A frequency scanning monopulse slot antenna and a manufacturing method thereof

Abstract

The present disclosure relates to a frequency scanning monopulse slot antenna and a manufacturing method thereof. The frequency scanning monopulse slot antenna comprises a waveguide, the inside of the waveguide is hollow, and the left end face and the right end face of the waveguide are both open; a plurality of array slot groups are uniformly arranged on the upper surface of the waveguide; a plurality of slots are arranged on the lower surface of the waveguide; a plurality of flanges, the plurality of flanges comprise a first flange, a second flange and a third flange which are respectively sleeved upwards from the lower surface of the waveguide; a plurality of sealing members, the plurality of sealing members are respectively arranged at the openings of the left end face and the right end face of the waveguide, and the plurality of sealing members are respectively used for sealing the left end face and the right end face of the waveguide; an isolation member, the isolation member vertically divides the frequency scanning monopulse slot antenna into left and right parts along the central axis of the waveguide; and each slot is correspondingly arranged with a flange. The present disclosure can ensure the phase continuity of the frequency scanning monopulse slot antenna, thereby improving the angle measurement accuracy of the radar.

Description

Technical Field

[0001] This disclosure relates to the field of microwave antenna technology, and in particular to a frequency-scanning single-pulse slot antenna and its fabrication method. Background Technology

[0002] Monopulse technique (MT) is a target tracking technology that obtains target information based on a single received pulse. It can simultaneously achieve sum and difference beams within a single pulse. Angle measurement using sum and difference beams with monopulse technology offers higher accuracy than other angle measurement methods such as sequential lobe beams. A slotted antenna, also known as a slotted antenna, is a waveguide antenna with arrayed slots spaced at regular intervals along the narrow side of the waveguide. It is a traveling-wave array frequency-scanned antenna. A frequency-scanned monopulse slotted antenna divides the frequency-scanning column in half from the middle, achieving a frequency-scanned monopulse beam by feeding simultaneous and out-of-phase phases. In a frequency-scanned monopulse slotted antenna, the slot spacing, slot tilt angle, and slot depth, particularly between the two segments of the frequency-scanning column, affect the phase continuity of the antenna, thus impacting the radar's accuracy.

[0003] Currently, the fabrication of frequency-scanned monopulse slot antennas involves either bonding a partition plate in the middle of the frequency-scan array or welding two waveguides together using connectors before processing the slot dimensions.

[0004] The method of bonding the separator in the middle of the frequency scan column is adopted. Since the waveguide is made of profile, the rounded corners of the inner cavity cannot guarantee seamless isolation on both sides of the separator. It is necessary to add conductive adhesive to fill it, which will increase the difficulty of later cleaning and easily damage the inner wall of the waveguide.

[0005] While welding two waveguides together with connectors can achieve physical isolation, it's difficult to guarantee the coaxiality of the two waveguide cavities separated by the midpoint of the frequency sweep array. This affects the slot spacing, slot tilt angle, and slot depth of the separated waveguides, resulting in phase discontinuities in the frequency sweep monopulse slot antenna.

[0006] Therefore, it is necessary to propose a solution to improve one or more problems existing in the above-mentioned related technical solutions.

[0007] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0008] A first aspect of this disclosure provides a frequency-scanning monopulse slot antenna, the frequency-scanning monopulse slot antenna comprising:

[0009] A waveguide, the waveguide being hollow inside, with both its left and right end faces open; a plurality of arrayed slot groups are evenly arranged on the upper surface of the waveguide; and a plurality of slots are provided on the lower surface of the waveguide.

[0010] The plurality of flanges includes a first flange sleeved upward from the lower surface of the left end of the waveguide, a second flange sleeved upward from the lower surface of the middle portion of the waveguide, and a third flange sleeved upward from the lower surface of the right end of the waveguide; and the distance from the center of the first flange to the center of the second flange is equal to the distance from the center of the second flange to the center of the third flange.

[0011] Multiple closures are provided at the openings on the left and right end faces of the waveguide, and the multiple closures are used to seal the left and right end faces of the waveguide, respectively.

[0012] An isolator that vertically divides the frequency-scanning monopulse slot antenna into left and right parts along the central axis of the waveguide;

[0013] Each of the slots is respectively provided with a corresponding flange component.

