Frequency control based microwave transmission method and single-in multiple-out microwave system

Abstract

The application discloses a microwave transmission method and device based on frequency control and a single-in multi-out microwave system, wherein the method comprises the following steps: adjusting the frequency of an input signal, taking input signals with different frequencies as input signals of the single-in multi-out microwave system; according to the frequency of the input signal, the input signal is distributed to a target output port in a plurality of output ports of the single-in multi-out microwave system; and signal output is performed through the target output port. Therefore, the system can be scaled to any waveband, and the output port can be increased to any number according to requirements.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of microwave transmission technology, in particular to a microwave transmission method based on frequency control and a single-in multi-out microwave system. BACKGROUND

[0002] In recent years, radiotherapy technology has developed rapidly, especially the technology aiming at precise conformal therapy greatly reduces the side effects of radiotherapy, expands the scope of radiotherapy indications, and also puts forward new requirements for medical accelerators. Single irradiation field intensity modulated radiotherapy can achieve conformal therapy in a two-dimensional plane in a single direction, but the dose distribution in three-dimensional space cannot meet the requirements of conformal therapy.

[0003] Most of the current radiotherapy systems use multi-angle and multi-irradiation field irradiation mode, which is often realized by a mechanical rotating accelerator system. Taking the relatively advanced helical tomotherapy (TOMO therapy) as an example, it adopts a CT scanning-like mode for radiotherapy. The linear accelerator is installed on a ring-shaped gantry, and during the treatment process, it can perform circular motion around the treatment bed where the patient is located, realizing multi-angle irradiation.

[0004] A prominent disadvantage of using a single accelerator mechanical rotating system is the long time consumption, which is a common problem of the mechanical moving irradiation field switching mode. On the one hand, due to stability considerations, the speed of the ring-shaped gantry cannot be too fast; on the other hand, the limitation of the movement speed of the multi-leaf collimator for adjusting the shape of the irradiation field also makes the mechanical movement cannot be too fast. This disadvantage is acceptable for conventional irradiation with low dose rate and long irradiation time, but it is unacceptable for flash therapy (FLASH therapy) with high dose rate and irradiation time less than 1 second.

[0005] Similar to radiotherapy, the current industrial CT also uses a mechanical moving accelerator mode. Since the scanning object of industrial CT is larger, the corresponding gantry is also larger, so the time-consuming disadvantage is more obvious.

[0006] Therefore, in order to realize multi-angle fast irradiation of the beam, a system with multiple accelerators needs to be used. Among the entire accelerator system, the power source is one of the main components of the cost. Multiple accelerators require multiple power inputs. If the traditional method of using one power source for one accelerating tube is adopted, multiple power sources are needed, and the cost of the system will be multiplied, and the reliability problem caused by power source sparking will be more serious. If a single power source is used to supply multiple accelerating tubes, the power of the power source needs to be large. Such a large power power source is usually bulky and has a low repetition frequency, which is difficult to apply to fast imaging or irradiation. SUMMARY

[0007] The present application aims to at least solve one of the technical problems in the related art to some extent.

[0008] To this end, one object of the present application is to provide a frequency control based microwave transmission method, which can selectively match output from a corresponding output port by adjusting the frequency of an input signal.

[0009] Another object of the present application is to provide a single-in multi-out microwave system.

[0010] Still another object of the present application is to provide a frequency control based microwave transmission device.

[0011] To achieve the above objects, one aspect of the present application provides a frequency control based microwave transmission method, comprising the following steps:

[0012] Adjusting the frequency of an input signal, and taking input signals of different frequencies as input signals of a single-in multi-out microwave system;

[0013] According to the frequency of the input signal, the input signal is distributed to a target output port of a plurality of output ports of the single-in multi-out microwave system;

[0014] Outputting a signal through the target output port.

[0015] To achieve the above objects, another aspect of the present application provides a single-in multi-out microwave system, comprising:

[0016] an input port, a 1-to-N microwave network, a plurality of bandpass filters, and a plurality of output ports;

[0017] The input port is used for inputting input signals of different frequencies;

[0018] The input end of the 1-to-N microwave network is connected with the input port, and the output end is connected with the input end of the bandpass filter, and is used for adjusting and matching;

[0019] The output end of the bandpass filter is connected with the output port, and is used for passing or reflecting the input signal according to the frequency of the input signal;

[0020] The output port is used for outputting a signal.

