A Compact High-Power Microwave CTS Array Antenna

Abstract

The present invention discloses a compact high-power microwave CTS array antenna, which includes two CTS antenna arrays on the left and right and a coaxial waveguide feeding system with a two-layer structure below the two CTS antenna arrays on the left and right. Among them, the CTS antenna array realizes radiation by continuously opening through transverse slits, i.e., stubs, on a planar waveguide. Electromagnetic waves are fed into the lower structure from the coaxial waveguide, then propagate radially outward to the parabolic reflectors on the left and right and propagate through the left and right parabolic reflector channels to the upper structure. The cylindrical electromagnetic waves propagating radially are converted into planar electromagnetic waves, and then enter the left and right sides of the antenna array flat plate from the left and right feeding ports respectively, and are transmitted to the left and right sides respectively in a traveling wave manner, and radiate energy outward through continuous transverse stubs. In the present invention, the coaxial waveguide feeding system uses a parabolic reflector type double-layer coaxial waveguide feeding structure, which solves the problem of the complex and large feeding system of the CTS antenna array system, makes the overall antenna system structure simpler and more compact, and has the advantages of flattening and easy processing at the same time.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-power microwave antennas, and more specifically, relates to a compact high-power microwave CTS array antenna. Background Art

[0002] High-Power Microwave (HPM) technology is a new discipline that emerged since the 1970s with the development of pulsed power technology, and is the product of the combination of pulsed power technology, plasma physics, and electro-vacuum technology.

[0003] High-power microwave technology has been widely applied in military, medical, and industrial fields. In the military field, directed energy weapons represented by high-power microwaves have broad application prospects and great application potential. High-power microwave weapons are directed energy weapons that use a high-power microwave beam with directional radiation to damage, degrade, disrupt, and interfere with the enemy's electronic systems to achieve combat effectiveness. In the medical field, high-power microwaves can be used for cancer treatment, disinfection, and sterilization. In the industrial field, high-power microwaves can be used for heating, drying, welding, and other aspects.

[0004] The key technologies of high-power microwave weapons include the design of high-power microwave sources and the design of high-power microwave antennas. Among them, the antenna is the interface between the high-power microwave source and free space. Therefore, the design of high-power microwave antennas is of great significance. Existing high-power microwave antennas generally sacrifice the structural compactness in order to achieve high power capacity as a whole. Therefore, compact high-power microwave antennas have become a research and application hotspot.

[0005] The Continuous Transverse Stub (CTS) array antenna realizes radiation by continuously opening through transverse slots on a flat waveguide. The radiation principle is similar to that of a waveguide slot antenna. Through a parallel plate waveguide as a transmission line, the longitudinal current of the parallel plate waveguide structure is cut off by the transverse stubs, and the transverse stubs are the radiation stubs. Energy is coupled out from the transverse stubs and radiated into free space as a linearly polarized wave. The analysis of CTS units can also draw on the method of establishing an equivalent circuit model for traditional waveguide slot arrays. By controlling the height of the transverse stubs, the width of the slots, and the spacing between each CTS unit, the radiation energy and pattern can be controlled. By adding steps to the continuous transverse stubs, better pattern radiation can be achieved. The CTS array antenna has the technical advantages of low profile, low cost, compactness, and high efficiency, and is widely used in airborne antennas, early warning radars, meteorological antennas, satellite antennas, and other fields.

[0006] There are two structures in the existing CTS array antenna for the feeding system. One is the radial line power division structure. Through the geometric transformation of the waveguide structure, it is fed into the parallel plate waveguide from the same plane. This multi-branch structure is too complex in the waveguide geometric transformation, making the overall structure not compact enough and not convenient for processing. The other is the radial line structure, such as the radial line CTS antenna array system designed by Sun Yunfei of the National University of Defense Technology. This form of feeding will cause a depression in the radiation of the antenna center and requires adding a lens for correction, making the overall system structure complex. How to make the feeding system of the CTS antenna array more compact and simple and then make the overall system structure more compact is a key research point. Summary of the Invention

[0007] Aiming at the defects of complex structure, insufficient compactness and inconvenience for processing in the prior art, the present invention provides a compact high-power microwave CTS array antenna to solve the problem of the complex feeding structure of the current CTS array antenna, making the overall structure of the high-power microwave CTS array antenna more compact and easy to process.

