Filter circuit and radio frequency power supply equipment
By designing a filter circuit containing N filter sub-circuits, the subharmonics present in the RF power supply equipment are filtered out using cable phase shift technology, which solves the problem that harmonics in RF power supply affect the output effect and achieves efficient filtering effect.
Patent Information
- Application Number
- CN202411651820.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-19
- Publication Date
- 2025-02-25
AI Technical Summary
There are difficult-to-suppress different harmonics such as first, third, fifth, and seventh times in the RF power supply equipment, which affects the output effect and these harmonics need to be effectively filtered out.
A filter circuit is designed, including N filter sub-circuits, each filter sub-circuit phase shifts the target harmonics in the radio frequency electrical energy through the first cable and the second cable, and the phase shifted harmonics are mixed at the output end to filter out at least a portion of the target harmonics.
It realizes effective filtering of different harmonics in radio frequency electrical energy, improves the output effect of radio frequency power supply, and meets the filtering requirements of radio frequency electrical energy.
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Figure CN119519386A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of radio frequency technology, and in particular to a filter circuit and a radio frequency power supply device. Background Art
[0002] At present, with the development of radio frequency (RF) technology, RF power supply equipment is increasingly used in various fields. However, when the RF power supply in the RF power supply equipment is output, the RF power output by the RF power supply often contains first, third, fifth, seventh and other harmonics that are difficult to suppress, which will greatly affect the output effect of the RF power supply. Therefore, how to effectively filter out the harmonics in the RF power to meet the filtering requirements of the RF power has become a problem that needs to be considered. Summary of the invention
[0003] The present application provides a filtering circuit and a radio frequency power supply device, which can meet the filtering requirements of radio frequency power.
[0004] In a first aspect, a filter circuit is provided, the filter circuit comprising N filter subcircuits, each filter subcircuit having a target filter frequency, the target filter frequencies of the N filter subcircuits being different from each other, N≥1. Each filter subcircuit comprises an input end, a first cable, a second cable, and an output end. The input end is used to connect to the output path of an RF power supply to input the RF power output by the RF power supply. The first cable is connected between the input end and the output end, the first cable has a first length, and the first cable is used to perform a corresponding phase shift on the target harmonic in the RF power output by the RF power supply based on the first length to obtain a first phase-shifted harmonic. The second cable is connected between the input end and the output end, the second cable has a second length, and the second cable is used to perform a corresponding phase shift on the target harmonic based on the second length to obtain a second phase-shifted harmonic. The first phase-shifted harmonic and the second phase-shifted harmonic are mixed at the output end to filter out at least part of the target harmonics in the RF power input at the input end, so that the RF power output at the output end includes part of the target harmonics or does not include the target harmonics, wherein the frequency of the target harmonic is the target filtering frequency corresponding to the filtering subcircuit.
[0005] In a possible implementation, the wavelength of the target harmonic corresponding to each filtering subcircuit when transmitted in the first cable and the second cable is the first wavelength. The sum of the lengths of the first length and the second length is the first wavelength, and the sum of the angles of the phase shift of the target harmonic by the first cable and the angle of the phase shift of the target harmonic by the second cable is 2π.
[0006] In a possible implementation, the first length is 1 / 4 of the first wavelength, and the first cable phase-shifts the target harmonic by π / 2 based on the first length to obtain the first phase-shifted harmonic. The second length is 3 / 4 of the first wavelength, and the second cable phase-shifts the target harmonic by 3π / 2 based on the second length to obtain the second phase-shifted harmonic.
[0007] In a possible implementation manner, the waveform of the first phase-shifted harmonic is complementary to the waveform of the second phase-shifted harmonic, so that the first phase-shifted harmonic and the second phase-shifted harmonic cancel each other out after being mixed at the output end, so that the RF power outputted from the output end does not include the target harmonic.
[0008] In a possible implementation, the first cable and the second cable are further used to phase shift the main wave in the RF power, respectively, and the main wave of the RF power after phase shift by the first cable and the second cable is mixed at the output end, wherein the main wave of the mixed RF power is the same as the main wave of the RF power output by the RF power supply.
[0009] In a possible implementation, the N filter subcircuits are connected in parallel in the output path of the RF power supply, and the N filter subcircuits filter at least part of the N target harmonics according to the target filter frequency of each filter subcircuit, and the N target harmonics are m1-m2 generated in the RF power output by the RF power supply. n Harmonics of order, among which, m1-m n Are different.
