An arbitrary waveform synthesizing device

Abstract

The present application relates to a kind of arbitrary waveform synthesis device, it includes: vacuum box, electrode plate is arranged in it, and the upper and lower ends of the vacuum box are respectively provided with the through hole for beam passing;First resonant cavity, it is arranged in one side of the vacuum box, for the even electric field generated is concentrated in the upper end of the electrode plate;Second resonant cavity, it is arranged in one side of the vacuum box with the first resonant cavity, and it is below the first resonant cavity, for the odd electric field generated is concentrated in the lower end of the electrode plate;The first resonant cavity uses half wavelength resonant cavity, and the second resonant cavity uses quarter wavelength resonant cavity.The present application can not be limited by frequency, voltage and its structure, and the periodic waveform of arbitrary frequency and voltage can be synthesized, which can be applied in the field of accelerator waveform generation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of accelerator waveform generation, in particular to an arbitrary waveform synthesizer. BACKGROUND

[0002] In the construction of accelerator equipment at home and abroad, the generation of some complex waveforms (such as sawtooth wave, square wave, etc.) is very difficult to achieve due to the limitations of repetition frequency and voltage amplitude.

[0003] Taking sawtooth wave as an example, the technical characteristics of the existing technology are compared:

[0004] 1. Electron tube charging and discharging method: the electrode composed capacitor is charged and discharged through the switching action of the electron tube to form a sawtooth wave. Although the circuit of this method is simple and easy to make, the power loss is large, and it is limited by the performance of the components, and currently no device can meet the demand of 40MHz or more sawtooth wave.

[0005] 2. Wideband amplifier method: generally use a wideband amplifier to amplify the waveform without distortion in the entire harmonic frequency band. The application of this method is strictly restricted by the performance of the amplifier. In order to improve the linearity of the sawtooth wave, the harmonic number must be increased, and the demand for voltage of the accelerator is also increasing. This means wide frequency band and high gain for the amplifier. It is impossible to always increase the special signal of high voltage and high frequency produced by the amplifier.

[0006] 3. Traditional resonance synthesis method: due to the limitation of its own structure, the traditional resonance synthesis method cannot generate four times, eight times and other harmonics, that is, the highest can realize the synthesis of three times harmonic. The efficiency and linearity of the sawtooth wave synthesized by this method are restricted by the structure and cannot be upgraded and expanded. SUMMARY

[0007] In view of the above problems, the purpose of the present application is to provide an arbitrary waveform synthesizer which can synthesize periodic waveforms of arbitrary frequency and voltage without being limited by frequency, voltage and its own structure.

[0008] To achieve the above purpose, the present application adopts the following technical scheme: an arbitrary waveform synthesizer, comprising: a vacuum box body, an electrode plate is arranged in the vacuum box body, and a through hole for beam passing is arranged at the upper and lower ends of the vacuum box body; a first resonant cavity is arranged on one side of the vacuum box body for concentrating the generated even electric field at the upper end of the electrode plate; a second resonant cavity is arranged on one side of the vacuum box body in parallel with the first resonant cavity and below the first resonant cavity for concentrating the generated odd electric field at the lower end of the electrode plate; the first resonant cavity adopts a one-half wavelength resonant cavity, and the second resonant cavity adopts a one-fourth wavelength resonant cavity.

[0009] Further, the outer conductor length of the first resonant cavity is the same as the outer conductor length of the second resonant cavity, and the inner conductor length of the first resonant cavity is smaller than the inner conductor length of the second resonant cavity.

[0010] Further, the length of the first resonant cavity is:

[0011]

[0012] wherein L is the length of the first resonant cavity, P is a positive integer, and λ is the resonant wavelength. r

[0013] Further, the first resonant cavity is provided with a first resonant cavity tuner, an even harmonic generator, and a sampler; the number of the even harmonic generators is set according to the use requirement, and the number of the even harmonic generators is the same as the number of the samplers.

[0014] Further, the first resonant cavity tuner is provided in two.

[0015] Further, the second resonant cavity is provided with a second resonant cavity tuner, an odd harmonic generator, and a sampler; the second resonant cavity tuner is provided in at least two, and the odd harmonic generator is located between the two second resonant cavity tuners.

[0016] Further, the sampler is provided in at least two.

[0017] Further, the resonant frequency f of the first resonant cavity is:

[0018]

[0019] wherein c is the speed of light, p is a natural number, and L is the length of the first resonant cavity;

[0020] The basic frequency of the first resonant cavity is set as twice the basic frequency of the second resonant cavity.

