High-power microwave antipodal Vivaldi antenna and parameter determination method

Abstract

The invention relates to the technical field of antennas, and discloses a high-power microwave antipodal Vivaldi antenna and a parameter determination method, so as to improve the power capacity of the antipodal Vivaldi antenna and improve the radiation gain of the antenna. In the antenna disclosed by the invention, the left comb-shaped metal oscillator and the right comb-shaped metal oscillator which are consistent in thickness are based on an all-metal structure; two middle vertical planes of the two comb-shaped metal oscillators based on a line segment where the thickness direction is located are two parallel planes which are equally spaced from the center of the metal floor, the inner contour and the outer contour of the middle vertical plane corresponding to the left comb-shaped metal oscillator respectively comprise two sections of gradual change curves, and the gradual change curve section at the bottom is connected with the metal floor through a rectangular square block; the inner and outer contours of the middle vertical plane corresponding to the right comb-shaped metal oscillator are respectively and directly connected with the metal floor through a section of gradual change curve; a cuboid empty groove which is dug and parallel to the rectangular metal floor is formed between the upper comb teeth of the left comb-shaped metal oscillator and the upper comb teeth of the right comb-shaped metal oscillator, and the cross sections, parallel to the middle vertical plane, of the comb-shaped metal oscillators are consistent in shape.

Description

Technical Field

[0001] The present invention relates to the field of antenna technology, and in particular to a high-power microwave antipodal Vivaldi antenna and a parameter determination method. Background Art

[0002] High-power microwave systems are generally composed of three modules: pulse power drive source, microwave source and radiation antenna. Among them, the working bandwidth of the ultra-wideband pulse power drive source working in the X-band generally does not exceed 1GHz; high-power microwave antenna refers to a radiation antenna that works in the range of 0.3-300GHz and has an input signal amplitude exceeding 100MW. Since the pulse power drive source at the back end of the high-power microwave antenna will output an extremely high-power pulse, the power capacity of the radiation antenna used in the high-power microwave system within the working frequency band is generally more than 8000W to prevent the electromagnetic wave transmitting device from being broken down.

[0003] The Vivaldi antenna is a special tapered slot antenna that uses an exponentially tapered slot line printed on the same side of a dielectric substrate to achieve a transition from a small size to a large size. Therefore, the Vivaldi antenna also has an extremely wide operating bandwidth. The antipodal Vivaldi antenna (also known as the "antipodal Vivaldi antenna") prints two exponentially tapered slot line oscillators on both sides of a dielectric substrate. Compared with ordinary Vivaldi antennas, the antipodal Vivaldi antenna has the advantages of achieving stable gain, improved cross-polarization, and a compact structure. It is widely used in wireless communications and radar detection. However, ordinary Vivaldi antennas are generally loaded on dielectric substrates with a dielectric constant of 2-5. Their power capacity is generally low, only 1000-3000W, and they are easily broken down in high-power microwave systems. Therefore, they cannot be used in high-power microwave systems.

[0004] The power capacity calculation method of a microwave device at a certain frequency point is: Among them, P in is the input power, which is set to 0.5W in the electromagnetic simulation software; E pr is the breakdown field strength in air environment, which is 3*10 6 V / m; E max is the maximum electric field strength value of the microwave device at this frequency. It can be seen that the power capacity of the microwave device is closely related to its electric field strength and is in inverse proportion. Therefore, in order to increase the power capacity, it is necessary to minimize the electric field strength of the microwave device within the working frequency band. Summary of the invention

[0005] The present invention aims to disclose a high-power microwave antipodal Vivaldi antenna and a parameter determination method, so as to increase the power capacity of the antipodal Vivaldi antenna, improve the radiation gain of the antenna, and further apply it to high-power microwave scenarios.