[0010] In a possible implementation, the N filter subcircuits are connected in series in the output path of the RF power supply, and the N filter subcircuits filter at least part of the N target harmonics in turn according to the target filtering frequency of each filter subcircuit, and the N target harmonics are m1-m2 generated in the RF power output by the RF power supply. n Harmonics of order, among which, m1-m n Are different.
[0011] In a possible implementation, N=3, and the target filtering frequencies of the three filtering sub-circuits correspond to the frequencies of the third harmonic, the fifth harmonic, and the seventh harmonic, respectively, so as to output, through the output end, radio frequency electrical energy including one or more of part of the third harmonic, part of the fifth harmonic, and part of the seventh harmonic, or excluding the third harmonic, the fifth harmonic, and the seventh harmonic.
[0012] In a possible implementation manner, the frequency of the radio frequency power output by the radio frequency power supply is between 300 MHz and 300 GHz.
[0013] In a second aspect, a radio frequency power supply device is also provided, the radio frequency power supply device comprising a radio frequency power supply and a filtering circuit. The filtering circuit comprises N filtering subcircuits, each filtering subcircuit having a target filtering frequency, and the target filtering frequencies of the N filtering subcircuits are different from each other, N≥1. Wherein, each filtering subcircuit comprises an input end, a first cable, a second cable and an output end. The input end is used to connect to the output path of the radio frequency power supply to input the radio frequency power output by the radio frequency power supply. The first cable is connected between the input end and the output end, the first cable has a first length, and the first cable is used to perform a corresponding phase shift on the target harmonic in the radio frequency power output by the radio frequency power supply based on the first length to obtain a first phase-shifted harmonic. The second cable is connected between the input end and the output end, the second cable has a second length, and the second cable is used to perform a corresponding phase shift on the target harmonic based on the second length to obtain a second phase-shifted harmonic. The first phase-shifted harmonic and the second phase-shifted harmonic are mixed at the output end to filter out at least part of the target harmonics in the RF power input at the input end, so that the RF power output at the output end includes part of the target harmonics or does not include the target harmonics, wherein the frequency of the target harmonic is the target filtering frequency corresponding to the filtering subcircuit.
[0014] The filter circuit and RF power supply device of the present application, by setting N filter sub-circuits connected to the output path of the RF power supply, can effectively filter out N different target harmonics respectively to meet the filtering requirements of the RF power, and each filter sub-circuit uses a first cable and a second cable to perform corresponding phase shifts on the target harmonics in the RF power output by the RF power supply to obtain a first phase-shifted harmonic and a second phase-shifted harmonic respectively, so that the first phase-shifted harmonic and the second phase-shifted harmonic are mixed at the output end to filter out at least part of the target harmonics, providing a convenient, effective and easy-to-use filter circuit. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the background technology, the drawings required for use in the embodiments of the present application or the background technology will be described below.
[0016] Figure 1 is a schematic diagram of a filter circuit in an embodiment of the present application.
[0017] Figure 2 FIG. 4 is a schematic diagram of a filter circuit in another embodiment of the present application.
[0018] Figure 3 Schematic diagram of a filter sub-circuit in an embodiment of the present application.
[0019] Figure 4 for Figure 1 Schematic diagram of the filter circuit when N=3.
[0020] Figure 5 It is a schematic diagram of a radio frequency power supply device in one embodiment of the present application.
[0021] Explanation of the reference numerals: 1000, RF power supply equipment, RF, RF power supply, RFP, RF power, 10, filtering circuit, 100, filtering sub-circuit, i1, input end, o1, output end, 110, first cable, L1, first length, 120, second cable, L2, second length, TH, target harmonic, THa, first phase-shifted harmonic, THb, second phase-shifted harmonic. DETAILED DESCRIPTION
[0022] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.
[0023] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0024] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, unless otherwise specified, "plurality" means two or more.
[0025] In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such process, method, product, or device.