[0014] In an exemplary embodiment of this disclosure, each array slot group comprises two array slots arranged in a figure-eight shape;

[0015] The plurality of slots include a first slot, a second slot, and a third slot; the first slot is disposed on the lower surface of the left end of the waveguide; the second slot is disposed on the lower surface of the middle part of the waveguide; and the third slot is disposed on the lower surface of the right end of the waveguide.

[0016] Multiple pairs of reinforcing members are respectively provided on the front and rear sides of the waveguide between the first flange and the second flange, and on the front and rear sides of the waveguide between the second flange and the third flange.

[0017] In an exemplary embodiment of this disclosure, the upper surface of the first flange is provided with a first U-shaped groove, the center of the bottom surface of the first U-shaped groove is provided with a first waveguide opening, and multiple pairs of first through holes are provided on the two opposite sides of the first U-shaped groove; the first waveguide opening and the first groove hole are provided correspondingly to each other, and the first waveguide opening and the first groove hole are coaxially corresponding to each other.

[0018] The upper surface of the third flange is provided with a third U-shaped groove, and the center of the bottom surface of the third U-shaped groove is provided with a third waveguide opening. Multiple pairs of third through holes are provided on the two opposite sides of the third U-shaped groove. The third waveguide opening and the third groove hole are provided in correspondence with each other, and the third waveguide opening and the third groove hole are coaxial.

[0019] In an exemplary embodiment of this disclosure, the upper surface of the second flange is provided with a second U-shaped groove, the center of the bottom surface of the second U-shaped groove is provided with a second waveguide opening, and multiple pairs of second through holes are provided on the two opposite sides of the second U-shaped groove; the second waveguide opening and the second groove hole are provided correspondingly to each other, and the second waveguide opening and the second groove hole are coaxially related.

[0020] The isolating member divides the second flange into an equal second left flange and a second right flange along the central axis of the waveguide, and also divides the second waveguide opening and the second slot into two symmetrical parts along the central axis of the waveguide.

[0021] Multiple countersunk holes are provided below each of the second through holes near the second waveguide opening on the second left flange and the second right flange, and an inductor pin is provided in each of the countersunk holes.

[0022] In an exemplary embodiment of this disclosure, the closure includes a connecting plate and a connecting block that are interconnected; wherein,

[0023] One end face of the connecting plate is a free end face, which facilitates the insertion or removal of the closure member from the end face opening of the waveguide; the other end face of the connecting plate is a connecting end face, which is fastened to the connecting block, and the area of ​​the connecting end face of the connecting plate is larger than the area of ​​the contact surface between the connecting plate and the connecting block.

[0024] The connecting block is stepped and includes a first connecting block and a second connecting block connected in sequence. One end face of the first connecting block is fastened to the connecting plate, and the other end face of the first connecting block is fastened to one end face of the second connecting block. The height of the first connecting block is greater than the height of the second connecting block.

[0025] When the closure is inserted into the end face opening of the waveguide, the connecting plate is located outside the waveguide and closes the end face opening of the waveguide; the connecting block is located inside the waveguide and is adapted to the waveguide; the length of the first connecting block is equal to the distance from the end face opening of the waveguide to the inlet surface of the first waveguide port or the third waveguide port; the second connecting block is located below the first waveguide port or the third waveguide port, and the length of the second connecting block is not greater than the length of the first waveguide port or the third waveguide port.

[0026] A second aspect of this disclosure provides a method for fabricating a frequency-scanning single-pulse slot antenna, the method comprising:

[0027] According to the electrical process design requirements, the size and specifications of multiple flanges on the waveguide are determined, multiple installation positions of the flanges are preset on the waveguide, and a slot is set at each installation position.

[0028] Process a plurality of flanges and install the plurality of flanges at a plurality of preset mounting positions on the waveguide respectively;

[0029] Multiple uniformly arranged array slot groups are machined on the upper surface of the waveguide; corresponding pairs of reinforcing members are respectively provided on the front and rear sides of the waveguide;

[0030] A sealing component adapted to the flange is provided on each of the two end faces of the waveguide; and an isolating component is inserted along the central axis of the waveguide to assemble the frequency-scanning monopulse slot antenna.

[0031] Each of the slots is respectively provided with one of the flange components;

[0032] The isolator vertically divides the frequency-scanning monopulse slot antenna into left and right parts along the central axis of the waveguide.