[0008] To achieve the above invention purpose, the compact high-power microwave CTS array antenna of the present invention is characterized by including:

[0009] Two CTS antenna arrays on the left and right. The CTS antenna array is composed of a hollow antenna array flat plate and continuous transverse stubs. The length of the hollow part of the antenna array flat plate is d0, the width is d1, and the height is h0. The continuous transverse stubs are located above the antenna array flat plate and are composed of a plurality of stubs with the same size placed parallel and aligned in sequence along the length direction of the antenna array flat plate. The length direction of each stub is consistent with the width direction of the hollow part of the antenna array flat plate, and the length of each stub is equal to the width of the hollow part of the antenna array flat plate and is aligned. The interval between adjacent stubs is the same, all being one wavelength. Each stub includes a first-level slot and a second-level slot. The first-level slot is a slot with a width of a0, a length of d1, and a step height of b1 on the hollow part of the antenna array flat plate. The second-level slot is above the first-level slot, with the length direction aligned and extending to both sides in width to form a slot with a width of a1, a length of d1, a step height of b2, and a width a1 greater than the width a0. The continuous transverse stubs of the two CTS antenna arrays on the left and right are not completely symmetrical. Among them, the continuous transverse stubs of one CTS antenna array move half a wavelength towards the center, i.e., the feeding port.

[0010] A coaxial waveguide feeding system with a two-layer structure is located below the middle of the left and right CTS antenna arrays. The lower layer structure is fed by a coaxial waveguide with an inner diameter of r0 and an outer diameter of r1. The height of the lower layer structure is h1, and the coaxial waveguide is connected to the lower layer structure. The height of the upper layer structure is h2. There is a partition in the middle of the upper layer structure along the width direction of the antenna array flat plate, dividing the upper layer structure into left and right sides. There is an upward opening, namely a feeding port, along the width direction of the antenna array flat plate on both sides of the partition. The left feeding port is connected to the hollow part of the antenna array flat plate under the left CTS antenna array, and the right feeding port is connected to the hollow part of the antenna array flat plate under the right CTS antenna array;

[0011] On the left and right sides of the upper and lower two-layer structures are parabolic reflectors with the focus located at the center of the coaxial waveguide and the same size. The connection line between the vertex and the focus of the parabolic reflector is parallel to the length direction of the antenna array flat plate. The parabolic reflectors of the upper and lower left and right two-layer structures are connected and extend inward respectively to form left and right parabolic reflector channels connecting the upper and lower two-layer structures. The height of the interval between the upper and lower two-layer structures, that is, the height of the left and right parabolic reflector channels, is h3;

[0012] During operation, electromagnetic waves are fed into the coaxial waveguide. In the lower layer structure of the coaxial waveguide feeding system, the electromagnetic waves propagate radially outward to the left and right parabolic reflectors, and then propagate to the upper layer structure of the coaxial waveguide feeding system through the left and right parabolic reflector channels. After being reflected by the left and right parabolic reflectors, the cylindrical electromagnetic waves propagating radially are converted into plane electromagnetic waves. The width of the plane electromagnetic waves is equal to the length of the feeding ports of the upper and lower layer structures. The plane electromagnetic waves propagate inward from the left and right parabolic reflectors to the left and right feeding ports of the upper layer structure respectively, and then enter the hollow parts of the left and right antenna array flat plates from the left and right feeding ports respectively, and are transmitted to the left and right sides respectively in the form of traveling waves, and radiate energy outward through continuous transverse branches.

