High-power microwave beat wave generator based on Ka-band to P-band beat frequency generation

Abstract

The present invention relates to a high-power microwave beat wave generator based on the Ka-band, which generates a P-band beat frequency. The device comprises two high-frequency structures: an external electromagnetic structure and an internal electromagnetic structure. The external electromagnetic structure includes an external cathode seat, an external cathode, an anode outer cylinder, an external cutoff neck, an external reflection cavity, an external first slow-wave structure, an external drift cavity, an external second slow-wave structure, an output waveguide, and a coil magnetic field. The internal electromagnetic structure includes an internal cathode seat, an internal cathode, an internal conductor, an internal cutoff neck, an internal modulation cavity, an internal first slow-wave structure, an internal drift cavity, and an internal second slow-wave structure. The fundamental wave of the device operates in the Ka-band, ultimately generating a beat wave with a P-band beat frequency. The device has a wide operating frequency band span and rich frequency components, making it effectively adaptable to various operating environments.

Description

Technical Field

[0001] The present invention relates to a microwave source device in the field of high-power microwave technology, in particular to a high-power microwave beat wave generating device based on Ka-band to generate P-band beat frequency, belonging to the field of high-power microwave technology. Background Art

[0002] As research into high-power microwave (HPM) effects deepens, researchers believe that, compared to traditional single-frequency microwaves, beat waves have higher instantaneous power and contain a richer range of frequency components. Using beat waves to attack electronic equipment can effectively lower the target's damage threshold. Therefore, research into beat wave generation holds significant research significance across all sectors of the national economy. Generating beat waves requires synthesizing two or more microwaves of similar frequencies in space. During this process, the phase difference between the microwaves gradually increases or decreases. For example, when two microwaves synthesize a beat wave, at certain moments, the phase difference between the two microwaves reaches an extreme value, causing interference and increasing the amplitude of the synthesized microwave waveform.

[0003] In the research of HPM beat wave generating devices, the main related work is as follows:

[0004] In 2003, Northwest Institute of Nuclear Technology proposed to use klystron amplifier to generate HPM beat wave (hereinafter referred to as prior art 1, such as Figure 1 (As shown). This technical solution utilizes the output microwaves of two milliwatt-level microwave signal sources, which are combined into one microwave using a power combiner. This microwave is then amplified in stages by a solid-state amplifier and a klystron amplifier, ultimately resulting in a megawatt-level microwave output. Because the two milliwatt-level microwave signal sources are incoherent, the microwaves synthesized through incoherent synthesis are beat waves. Ultimately, this solution achieved a maximum output power of 1 MW at a main operating frequency of 2.85 GHz, with a high-power beat wave output with an adjustable beat frequency range of 20-120 MHz. To achieve a continuously adjustable beat wave output, this solution employed a low-power signal source for beat wave synthesis, but the output power of this solution was not high, with the maximum beat wave power reaching only 1 MW.

[0005] In 2013, the University of Electronic Science and Technology of China proposed a single electron beam dual-band coaxial relativistic backward wave tube (hereinafter referred to as prior art 2, such as Figure 2This technical solution utilizes a coaxial electron beam to drive a coupled impedance-jump slow-wave structure. The slow-wave structures at both ends excite microwaves of different frequencies. This dual-frequency microwave system produces a beat-wave effect, which in turn outputs HPM beat waves. With a diode voltage of 511 kV, an electron beam current of 8.95 kA, and a guiding magnetic field of 0.73 T, this solution achieved a microwave output of 1.0 GW at two frequencies of 8.09 GHz and 9.91 GHz, respectively, with a beat frequency of 1.82 GHz. This solution achieves gigawatt-level beat-wave output, but the beat frequency is still relatively high compared to the operating frequency of electronic devices.

