thermal resistance of the power amplifier, Ω.
It can be appreciated that in other embodiments, the junction temperature of the power amplifier may be obtained by other manners, such as a thermosensitive electrical parameter method, an electrothermal coupling model junction temperature measurement method, etc., which is not limited in the method for obtaining the junction temperature rise of the power amplifier.
In this embodiment, the compensation amount obtaining module 112 is configured to obtain the gain compensation amount of the rf power amplifier 2 based on the compensation parameter of the rf power amplifier 2 and the preset compensation rule. Specifically, the compensation rule is a mapping relationship between different power supply voltages, different junction temperatures, different output powers and corresponding gain compensation amounts. When the mapping relationship may be a gain compensation table between the compensation parameter and the corresponding gain compensation amount, the compensation amount obtaining module 112 queries a pre-stored gain compensation table according to the currently acquired compensation parameter, so as to obtain the gain compensation amount obtained by query. When the mapping relationship is a functional relationship between the compensation parameter obtained by the data fitting manner and the corresponding gain compensation amount, the compensation amount obtaining module 112 calculates according to the currently collected compensation parameter and according to a pre-stored functional relationship, so as to obtain the corresponding gain compensation amount.
As shown in fig. 6, in one embodiment, the present embodiment further provides a radio frequency system, which includes the output stabilizer 1 of any one of the radio frequency power amplifiers 2, the radio frequency power amplifier 2, and the radio frequency coil 3, where the radio frequency power amplifier 2 is connected to the output stabilizer 1 and the radio frequency coil 3, and a radio frequency input signal is compensated by the output stabilizer 1 and amplified by the radio frequency power amplifier 2 and then sent out by the radio frequency coil 3. The output stabilizing device 1 is connected and configured with the radio frequency power amplifier 2, so that the radio frequency power amplifier 2 can stably output under different working conditions.
In one embodiment, the present embodiment also provides a magnetic resonance system comprising a radio frequency system as described above. By using the radio frequency system, artifacts and distortion of the magnetic resonance system imaging can be reduced, and the picture quality is ensured.
The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The above examples merely represent a few embodiments of the present application, which are described in more detail and are not to be construed as limiting the scope of the utility model. It should be noted that it would be apparent to those skilled in the art that various modifications and improvements could be made without departing from the spirit of the present application, which would be within the scope of the present application. Accordingly, the scope of protection of the present application is to be determined by the claims appended hereto.
Claims (10)
1. The radio frequency system is characterized by comprising a radio frequency power amplifier (2), an output stabilizing device (1) and a radio frequency coil (3), wherein the radio frequency power amplifier (2) is connected with the output stabilizing device (1) and the radio frequency coil (3), and a radio frequency input signal is compensated by the output stabilizing device (1) and is amplified by the radio frequency power amplifier (2) and then is sent out by the radio frequency coil (3);
the output stabilizing device (1) is connected with the radio frequency power amplifier (2) and comprises a gain compensation module (11); the gain compensation module (11) is used for compensating the radio frequency input signal according to the compensation parameters and a preset compensation rule; the compensation parameters include at least one of supply voltage, junction temperature and power of the radio frequency power amplifier (2).
2. The radio frequency system according to claim 1, wherein the output stabilizing means (1) further comprises a non-linearity correction module (12) for non-linearly correcting the radio frequency input signal.
3. The radio frequency system according to claim 1, wherein the compensation rules are mapping relationships between different supply voltages, different junction temperatures, different output powers and corresponding gain compensation amounts; the gain compensation amount is the difference between the gain of the power amplifier and the expected gain.
4. A radio frequency system according to claim 3, wherein the mapping relationship is a gain compensation table between compensation parameters and corresponding gain compensation amounts.
5. A radio frequency system according to claim 3, wherein the mapping relationship is a functional relationship between the compensation parameter obtained by the data fitting method and the corresponding gain compensation amount.
6. The radio frequency system according to claim 1, wherein the gain compensation module (11) further comprises: the signal acquisition module (111) and the compensation amount acquisition module (112), wherein the signal acquisition module (111) is connected with the radio frequency power amplifier (2) and the compensation amount acquisition module (112);
the signal acquisition module (111) is used for acquiring compensation parameters of the radio frequency power amplifier (2) and outputting the compensation parameters to the compensation quantity acquisition module (112);
the compensation amount acquisition module (112) is configured to obtain a gain compensation amount of the radio frequency power amplifier (2) based on the compensation parameter of the radio frequency power amplifier (2) and the preset compensation rule.
7. The radio frequency system according to claim 6, wherein the signal acquisition module (111) comprises: the device comprises a temperature acquisition module, a power supply voltage acquisition module and a power acquisition module;
the power supply voltage acquisition module is used for acquiring the power supply voltage of the radio frequency power amplifier (2);
the temperature acquisition module is used for acquiring the junction temperature of the radio frequency power amplifier (2);
the power acquisition module is used for acquiring the power of the radio frequency power amplifier (2).
8. The radio frequency system according to claim 1, characterized in that the junction temperature of the radio frequency power amplifier (2) is the sum of the ambient temperature and the power amplifier junction temperature rise.
9. The radio frequency system according to claim 8, characterized in that the power amplifier junction temperature rise is calculated based on the loss power and equivalent thermal resistance of the radio frequency power amplifier (2).
10. A magnetic resonance system comprising a radio frequency system as claimed in any one of claims 1-9.
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