[0006] To achieve the above-mentioned purpose, the high-power microwave antipodal Vivaldi antenna disclosed in the present invention comprises two left and right comb-shaped metal oscillators of the same thickness based on an all-metal structure, a rectangular metal floor and a coaxial probe for feeding; the rectangular metal floor is provided with a circular groove, the right comb-shaped metal oscillator is connected to the coaxial probe for feeding, and the insulating medium outside the coaxial probe is embedded in the circular groove; the two mid-vertical planes of the two comb-shaped metal oscillators based on the line segments in the thickness direction are two parallel planes that are not in the same plane, and the two parallel planes are equidistant from the center of the metal floor; the inner and outer contours of the mid-vertical plane corresponding to the left comb-shaped metal oscillator each include two sections of gradual curves, and the bottom gradual curve section is connected to the metal floor via a rectangular block; the inner and outer contours of the mid-vertical plane corresponding to the right comb-shaped metal oscillator each are directly connected to the metal floor by a section of gradual curve; between the upper comb teeth of the left and right comb-shaped metal oscillators is a rectangular parallelepiped empty groove that is dug and parallel to the rectangular metal floor, and the shapes of the cross sections of each comb-shaped metal oscillator parallel to the mid-vertical plane are consistent.

[0007] Preferably, the comb teeth of the two left and right comb-shaped metal vibrators projected in the thickness direction are arranged symmetrically.

[0008] Preferably, the center of the rectangular metal bottom plate is taken as the origin, the direction perpendicular to the metal floor is taken as the Y axis, and the intersection of the median perpendicular plane of the line segment of the comb-shaped metal vibrator based on the thickness direction and the metal floor is taken as the X axis. The equation of the gradient curve is: y = ae x +b; where a and b are coefficients.

[0009] Preferably, the projections of the inner and outer gradient curves on the upper part of the left comb-shaped metal vibrator and the inner and outer gradient curves on the right comb-shaped metal vibrator in the thickness direction are arranged in a hand-shaped symmetrical arrangement.

[0010] Preferably, the external insulating dielectric material of the coaxial probe is PTFE (Polytetrafluoroethylene) with a dielectric constant of 2.2 and a radius of 2.05 mm; the inner conductor is a metal material with a radius of 0.635 mm; the height of the rectangular metal floor 2 is 3 mm, and the length and width are both 35 mm; the height of the right comb-shaped metal vibrator and the left comb-shaped metal vibrator are both 24 mm, the width of the bottom of the right comb-shaped metal vibrator is 1.9 mm, the width and height of the bottom of the left comb-shaped metal vibrator are 7.6 mm and 2 mm respectively, the distance between the left and right comb-shaped metal vibrators is 11.4 mm, and the thickness between the left and right comb-shaped metal vibrators is 1.3 mm; the metal material used in each part is aluminum alloy.

[0011] To achieve the above-mentioned purpose, the present invention also discloses a method for determining parameters of a high-power microwave antipodal Vivaldi antenna, which is used to prepare the high-power microwave antipodal Vivaldi antenna as described above, comprising: first determining the parameters of the gradient curve, then designing a rectangular slot and a branch structure to improve the antenna impedance characteristics, and then judging whether the power capacity, resonance depth and gain simulation results within the target frequency band meet the requirements. If not, returning to adjust the design parameters until the simulation results meet the requirements, and finally preparing a sample to measure the actual performance of the power capacity, resonance depth and gain.

[0012] The present invention has the following beneficial effects:

[0013] 1. The all-metal structure design of the toe-to-toe Vivaldi antenna improves the power capacity of the antenna, so that it can be used as a radiating antenna in high-power microwave systems.

[0014] 2. In the present invention, a rectangular metal floor is provided with a circular groove, the right comb-shaped metal vibrator is connected to the coaxial probe feeder, and the insulating medium outside the coaxial probe is embedded in the circular groove; the two mid-vertical planes of the two comb-shaped metal vibrators based on the line segment in the thickness direction are two parallel planes that are not in the same plane, and the two parallel planes are equidistant from the center of the metal floor; the inner and outer contours of the mid-vertical plane corresponding to the left comb-shaped metal vibrator each include two sections of gradient curves, and the bottom gradient curve section is connected to the metal floor through a rectangular block; the inner and outer contours of the mid-vertical plane corresponding to the right comb-shaped metal vibrator are directly connected to the metal floor by a section of gradient curve; between the upper comb teeth of the left and right comb-shaped metal vibrators is a rectangular parallelepiped empty groove that is dug and parallel to the rectangular metal floor. Based on the above-mentioned special proprietary structure, the gain improvement of the Vivaldi antenna can be greatly achieved.

[0015] The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0017] Figure 1 It is an iterative schematic diagram of the antenna disclosed in the embodiment of the present invention.