[0006] An analysis of the above research status shows that although HPM beat wave generating devices have made great progress, most technical solutions have the problem of frequency and power not being able to be balanced. As the operating frequency of devices rapidly expands to high frequency bands, how to achieve high-power beat wave output at higher frequency bands has become an urgent problem that needs to be solved. Summary of the Invention

[0007] The technical problem to be solved by the present invention is: the present invention proposes a high-power microwave beat wave generating device based on the Ka-band to generate P-band beat frequency. Unlike the traditional beat wave generation scheme in which the fundamental frequency and beat frequency are both in the low frequency band, the present invention is based on the Ka-band internal and external nested HPM oscillator, which directly couples the output of the internal oscillator to the external oscillator, forms a beat wave effect inside the oscillator, and outputs HPM beat waves of the P-band beat frequency, which has the advantages of compact structure and rich frequency components.

[0008] The technical solution of the present invention is:

[0009] The high-power microwave beat wave generating device for generating P-band beat frequency based on the Ka-band is composed of two sets of high-frequency structures: an external electromagnetic structure and an internal electromagnetic structure. The external electromagnetic structure includes an external cathode seat, an external cathode, an anode outer cylinder, an external cutoff neck, an external reflection cavity, an external first slow-wave structure, an external drift cavity, an external second slow-wave structure, an output waveguide, and a coil magnetic field. The internal electromagnetic structure includes an internal cathode seat, an internal cathode, an inner conductor, an inner cutoff neck, an internal modulation cavity, an internal first slow-wave structure, an internal drift cavity, and an internal second slow-wave structure.

[0010] The outer cathode and the inner cathode are both thin-walled cylinders with a wall thickness of 1 mm. The radii of the outer cathode and the inner cathode are R1 and R'1 respectively, and are respectively sleeved on the right ends of the outer cathode seat and the inner cathode seat;

[0011] The outer first slow-wave structure consists of four annular cavities with an outer radius of R5, an inner radius of R2, and a width of L4, and four disks with a radius of R2 and a width of L5, satisfying R5>R2, L4 is 1mm-1.6mm, and L5 is 1.5mm-2.5mm; the outer drift cavity is a annular cavity with an outer radius of R5, an inner radius of R2, and a width of L6, where L6 is 0.7-1 times the working wavelength λ2; the outer second slow-wave structure consists of six annular cavities with an outer radius of R5, an inner radius of R2, and a width of L4, and seven disks with a radius of R2 and a width of L5;

[0012] The first inner slow-wave structure consists of three circular cavities with an outer radius of R`4, an inner radius of R`2, and a width of L`4, and three disks with a radius of R`2 and a width of L`5, satisfying R`4>R`2, L`4 takes a value of 1.6mm-2.0mm, and L`5 takes a value of 1.4mm-1.8mm; the inner drift cavity is a circular cavity with an outer radius of R`5, an inner radius of R`2, and a width of L`6, satisfying R`5>R`2, and L`6 takes a value of 1.1-1.4 times the working wavelength λ1; the second inner slow-wave structure consists of eight circular cavities with an outer radius of R`4, an inner radius of R`2, and a width of L`4, and eight disks with a radius of R`2 and a width of L`5.

[0013] The outer cutoff neck is a circular ring cavity with an outer radius of R2, an inner radius of R3, and a width of L1, satisfying R2>R3. L1 is optimized according to the phase of the external electron beam entering the external electromagnetic structure, and its value is 0.4-0.7 times the working wavelength λ2.

[0014] The inner cutoff neck is a cylindrical cavity with a radius of R'2 and a width of L'1. L'1 is optimized according to the phase of the inner electron beam entering the internal electromagnetic structure and is set to 0.9-1.3 times the operating wavelength λ1.

[0015] The external modulation cavity is a circular ring-shaped cavity with an outer radius of R4, an inner radius of R2, and a width of L2, satisfying R4>R2, and L2 is 0.5-0.8 times the working wavelength λ2; the external modulation cavity and the outer first slow-wave structure are connected by a circular ring-shaped cavity with an outer radius of R2, an inner radius of R3, and a width of L3, and L3 is 0.8-1.5 times the working wavelength λ2;

[0016] The external output waveguide is a circular waveguide with an outer radius of R5 and an inner radius of R3, and a length L7 that is 3-5 times the operating wavelength λ2;