[0026] Please also read Figure 1 , Figure 2 , Figure 3 , Figure 1 is a schematic diagram of a filter circuit 10 in an embodiment of the present application, Figure 2 is a schematic diagram of a filter circuit 10 in another embodiment of the present application, Figure 3 FIG. 1 is a schematic diagram of a filter subcircuit 100 in an embodiment of the present application. Figure 1 , Figure 2 , Figure 3 As shown, the present application provides a filter circuit 10, the filter circuit 10 includes N filter subcircuits 100, each filter subcircuit 100 has a target filter frequency, and the target filter frequencies of the N filter subcircuits 100 are different from each other, N≥1. Each filter subcircuit 100 includes an input terminal i1, a first cable 110, a second cable 120, and an output terminal o1. The input terminal i1 is used to connect to the output path of the radio frequency power supply RF to input the radio frequency power RFP output by the radio frequency power supply RF. The first cable 110 is connected between the input terminal i1 and the output terminal o1, and the first cable 110 has a first length L1. The first cable 110 is used to perform a corresponding phase shift on the target harmonic in the radio frequency power RFP output by the radio frequency power supply RF based on the first length L1 to obtain a first phase-shifted harmonic THa. The second cable 120 is connected between the input terminal i1 and the output terminal o1, and the second cable 120 has a second length L2. The second cable 120 is used to perform a corresponding phase shift on the target harmonic based on the second length L2 to obtain a second phase-shifted harmonic THb. The first phase-shifted harmonic THa and the second phase-shifted harmonic THb are mixed at the output end o1 to filter out at least part of the target harmonics in the radio frequency power RFP input by the input end i1, so that the radio frequency power RFP output by the output end o1 includes part of the target harmonics or does not include the target harmonics, wherein the frequency of the target harmonic is the target filtering frequency corresponding to the filtering sub-circuit 100.
[0027] Therefore, the above-mentioned filter circuit 10 in the present application, by setting N filter sub-circuits 100 connected to the output path of the radio frequency power supply RF, can effectively filter out N different target harmonics respectively to meet the filtering requirements of the radio frequency power RFP, and each filter sub-circuit 100 adopts the first cable 110 and the second cable 120 to cooperate with each other to perform corresponding phase shifts on the target harmonics in the radio frequency power RFP output by the radio frequency power supply RF, so as to obtain the first phase-shifted harmonic THa and the second phase-shifted harmonic THb respectively, so that the first phase-shifted harmonic THa and the second phase-shifted harmonic THb are mixed at the output end o1 to filter out at least part of the target harmonics, thereby providing a convenient, effective and easy-to-use filter circuit 10.
[0028] Specifically, the first cable 110 and the second cable 120 can perform corresponding phase shifts on target harmonics of a specific frequency based on the first length L1 and the second length L2, respectively, so that the first phase-shifted harmonic THa and the second phase-shifted harmonic THb obtained respectively can be offset at the output end o1, so that the radio frequency power RFP outputted from the output end o1 includes part of the target harmonics or does not include the target harmonics.
[0029] In one or more embodiments, the first cable 110 and the second cable 120 of each filtering sub-circuit 100 may be coaxial cables.
[0030] The wavelength of the target harmonic corresponding to each filtering subcircuit 100 when transmitted in the first cable 110 and the second cable 120 is the first wavelength. The sum of the lengths of the first length L1 and the second length L2 is the first wavelength, and the sum of the angles of the phase shift of the target harmonic by the first cable 110 and the phase shift of the target harmonic by the second cable 120 is 2π.
[0031] Thus, in the above-mentioned filter circuit 10 in the present application, the wavelength of the target harmonic corresponding to each filter sub-circuit 100 when transmitted in the first cable 110 and the second cable 120 is the first wavelength, and when the sum of the lengths of the first length L1 and the second length L2 is the first wavelength, the sum of the angles of the phase shift of the target harmonic by the first cable 110 and the angles of the phase shift of the target harmonic by the second cable 120 is 2π, so that the first phase-shifted harmonic THa and the second phase-shifted harmonic THb can be offset at the output end o1 to filter out at least part of the target harmonic.
[0032] like Figure 3 As shown, the first length L1 is 1 / 4 of the first wavelength, and the first cable 110 phase-shifts the target harmonic by π / 2 based on the first length L1 to obtain the first phase-shifted harmonic THa. The second length L2 is 3 / 4 of the first wavelength, and the second cable 120 phase-shifts the target harmonic by 3π / 2 based on the second length L2 to obtain the second phase-shifted harmonic THb.