[0013] The object of the present invention is achieved as follows:

[0014] To solve the problem of compactification of high-power CTS array antennas, the present invention proposes a compact high-power microwave CTS array antenna, which includes two CTS antenna arrays on the left and right and a coaxial waveguide feeding system with a two-layer structure below between the two CTS antenna arrays on the left and right. Among them, the CTS antenna array realizes radiation by continuously opening through horizontal slots, i.e., stubs, on a flat waveguide, and the radiation principle is similar to that of a waveguide slot antenna. The coaxial waveguide feeding system has parabolic reflectors on both the left and right sides. Electromagnetic waves are fed into the lower layer structure from the coaxial waveguide, then propagate radially outward to the parabolic reflectors on both the left and right sides and propagate to the upper layer structure through the channels of the left and right parabolic reflectors. The cylindrical electromagnetic waves propagating radially are converted into plane electromagnetic waves, and then enter the left and right sides of the antenna array flat plate from the left and right feeding ports respectively, and are transmitted to the left and right sides respectively in a traveling wave manner, and radiate energy outward through continuous horizontal stubs. In the present invention, the coaxial waveguide feeding system uses a parabolic reflector-type double-layer coaxial waveguide feeding structure, which innovatively solves the problem of the complex and large feeding system of the CTS antenna array system, makes the overall antenna system structure simpler and more compact, and has the advantages of flattening and easy processing. In addition, the array antenna can carry a GW-level power capacity, has a high aperture transmission efficiency, can realize the function of beam directional radiation, and the realized gain reaches 22 dB. Description of the Drawings

[0015] Figure 1 is a top view structural schematic diagram of a specific embodiment of the two CTS antenna arrays on the left and right in the present invention;

[0016] Figure 2 is Figure 1 a cross-sectional structural schematic diagram of the right CTS antenna array shown;

[0017] Figure 3 is Figure 2 a cross-sectional structural schematic diagram of a single stub in;

[0018] Figure 4 is a cross-sectional structural schematic diagram of a coaxial waveguide feeding system with a two-layer structure;

[0019] Figure 5 is a bottom view structural schematic diagram of a coaxial waveguide feeding system with a two-layer structure.

[0020] Figure 6 is a 3D realized gain diagram of the far-field radiation of the compact high-power microwave CTS array antenna of the present invention;

[0021] Figure 7 is a realized gain diagram of the far-field radiation E-plane (along the direction of φ = 0°) of the compact high-power microwave CTS array antenna of the present invention;

[0022] Figure 8It is the realized gain diagram of the H-plane (along the φ = 90° direction) of the far-field radiation of the compact high-power microwave CTS array antenna of the present invention. Detailed implementation manners

[0023] The following describes the detailed implementation manners of the present invention with reference to the accompanying drawings, so that those skilled in the art can better understand the present invention. It should be particularly noted that in the following descriptions, when the detailed descriptions of known functions and designs may dilute the main content of the present invention, these descriptions will be omitted here.

[0024] The feeding system of the traditional microwave CTS array antenna is large and complex in structure, which in turn leads to the overall structure of the antenna not being compact enough. To solve the problem of the compactness of the high-power CTS array antenna, the CTS antenna array of the present invention realizes radiation by continuously opening through transverse slots on a planar waveguide, and the radiation principle is similar to that of a waveguide slot antenna. At the same time, an innovative compact feeding system is proposed, making the overall system structure of the antenna array more compact while being able to carry a high power capacity. Specifically, the compact high-power microwave CTS array antenna of the present invention includes two sections of CTS antenna arrays on the left and right and a coaxial waveguide feeding system with a two-layer structure.

[0025] In this embodiment, as Figure 1 shown, the two sections of CTS antenna arrays on the left and right are composed of the left-section CTS antenna array 1 and the right-section CTS antenna array 2. The continuous transverse branches 101 of the left CTS antenna array 1 are placed on the antenna array flat plate 102, and the continuous transverse branches 201 of the right CTS antenna array 2 are placed on the antenna array flat plate 202. In this embodiment, except that the continuous transverse branches 101 of the left CTS antenna array 1 are moved towards the center, that is, the feeding port, by half a wavelength compared to the continuous transverse branches 201 of the right CTS antenna array 2, the two sections of CTS antenna arrays on the left and right are the same.

[0026] To more clearly show the CTS antenna array, Figure 2 a cross-sectional view of the right-section CTS antenna array is given. The structure of the left CTS antenna array is the same as the rest except that the continuous transverse branches 101 are moved towards the center by a wavelength. Therefore, only the right-section CTS antenna array will be described in more detail here.