[0033] In an exemplary embodiment of this disclosure, the steps of determining the dimensions and specifications of multiple flanges on the waveguide according to electrical process design requirements, pre-setting installation positions for multiple flanges on the waveguide, and providing a corresponding slot at each installation position include:

[0034] The plurality of flanges include a first flange sleeved upward from the lower surface of the left end of the waveguide, a second flange sleeved upward from the lower surface of the middle portion of the waveguide, and a third flange sleeved upward from the lower surface of the right end of the waveguide; and the distance from the center of the first flange to the center of the second flange is equal to the distance from the center of the second flange to the center of the third flange;

[0035] Multiple pairs of reinforcing members are respectively provided on the front and rear sides of the waveguide between the first flange and the second flange, and on the front and rear sides of the waveguide between the second flange and the third flange;

[0036] The plurality of slots include a first slot, a second slot, and a third slot; the first slot is disposed on the lower surface of the left end of the waveguide; the second slot is disposed on the lower surface of the middle part of the waveguide; and the third slot is disposed on the lower surface of the right end of the waveguide.

[0037] In an exemplary embodiment of this disclosure, the step of processing a plurality of flanges and installing the plurality of flanges at a plurality of preset mounting positions on the waveguide includes:

[0038] The upper surface of the first flange is provided with a first U-shaped groove, and the center of the bottom surface of the first U-shaped groove is provided with a first waveguide opening. Multiple pairs of first through holes are provided on the two opposite sides of the first U-shaped groove. The first waveguide opening and the first groove hole are provided in correspondence with each other, and the first waveguide opening and the first groove hole are coaxial.

[0039] The upper surface of the second flange is provided with a second U-shaped groove, and the center of the bottom surface of the second U-shaped groove is provided with a second waveguide opening. Multiple pairs of second through holes are provided on the two opposite sides of the second U-shaped groove. The second waveguide opening and the second groove hole are provided in correspondence with each other, and the second waveguide opening and the second groove hole are coaxial.

[0040] The isolating member divides the second flange into an equal second left flange and a second right flange along the central axis of the waveguide, and also divides the second waveguide opening and the second slot into two symmetrical parts along the central axis of the waveguide.

[0041] Multiple countersunk holes are provided below each of the second through holes near the second waveguide opening on the second left flange and the second right flange, and an inductor pin is provided in each of the countersunk holes;

[0042] The upper surface of the third flange is provided with a third U-shaped groove, and the center of the bottom surface of the third U-shaped groove is provided with a third waveguide opening. Multiple pairs of third through holes are provided on the two opposite sides of the third U-shaped groove. The third waveguide opening and the third groove hole are provided in correspondence with each other, and the third waveguide opening and the third groove hole are coaxial.

[0043] In an exemplary embodiment of this disclosure, the steps of processing a plurality of uniformly arranged array slot groups on the upper surface of the waveguide and respectively providing a plurality of corresponding pairs of reinforcing members on the front and rear sides of the waveguide include:

[0044] The waveguide is hollow inside, and both the left and right end faces of the waveguide are open;

[0045] Each of the array slot groups comprises two array slots arranged in a figure-eight shape; and the middle array slot group on the waveguide is divided into two symmetrical parts by the isolator.

[0046] In an exemplary embodiment of this disclosure, the steps of processing a plurality of uniformly arranged array slot groups on the upper surface of the waveguide; providing closures adapted to the flange on both end faces of the waveguide; and inserting isolation members along the central axis of the waveguide to assemble the frequency-scanning monopulse slot antenna include:

[0047] The closure includes interconnected connecting plates and connecting blocks; wherein...

[0048] One end face of the connecting plate is a free end face, used to insert or pull out the end face opening of the waveguide. The other end face of the connecting plate is fastened to the connecting block, and the area of ​​the connecting end face of the connecting plate is larger than the area of ​​the contact surface between the connecting plate and the connecting block.

[0049] The connecting block is stepped and includes a first connecting block and a second connecting block connected in sequence. One end face of the first connecting block is fastened to the connecting plate, and the other end face of the first connecting block is fastened to one end face of the second connecting block. The height of the first connecting block is greater than the height of the second connecting block.

[0050] When the closure is inserted into the end face opening of the waveguide, the connecting plate is located outside the waveguide and closes the end face opening of the waveguide; the connecting block is located inside the waveguide and is adapted to the waveguide; the length of the first connecting block is equal to the distance from the end face opening of the waveguide to the inlet surface of the first waveguide port or the third waveguide port; the second connecting block is located below the first waveguide port or the third waveguide port, and the length of the second connecting block is not greater than the length of the first waveguide port or the third waveguide port.

