Waveguide slot standing wave array antenna

Abstract

The invention relates to a waveguide slot standing wave array antenna, and belongs to the technical field of antennas. Comprising a plurality of waveguide slot standing wave array antenna linear arrays which are arranged at equal intervals; the waveguide slot standing wave array antenna linear array comprises a radiation waveguide and a waveguide power divider; the whole waveguide antenna is divided into a plurality of sub-arrays by adding a metal partition plate in the radiation waveguide; each sub-array comprises a waveguide feeder line and a plurality of radiation units, and each radiation unit comprises a waveguide slot and two loading metal blocks; and the waveguide power divider feeds each sub-array. A metal block is adopted to load a waveguide narrow-side transverse seam to serve as a radiation unit of the waveguide standing wave linear array, the requirement for large conductivity of a standing wave array antenna subarray unit is met, the radiation characteristic that the polarization direction of an array antenna is parallel to the axis of a waveguide feeder line is achieved, and meanwhile the waveguide standing wave linear array can be used as a large-angle phase scanning array antenna unit.

Description

Technical Field

[0001] The present invention belongs to the field of antenna technology, and specifically relates to a waveguide slot standing wave array antenna, which is mainly used in a waveguide array antenna system that requires a dispersion-free fixed beam in the normal direction, a polarization direction parallel to the waveguide feeder axis, and low side lobes, and can also be used as a phased array antenna system unit that requires a one-dimensional fixed beam and a one-dimensional large phase scanning angle. Background Art

[0002] Array antennas are divided into standing wave array antennas and traveling wave array antennas according to the different forms of electromagnetic waves transmitted in the feeder. Traveling wave array antennas use the principle of electromagnetic wave traveling wave transmission to achieve the change of "intra-array phase" between antenna units by changing the signal frequency to change the beam direction. Standing wave array antenna is a fixed beam antenna that uses the principle of electromagnetic wave standing wave transmission. The spacing between radiating units is half of the wavelength in the feeder guide. The antenna beam is pointed in the normal direction of the antenna array and has no dispersion within the frequency band. Waveguide feeders have the advantages of uniform structure, low feeder loss and high efficiency. They are often used as feeders for standing wave array antennas. For waveguide feeders, the radiating units are realized by opening slots on the wide or narrow side walls of the waveguide. Slots on different walls can achieve different radiation characteristics. The polarization of the antenna is used to describe the spatial direction of the electromagnetic wave field vector radiated by the antenna. It is an important parameter of the radar system. Different radar systems have different specific requirements for antenna polarization.

[0003] Waveguide slot array antennas can be divided into standing wave antennas and traveling wave antennas according to the form of electromagnetic waves transmitted in the feeder, and can be divided into wide-side slot antennas and narrow-side slot antennas according to the slot position. Different antenna forms have different design requirements and can achieve different radiation characteristics. Traveling wave antennas generally have more radiating units, requiring each radiating unit to have a smaller conductance value. In order to meet the matching bandwidth requirements, standing wave antennas need to be divided into multiple small arrays, each with fewer radiating units, requiring each radiating unit to have a larger conductance value. The slots on the narrow side of the waveguide are oblique slots, the polarization mode is horizontal to the axial direction of the waveguide feeder, and the slot conductance value is small. The wide side of the waveguide can have a longitudinal slot or an oblique slot, the polarization mode is perpendicular to the axial direction of the waveguide feeder, and the slot conductance value is large. Summary of the invention

[0004] The technical problems to be solved by the present invention are:

[0005] In order to solve the problem that the narrow-side slanted slots of the waveguide can achieve a polarization mode parallel to the axial direction of the waveguide feeder but cannot meet the requirements of being a large conductive radiating unit of a standing wave array antenna, and at the same time to meet the requirements of low side lobes, the present invention proposes a waveguide slot standing wave array antenna.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] A waveguide slot standing wave array antenna, comprising a plurality of waveguide slot standing wave array antenna linear arrays arranged at equal intervals; the waveguide slot standing wave array antenna linear array comprises a radiating waveguide and a waveguide power divider; characterized in that:

[0008] The whole waveguide antenna is divided into a plurality of sub-arrays by adding a metal partition in the radiation waveguide; the sub-array includes a waveguide feeder and a plurality of radiation units, each radiation unit includes a waveguide slot and two loading metal blocks; the waveguide slot is located on the narrow side of the waveguide feeder, the waveguide slot is axially perpendicular to the waveguide feeder, and the two loading metal blocks are respectively located on both sides of the waveguide slot in a central symmetric manner; the radiation unit resonates at the central frequency point to realize the radiation of the radio frequency signal transmitted in the waveguide feeder into space;

[0009] The waveguide power divider feeds each subarray.