[0018] Figure 2 It is a front view of the high-power microwave antipodal Vivaldi antenna disclosed in an embodiment of the present invention after weakening the grayscale of the left comb-shaped metal oscillator.

[0019] Figure 3 The high-power microwave antipodal Vivaldi antenna disclosed in the embodiment of the present invention will Figure 2Special effect image after the transmission relationship between the left and right comb-shaped metal oscillators is swapped (not the rear view).

[0020] Figure 4 It is a left view of the high-power microwave antipodal Vivaldi antenna disclosed in an embodiment of the present invention.

[0021] Figure 5 It is a schematic diagram of S parameter simulation results corresponding to the embodiment of the present invention and two comparative schemes respectively.

[0022] Figure 6 It is a schematic diagram of power capacity simulation results corresponding to the embodiment scheme of the present invention and the iterative intermediate scheme respectively.

[0023] Figure 7 It is a schematic diagram of the maximum gain simulation result corresponding to the embodiment of the present invention.

[0024] Figure 8 It is a schematic diagram comparing the antenna simulation and measured return loss results disclosed in the embodiment of the present invention.

[0025] Fig. 9 , Fig.10 They are schematic diagrams of the results of the 9.8 GHz antenna simulation and measured directional patterns on the E plane and the H plane respectively according to the embodiments of the present invention. DETAILED DESCRIPTION

[0026] The embodiments of the present invention are described in detail below with reference to the accompanying drawings, but the present invention can be implemented in many different ways as defined and covered by the claims.

[0027] Example 1

[0028] Reference Figures 2 to 4 The high-power microwave antipodal Vivaldi antenna disclosed in this embodiment includes a coaxial probe 1 for feeding, a rectangular metal floor 2, a right comb-shaped metal vibrator 3, a left comb-shaped metal vibrator 4, an outer exponential gradient curve 5, an inner exponential gradient curve 6 and a comb-shaped slot structure 7.

[0029] The two left and right comb-shaped metal vibrators with the same thickness are based on a full metal structure, and the corresponding metal material can be aluminum alloy. The rectangular metal floor is provided with a circular groove, and the right comb-shaped metal vibrator is connected to the coaxial probe feeder, and the insulating medium outside the coaxial probe is embedded in the circular groove, thereby forming a fixed relationship between the left and right comb-shaped metal arrays.

[0030] In this embodiment, the two median perpendicular planes of the two comb-shaped metal vibrators based on the line segments in the thickness direction are two parallel planes that are not in the same plane, and the two parallel planes are equidistant from the center of the metal floor; the inner and outer contours of the median perpendicular plane corresponding to the left comb-shaped metal vibrator each include two sections of gradual curves, and the bottom gradual curve section is connected to the metal floor via a rectangular block; the inner and outer contours of the median perpendicular plane corresponding to the right comb-shaped metal vibrator are each directly connected to the metal floor by a section of gradual curve; between the upper comb teeth of the left and right comb-shaped metal vibrators is a rectangular parallelepiped empty groove parallel to the rectangular metal floor, and the shapes of the cross sections of each comb-shaped metal vibrator parallel to the median perpendicular plane are consistent.

[0031] Preferably, the comb teeth of the left and right comb-shaped metal vibrators are arranged symmetrically in the thickness direction; at the same time, the inner and outer gradient curves on the upper part of the left comb-shaped metal vibrator and the inner and outer gradient curves of the right comb-shaped metal vibrator are arranged symmetrically in the thickness direction. With the center of the rectangular metal bottom plate as the origin, the direction perpendicular to the metal floor as the Y axis, and the intersection of the median perpendicular plane of the line segment of the comb-shaped metal vibrator based on the thickness direction and the metal floor as the X axis, the equation of the gradient curve is: y = ae x +b; where a and b are coefficients.

[0032] Preferably, the external insulating dielectric material of the coaxial probe is PTFE (Polytetrafluoroethylene) with a dielectric constant of 2.2 and a radius of 2.05 mm; the inner conductor is a metal material with a radius of 0.635 mm; the height of the rectangular metal floor 2 is 3 mm, and the length and width are both 35 mm; the height of the right comb-shaped metal vibrator and the left comb-shaped metal vibrator are both 24 mm, the width of the bottom of the right comb-shaped metal vibrator is 1.9 mm, the width and height of the bottom of the left comb-shaped metal vibrator are 7.6 mm and 2 mm respectively, the distance between the left and right comb-shaped metal vibrators is 11.4 mm, and the thickness between the left and right comb-shaped metal vibrators is 1.3 mm; the values ​​of the coefficients a and b of the outer and inner exponential gradient curves are -28 and 15.9 and -9.9 and 24 respectively; the length and width of the comb-shaped groove structure 7 are 11 mm and 0.9 mm respectively, and the spacing between the rectangular grooves is 1 mm.