[0051] This disclosure presents a frequency-scanning monopulse slot antenna and its fabrication method. By utilizing a waveguide to effectively isolate the antenna at the middle position of the frequency-scanning array, the consistency of the internal dimensions of the waveguide is ensured, the welding deformation along the length of the waveguide is reduced, and the requirements for the slot spacing, slot tilt angle, and slot depth of the isolated two-end waveguide slot antennas are guaranteed. This ensures the phase continuity of the frequency-scanning monopulse slot antenna and improves the angle measurement accuracy of the radar. Attached Figure Description

[0052] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0053] Figure 1 This diagram illustrates the structure of a frequency-scanned monopulse slot antenna in an exemplary embodiment of this disclosure.

[0054] Figure 2 A schematic diagram illustrating the steps of a method for manufacturing a frequency-scanned monopulse antenna in an exemplary embodiment of this disclosure;

[0055] Figure 3 A schematic diagram showing the structure of the slot on the lower surface of the waveguide in an exemplary embodiment of this disclosure is shown.

[0056] Figure 4 This diagram illustrates the structure of the array of slots on the upper surface of the waveguide in an exemplary embodiment of this disclosure.

[0057] Figure 5 This diagram illustrates the structure of the first flange in an exemplary embodiment of this disclosure.

[0058] Figure 6 This diagram illustrates the structure of the third flange in an exemplary embodiment of this disclosure.

[0059] Figure 7 This diagram illustrates the structure of the second flange in an exemplary embodiment of this disclosure.

[0060] Figure 8 This diagram illustrates the structure of the closure in an exemplary embodiment of this disclosure.

[0061] Figure 9 A schematic diagram showing the lengths of each flange, the waveguide, and the dimensions of the waveguides between each flange in an exemplary embodiment of this disclosure;

[0062] Figure 10 A schematic diagram showing the reserved positions of various flange components on the waveguide in an exemplary embodiment of this disclosure;

[0063] Figure 11 A schematic diagram showing the structure and dimensions of the isolator in an exemplary embodiment of this disclosure is provided.

[0064] Among them, 100 is a waveguide; 110 is an array slot group; 111 is an array slot; 120 is a first slot; 130 is a second slot; 140 is a third slot; 150 is a reinforcing member; 200 is a first flange; 210 is the bottom of the first U-shaped groove; 211 is the first waveguide opening; 220 is the edge of the first U-shaped groove; 221 is the first through hole; 300 is a second flange; 310 is the bottom of the second U-shaped groove; and 311 is the second waveguide opening. 320. Side of the second U-shaped groove; 321. Second through hole; 322. Countersunk hole; 330. Isolator; 340. Placement groove; 400. Third flange; 410. Bottom of the third U-shaped groove; 411. Third waveguide opening; 420. Side of the third U-shaped groove; 421. Third through hole; 500. Sealing component; 510. Connecting plate; 520. Connecting block; 521. First connecting block; 522. Second connecting block; 600. Weight reduction port. Detailed Implementation

[0065] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, they are provided so that this disclosure will be more comprehensive and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0066] Furthermore, the accompanying drawings are merely illustrative of this disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0067] This example implementation provides a frequency-scanned monopulse slot antenna, such as... Figure 1 As shown, the frequency-scanning monopulse slot antenna includes:

[0068] Waveguide 100, the waveguide 100 is hollow inside, and both the left end face and the right end face of the waveguide 100 are open; multiple array slot groups 110 are evenly arranged on the upper surface of the waveguide 100; multiple slots are provided on the lower surface of the waveguide 100.

[0069] Multiple flanges, including a first flange 200 fitted upward from the lower surface of the left end of the waveguide 100, a second flange 300 fitted upward from the lower surface of the middle part of the waveguide 100, and a third flange 400 fitted upward from the lower surface of the right end of the waveguide 100; and the distance from the center of the first flange 200 to the center of the second flange 300 is equal to the distance from the center of the second flange 300 to the center of the third flange 400;

[0070] Multiple sealing elements 500 are respectively disposed at the openings on the left and right end faces of the waveguide 100, and the multiple sealing elements 500 are respectively used to seal the left and right end faces of the waveguide 100.