[0027] As Figure 2 shown, the right-section CTS antenna array 2 is composed of a hollow antenna array flat plate 202 and continuous transverse branches 201. The length of the hollow part of the antenna array flat plate 201 is d0, the width is d1 ( Figure 1 shown), the height is h0, and the continuous transverse branches 202 are located on the antenna array flat plate 201 and are composed of a plurality of branches with the same size placed parallel and aligned in sequence along the length direction of the antenna array flat plate.

[0028] As Figure 1 shown, the length direction of each branch 101, 201 is consistent with the width direction of the hollow part of the antenna array plates 102, 202, and the length of each branch 101, 201 is equal to the width of the hollow part of the antenna array plates 101, 202 and they are aligned. The intervals between adjacent branches are the same, all being one wavelength. As Figure 2 、 3 shown, each branch 201 includes a first-stage slot 2011 and a second-stage slot 2012. The first-stage slot 2011 is a slot on the hollow part of the antenna array plate 202 with a width of a0, a length of d1, and a step height of b1. The second-stage slot 2012 is formed above the first-stage slot 2011, with the length direction aligned and extending to both sides in width to form a slot with a width of a1, a length of d1, a step height of b2, and a width a1 greater than the width a0. As Figure 1 shown, the continuous transverse branches 101, 201 of the left and right two-segment CTS antenna arrays 1, 2 are not completely symmetric. Among them, for one segment of the CTS antenna array, in this embodiment, the continuous transverse branches of the left two-segment CTS antenna array 1 as a whole move half a wavelength towards the center, i.e., the feeding port.

[0029] In this embodiment, as Figure 4 shown, the coaxial waveguide feeding system 3 with a two-layer structure is located below and between the left and right two-segment CTS antenna arrays 1, 2. Its lower-layer structure 301 is fed by a coaxial waveguide 303. The inner diameter of the coaxial waveguide 303 is r0, the outer diameter is r1, the height of the lower-layer structure 301 is h1, the coaxial waveguide 303 is in communication with the lower-layer structure 301. The height of the upper-layer structure 302 is h2. There is a partition 304 along the width direction of the antenna array plate in the middle of the upper-layer structure 302, which divides the upper-layer structure into left and right sides. There is an upward opening, i.e., a feeding port 305, along the width direction of the antenna array plate on both sides of the partition 304. The left feeding port is in communication with the hollow part of the antenna array plate 102 under the left-segment CTS antenna array 1, and the right feeding port is in communication with the hollow part of the antenna array plate 202 under the right-segment CTS antenna array 2.

[0030] As Figure 4 、 5As shown in the figure, on the left and right sides of the upper and lower two-layer structures 301 and 302 are parabolic reflectors 306 with the foci located at the center of the coaxial waveguide 303 and the same size. The line connecting the vertex and the focus of the parabolic reflector 306 is parallel to the length direction of the antenna array flat plates 102 and 202. The parabolic reflectors 306 of the upper and lower two-layer structures penetrate through each other and extend inward respectively to form left and right parabolic reflector channels 307 connecting the upper and lower two-layer structures. The height of the interval between the upper and lower two-layer structures 301 and 302, that is, the height of the left and right parabolic reflector channels 307 is h3. In order to reduce the reflection at the connection, in this embodiment, the upper and lower edges of the parabolic reflector 306 are chamfered by q.

[0031] As Figure 4 shown in the figure, during operation, electromagnetic waves (the thick black arrow on the left, for the sake of simplicity of the drawing, the electromagnetic waves on the right are not drawn) are fed from the coaxial waveguide 303. In the lower-layer structure 301 of the coaxial waveguide feeding system, the electromagnetic waves propagate radially outward to the left and right parabolic reflectors 306, and then propagate through the left and right parabolic reflector channels 307 to the upper-layer structure 302 of the coaxial waveguide feeding system. After being reflected by the left and right parabolic reflectors 306, the cylindrical electromagnetic waves propagating radially are converted into plane electromagnetic waves. The width of the plane electromagnetic waves is equal to the length of the feeding ports 305 of the upper and lower layer structures. The plane electromagnetic waves propagate inward from the left and right parabolic reflectors 306 to the left and right feeding ports 305 of the upper layer structure respectively, and then enter the hollow parts of the left and right antenna array flat plates 102 and 202 from the left and right feeding ports 305 respectively, and are transmitted to the left and right sides respectively in the form of traveling waves, and radiate energy outward through the continuous transverse stubs 101 and 201.