[0021] To achieve the above objects, still another aspect of the present application provides a frequency control based microwave transmission device, comprising:

[0022] an input module, which is used for adjusting the frequency of an input signal, and taking input signals of different frequencies as input signals of a single-in multi-out microwave system;

[0023] a distribution module, configured to distribute the input signal to a target output port of a plurality of output ports of the single-in multi-out microwave system according to the frequency of the input signal;

[0024] an output module, configured to output a signal through the target output port.

[0025] The frequency control-based microwave transmission method, device and single-in multi-out microwave system according to the embodiments of the present application input input signals of different frequencies through an input port, and select corresponding output ports for output through the cooperative adjustment of a 1 / N microwave network and a band-pass filter, so that the output ports are selected for output by adjusting the frequency of the input signal input through the input port, and the number of output ports can be expanded according to actual requirements.

[0026] Additional aspects and advantages of the present application will be made apparent by the following description and the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0027] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the accompanying drawings, in which:

[0028] Figure 1 a flow chart of a frequency control-based microwave transmission method according to an embodiment of the present application;

[0029] Figure 2 a structural schematic diagram of a single-in multi-out microwave system according to an embodiment of the present application;

[0030] Figure 3 a structural schematic diagram of a single-in multi-out microwave system according to another embodiment of the present application;

[0031] Figure 4 a structural schematic diagram of a single-in multi-out microwave system according to still another embodiment of the present application;

[0032] Figure 5 a structural schematic diagram of a single-in multi-out microwave system according to yet another embodiment of the present application;

[0033] Figure 6 a specific structural schematic diagram of a single-in multi-out microwave system according to an embodiment of the present application;

[0034] Figure 7 a structural schematic diagram of a frequency control-based microwave transmission device according to an embodiment of the present application. DETAILED DESCRIPTION

[0035] Embodiments of the present application are described below in detail with reference to the accompanying drawings, wherein like or similar elements are denoted by the same or similar reference signs throughout the drawings. The embodiments described below are exemplary and are intended to explain the present application, and are not to be understood as limiting the present application.

[0036] A frequency control based microwave transmission method, device and single-in multi-out microwave system are described below with reference to the accompanying drawings according to embodiments of the present application.

[0037] Firstly, a frequency control based microwave transmission method according to embodiments of the present application is described with reference to the accompanying drawings.

[0038] Figure 1 A flow chart of the frequency control based microwave transmission method according to one embodiment of the present application is shown.

[0039] Step S1, the frequency of the input signal is adjusted, and input signals of different frequencies are used as input signals of the single-in multi-out microwave system.

[0040] Specifically, the power source can generate input signals of different frequencies within a certain frequency range.

[0041] Step S2, according to the frequency of the input signal, the input signal is distributed to a target output port of the multiple output ports of the single-in multi-out microwave system.

[0042] Further, the single-in multi-out microwave system includes one input port and multiple output ports, and any output port only allows input signals within a preset frequency range to pass through, and input signals outside the preset frequency range are reflected. When the frequency of the input signal is within the preset frequency range of the output port, the input port is matched without reflection.

[0043] It can be understood that when input signals of a certain frequency are input, each output port of the single-in multi-out microwave system corresponds to a preset frequency range, and when the frequency of the input signal is within the preset frequency range, the input signal can be output, otherwise it will be reflected. The specific value of the preset frequency range is set according to the specific structure of the microwave system.

[0044] Step S3, signal output is performed through the target output port.

[0045] Specifically, after the target output port is selected, the signal is output.

[0046] According to the frequency control-based microwave transmission method provided in the embodiment of the present application, the frequency of the input signal is adjusted, and input signals of different frequencies are taken as input signals of the single-input multiple-output microwave system; according to the frequency of the input signal, the input signal is distributed to a target output port of the multiple output ports of the single-input multiple-output microwave system; and the signal is output through the target output port. In this way, when the frequency of the input signal is adjusted, the function of selectively matching and outputting from the corresponding output port can be realized.

[0047] The single-input multiple-output microwave system according to the embodiment of the present application is described below.