[0071] Isolator 330 vertically divides the frequency-scanning monopulse slot antenna into left and right parts along the central axis of waveguide 100;

[0072] Each of the slots is respectively provided with a flange component.

[0073] The second aspect of this disclosure provides a method for fabricating such a frequency-scanning monopulse slot antenna, such as... Figure 2 As shown, the manufacturing method includes:

[0074] Step S101: According to the electrical process design requirements, determine the size and specifications of multiple flanges on the waveguide 100, preset the installation positions of multiple flanges on the waveguide 100, and set a slot at each installation position.

[0075] Step S102: Machining multiple flanges and installing them at multiple preset installation positions on the waveguide 100.

[0076] Step S103: A plurality of uniformly arranged array slot groups 110 are machined on the upper surface of the waveguide 100; a plurality of corresponding pairs of reinforcing members 150 are respectively provided on the front and rear sides of the waveguide 100.

[0077] Step S104: Set sealing members 500 that are compatible with flanges on the two end faces of waveguide 100 respectively; and insert isolation members 330 along the central axis of waveguide 100 to assemble the frequency-scanning single-pulse slot antenna.

[0078] Here, each slot corresponds to a flange component;

[0079] The isolator 330 vertically divides the frequency-scanning monopulse slot antenna into two independent parts, left and right, along the central axis of the waveguide 100.

[0080] This disclosure discloses a frequency-scanning monopulse slot antenna and its manufacturing method. By using a waveguide 100 to effectively isolate the antenna at the middle position of the frequency-scanning array, the consistency of the internal dimensions of the waveguide 100 is ensured, the welding deformation along the length of the waveguide 100 is reduced, and the requirements for the slot spacing, slot tilt angle, and slot depth of the isolated two-end waveguide slot antennas are guaranteed. This ensures the phase continuity of the frequency-scanning monopulse slot antenna and improves the angle measurement accuracy of the radar.

[0081] The frequency-scanned monopulse slot antenna in this example embodiment will now be described in more detail.

[0082] This disclosure presents a frequency-scanning monopulse slot antenna and a method for manufacturing the same. Figure 1 and Figure 2 As you can see,

[0083] First, in step S101, according to the electrical process design requirements, the size and specifications of multiple flanges on the waveguide 100 are determined, the installation positions of multiple flanges are preset on the waveguide 100, and a slot is set at each installation position.

[0084] Secondly, in step S102, multiple flanges meeting the specified dimensions and specifications are fabricated and installed at predetermined mounting positions on the waveguide 100. In this embodiment, a total of three flanges are fabricated: a first flange 200, a second flange 300, and a third flange 400. Using multiple flanges facilitates the connection between the feeding waveguide and the absorbing load.

[0085] like Figure 5 As shown in a and 5b, the structure of the first flange 200 is as follows:

[0086] The upper surface of the first flange 200 is configured as a U-shaped groove structure, i.e., a first U-shaped groove. A first waveguide port 211 is provided at the center of the bottom 210 surface of the first U-shaped groove. The function of the first waveguide port 211 is to feed electromagnetic waves from this port. Multiple pairs of first through holes 221 are correspondingly provided on the two opposite sides 220 of the first U-shaped groove. The first U-shaped groove is then secured to the outer wall of the waveguide 100 and welded, which enhances the reliability of the connection. The first flange 200 is fitted onto the waveguide 100 from the lower left end surface upwards, preferably by aluminum brazing. When using aluminum brazing, the first through holes 221 increase the welding area, which enhances the welding strength and ensures a reliable connection of the first flange 200 to the waveguide 100. Furthermore, the first waveguide port 211 and the first groove hole 120 are correspondingly arranged, and after welding, the first waveguide port 211 and the first groove hole 120 are coaxial. The coaxial design is used here to reduce electromagnetic wave reflection, which in turn reduces standing waves to some extent.

[0087] Furthermore, in this embodiment, as Figure 5 c and Figure 5 As shown in d, the depth H3 of the first U-shaped groove is 10mm. The width b1 of the first U-shaped groove is 7.4mm; the length L6 of the first flange 200 is 31mm.