[0033] Thus, in the above-mentioned filtering circuit 10 in the present application, since the length of the cable corresponds to the phase shift angle, when the first length L1 is 1 / 4 of the first wavelength, the first cable 110 phase shifts the target harmonic by π / 2 based on the first length L1, and when the second length L2 is 3 / 4 of the first wavelength, the second cable 120 phase shifts the target harmonic by 3π / 2 based on the second length L2.
[0034] Furthermore, the waveform of the first phase-shifted harmonic THa is complementary to the waveform of the second phase-shifted harmonic THb, so that the first phase-shifted harmonic THa and the second phase-shifted harmonic THb cancel each other out after mixing at the output end o1, so that the radio frequency power RFP outputted from the output end o1 does not include the target harmonic.
[0035] Therefore, in the above-mentioned filter circuit 10 in the present application, when the first length L1 is 1 / 4 of the first wavelength and the second length L2 is 3 / 4 of the first wavelength, the waveform of the first phase-shifted harmonic THa is complementary to the waveform of the second phase-shifted harmonic THb, so that the first phase-shifted harmonic THa and the second phase-shifted harmonic THb cancel each other after mixing at the output end o1, so that the radio frequency power RFP outputted from the output end o1 does not include the target harmonic.
[0036] Specifically, taking the target harmonic as u×cos(ωt) as an example, where u is the voltage value of the target harmonic, the first phase-shifted harmonic THa is u×cos(ωt-π / 2), and the second phase-shifted harmonic THb is u×cos(ωt-3π / 2), that is, -u×cos(ωt-π / 2), that is, the waveform of the first phase-shifted harmonic THa is complementary to the waveform of the second phase-shifted harmonic THb, and then the sum of the first phase-shifted harmonic THa and the second phase-shifted harmonic THb is zero, so that the radio frequency power RFP outputted from the output terminal o1 does not include the target harmonic.
[0037] Among them, the first cable 110 and the second cable 120 are also used to phase shift the main wave in the radio frequency power RFP respectively, and the main wave of the radio frequency power RFP after phase shift by the first cable 110 and the second cable 120 is mixed at the output end o1, wherein the main wave of the mixed radio frequency power RFP is the same as the main wave of the radio frequency power RFP output by the radio frequency power supply RF.
[0038] Therefore, in the above-mentioned filtering circuit 10 in the present application, since the lengths of the first cable 110 and the second cable 120 do not correspond to the frequency of the main wave in the radio frequency power RFP, although the first cable 110 and the second cable 120 will also phase-shift the main wave in the radio frequency power RFP respectively, since the main waves of the radio frequency power RFP after phase shift by the first cable 110 and the second cable 120 are mixed at the output end o1, the main wave of the fused radio frequency power RFP is the same as the main wave of the radio frequency power RFP output by the radio frequency power supply RF, and the main wave of the radio frequency power RFP will not be filtered out.
[0039] like Figure 1 As shown, N filter subcircuits 100 are connected in parallel in the output path of the radio frequency power supply RF. The N filter subcircuits 100 filter out at least part of the N target harmonics according to the target filtering frequency of each filter subcircuit 100. The N target harmonics are m1-m2 generated in the radio frequency power RFP output by the radio frequency power supply RF.n Harmonics of order, among which, m1-m n Are different.
[0040] Thus, the above-mentioned filter circuit 10 in the present application is provided with N filter sub-circuits 100 connected in parallel in the output path of the radio frequency power supply RF, and the N filter sub-circuits 100 respectively filter out at least part of the N target harmonics, and the N target harmonics are m1-m2 generated in the radio frequency power RFP output by the radio frequency power supply RF. n Harmonics of the order.
[0041] like Figure 2 As shown, N filter subcircuits 100 are connected in series in the output path of the radio frequency power supply RF. The N filter subcircuits 100 filter out at least part of the N target harmonics in turn according to the target filtering frequency of each filter subcircuit 100. The N target harmonics are m1-m2 generated in the radio frequency power RFP output by the radio frequency power supply RF. n Harmonics of order, among which, m1-m n Are different.