[0021] Further, the electrode plate is provided in an X shape, and a gap for the electron beam to pass through is arranged at the geometric center position of the electrode plate; any harmonic wave is synthesized in the gap of the electrode plate, and the synthesis method is:

[0022] According to the requirement, the required harmonic number and the basic frequency are calculated, the first resonant cavity and the second resonant cavity are configured respectively, the input voltage and phase are adjusted, all modes are generated in the gap between the two ports of the electrode plate, the harmonic superposition is realized on the electrode plate, and the required waveform is synthesized.

[0023] Further, the shape of the electrode plate is an approximate hollow cylinder.​

[0024] The present application has the following advantages due to the above technical solutions:

[0025] 1. The present application can generate different order sine and cosine triangular signals (harmonics), and realize synthesis of arbitrary waveforms through superposition.

[0026] 2. The present application breaks through the limitation of traditional structure that cannot generate fourth, eighth and other harmonics, and can generate harmonics of any order, so that the design of harmonic synthesis scheme is not limited by frequency and voltage, and periodic waveforms of any frequency and voltage can be synthesized.

[0027] 3. The present application basically gets rid of the limitation of frequency and voltage through resonance, and utilizes a resonator to synthesize multiple harmonics, so as to realize synthesis of arbitrary periodic signals with high voltage and high frequency. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a structure schematic diagram of an arbitrary waveform synthesis device in an embodiment of the present application;

[0029] Figure 2 is a structure schematic diagram of a device for synthesizing sawtooth waves with fifth harmonics in an embodiment of the present application;

[0030] Figure 3 is a system structure schematic diagram of a device for synthesizing sawtooth waves with fifth harmonics in an embodiment of the present application;

[0031] Figure 4 is a linearity comparison diagram of synthesizing sawtooth waves with second, third, fourth and fifth harmonics in an embodiment of the present application. DETAILED DESCRIPTION

[0032] To make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the embodiments of the present application will be described clearly and completely below in combination with the drawings of the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the described embodiments of the present application, all other embodiments obtained by those skilled in the art belong to the scope of protection of the present application.

[0033] It should be noted that the terms used herein are only intended to describe specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and it should also be understood that when the terms "comprise" and / or "include" are used in the specification, there is a presence of a feature, step, operation, device, component and / or combination thereof.

[0034] The existing multi-harmonic synthesizer is composed of two quarter wavelength resonant cavities (QWR), and the working principles of the two cavities are the same. The resonant frequency f' of the quarter wavelength resonant cavity is:

[0035]

[0036] In the formula, c is the speed of light, p is a natural number, and L is the cavity length.

[0037] The basic frequency f0 of the quarter wavelength resonant cavity is:

[0038]

[0039] Therefore, a single cavity can only work at odd multiples of the basic frequency f0, i.e. f0, 3f0, 5f0,...

[0040] In order to supplement the frequency of 2f0, the length of one of the cavities is shortened (reduced by 1 / 2), i.e. the working frequency of the short cavity is an odd multiple of 2f0, i.e. 2f0, 6f0, 10f0,...

[0041] Due to the lack of the fourth harmonic (4f0), the harmonic synthesis can only be selected up to the third harmonic synthesis scheme.

[0042] In order to solve the problem of lack of fourth harmonic, eighth harmonic,..., and the limitation of only up to third harmonic synthesis in the prior art, according to Fourier expansion, any periodic function f(t) can be represented by an infinite series of sine and cosine triangular functions as:

[0043]

[0044] In the formula, ω0 is the angular frequency, n is a positive integer, a0 is the direct current component, a n is the amplitude of the n-th frequency cosine harmonic, b n is the amplitude of the n-th frequency sine harmonic, and t is time.

[0045] The present application can generate sine and cosine triangular signals (harmonics) of different orders, and realize the synthesis of any waveform through superposition.

[0046] The present application breaks through the limitation of traditional structure that cannot generate fourth, eighth and other harmonics, and can generate harmonics of any order. Therefore, the design of the harmonic synthesis scheme is not limited by frequency and voltage, and periodic waveforms of any frequency and voltage can be synthesized.

[0047] In one embodiment of the present application, an arbitrary waveform synthesizer is provided. As shown in Figure 1 , the device comprises:

[0048] A vacuum box 6, in which an electrode plate 7 is arranged, and the upper and lower ends of the vacuum box 1 are respectively provided with through holes for beam to pass through;

[0049] A first resonant cavity 8 is arranged on one side of the vacuum box 6, and is used for concentrating the generated even-order electric field on the upper end of the electrode plate 7.