[0010] A further technical solution of the present invention is as follows: the waveguide feed line adopts a rectangular metal straight waveguide, which is a standard waveguide or a non-standard waveguide.

[0011] A further technical solution of the present invention is that the spacing between adjacent radiation units is equal to half of the wavelength within the waveguide feeder, and the spacing between all radiation units is the same.

[0012] A further technical solution of the present invention is as follows: the length of the waveguide slot is equal to the sum of the narrow side size of the waveguide and the cutting depth of the two wide sides.

[0013] A further technical solution of the present invention is that the size of the loaded metal block and the cutting depth of the waveguide slot in each radiation unit are different.

[0014] A further technical solution of the present invention is as follows: the waveguide power divider is composed of a multi-order waveguide H-plane T-junction, the waveguide is a rectangular metal straight waveguide, and the inner cavity size is the same as the waveguide feed line size.

[0015] A further technical solution of the present invention is as follows: a matching metal plate and two metal cylindrical platforms are provided in the H-surface T-junction, and the two metal cylindrical platforms are located on both sides of the matching metal plate in a mirror-symmetrical manner.

[0016] A further technical solution of the present invention is that the sizes of the matching metal plates and metal cylindrical platforms in each H-surface T-junction are different.

[0017] An optimization method for a waveguide slot standing wave array antenna is characterized in that the size of each H-plane T-junction in a waveguide power divider and each radiating unit in a subarray is optimized to meet the requirements of unequal power distribution of the waveguide power divider and tapered amplitude of the array antenna, thereby achieving low sidelobe performance of the waveguide standing wave array antenna.

[0018] The beneficial effects of the present invention are:

[0019] The present invention provides a waveguide slot standing wave array antenna, which can realize the polarization mode along the axial direction of the waveguide and the fixed beam low sidelobe characteristics. Compared with the prior art, it has the following advantages:

[0020] 1. The narrow side transverse slits of the waveguide loaded with metal blocks are used as the radiation units of the waveguide standing wave array, which meets the large conductance requirements of the subarray unit of the standing wave array antenna and realizes the radiation characteristics that the polarization direction of the array antenna is parallel to the axis of the waveguide feeder. At the same time, the waveguide standing wave array can be used as a large-angle phase-scanning array antenna unit.

[0021] 2. The parameters of each H-plane T-junction in the waveguide power divider and each radiating unit in the array antenna are optimized to meet the requirements of unequal power distribution of the waveguide power divider and tapering amplitude of the array antenna, and achieve low sidelobe performance of the waveguide standing wave array antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0023] Figure 1 A schematic diagram of a waveguide narrow-side slotted standing wave array antenna according to an embodiment of the present invention is shown.

[0024] Figure 2 A schematic diagram of a waveguide narrow-side slotted standing wave array antenna linear array according to an embodiment of the present invention is shown.

[0025] Figure 3 A schematic diagram of a waveguide standing wave linear array subarray according to an embodiment of the present invention is shown.

[0026] Figure 4 A schematic diagram of a radiation slot according to an embodiment of the present invention is shown.

[0027] Figure 5 It represents the structural parameters of the radiation slot in the top view according to the embodiment of the present invention.

[0028] Figure 6 It represents the structural parameters of the radiation slot front view according to the embodiment of the present invention.

[0029] Figure 7 A schematic diagram of a waveguide standing wave linear array parallel-fed power divider according to an embodiment of the present invention is shown.

[0030] Figure 8 Graph showing the structural parameters of the top view of the H-plane T-junction according to an embodiment of the present invention.

[0031] Fig. 9 Graph showing the structural parameters of the front view of the H-plane T-junction according to an embodiment of the present invention.

[0032] Fig.10 It shows the simulated standing wave curve of the waveguide standing wave linear array according to the embodiment of the present invention.

[0033] Fig.11 It shows the simulated directional diagram of the waveguide standing wave linear array according to the embodiment of the present invention.

[0034] Fig.12 It shows the phase scanning direction diagram of the embodiment of the present invention.

[0035] Markings in the figure:

[0036] 1-waveguide slot standing wave array antenna linear array; 2-radiating waveguide; 3-first parallel-fed power divider; 4-second parallel-fed power divider; 5-metal partition; 6-subarray; 7-radiating unit; 31-first H-plane T-junction; 32-second H-plane T-junction; 33-third H-plane T-junction; 311-matching metal plate; 312-metal cylindrical platform; 71-waveguide slot; 72-loading metal block. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0038] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0039] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0040] The present invention provides a waveguide slot standing wave array antenna, in which a slot is opened on the narrow side of a waveguide feeder so that the radio frequency signal energy transmitted in the feeder is radiated into space, and the distance between adjacent radiation units is d. A metal partition is added in the middle of the waveguide feeder to divide the entire waveguide antenna into multiple sub-arrays, and each sub-array is fed through a waveguide parallel-feed power divider. The waveguide standing wave array antenna includes a radiation waveguide and a waveguide power divider, and the radiation waveguide is composed of a waveguide feeder and a radiation unit.