[0088] Similarly, such as Figure 6 a and Figure 6 As shown in b, the structure of the third flange 400 is as follows:

[0089] The upper surface of the third flange 400 is also configured as a U-shaped groove structure, i.e., a third U-shaped groove. A third waveguide opening 411 is provided at the center of the bottom surface 410 of this third U-shaped groove. Multiple pairs of third through holes 421 are correspondingly provided on the two opposite sides 420 of the third U-shaped groove. The third flange 400 is fitted onto the waveguide 100 from the lower right end surface upwards, preferably by aluminum brazing. When using aluminum brazing, the third through holes 421 increase the brazing area. Furthermore, the third waveguide opening 411 and the third groove hole 140 are correspondingly arranged, and after welding, the third waveguide opening 411 and the third groove hole 140 are coaxial.

[0090] Furthermore, in this embodiment, as Figure 6 c and Figure 6 As shown in d, the depth of the third U-shaped groove is equal to the depth of the first U-shaped groove, both denoted by H3, where H3 = 10 mm. The width of the third U-shaped groove is equal to the width of the first U-shaped groove, both denoted by b1; b1 = 7.4 mm. The length L8 of the third flange 400 is 31.5 mm, slightly longer than the length L6 of the first flange 200.

[0091] like Figure 7 As shown in Figure a, the structure of the second flange 300 is as follows:

[0092] Similarly, the upper surface of the second flange 300 is also configured as a U-shaped groove structure, i.e., a second U-shaped groove. A second waveguide opening 311 is located at the center of the bottom 310 surface of this second U-shaped groove. Multiple pairs of second through holes 321 are correspondingly provided on the two opposite sides 320 of the second U-shaped groove. The second flange 300 is fitted onto the waveguide 100 from the lower surface of the middle portion upwards, preferably by aluminum brazing. When using aluminum brazing, the second through holes 321 increase the brazing area. Furthermore, the second waveguide opening 311 and the second groove 130 are correspondingly arranged, and after welding, the second waveguide opening 311 and the second groove 130 are coaxial.

[0093] Furthermore, in this embodiment, as Figure 7 As shown in 7a and 7b, the depth of the second U-shaped groove is equal to that of the first U-shaped groove, both denoted by H3, where H3 = 10 mm. The width of the second U-shaped groove is equal to that of the first U-shaped groove, both denoted by b1; b1 = 7.4 mm. The width b2 of the second flange 300 is 12.6 mm; the length L7 of the second flange 300 is 70 mm. It can be seen that the length of the second flange 300 is basically twice the length of the first flange 200 or the third flange 400. Thus, after being divided by the isolator 330, there are essentially two basically equal flanges at each end of the frequency-scanning monopulse slot antenna. This design ensures that the distances from the array slots 111 of the array slot group 110 divided in the middle of the waveguide 100 to the isolator 330 are equal, thereby ensuring the phase continuity of the frequency-scanning monopulse slot antenna; the isolator 330 also serves as a physical isolation element. Here we can see that each array gap 111 consists of two parallel array lines and the gap formed between them.

[0094] After machining each flange component, use tooling to install the first flange 200, the second flange 300, and the third flange 400 into their respective positions on the waveguide 100. Ensure that the coaxiality of the first waveguide port 211 with the first slot 120, the second waveguide port 311 with the second slot 130, and the third waveguide port 411 with the third slot 140 is approximately 0.05. Similarly, this coaxiality is designed to reduce electromagnetic wave reflection, thereby reducing standing waves to some extent.

[0095] At the same time, it is necessary to ensure that during the installation of each flange component, the first flange component 200, the second flange component 300, the third flange component 400, and the waveguide 100 are heated simultaneously to ensure their temperature consistency, and the temperature error of each part is no more than 5℃.

[0096] Next, in step S103, the waveguide 100 is processed. In this embodiment, the selected waveguide 100 is rectangular and hollow, and both the left and right end faces of the waveguide 100 are open. A plurality of evenly arranged array slot groups 110 are processed on the upper surface of the waveguide 100, and a plurality of slots are provided on the lower surface of the opposite waveguide 100.

[0097] Furthermore, such as Figure 3 As shown, Figure 3 The diagram shows the frequency-scanning monopulse slot antenna with its upper and lower surfaces flipped. It reveals multiple slots, including a first slot 120 on the lower left surface of the waveguide 100; a second slot 130 on the lower middle surface of the waveguide 100; and a third slot 140 on the lower right surface of the waveguide 100. This design allows electromagnetic waves fed in through the first slot 120 to propagate towards the third flange 400, radiating out from the multiple array slots 111. Since the second slot 130 and the second waveguide port 311 are divided into left and right parts by the isolator 330, the left part of the second waveguide port 311 connects to an absorption load to absorb excess electromagnetic waves during propagation. Electromagnetic waves are fed in through the right part of the second waveguide port 311, and the third slot 140 connects to the absorption load to absorb excess electromagnetic waves during propagation.