[0050] A second resonant cavity 9 is arranged on one side of the vacuum box 6 in parallel with the first resonant cavity 8 and below the first resonant cavity 8, and is used for concentrating the generated odd-order electric field on the lower end of the electrode plate 7.

[0051] The first resonant cavity 8 adopts a half-wavelength resonant cavity, and the second resonant cavity 9 adopts a quarter-wavelength resonant cavity.

[0052] In the above embodiment, the outer conductor length of the first resonant cavity 8 is the same as that of the second resonant cavity 9, but the inner conductor is different, and the inner conductor length of the first resonant cavity 8 is smaller than that of the second resonant cavity 9.

[0053] In the present embodiment, the length L of the first resonant cavity 8 is:

[0054]

[0055] Wherein, P is a positive integer, λ r is the resonant wavelength.

[0056] In the above embodiment, the first resonant cavity 8 is provided with a first resonant cavity tuner 5, an even-order harmonic generator 2 and a sampler 3. The number of even-order harmonic generators 2 is set according to the use requirement, and the number of even-order harmonic generators 2 is the same as that of the sampler 3.

[0057] In the present embodiment, the first resonant cavity tuner 5 is provided with two, and all the even-order harmonic generators 2 are located between the two first resonant cavity tuners 5.

[0058] In the above embodiment, the second resonant cavity 9 is provided with a second resonant cavity tuner 4, an odd-order harmonic generator 1 and a sampler 3; all the strong magnetic regions of the harmonic are arranged away from one end of the vacuum box 6, and the components can be arranged in coincidence, preferably, the odd-order harmonic generator 1 is arranged in the strong magnetic region. The second resonant cavity tuner 4 is provided with at least two, and the odd-order harmonic generator 1 is arranged on the second resonant cavity 9 away from the vacuum box 6, and the odd-order harmonic generator 1 is located between the two second resonant cavity tuners 4.

[0059] In the present embodiment, the sampler 3 is provided with at least two, and the specific number is set according to the use requirement.

[0060] In the above embodiment, the first resonant cavity 8 adopts a half-wavelength resonant cavity, and the resonant frequency f thereof is:

[0061]

[0062] In the formula, c is the speed of light, p is a natural number, and L is the length of the first resonant cavity 8.

[0063] The fundamental frequency f of the half-wavelength resonant cavity H for:

[0064]

[0065] Therefore, it can be concluded that the first resonant cavity 8 can operate at the fundamental frequency f. H Any integer multiple of f, i.e.: H ,2f H ,3f H , ...

[0066] In the above embodiment, the resonant frequency of the second resonant cavity 9 is an odd number of frequencies, namely f0, 3f0, 5f0, ...

[0067] In this embodiment, to supplement the harmonic with a frequency of 2f0, the fundamental frequency of the first resonant cavity 8 is set to 2f0 (this can be achieved by changing the cavity length; in this embodiment, the first resonant cavity 8 and the second resonant cavity 9 are of the same length). That is, the operating frequency of the first resonant cavity 8 is an integer multiple of 2f0 (2f0, 4f0, 6f0, 8f0, ...).

[0068] The structure of this invention overcomes the limitation of existing technologies in generating 4th and 8th harmonics, thus enabling the synthesis of waveforms of any order. For the synthesized signal, the number of harmonics directly determines the signal quality. The more harmonics used, the closer the synthesized signal is to the desired signal.

[0069] In the above embodiment, the electrode plates 7 inside the vacuum chamber 6 are arranged in an approximately X-shape, and a gap for the electron beam to pass through is provided at the geometric center of the electrode plates 7. Any harmonic can be synthesized within the gap of the electrode plates 7.

[0070] The synthesis method is as follows: Since the first resonant cavity 8 is located above the second resonant cavity 9, during resonance, the first resonant cavity 8 and the second resonant cavity 9 work relatively independently. The even-order electric field is concentrated at the upper end of the electrode plate 7, and the odd-order electric field is concentrated at the lower end of the electrode plate 7. According to the requirements, the required harmonic order and fundamental frequency are calculated, and the two resonant cavities are configured respectively. The input voltage and phase are adjusted, and all modes are generated in the gap between the two ports of the electrode plate 7. That is, harmonic superposition is realized on the electrode, and the required waveform is synthesized, thereby realizing the synthesis of arbitrary waveforms.

[0071] This invention breaks through the structural limitation of traditional schemes that cannot generate even-numbered harmonics, and can realize the synthesis of arbitrary periodic waveforms.