[0017] The inner modulation cavity is a circular ring-shaped cavity with an outer radius of R`3, an inner radius of R`2, and a width of L`2, satisfying R`3>R`2, and L`2 is 0.5-0.8 times the working wavelength λ1; the inner modulation cavity and the inner first slow-wave structure are connected by a cylindrical cavity with a radius of R`2 and a width of L`3, and L`3 is 0.5-0.8 times the working wavelength λ1;

[0018] Between the inner second slow-wave structure and the thick wall on the right side of the inner conductor is a cylindrical cavity with a radius of R'2 and a width of L'7, where L'7 is 2-3 times the working wavelength λ1.

[0019] The coil magnetic field is sheathed on the outer wall of the anode outer cylinder 303a, and the coil magnetic field can be energized to transmit the inner and outer electron beams to the inner and outer electromagnetic structures respectively.

[0020] The working process of the present invention is as follows: the high voltage generated by the pulse drive source acts on the outer cathode and inner cathode through the outer cathode seat and the inner cathode seat. The right end surfaces of the outer cathode and the inner cathode generate a double-ring electron beam based on explosive emission. Under the guidance of the coil magnetic field, the inner and outer electron beams are transmitted axially. The inner and outer electron beams enter the internal electromagnetic structure and the outer electromagnetic structure respectively. The outer electron beam eventually bombards the inner surface of the anode outer cylinder, and the inner electron beam eventually bombards the inner surface of the inner conductor. Because the inner conductor is a closed structure, the HPM generated by the internal electromagnetic structure will be totally reflected into the diode area and ultimately coupled into the external electromagnetic structure. Because the operating frequency of the internal electromagnetic structure is different from the operating frequency of the external electromagnetic structure, the HPM generated from the internal electromagnetic structure and leaked into the external electromagnetic structure will be subjected to frequency modulation of the external electron beam, thereby causing the HPM to produce a beat wave effect in the external electromagnetic structure, that is, generating an HPM beat wave. The HPM beat wave generated by the oscillation is ultimately radiated outward through the output waveguide.

[0021] Compared with the prior art, the present invention can achieve the following technical effects:

[0022] 1. The high-power microwave beat-wave generator device proposed in this invention, which generates P-band beat frequencies from the Ka-band, operates with its fundamental wave in the Ka-band, ultimately generating beat waves at the P-band beat frequency. Its wide operating frequency band and rich frequency components make it adaptable to various operating environments.

[0023] 2. The high-power microwave beat wave generating device based on Ka-band to generate P-band beat frequency proposed in the present invention can achieve an instantaneous power of 2GW compared with the traditional Ka-band HPM generating device, which greatly improves the power level of Ka-band HPM and provides a feasible technical route for increasing the output power of Ka-band HPM generating devices.

[0024] 3. Compared with the traditional beat wave generation technology route, the high-power microwave beat wave generating device based on Ka-band to generate P-band beat frequency proposed in the present invention does not require an external subsequent power synthesis structure and can generate a beat wave effect inside the device, which has guiding significance for the miniaturization and compactness of the beat wave generation system.

[0025] Please refer to the following description of various embodiments of the high-power microwave beat wave generating device based on Ka-band to generate P-band beat frequency according to the present invention, which will make the above and other aspects of the present invention apparent. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of an experiment for generating high-power microwave beat waves using a klystron amplifier disclosed in prior art 1 in the background introduction;

[0027] Figure 2 This is a schematic structural diagram of the single electron beam dual-band coaxial relativistic backward wave tube disclosed in the prior art 2 in the background introduction;

[0028] In the figure: 201 is a cathode, 202 is a reflective cavity, 203 is a first slow-wave structure, 204 is a second slow-wave structure, 205 is an electron beam, and 206 is an inner conductor;

[0029] Figure 3 A-A cross-sectional view of a preferred embodiment of a high-power microwave beat wave generating device based on Ka-band to generate P-band beat frequency proposed by the present invention;