[0032] In this embodiment, the operating frequency band is in the X band, the center frequency is selected as 9.3 GHz, and the input energy is 1 GW. The inner diameter of the coaxial waveguide is r0 = 15 mm, and the outer diameter is r1 = 20 mm. The height of the lower-layer structure of the coaxial waveguide feeding system is h1 = 8 mm, the height of the upper-layer structure is h2 = 8 mm, and the upper and lower two-layer structures are connected by the left and right parabolic reflector channels with a height of h3 = 10 mm. The edge surfaces of the left and right parabolic reflector channels are parabolic reflectors, the focus of the parabolic reflector is the center of the coaxial waveguide, and the upper and lower edges of the parabolic surface are chamfered by q = 6 mm. The overall structure is symmetric about the left and right.

[0033] In this embodiment, for the CTS antenna array, the stubs are arranged at equal intervals towards both ends. The length of the CTS antenna array is d0 = 330.7 mm, the width is d1 = 221.1 mm, the thickness is h0 = 8 mm, and the interval between the stubs is one wavelength of the center frequency of the electromagnetic wave. A first-level step is designed in the stubs of the CTS antenna array. The height of the first-level step is b1 = 5 mm, the width is a0 = 5 mm, the height of the remaining stubs is b2 = 15 mm, and the width is a1 = 18 mm.

[0034] During operation, electromagnetic waves are fed into the coaxial waveguide. In the lower layer structure of the coaxial waveguide feeding system, the electromagnetic waves propagate radially outward to the parabolic reflector. At this time, the electromagnetic waves are transmitted in the form of cylindrical electromagnetic waves. According to the characteristics of the parabolic reflector, the reflected electromagnetic waves will be converted from the radially propagating cylindrical electromagnetic waves into plane electromagnetic waves. Thus, the cylindrical electromagnetic waves in the lower layer structure are reflected by the parabolic reflector and become plane electromagnetic waves, entering the upper layer structure of the coaxial waveguide feeding system. The plane electromagnetic waves propagate inward from the parabolic reflector in the upper layer structure of the coaxial waveguide feeding system to the left and right feeding ports near the center of the upper layer structure of the coaxial waveguide feeding system, and enter the left and right CTS antenna arrays upward from the feeding ports. The left and right CTS antenna arrays are located above the coaxial waveguide feeding system. After the electromagnetic waves enter the left and right CTS antenna arrays, they are transmitted to the other end of the array in the form of traveling waves, and radiate energy outward through the stubs. The radiation principle of the stubs is similar to that of the waveguide slot antenna, that is, radiation is achieved by cutting the electric field lines. Overall, the transmission path of the electromagnetic waves is: radially outward in the form of cylindrical waves from the coaxial waveguide, reflected by the parabolic reflector and then transmitted inward in the form of plane waves in the upper layer structure of the coaxial waveguide feeding system, and then enter the left and right CTS antenna arrays upward through the feeding ports, and are transmitted from the inside to the outside in the form of plane waves to the other end of the antenna array. Since the feeding system is symmetric left and right, the electromagnetic waves entering the two CTS antenna arrays through the feeding system are also completely symmetric, that is, the electric field line distributions are the same. However, in order to make the radiation results of the stubs in the far field in the same direction, the stubs of the left and right CTS antenna arrays are not completely symmetric. In this embodiment, the stubs of the left CTS array are moved half a wavelength as a whole towards the feeding port.

[0035] Figure 6 Fig. shows the 3D beam radiation far-field result diagram of the compact high-power microwave CTS array antenna of the present invention in this embodiment under the input of 1 GW energy at the center frequency of 9.3 GHz. It can be seen that the antenna has the maximum radiation value in the normal direction.

[0036] Figure 7 Fig. shows the antenna far-field real gain diagram along the direction of φ = 0° of the compact high-power microwave CTS array antenna of the present invention in this embodiment under the input of 1 GW energy at the center frequency of 9.3 GHz. It can be seen from the figure that the antenna has the maximum gain in the normal direction, and the gain value can reach 22 dB.