[0072] Embodiment: Based on the actual engineering, in this embodiment, a five harmonic synthesis sawtooth wave device is set up, the device structure is as shown in Figure 2 The first, third and fifth harmonic generator 1, the second harmonic generator 2 and the fourth harmonic generator 10 are all composed of corresponding couplers and tuners. In order to save space, the first harmonic frequency generated by the first, third and fifth harmonic generator 1 is 40MHz, the third harmonic frequency is 120MHz, and the fifth harmonic frequency is 200MHz. The second harmonic frequency generated by the second harmonic generator 2 is 80MHz, and the fourth harmonic frequency generated by the fourth harmonic generator 10 is 160MHz. Each frequency has a corresponding tuner to ensure that the resonant cavity works at the correct resonant frequency. Through the correct installation position of the tuner, the individual debugging between each frequency can be realized.

[0073] In order to achieve higher efficiency, the shape of the electrode plate 7 in the vacuum box 6 is an approximate hollow cylinder, and the first resonant cavity 8 and the second resonant cavity 9 work relatively independently to generate second and fourth harmonics and first, third and fifth harmonics respectively. Finally, the synthesized sawtooth wave electric field is realized in the gap of the electrode plate 7.

[0074] As shown in Figure 3 The entire five harmonic synthesis system composition, five-way signal has independent tuning ability of amplitude and phase, the radio frequency system also includes a plurality of power combiner, directional coupler, circulator and temperature, power and other state monitoring and communication module. Control unit, water cooling system and power transmission system.

[0075] As shown in Figure 4 The final five harmonic synthesis sawtooth wave pattern (other waveforms are also generated by the same principle), due to the theoretical limitations of five synthesis, its linearity and efficiency have limits, if there is a higher precision requirement, the harmonic number can be increased, and theoretically this scheme can realize arbitrary harmonic superposition synthesis.

[0076] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An arbitrary waveform synthesizing device characterized by comprising: The application relates to a vacuum box body, which is internally provided with an electrode plate, and the upper and lower ends of the vacuum box body are respectively provided with through holes for beam passing; a first resonant cavity is arranged on one side of the vacuum box body and used for concentrating generated even-order electric fields on the upper end of the electrode plate; a second resonant cavity is arranged on one side of the vacuum box body in parallel with the first resonant cavity and below the first resonant cavity, and is used for concentrating generated odd-order electric fields on the lower end of the electrode plate; the first resonant cavity adopts a half-wavelength resonant cavity, and the second resonant cavity adopts a quarter-wavelength resonant cavity; a first resonant cavity tuner, an even-order harmonic generator and a sampler are arranged on the first resonant cavity; the number of the even-order harmonic generators is arranged according to use requirements, and the number of the even-order harmonic generators is the same as that of the samplers; a second resonant cavity tuner, an odd-order harmonic generator and a sampler are arranged on the second resonant cavity; the second resonant cavity tuner is arranged at least in two, and the odd-order harmonic generator is located between the two second resonant cavity tuners. The outer conductor length of the first resonant cavity is the same as that of the second resonant cavity, and the inner conductor length of the first resonant cavity is smaller than that of the second resonant cavity. The length of the first resonant cavity is: The first resonant cavity tuner is arranged in two. The sampler is arranged at least in two. The resonant frequency f of the first resonant cavity is: In the formula, c is the speed of light, p is a natural number, and L is the length of the first resonant cavity.

2. The arbitrary waveform synthesizing apparatus of claim 1, wherein The basic frequency of the first resonant cavity is set as twice the basic frequency of the second resonant cavity.

3. The arbitrary waveform synthesizing apparatus of claim 2, wherein The electrode plate adopts an X-shaped arrangement, and a gap for electron beam passing is arranged at the geometric center position of the electrode plate; any order harmonic is synthesized in the gap of the electrode plate, and the synthesis method is: where L is the length of the first resonant cavity, P is a positive integer, and λ r is the resonant wavelength.

4. The arbitrary waveform synthesizing apparatus of claim 1, wherein According to requirements, the required harmonic order and the basic frequency are calculated, the first resonant cavity and the second resonant cavity are configured, the input voltage and phase are adjusted, all modes are generated in the gap between the two ports of the electrode plate, the harmonic superposition is realized on the electrode plate, and the required waveform is synthesized.

5. The arbitrary waveform synthesizing apparatus of claim 1, wherein The shape of the electrode plate is an approximate hollow cylinder.

6. The arbitrary waveform synthesizing apparatus of claim 1, wherein ​ ​ ​ 7. The arbitrary waveform synthesizing apparatus of claim 1, wherein ​ ​ 8. The arbitrary waveform synthesizing apparatus of claim 7, wherein ​

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