[0030] 301a is the outer cathode seat, 302a is the outer cathode, 303a is the anode outer cylinder, 304a is the outer cutoff neck, 305a is the outer reflection cavity, 306a is the outer first slow-wave structure, 307a is the outer drift cavity, 308a is the outer second slow-wave structure, 309a is the output waveguide, 310 is the coil magnetic field, 301b is the inner cathode seat, 302b is the inner cathode, 303b is the inner conductor, 304b is the inner cutoff neck, 305b is the inner modulation cavity, 306b is the inner first slow-wave structure, 307b is the inner drift cavity, and 308b is the inner second slow-wave structure;

[0031] Figure 4 This is a radial electric field diagram of the output microwave of a preferred embodiment of a high-power microwave beat wave generating device based on Ka-band to generate P-band beat frequency proposed by the present invention;

[0032] Figure 5 This is a spectrum diagram of the output microwave in the Ka band of a preferred embodiment of the high-power microwave beat wave generating device for generating P-band beat frequency based on the Ka band proposed by the present invention;

[0033] Figure 6This is a spectrum diagram of the output microwave in the P-band of a preferred embodiment of the high-power microwave beat wave generating device based on the Ka-band to generate P-band beat frequency proposed by the present invention;

[0034] Figure 7 This is a diagram of the instantaneous power of the output microwaves of a preferred embodiment of the high-power microwave beat wave generating device for generating P-band beat frequency based on the Ka-band proposed by the present invention;

[0035] Figure 8 This is a diagram of the output microwave average power of a preferred embodiment of the high-power microwave beat wave generating device for generating P-band beat frequency based on the Ka-band proposed by the present invention. DETAILED DESCRIPTION

[0036] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0037] The present invention comprises two high-frequency structures: an external electromagnetic structure and an internal electromagnetic structure. The external electromagnetic structure includes an external cathode holder 301a, an external cathode 302a, an anode outer cylinder 303a, an external cutoff neck 304a, an external reflection cavity 305a, an external first slow-wave structure 306a, an external drift cavity 307a, an external second slow-wave structure 308a, an output waveguide 309a, and a coil magnetic field 310. The internal electromagnetic structure includes an internal cathode holder 301b, an internal cathode 302b, an inner conductor 303b, an internal cutoff neck 304b, an internal modulation cavity 305b, an internal first slow-wave structure 306b, an internal drift cavity 307b, and an internal second slow-wave structure 308b. The entire structure is rotationally symmetrical about its central axis.

[0038] The outer cathode holder 301a, inner cathode holder 301b, anode outer cylinder 303a, and inner conductor 303b are typically made of non-magnetic stainless steel. The outer cathode 302a and inner cathode 302b can be made of high-hardness graphite or heat-resistant glass cloth-epoxy resin copper-clad laminate (FR-5). The magnetic field coil 310 is wound with enameled copper wire or glass-fiber-wrapped copper wire. The left end of the outer cathode holder 301a is connected to the inner conductor of an external pulse power source, while the left end of the anode outer cylinder 303a is connected to the outer conductor of the external pulse power source.

[0039] When the present invention is in operation, a pulse power drive source applies a high voltage to the outer cathode holder 301a, causing the outer cathode 302a and the inner cathode 302b to emit a dual-annular electron beam. First, the outer electron beam and the inner electron beam are pre-modulated in the outer reflection cavity 305a and the inner modulation cavity 305b, respectively, i.e., initial velocity modulation. The inner and outer electron beams then undergo further velocity modulation at the inner and outer first slow-wave structures, where the velocity modulation gradually turns into density modulation, and the electron beams cluster. The clustered electron beams generate Cherenkov radiation at the inner and outer second slow-wave structures, thereby generating HPM. The HPM generated by the internal electromagnetic structure is totally reflected to the diode region and coupled to the external electromagnetic structure via the diode region. The HPMs of the two frequencies will produce a beat wave effect in the external electromagnetic structure, and the resulting beat wave will radiate outward via the output waveguide 309a.