[0042] Thus, the above-mentioned filter circuit 10 in the present application is configured to connect N filter sub-circuits 100 in series in the output path of the radio frequency power supply RF, and the N filter sub-circuits 100 filter at least part of the N target harmonics in turn, and the N target harmonics are m1-m2 generated in the radio frequency power RFP output by the radio frequency power supply RF. n Harmonics of the order.
[0043] See also Figure 4 , Figure 4 for Figure 1 The schematic diagram of the filter circuit 10 when N=3 is shown. Figure 4 As shown, N=3, and the target filtering frequencies of the three filtering sub-circuits 100 correspond to the frequencies of the third harmonic, the fifth harmonic, and the seventh harmonic, respectively, so as to output the radio frequency power RFP including one or more of part of the third harmonic, part of the fifth harmonic, and part of the seventh harmonic, or excluding the third harmonic, the fifth harmonic, and the seventh harmonic through the output terminal o1.
[0044] Therefore, the above-mentioned filtering circuit 10 in the present application can set the target filtering frequencies of the three filtering sub-circuits 100 according to the frequencies of the third harmonic, the fifth harmonic and the seventh harmonic, which are the most serious harmonics in the radio frequency power RFP, so as to at least partially filter out the third harmonic, the fifth harmonic and the seventh harmonic.
[0045] In one or more embodiments, the frequency of the radio frequency power RFP output by the radio frequency power source RF is between 300 MHz and 300 GHz.
[0046] Therefore, in the above-mentioned filtering circuit 10 in the present application, the frequency of the radio frequency power RFP output by the radio frequency power supply RF is related to the wavelength. When the frequency of the radio frequency power RFP output by the radio frequency power supply RF is between 300 MHz and 300 GHz, that is, when the frequency of the radio frequency power RFP is a microwave frequency, the wavelength is shorter, and the lengths of the first cable 110 and the second cable 120 are also shorter, saving space.
[0047] The filter circuit 10 of the present application, through the above structure, provides a convenient and effective filter circuit 10, and can filter out at least part of the target harmonics according to specific needs to meet the filtering requirements of the radio frequency power RFP.
[0048] See also Figure 5 , Figure 5 FIG. 1 is a schematic diagram of a radio frequency power supply device 1000 in an embodiment of the present application. Figure 5 As shown, the present application further provides a radio frequency power supply device 1000, which includes a radio frequency power supply RF and the filter circuit 10 in any of the aforementioned embodiments.
[0049] Please refer again Figure 1 , Figure 2 , Figure 3 .like Figure 1 , Figure 2 , Figure 3 As shown, the filter circuit 10 includes N filter subcircuits 100, each filter subcircuit 100 has a target filter frequency, and the target filter frequencies of the N filter subcircuits 100 are different from each other, N≥1. Each filter subcircuit 100 includes an input terminal i1, a first cable 110, a second cable 120, and an output terminal o1. The input terminal i1 is used to connect to the output path of the radio frequency power supply RF to input the radio frequency power RFP output by the radio frequency power supply RF. The first cable 110 is connected between the input terminal i1 and the output terminal o1, and the first cable 110 has a first length L1. The first cable 110 is used to perform a corresponding phase shift on the target harmonic in the radio frequency power RFP output by the radio frequency power supply RF based on the first length L1 to obtain a first phase-shifted harmonic THa. The second cable 120 is connected between the input terminal i1 and the output terminal o1, and the second cable 120 has a second length L2. The second cable 120 is used to perform a corresponding phase shift on the target harmonic based on the second length L2 to obtain a second phase-shifted harmonic THb. The first phase-shifted harmonic THa and the second phase-shifted harmonic THb are mixed at the output end o1 to filter out at least part of the target harmonics in the radio frequency power RFP input by the input end i1, so that the radio frequency power RFP output by the output end o1 includes part of the target harmonics or does not include the target harmonics, wherein the frequency of the target harmonic is the target filtering frequency corresponding to the filtering sub-circuit 100.
[0050] The more specific structure of the filter circuit 10 can refer to the relevant content of the filter circuit 10 in any of the aforementioned embodiments, which will not be repeated here.
[0051] The filter circuit 10 and the electronic device of the present application provide a convenient and effective filter circuit 10 through the above structure, and can filter out at least part of the target harmonics according to specific needs to meet the filtering requirements of the radio frequency power RFP.