[0037] Figure 8 Fig. shows the antenna far-field real gain diagram along the direction of φ = 90° of the compact high-power microwave CTS array antenna of the present invention in this embodiment under the input of 1 GW energy at the center frequency of 9.3 GHz. It can be seen from the figure that the antenna has the maximum gain in the normal direction, and the gain value reaches 22 dB.

[0038] Although the above described illustrative embodiments of the present invention are provided for the understanding of those skilled in the art of the present technology, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those of ordinary skill in the art of the present technology, as long as various changes are within the spirit and scope of the present invention defined and determined by the appended claims, these changes are obvious, and all inventions made using the concept of the present invention are within the scope of protection.

Claims

1. A compact high-power microwave CTS array antenna, characterized in that, Comprising: Two CTS antenna arrays on the left and right. The CTS antenna array consists of a hollow antenna array flat plate and continuous transverse stubs. The length of the hollow part of the antenna array flat plate is d0, the width is d1, and the height is h0. The continuous transverse stubs are located above the antenna array flat plate and are composed of multiple stubs of the same size placed parallel and aligned in sequence along the length direction of the antenna array flat plate. The length direction of each stub is consistent with the width direction of the hollow part of the antenna array flat plate, and the length of each stub is equal to the width of the hollow part of the antenna array flat plate and is aligned. The interval between adjacent stubs is the same, all being one wavelength. Each stub includes a first-level slot and a second-level slot. The first-level slot is a slot on the hollow part of the antenna array flat plate with a width of a0, a length of d1, and a step height of b1. The second-level slot is above the first-level slot, with the length direction aligned and extending to both sides in width to form a slot with a width of a1, a length of d1, a step height of b2, and a width a1 greater than width a0. The continuous transverse stubs of the two CTS antenna arrays on the left and right are not completely symmetric. Among them, the continuous transverse stubs of one CTS antenna array move half a wavelength towards the center, i.e., the feed port. A coaxial waveguide feeding system with a two-layer structure, located below and between the two CTS antenna arrays on the left and right. Its lower-layer structure is fed by a coaxial waveguide. The inner diameter of the coaxial waveguide is r0, the outer diameter is r1, the height of the lower-layer structure is h1, and the coaxial waveguide is connected to the lower-layer structure. The height of the upper-layer structure is h2. There is a partition along the width direction of the antenna array flat plate in the middle of the upper-layer structure, separating the upper-layer structure into left and right sides. There is an upward opening, i.e., a feed port, along the width direction of the antenna array flat plate on each side of the partition. The left feed port is bent to the left and connected to the hollow part of the antenna array flat plate under the left CTS antenna array, and the right feed port is bent to the right and connected to the hollow part of the antenna array flat plate under the right CTS antenna array. The left and right sides of the upper and lower two-layer structures are parabolic reflectors with the same size and the focus located at the center of the coaxial waveguide. The line connecting the vertex and the focus of the parabolic reflector is parallel to the length direction of the antenna array flat plate. The parabolic reflectors of the upper and lower two-layer structures on the left and right are connected and both extend inward to form left and right parabolic reflector channels connecting the upper and lower two-layer structures respectively. The interval between the upper and lower two-layer structures, i.e., the height of the left and right parabolic reflector channels, is h3. During operation, electromagnetic waves are fed into the coaxial waveguide. In the lower-layer structure of the coaxial waveguide feeding system, the electromagnetic waves propagate radially outward to the left and right parabolic reflectors, and then propagate through the left and right parabolic reflector channels to the upper-layer structure of the coaxial waveguide feeding system. After being reflected by the left and right parabolic reflectors, the cylindrical electromagnetic waves propagating radially are converted into plane electromagnetic waves. The width of the plane electromagnetic waves is equal to the length of the feed ports of the upper and lower layer structures. The plane electromagnetic waves propagate inward from the left and right parabolic reflectors to the left and right feed ports of the upper-layer structure respectively, and then enter the hollow parts of the antenna array flat plates on the left and right from the left and right feed ports respectively, and are transmitted to the left and right sides respectively in the form of traveling waves, and radiate energy outward through the continuous transverse stubs.

2. The compact high-power microwave CTS array antenna according to claim 1, wherein The upper and lower edges of the parabolic reflector are chamfered by q.

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