[0048] Figure 2 The structural schematic diagram of the single-input multiple-output microwave system according to one embodiment of the present application is shown.

[0049] As shown in Figure 2 , the single-input multiple-output microwave system comprises an input port, a 1-to-N microwave network, multiple bandpass filters, and multiple output ports.

[0050] The input port is configured to input input signals of different frequencies.

[0051] The 1-to-N microwave network comprises an input end and N output ends, the input end of the 1-to-N microwave network is connected with the input port, and the output ends are connected with the input ends of the bandpass filters, and are configured to perform adjustment and matching.

[0052] The output ends of the bandpass filters are connected with the output ports, and are configured to pass or reflect the input signals according to the frequency of the input signals.

[0053] The output ports are configured to output signals.

[0054] The single-input multiple-output (SIMO) microwave system is provided with only one input port, and different frequency input signals can be input through the input port; and multiple output ports are provided, and the number of the output ports can be expanded according to actual needs.

[0055] Further, in the embodiment of the present application, the 1-to-N microwave network is essentially a multi-port network with scattering parameters S satisfying certain conditions, the 1-to-N microwave network comprises one input port and N output ports, and the N output branches are symmetrical. When (N-1) output branches are reflected, the remaining one output end and the input end are matched without reflection, and the microwave is transmitted from the input end to the remaining one output end. For the 1-to-N microwave network, the ideal S matrix can be expressed as:

[0056]

[0057] Furthermore, the band-pass filter is further configured to allow all input signals to pass through the band-pass filter when the frequency of the input signal is within the frequency passband of the band-pass filter.

[0058] Specifically, a bandpass filter is a microwave device that allows microwaves within a specific frequency band to pass through while reflecting microwaves in other frequency bands. An ideal bandpass filter allows all microwaves within the passband and completely reflects incident microwaves outside the passband. As a specific embodiment, the bandpass filter can be a through-resonant cavity. When the input signal frequency is at the resonant frequency of the cavity, the input signal completely passes through the cavity.

[0059] In practical applications, characteristics such as the center frequency, passband width, and transmission efficiency of a bandpass filter affect system parameters such as frequency, bandwidth, and loss, requiring design and optimization. The design should use an appropriate bandwidth, allowing for a certain degree of frequency adjustment error while ensuring that the passbands of the individual bandpass filters do not overlap.

[0060] Furthermore, the center frequencies of the bandpass filters are different, and the center frequencies are f1, f2…f n The frequency of the input signal is adjustable. If the frequency of the input signal is the center frequency f of a certain resonant cavity i , then the microwave signal can be fully transmitted in the bandpass filter and fully reflected by other bandpass filters. The input end of each bandpass filter is connected to the N output ports of a one-to-N microwave network. When the input frequency is the center frequency f of the i-th bandpass filter, i When , only the i-th branch is matched without reflection, while the other (N-1) branches are fully reflected. According to the previously designed one-to-N microwave network function, the input port of the one-to-N microwave network is also matched at this time, and the microwave power is fully transmitted from the input port to the center frequency f i The output port of the branch where the i-th bandpass filter is located. Thus, fast switching of different ports can be achieved by controlling the frequency of the power source.

[0061] like Figure 3 The figure shows an application scenario of a single-input multiple-output microwave transmission system. Specifically, the input port can be connected to a power source, which emits input signals of different frequencies within a certain microwave frequency range.

[0062] Furthermore, multiple output ports can be connected to multiple device loads. After connecting to a power source, they can each supply energy to a single device load, and switch between different device loads by adjusting the power source input frequency. For example, multiple ports can be connected to multiple accelerators.

[0063] In the embodiment of the present application, the output port can be connected to multiple accelerators, and different port outputs can be selected by power source frequency adjustment to supply different accelerators. Further, if different accelerators are installed at different irradiation angles, rapid switching between multi-angle irradiation fields can be realized. Compared with the scheme of mechanically rotating a single accelerator, the speed is faster, compared with the scheme of multiple power sources and multiple outputs, the cost is lower, and the reliability is higher, which has unique advantages.