[0041] The waveguide feeder in the present invention adopts a rectangular metal straight waveguide, which can be a standard waveguide or a non-standard waveguide. The wide side size of the waveguide cavity is a, the narrow side size is b, and the wall thickness is t, ensuring efficient transmission of radio frequency signals in the waveguide feeder.

[0042] In the present invention, the spacing d between adjacent radiation units in the array antenna is determined by the width of the waveguide cavity and the operating frequency, which is equal to half the wavelength of the waveguide feeder line, and the spacing between all radiation units is the same.

[0043] The radiation unit in the present invention consists of two parts: a waveguide slot and a loaded metal block. The radiation unit resonates at a central frequency point to radiate the radio frequency signal transmitted in the waveguide feeder into space.

[0044] The waveguide slot in the radiation unit of the present invention is located at the narrow side of the waveguide, the slot is perpendicular to the axial direction of the waveguide feeder, and the length is equal to the sum of the narrow side size of the waveguide and the cutting depth of the two wide sides, which is approximately equal to half the wavelength of the center frequency.

[0045] In the present invention, there are two loading metal blocks in each radiation unit, which are located symmetrically on both sides of the waveguide slot.

[0046] In the present invention, the size of the loaded metal block and the cutting depth of the waveguide slot in each radiation unit are different.

[0047] The waveguide power divider in the present invention is composed of a multi-order waveguide H-plane T-junction, the waveguide is a rectangular metal straight waveguide, and the inner cavity size is the same as the waveguide feed line size.

[0048] Each H-plane T-junction of the waveguide power divider in the present invention comprises a matching metal plate and two metal cylindrical platforms, and the metal cylindrical platforms are located on both sides of the matching metal plate in a mirror-symmetrical manner.

[0049] The sizes of the matching metal plates and metal cylindrical cones in each H-surface T-junction of the present invention are different.

[0050] In order to enable those skilled in the art to better understand the present invention, the present invention is described in detail below in conjunction with specific embodiments.

[0051] like Figure 1As shown, the waveguide slot standing wave array antenna linear array 1 of the present invention realizes a normal fixed beam, and the radiation unit parameters are mirror-symmetric about the center of the linear array. At the same time, as a phased scanning unit in a phased scanning antenna system, the spacing between adjacent antenna linear arrays 1 is d1, realizing large-angle phased scanning.

[0052] like Figure 2 As shown, the waveguide slot standing wave array antenna linear array 1 includes three parts: a radiation waveguide 2, a first parallel-fed power divider 3, and a second parallel-fed power divider 4. The radiation waveguide 2 is divided into eight sub-arrays 6 by a metal partition 5. The first parallel-fed power divider 3 feeds the first four sub-arrays 6, and the second parallel-fed power divider 4 feeds the last four sub-arrays 6.

[0053] like Figure 3 As shown, each sub-array 6 has four radiation units 7, and there is a metal partition 5 on the left and right of the waveguide feed line, and the distance between adjacent radiation units 7 is d.

[0054] like Figure 4 As shown, each radiation unit 7 consists of a waveguide slot 71 and two loading metal blocks 72 .

[0055] like Figure 5 , 6 As shown, the structural parameters of the top view and the front view of the radiation unit 7, the width of the waveguide slot 71 is W, the total length is the sum of the narrow side cavity size b of the waveguide feeder and the cutting depth t1 of the two sections, the sizes of the loading metal blocks 72 are L1, L2, and L3 respectively, and L1 and L2 of each loading metal block 72 are the same, which are 5.3 mm and 6.0 mm respectively. The cutting depth t1 of each waveguide slot and the size L3 of each loading metal block 72 are shown in Table 1.

[0056] like Figure 7 As shown, each first parallel-fed power divider 3 or second parallel-fed power divider 4 is composed of three H-plane T-junctions 31 , 32 , 33 of two orders, and each H-plane T-junction includes a matching metal plate 311 and two metal cylindrical stages 312 .

[0057] like Figure 8 , 9 As shown in the figure, the structural parameters of the top view and the front view of the H-plane T-junction are shown. The width of the matching metal plate 311 is 1 mm, the height is b, the depth of the waveguide cavity is h, and the distance between the matching metal plate and the waveguide center is del. The radius of the metal cylindrical platform is 1.5 mm, the height is h1, and the distance between the center of the matching metal plate is 11.2 mm. The values ​​of h, del, and h1 are shown in Table 2.