[0052] In the multiple embodiments provided in the present application, it should be understood that the disclosed devices and equipment can be implemented in other ways. For example, the device embodiments described above are only schematic; for example, the division of units is only a logical function division, and there may be other division methods in actual implementation; for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.
[0053] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
[0054] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may be physically included separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of hardware plus software functional units.
[0055] The above description is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application; in the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.
Claims
1. A filter circuit, characterized in that: The method comprises N filter subcircuits, each filter subcircuit having a target filter frequency, the target filter frequencies of the N filter subcircuits are different from each other, and N≥1; Wherein, each filtering subcircuit comprises an input end, a first cable, a second cable and an output end; The input end is used to be connected to the output path of the radio frequency power supply to input the radio frequency power output by the radio frequency power supply; The first cable is connected between the input end and the output end, the first cable has a first length, and the first cable is used to perform a corresponding phase shift on a target harmonic in the radio frequency power output by the radio frequency power supply based on the first length to obtain a first phase-shifted harmonic; The second cable is connected between the input end and the output end, the second cable has a second length, and the second cable is used to perform a corresponding phase shift on the target harmonic based on the second length to obtain a second phase-shifted harmonic; The first phase-shifted harmonic and the second phase-shifted harmonic are mixed at the output end to filter out at least part of the target harmonics in the RF power input at the input end, so that the RF power output at the output end includes part of the target harmonics or does not include the target harmonics, wherein the frequency of the target harmonic is the target filtering frequency corresponding to the filtering subcircuit.
2. The filter circuit according to claim 1, characterized in that: The wavelength of the target harmonic corresponding to each filtering sub-circuit when transmitted in the first cable and the second cable is the first wavelength; The sum of the first length and the second length is the first wavelength, and the sum of the angle at which the first cable phase shifts the target harmonic and the angle at which the second cable phase shifts the target harmonic is 2π.
3. The filter circuit according to claim 2, characterized in that: The first length is 1 / 4 of the first wavelength, and the first cable phase-shifts the target harmonic by π / 2 based on the first length to obtain the first phase-shifted harmonic; The second length is ¾ of the first wavelength, and the second cable phase-shifts the target harmonic by 3π / 2 based on the second length to obtain the second phase-shifted harmonic.
4. The filter circuit according to claim 3, characterized in that: The waveform of the first phase-shifted harmonic is complementary to the waveform of the second phase-shifted harmonic, so that the first phase-shifted harmonic and the second phase-shifted harmonic cancel each other out after being mixed at the output end, so that the RF power outputted from the output end does not include the target harmonic.
5. The filter circuit according to claim 1, characterized in that: The first cable and the second cable are also used to phase shift the main wave in the radio frequency power respectively, and the main wave of the radio frequency power after phase shift by the first cable and the second cable is mixed at the output end, wherein the main wave of the mixed radio frequency power is the same as the main wave of the radio frequency power output by the radio frequency power supply.
6. The filter circuit according to claim 1, characterized in that: The N filtering subcircuits are connected in parallel in the output path of the RF power supply, and the N filtering subcircuits filter at least part of the N target harmonics according to the target filtering frequency of each filtering subcircuit, wherein the N target harmonics are m1-m2 generated in the RF power output by the RF power supply. n Harmonics of order m1-m n Are different.
7. The filter circuit according to claim 1, characterized in that: The N filter subcircuits are connected in series in the output path of the RF power supply, and the N filter subcircuits filter at least part of the N target harmonics in turn according to the target filter frequency of each filter subcircuit, wherein the N target harmonics are m1-m2 generated in the RF power output by the RF power supply. n Harmonics of order m1-m n Are different.
8. The filter circuit according to claim 1, characterized in that: N=3, the target filtering frequencies of the three filtering sub-circuits correspond to the frequencies of the third harmonic, the fifth harmonic, and the seventh harmonic, respectively, so as to output radio frequency electrical energy including one or more of part of the third harmonic, part of the fifth harmonic, and part of the seventh harmonic, or excluding the third harmonic, the fifth harmonic, and the seventh harmonic through the output end.
9. The filter circuit according to claim 1, characterized in that: The frequency of the radio frequency power output by the radio frequency power supply is between 300 MHz and 300 GHz.
10. A radio frequency power supply device, characterized in that: It comprises a radio frequency power supply and a filtering circuit as claimed in any one of claims 1 to 9.