[0040] This embodiment realizes that the internal and external operating frequencies are f1=29.94GHz and f2=30.20GHz (corresponding to microwave wavelengths 1=10.02mm and 2= A high-power microwave beat wave generator based on Ka-band and P-band beat frequency is designed (9.93mm) (the corresponding dimensions are designed as follows: R1=33mm, R2=36mm, R3=31mm, R4=38mm, R5=37.6mm, R`1=20mm, R`2=23mm, R`3=25mm, R`4=24.6mm, R`5=25mm, L1=5mm, L2=6.6mm, L3=11mm, L4=1.4mm, L5=2mm, L6=8.4mm, L7=40mm, L`1=11mm, L`2=7mm, L`3=7.4mm, L`4=1.8mm, L`5=1.6mm, L`6=13.2mm, L`7=25mm).

[0041] In particle simulations, under the conditions of a diode voltage of 460 kV, an external current of 4.5 kA, an internal current of 3.1 kA, and a guiding magnetic field of 0.8 T, the output microwaves contained three frequency components: 29.94 GHz, 30.20 GHz, and 0.26 GHz, with an instantaneous peak power of 2 GW. These results demonstrate that, based on the Ka-band, the present invention utilizes two Ka-band HPM channels (29.94 GHz and 30.20 GHz) to generate an HPM beat wave with a P-band beat frequency (0.26 GHz).

[0042] See also Figure 4 It can be seen that when t=20ns, the outer envelope of the radial electric field of the output waveguide has fluctuated periodically, that is, the beat wave effect has occurred.

[0043] See also Figure 5 It can be seen that the spectrum of the microwave output by the device has two components in the Ka band, which are 29.94 GHz and 30.20 GHz respectively.

[0044] See also Figure 6 It can be seen that the spectrum of the microwave output by the device has a component in the P band, which is 0.26 GHz, that is, the beat frequency is 0.26 GHz.

[0045] See also Figure 7 , it can be seen that the instantaneous peak power of the microwave output by the device is 2GW.

[0046] See also Figure 8 It can be seen that the average peak power of the device's microwave output is 1GW. Compared with the existing Ka-band high-power microwave generating devices, this device can achieve GW-level output power, which can greatly improve the power level of the Ka-band.

Claims

1. A high-power microwave beat wave generator device for generating P-band beat frequencies based on the Ka-band, characterized by: The device is composed of two sets of high-frequency structures, an external electromagnetic structure and an internal electromagnetic structure: the external electromagnetic structure includes an external cathode seat, an external cathode, an anode outer cylinder, an external cutoff neck, an external reflection cavity, an external first slow-wave structure, an external drift cavity, an external second slow-wave structure, an output waveguide, and a coil magnetic field; the internal electromagnetic structure includes an internal cathode seat, an internal cathode, an internal conductor, an internal cutoff neck, an internal modulation cavity, an internal first slow-wave structure, an internal drift cavity, and an internal second slow-wave structure; The outer cathode and inner cathode have radii of R1 and R'1, which are respectively sleeved on the right ends of the outer cathode seat and the inner cathode seat; The outer first slow-wave structure consists of four annular cavities with an outer radius of R5, an inner radius of R2, and a width of L4, and four disks with a radius of R2 and a width of L5, satisfying R5>R2, L4 is 1mm-1.6mm, and L5 is 1.5mm-2.5mm; the outer drift cavity is a annular cavity with an outer radius of R5, an inner radius of R2, and a width of L6, where L6 is 0.7-1 times the working wavelength λ2; the outer second slow-wave structure consists of six annular cavities with an outer radius of R5, an inner radius of R2, and a width of L4, and seven disks with a radius of R2 and a width of L5; The first inner slow-wave structure consists of three circular cavities with an outer radius of R`4, an inner radius of R`2, and a width of L`4, and three disks with a radius of R`2 and a width of L`5, satisfying R`4>R`2, L`4 takes a value of 1.6mm-2.0mm, and L`5 takes a value of 1.4mm-1.8mm; the inner drift cavity is a circular cavity with an outer radius of R`5, an inner radius of R`2, and a width of L`6, satisfying R`5>R`2, and L`6 takes a value of 1.1-1.4 times the working wavelength λ1; the second inner slow-wave structure consists of eight circular cavities with an outer radius of R`4, an inner radius of R`2, and a width of L`4, and eight disks with a radius of R`2 and a width of L`5.