[0058] The embodiment of the present invention realizes the low sidelobe waveguide slot standing wave array antenna introduced above in C band. The radiation waveguide adopts non-standard waveguide. The waveguide cavity size is 36.6mm*17mm and the wall thickness is 1.5mm. The number of radiation units is 32, the spacing is 40.5mm, the number of standing wave array antenna lines is 8, the spacing is 27.5mm, the amplitude distribution of the line array is designed according to Taylor distribution and sidelobe -25dB, and the simulated standing wave curve is as follows: Fig.10 As shown, the fixed beam pattern within the frequency band is as follows Fig.11 As shown, the phase sweep direction diagram is as follows Fig.12 shown.

[0059] It can be seen from the simulation results that the waveguide slot standing wave array antenna array of the present invention realizes a dispersion-free fixed beam, horizontal polarization, a standing wave relative bandwidth greater than 10%, a side lobe less than -24.5dB, and the antenna array as a phased scanning unit has a phase scanning range of ±50°, realizing the use requirements of a fixed normal beam within the frequency band, a polarization mode parallel to the waveguide feed line, low side lobes and a large angle phase scanning.

[0060] Table 1

[0061] Radiation unit number Waveguide slot cutting depth t1(mm) Loading metal block L3(mm) 1 6.5 10.0 2 6.8 10.3 3 5.7 10.3 4 6.5 10.3 5 7.5 9.6 6 6.5 9.6 7 5.5 11.0 8 6.5 10.7 9 7.0 9.8 10 7.2 9.8 11 6.0 10.7 12 6.1 10.7 13 5.9 11.3 14 7.3 11.3 15 7.2 11.5 16 6.5 11.3

[0062] Table 2

[0063]

[0064] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should be included in the protection scope of the present invention.

Claims

1. A waveguide slot standing wave array antenna, comprising a plurality of waveguide slot standing wave array antenna linear arrays arranged at equal intervals; the waveguide slot standing wave array antenna linear array comprises a radiating waveguide and a waveguide power divider; characterized in that: The whole waveguide antenna is divided into a plurality of sub-arrays by adding a metal partition in the radiation waveguide; the sub-array includes a waveguide feeder and a plurality of radiation units, each radiation unit includes a waveguide slot and two loading metal blocks; the waveguide slot is located on the narrow side of the waveguide feeder, the waveguide slot is axially perpendicular to the waveguide feeder, and the two loading metal blocks are respectively located on both sides of the waveguide slot in a central symmetric manner; the radiation unit resonates at the central frequency point to realize the radiation of the radio frequency signal transmitted in the waveguide feeder into space; The waveguide power divider feeds each subarray.

2. A waveguide slot standing wave array antenna according to claim 1, characterized in that: The waveguide feed line adopts a rectangular metal straight waveguide, which is a standard waveguide or a non-standard waveguide.

3. A waveguide slot standing wave array antenna according to claim 1, characterized in that: The distance between adjacent radiating elements is equal to half the wavelength of the waveguide feed line, and the distance between all radiating elements is the same.

4. A waveguide slot standing wave array antenna according to claim 1, characterized in that: The length of the waveguide slot is equal to the sum of the narrow side size of the waveguide and the cutting depth of the two wide sides.

5. A waveguide slot standing wave array antenna according to claim 1, characterized in that: The size of the loaded metal block and the cutting depth of the waveguide slot are different in each radiating element.

6. A waveguide slot standing wave array antenna according to claim 1, characterized in that: The waveguide power divider is composed of a multi-order waveguide H-plane T-junction, the waveguide is a rectangular metal straight waveguide, and the inner cavity size is the same as the waveguide feed line size.

7. A waveguide slot standing wave array antenna according to claim 1, characterized in that: The H-surface T-junction is provided with a matching metal plate and two metal cylindrical platforms, and the two metal cylindrical platforms are located on both sides of the matching metal plate in a mirror-symmetrical manner.

8. A waveguide slot standing wave array antenna according to claim 7, characterized in that: The matching metal plates and metal cylindrical stages in each H-face T-junction are of different sizes.

9. A method for optimizing a waveguide slot standing wave array antenna, characterized in that: The dimensions of each H-plane T-junction in the waveguide power divider and each radiating unit in the subarray are optimized to meet the requirements of unequal power distribution of the waveguide power divider and tapered amplitude of the array antenna, thereby achieving low sidelobe performance of the waveguide standing wave array antenna.

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