[0098] Furthermore, such as Figure 4 As shown, each array slot group 110 includes two array slots 111 arranged in a figure-eight shape, and they are evenly distributed on the upper surface of the waveguide 100. The evenly distributed array slots 111 in a figure-eight shape play a role in suppressing cross-polarization.

[0099] Furthermore, multiple pairs of reinforcing members 150 are correspondingly provided on the front and rear sides of the waveguide 100 between the first flange 200 and the second flange 300, and on the front and rear sides of the waveguide 100 of the second flange 300 and the third flange 400. The reinforcement members 150 can enhance the rigidity of the frequency-scanning monopulse slot antenna and reduce deformation. By suppressing the current on the surface of the multiple array slots 111, the effect of suppressing cross-polarization is achieved.

[0100] Finally, in step S104, as Figure 8 As shown, the closure 500 includes a connecting plate 510 and a connecting block 520 that are interconnected; wherein,

[0101] One end face of the connecting plate 510 is a free end face, used to insert or pull the closure 500 into or out of the end face opening of the waveguide 100. The other end face of the connecting plate 510 is fastened to the connecting block 520, and the area of ​​the connecting end face of the connecting plate 510 is greater than the area of ​​the contact surface between the connecting plate 510 and the connecting block 520.

[0102] The connecting block 520 is stepped and includes a first connecting block 521 and a second connecting block 522 connected in sequence. One end face of the first connecting block 521 is fastened to the connecting plate 510, and the other end face of the first connecting block 521 is fastened to one end face of the second connecting block 522. The height of the first connecting block 521 is greater than the height of the second connecting block 522.

[0103] When the closure 500 is inserted into the end face opening of the waveguide 100, the connecting plate 510 is located outside the waveguide 100 and closes the end face opening of the waveguide 100; the connecting block 520 is located inside the waveguide 100 and is adapted to the waveguide 100; the length of the first connecting block 521 is equal to the distance from the end face opening of the waveguide 100 to the inlet surface of the first waveguide port 211 or the third waveguide port 411; the second connecting block 522 is located below the first waveguide port 211 or the third waveguide port 411, and the length of the second connecting block 522 is not greater than the length of the first waveguide port 211 or the third waveguide port 411. This arrangement reduces standing waves.

[0104] The isolator 330 divides the second flange 300 into equal second left flange and second right flange along the central axis of the waveguide 100, and divides the second waveguide port 311 and the second slot 130 into two equal parts along the central axis of the waveguide 100.

[0105] Multiple countersunk holes 322 are respectively provided below each second through hole 321 near the second waveguide port 311 on the second left flange and the second right flange. An inductor pin is installed in the countersunk hole 322. The countersunk hole 322 is provided to facilitate the installation of the inductor pin. The inductor pin plays a role in tuning and matching.

[0106] It should be noted that the specific dimensions and specifications of the frequency-scanned monopulse slot antenna finally fabricated in this embodiment are as follows:

[0107] like Figure 9 As shown in Figure a, after installing each flange onto the waveguide 100, the distance L1 from the center of the first flange 200 to the center of the second flange 300 must be equal to the distance L2 from the center of the second flange 300 to the center of the third flange 400. Both ends of each reinforcing member 150 are securely connected to the contact surface of the adjacent flange, indicating that the lengths of the reinforcing members 150 are all equal. In this embodiment, the frequency-scanning monopulse slot antenna fabricated according to this method has L1 = L2 = 290 mm. The height H1 of the second flange 300 is 21 mm. Figure 9As shown in Figure b, the width d4 of the second waveguide opening 311 is 5.25 mm. The width d3 from the horizontal centerline of the second waveguide opening 311 to one edge of the lower surface of the waveguide 100 is 2 mm. This is because a countersunk hole 322 is machined on the side of the second flange 300, and the inductor pin is inserted into the countersunk hole 322. The size of the inductor pin inside the waveguide 100 is adjusted to ensure that d4 > 2d3; thus, the voltage standing wave ratio (VSWR) of the frequency-scanning monopulse slot antenna is ≤ 1.05. After that, the inductor pin is glued on, completing the fabrication of the frequency-scanning monopulse slot antenna. Figure 9 As shown in Figure c, the width b0 of the waveguide 100 is 7.25 mm. The height a0 of the waveguide 100 is 12.5 mm. The height H2 of the reinforcing member 150 to the lower surface of the waveguide 100 is 8.7 mm.