2. The high-power microwave beat wave generating device for generating P-band beat frequency based on Ka-band according to claim 1, characterized in that: The outer cathode and the inner cathode are both thin-walled cylinders with a wall thickness of 1 mm.

3. The high-power microwave beat wave generating device for generating P-band beat frequency based on Ka-band according to claim 1, characterized in that: The outer cutoff neck is a circular ring cavity with an outer radius of R2, an inner radius of R3, and a width of L1, satisfying R2>R3. L1 is optimized according to the phase of the external electron beam entering the external electromagnetic structure, and its value is 0.4-0.7 times the working wavelength λ2.

4. The high-power microwave beat wave generating device for generating P-band beat frequency based on Ka-band according to claim 1, characterized in that: The inner cutoff neck is a cylindrical cavity with a radius of R'2 and a width of L'1. L'1 is optimized according to the phase of the inner electron beam entering the internal electromagnetic structure and is set to 0.9-1.3 times the operating wavelength λ1.

5. The high-power microwave beat wave generating device for generating P-band beat frequency based on Ka-band according to claim 1, characterized in that: The external modulation cavity is a circular ring cavity with an outer radius of R4, an inner radius of R2, and a width of L2, satisfying R4>R2, and L2 is 0.5-0.8 times the working wavelength λ2; the external modulation cavity and the external first slow-wave structure are connected by a circular ring cavity with an outer radius of R2, an inner radius of R3, and a width of L3, and L3 is 0.8-1.5 times the working wavelength λ2.

6. The high-power microwave beat wave generating device for generating P-band beat frequency based on Ka-band according to claim 1, characterized in that: The outer output waveguide is a circular waveguide with an outer radius of R5 and an inner radius of R3, and a length L7 that is 3-5 times the working wavelength λ2.

7. The high-power microwave beat wave generating device for generating P-band beat frequency based on Ka-band according to claim 1, characterized in that: The inner modulation cavity is a circular ring cavity with an outer radius of R`3, an inner radius of R`2, and a width of L`2, satisfying R`3>R`2, and L`2 is 0.5-0.8 times the working wavelength λ1; the inner modulation cavity and the inner first slow-wave structure are connected by a cylindrical cavity with a radius of R`2 and a width of L`3, and L`3 is 0.5-0.8 times the working wavelength λ1.

8. The high-power microwave beat wave generating device for generating P-band beat frequency based on Ka-band according to claim 1, characterized in that: Between the inner second slow-wave structure and the thick wall on the right side of the inner conductor is a cylindrical cavity with a radius of R'2 and a width of L'7, where L'7 is 2-3 times the working wavelength λ1.

9. The high-power microwave beat wave generating device for generating P-band beat frequency based on Ka-band according to claim 1, characterized in that: The coil magnetic field is sheathed on the outer wall of the anode outer cylinder (303a), and the coil magnetic field can be energized to transmit the inner and outer electron beams to the inner and outer electromagnetic structures respectively.

10. The high-power microwave beat wave generating device for generating a P-band beat frequency based on the Ka-band according to any one of claims 1 to 9, characterized in that: The internal and external operating frequencies are f1=29.94GHz and f2=30.20GHz, respectively, corresponding to microwave wavelengths 1=10.02mm and 2= The 9.93mm high-power microwave beat wave generator based on Ka-band to generate P-band beat frequency has the following dimensions: R1=33mm, R2=36mm, R3=31mm, R4=38mm, R5=37.6mm, R`1=20mm, R`2=23mm, R`3=25mm, R`4=24.6mm, R`5=25mm, L1=5mm, L2=6.6mm, L3=11mm, L4=1.4mm, L5=2mm, L6=8.4mm, L7=40mm, L`1=11mm, L`2=7mm, L`3=7.4mm, L`4=1.8mm, L`5=1.6mm, L`6=13.2mm, L`7=25mm.

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