[0033] Figure 1This is a schematic diagram of the iterative process of the antenna of this embodiment. The power capacity of the toe-toed Vivaldi antenna (Ant I) loaded on a dielectric substrate cannot meet the power capacity requirements of the high-power microwave system. After the full metallization design of Ant I, a full-metal toe-toed Vivaldi antenna (Ant II) with qualified power capacity was obtained. The resonance depth of the fully metallized Ant II is less than -20dB, indicating that the reflection of electromagnetic waves is large. In a high-power microwave system, if the resonance depth of the terminal antenna is too shallow, the electronic components at the back end may be damaged. Therefore, on the basis of Ant II, rectangular slots and branch structures are introduced at the radiating oscillator and the ground end of the Vivaldi antenna, respectively, which can achieve the effect of improving the antenna impedance characteristics.

[0034] Figure 5 The S parameter simulation results of the present invention show that the -10dB and -15dB impedance bandwidths of the all-metal structure toe-comb Vivaldi antenna cover 8.38-10.6GHz and 9.2-10.2GHz respectively, and the deepest resonance reaches -26.6dB at 9.77GHz. The maximum electric field strength at different frequencies such as 9.3GHz, 9.8GHz, and 10.3GHz are 18423.7V / m, 20507V / m, and 22183.8V / m respectively, which is much smaller than the breakdown field strength of 3*10 6 V / m.

[0035] Figure 6 The power capacity simulation comparison results of the present invention and the Ant II solution in the iterative process are as follows: the power capacity of the present invention is greater than 8000W in the target frequency band, and the power capacity at 9.2GHz reaches a maximum value of 13193W.

[0036] Figure 7 The maximum gain simulation result of the present invention shows that the antenna achieves a gain greater than 5dBi in the target frequency band. At the same time, the simulation results of the E-plane and H-plane radiation patterns of the present invention at different frequencies show that the maximum gain of the E-plane pattern is offset by about 7-8° from the main axis, and the H-plane pattern can basically achieve bilateral symmetry.

[0037] Figure 8 The measured return loss results and the simulated return loss results are basically consistent with the simulated results. The measured -10dB impedance bandwidth covers 8.3-10.66GHz, and the deepest resonance depth reaches -29.9dB at 9.71GHz, which deviates by about 0.06GHz compared with the simulated results.

[0038] Fig. 9 and Fig.10The radiation pattern results of the E-plane and H-plane at 9.8GHz obtained by the actual measurement and simulation of the present invention are respectively consistent with each other in multiple frequency points. The maximum gain of the measured antenna is 5.68dBi, the main lobe of the measured E-plane pattern is offset by about 7-8° compared to the main axis, and the measured H-plane symmetry is good.

[0039] Example 2

[0040] Corresponding to the above-mentioned embodiment, the present embodiment discloses a method for determining parameters of a high-power microwave antipodal Vivaldi antenna, which is used to prepare the high-power microwave antipodal Vivaldi antenna as described above, comprising: first determining the parameters of the gradient curve, then designing a rectangular slot and a branch structure to improve the antenna impedance characteristics, and then judging whether the power capacity, resonance depth and gain simulation results within the target frequency band meet the requirements. If not, returning to adjust the design parameters until the simulation results meet the requirements, and finally preparing a sample to measure the actual performance of the power capacity, resonance depth and gain.

[0041] In summary, the devices and methods disclosed in the above two embodiments of the present invention respectively have at least the following beneficial effects:

[0042] 1. The all-metal structure design of the toe-to-toe Vivaldi antenna improves the power capacity of the antenna, so that it can be used as a radiating antenna in high-power microwave systems.