[0064] As shown in Figure 4 , an application scenario of the single-in multi-out microwave system is shown. Multiple output ports are connected to multiple machine heads, different frequency input signals are sent by the power source, and different machine heads are output after the system. The machine heads can be installed at different irradiation angles, and rapid switching between multi-angle irradiation fields can be realized. In order to ensure the stability of the system, the frequency switching is performed between the power source output macro pulses, and the switching speed can reach milliseconds or even microseconds, which meets the demand of flash radiotherapy (FLASH radiotherapy). Compared with the scheme of mechanically rotating a single accelerator, the speed is faster, compared with the scheme of multiple power sources and multiple outputs, the cost is lower, and the reliability is higher, which has unique advantages.

[0065] As shown in Figure 5 , a specific structure of the single-in multi-out microwave system in the embodiment of the present application is shown. The mechanism of the 1:N microwave network can include: at least one impedance adder, the input impedance of one port of the impedance adder is equal to the sum of the impedances of the remaining ports. A matching waveguide section is arranged between the impedance adder and the bandpass filter for impedance matching.

[0066] As shown in Figure 5 and Figure 6 , in Figure 6 , 1 is an input port of the single-in multi-out microwave system; 2 and 3 are impedance adders, Figure 6 only two impedance adders are shown, in actual application, the number of impedance adders is set according to the number of output ports; 4, 5 and 6 are matching waveguide sections for impedance matching; 7, 8 and 9 are bandpass filters; 10, 11 and 12 are output ports. The number of matching waveguide sections and bandpass filters is set according to the actual number of output ports, so that the microwave system of the present application can be arbitrarily expanded to multiple ports.

[0067] The single-in multi-out microwave system is mainly composed of impedance adders, bandpass filters and matching waveguide sections, combined with Figure 5 and Figure 6 , the components will be described below.

[0068] Specifically, the impedance adder is essentially a multi-port network with scattering parameters S satisfying certain conditions, and the function is that the input impedance of one port of the multi-port network is equal to the sum of the impedances of the remaining ports, so it is called impedance adder. When the impedance adder is multiple, the function of the microwave system is realized by cascading multiple basic three-port impedance adders.

[0069] There are many devices that can be used as bandpass filters. In one specific embodiment of the present application, a through-type resonant cavity is taken as an example. When the input signal is at a specific resonant frequency, it can be completely transmitted, and when it deviates from the frequency, it will be partially or completely reflected. The resonant frequency, Q value (quality factor) and coupling degree of the resonant cavity will affect the frequency, bandwidth and loss of the system, and need to be designed and optimized.

[0070] Specifically, the matching waveguide section is located between the impedance adder and each bandpass filter, and is used for impedance matching. Figure 6 As shown in FIG. 1, the waveguide transmission line between the output end of the impedance adder and the input end of the bandpass filter serves as the matching waveguide section, and its length needs to be specifically designed. The impedance when the bandpass filter fully reflects the input signal is not a fixed value. In order to make the input signal output at a specific output port, the impedance of a certain output end of the impedance adder when reflecting needs to be short-circuited, i.e. 0, so that the impedance matching is performed through the matching waveguide section, and the impedance of the output end of the impedance adder is set to the desired impedance.

[0071] Further, the center frequencies of the respective bandpass filters are different. Taking the resonant cavity as an example, the resonant frequencies of the respective cavities are f1, f2…f n The microwave frequency output by the power source is adjustable within a certain range. If the frequency of the input signal is the resonant frequency f i of a certain resonant cavity, the resonant cavity can completely transmit, and the other resonant cavities fully reflect. After the matching waveguide section, the matching impedance without reflection is 1, and the impedance of full reflection is the same as the short-circuit condition, which is 0. Due to the effect of the impedance adder, the impedance of the input end is the sum of the impedances of all ports, which is 1+(n-1)*0=1, indicating that the input port is matched, and the power is completely transmitted to the branch where the resonant cavity with the resonant frequency f i is located. Thus, by controlling the frequency of the power source, the rapid switching of different ports is realized.

[0072] The single-input multi-output microwave system according to the embodiment of the present application provides a single-power-source-powered multi-port-output microwave system, and the rapid switching of different ports is realized by controlling the frequency of the power source. The accelerator array is connected after the output port, and the same multi-field irradiation function as the current single-accelerator-rack rotating scanning scheme can be realized, and the speed of switching between fields is greatly increased. Moreover, the system can be expanded to any number of output ports and scaled to any frequency.

[0073] Figure 7 A structure diagram of a frequency control based microwave transmission device according to an embodiment of the present application.

[0074] As shown in Figure 7 , the frequency control based microwave transmission device comprises an input module 701, a distribution module 702 and an output module 703.

[0075] The input module 701 is configured to adjust the frequency of an input signal, and input signals of different frequencies are used as input signals of a single-in multiple-out microwave system.

[0076] The distribution module 702 is configured to distribute the input signal to a target output port of a plurality of output ports of the single-in multiple-out microwave system according to the frequency of the input signal.

[0077] The output module 703 is configured to output the signal through the target output port.

[0078] Further, in an embodiment of the present application, the single-in multiple-out microwave system comprises an input port and a plurality of output ports, any output port only allows input signals in a preset frequency range to pass through, and input signals outside the preset frequency range are reflected, and the input port is matched without reflection when the frequency of the input signal is in the preset frequency range of the output port.

[0079] According to the frequency control based microwave transmission device provided by the embodiment of the present application, the frequency of the input signal is adjusted, and input signals of different frequencies are used as input signals of the single-in multiple-out microwave system; the input signal is distributed to a target output port of a plurality of output ports of the single-in multiple-out microwave system according to the frequency of the input signal; and the signal is output through the target output port. Thus, the function of selectively matching and outputting from the corresponding output port when the frequency of the input signal is adjusted is realized.

[0080] In addition, the terms "first", "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0081] In the description of the specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are contained in at least one embodiment or example of the present application. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any suitable manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples without contradiction.

[0082] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary and are not to be construed as limiting the present application, and the person skilled in the art can make changes, modifications, replacements and variations to the above-described embodiments within the scope of the present application.

Claims

1. A single-in multiple-out microwave system, characterized by, The single-in multi-out microwave system comprises an input port, a 1-to-N microwave network, a plurality of band-pass filters, and a plurality of output ports. The input port is configured to input input signals of different frequencies. The 1-to-N microwave network comprises an input end and N output ends, the input end of the 1-to-N microwave network is connected with the input port, and the output ends are connected with the input ends of the band-pass filters for adjustment and matching. The output ends of the band-pass filters are connected with the output ports, and the input signals are transmitted or reflected according to the frequencies of the input signals. The output ports are configured to output signals. When any N-1 output ends of the 1-to-N microwave network are reflected, the remaining one output end and the input end are matched without reflection, and microwaves are transmitted from the input end to the remaining one output end. The 1-to-N microwave network comprises at least one impedance adder, and the input impedance of one port of the impedance adder is equal to the sum of the impedances of the remaining ports. When the impedance adder is a plurality of impedance adders, the plurality of impedance adders are cascaded by a plurality of basic three-port impedance adders. A matching waveguide section is arranged between the impedance adder and the band-pass filter for impedance matching. The matching waveguide section arranged between the impedance adder and the band-pass filter forms a microwave network, and the scattering parameter matrix S of the microwave network is as follows: wherein N is the number of output ports of the 1-to-N microwave network formed by the impedance adder.

2. The single-in multi-out microwave system according to claim 1, wherein the input port is connected with a power source, and the power source emits input signals of different frequencies in a microwave frequency range.

3. The single-in multi-out microwave system according to claim 1, wherein the plurality of output ports are connected with a plurality of device loads, and the input signals of different frequencies are used to supply power to specific device loads.

4. The single-in multi-out microwave system according to claim 1 or 3, wherein the plurality of output ports are connected with a plurality of accelerators, and the plurality of accelerators are installed at different irradiation angles to switch between multi-angle irradiation fields according to input signals of different frequencies. The band-pass filter is further configured to transmit all the input signals through the band-pass filter when the frequencies of the input signals are within the frequency passband of the band-pass filter.

6. The single-in multi-out microwave system according to claim 1 or 5, wherein the band-pass filter comprises a through-type resonant cavity, and all the input signals are transmitted through the resonant cavity when the frequencies of the input signals are resonant frequencies of the resonant cavity. ​ ​ 5. The single-in multi-out microwave system of claim 1, wherein, ​ ​ ​

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