[0043] 2. In the present invention, a rectangular metal floor is provided with a circular groove, the right comb-shaped metal vibrator is connected to the coaxial probe feeder, and the insulating medium outside the coaxial probe is embedded in the circular groove; the two mid-vertical planes of the two comb-shaped metal vibrators based on the line segment in the thickness direction are two parallel planes that are not in the same plane, and the two parallel planes are equidistant from the center of the metal floor; the inner and outer contours of the mid-vertical plane corresponding to the left comb-shaped metal vibrator each include two sections of gradient curves, and the bottom gradient curve section is connected to the metal floor through a rectangular block; the inner and outer contours of the mid-vertical plane corresponding to the right comb-shaped metal vibrator are directly connected to the metal floor by a section of gradient curve; between the upper comb teeth of the left and right comb-shaped metal vibrators is a rectangular parallelepiped empty groove that is dug and parallel to the rectangular metal floor. Based on the above-mentioned special proprietary structure, the gain improvement of the Vivaldi antenna can be greatly achieved.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high-power microwave antipodal Vivaldi antenna, characterized in that: It includes two left and right comb-shaped metal vibrators of the same thickness based on an all-metal structure, a rectangular metal floor and a coaxial probe for feeding; the rectangular metal floor is provided with a circular groove, the right comb-shaped metal vibrator is connected to the coaxial probe for feeding, and the insulating medium outside the coaxial probe is embedded in the circular groove; the two mid-vertical planes of the line segments of the two comb-shaped metal vibrators based on the thickness direction are two parallel planes that are not in the same plane, and the two parallel planes are equidistant from the center of the metal floor; the inner and outer contours of the mid-vertical plane corresponding to the left comb-shaped metal vibrator each include two sections of gradient curves, and the bottom gradient curve section is connected to the metal floor through a rectangular block; The inner and outer contours of the median perpendicular plane corresponding to the right comb-shaped metal vibrator are directly connected to the metal floor by a gradual curve; between the upper comb teeth of the left and right comb-shaped metal vibrators is a rectangular parallelepiped slot parallel to the rectangular metal floor, and the shapes of the cross sections of each comb-shaped metal vibrator parallel to the median perpendicular plane are consistent.

2. The high-power microwave antipodal Vivaldi antenna according to claim 1, characterized in that: The comb teeth of the two left and right comb-shaped metal vibrators projected in the thickness direction are arranged symmetrically.

3. The high-power microwave antipodal Vivaldi antenna according to claim 2, characterized in that: With the center of the rectangular metal bottom plate as the origin, the direction perpendicular to the metal floor as the Y axis, and the intersection of the median perpendicular plane of the line segment of the comb-shaped metal vibrator based on the thickness direction and the metal floor as the X axis, the equation of the gradient curve is: y = ae x +b; where a and b are coefficients.

4. The high-power microwave antipodal Vivaldi antenna according to claim 3, characterized in that: The projections of the inner and outer gradient curves on the upper part of the left comb-shaped metal vibrator and the inner and outer gradient curves on the right comb-shaped metal vibrator in the thickness direction are arranged in a hand-shaped symmetrical arrangement.

5. The high-power microwave antipodal Vivaldi antenna according to any one of claims 1 to 4, characterized in that: The outer insulating dielectric material of the coaxial probe is PTFE with a dielectric constant of 2.2 and a radius of 2.05mm. The inner conductor is made of metal material with a radius of 0.635mm. The height of the rectangular metal floor 2 is 3mm, and the length and width are both 35mm. The height of the right comb-shaped metal vibrator and the left comb-shaped metal vibrator are both 24mm, the width of the bottom of the right comb-shaped metal vibrator is 1.9mm, and the width and height of the bottom of the left comb-shaped metal vibrator are 7.6mm and 2mm respectively. The distance between the left and right comb-shaped metal vibrators is 11.4mm, and the thickness between the left and right comb-shaped metal vibrators is 1.3mm. The metal material used in each part is aluminum alloy.

6. A method for determining parameters of a high-power microwave antipodal Vivaldi antenna, used for preparing the high-power microwave antipodal Vivaldi antenna as claimed in any one of claims 1 to 5, characterized in that: include: First determine the parameters of the gradient curve, then design the rectangular slot and branch structure to improve the antenna impedance characteristics, and then determine whether the power capacity, resonance depth and gain simulation results within the target frequency band meet the requirements. If not, return to adjust the design parameters until the simulation results meet the requirements. Finally, prepare samples to measure the actual performance of power capacity, resonance depth and gain.

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