[0108] like Figure 10 Figure a shows the installation position dimensions of the first flange 200 pre-installed on the waveguide 100. The width of the waveguide 100 is b0 = 7.25 mm; the length L3 of the pre-installed first flange 200 on the waveguide 100 is 31.2 mm, slightly larger than the length of the first flange 200, facilitating its installation.

[0109] like Figure 10 Figure b shows the installation position dimensions of the second flange 300 pre-installed on the waveguide 100. The length of the pre-installed second flange 300 on the waveguide 100 is 70.15 mm, slightly longer than the actual length of the second flange 300, facilitating its installation.

[0110] like Figure 10 Figure c shows the installation position dimensions of the third flange 400 pre-installed on the waveguide 100. The position length L5 of the third flange 400 pre-installed on the waveguide 100 is 31.65 mm, slightly larger than the length of the third flange 400, facilitating its installation.

[0111] like Figure 11 As shown in Figure a, the spacer 330 is preferably a partition, the width b3 of the spacer 330 is 15.6 mm, and the length H5 of the spacer 330 is 25 mm. Figure 11 As shown in a and 11b, when setting the isolator 330, a placement groove 340 is first set on the central axis of the waveguide 100 with the flange installed. The width d1 of the placement groove 340 is 1.05mm, and the width d2 of the isolator 330 is 1mm, which is slightly smaller than the width of the placement groove 340, which is conducive to insertion.

[0112] To meet the fabrication requirements for frequency-scanning monopulse slot antennas of different sizes, the following dimensional relationships must be met during assembly:

[0113] When the waveguide 100 with reinforcement 150 is assembled with each flange, the following dimensional relationships must be met:

[0114] L6+0.3>L3>L6+0.1

[0115] L7+0.3>L4>L7+0.1

[0116] L8+0.3>L5>L8+0.1

[0117] b0+0.4>b1>b0+0.2

[0118] a0>H3>H2

[0119] Simultaneously heat the waveguide 100 and all flanges, and weld the reinforcing member 150, waveguide 100, all flanges, and corresponding slots, while meeting the following dimensional relationships:

[0120] d2+0.1>d1>d2

[0121] b² + 4 > b³ > b² + 2

[0122] H5 > H4 > a0

[0123] H4≥H1+2.5

[0124] The distance between the end face of the flange and the array of slots 111 on the surface of the waveguide 100 satisfies the following relationship:

[0125] H4>H1+2.5

[0126] Additionally, weight-reducing openings 600 can be provided on the left and right end faces of the second flange 300 and the third flange 400. These openings are created by hollowing out the end faces of the second flange 300 and the third flange 400 to reduce their weight. Generally, weight-reducing openings 600 are not provided on the first flange 200 because its height is less than 10mm. Adding a weight-reducing opening 600 would hinder the threaded connection of the first flange 200 and reduce the reliability of the connection. However, the second flange 300 and the third flange 400 are both greater than 10mm in height and are used to absorb loads. Providing weight-reducing openings 600 on these two flanges does not affect the connection reliability while simultaneously reducing weight.

[0127] This disclosure presents a frequency-scanning monopulse antenna and its fabrication method. By utilizing the same waveguide 100, effective isolation is achieved at the middle position of the frequency-scanning array, ensuring the consistency of the internal dimensions of the waveguide 100, reducing welding deformation in the length direction of the waveguide 100, and simultaneously ensuring the required specifications for the gap spacing, gap tilt angle, and gap depth of the two separated frequency-scanning monopulse antenna segments. This ensures the phase continuity of the frequency-scanning monopulse antenna and improves the angle measurement accuracy of the radar.

[0128] It should be noted that although several units of the system for executing actions have been mentioned in the detailed description above, this division is not mandatory. In fact, according to embodiments of this disclosure, the features and functions of two or more units described above can be embodied in one unit. Conversely, the features and functions of one unit described above can be further divided and embodied by multiple units. Some or all of the units can be selected to achieve the purpose of this disclosure according to actual needs. Those skilled in the art can understand and implement this without any inventive effort.

[0129] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the appended claims.

Claims

1. A frequency-scanning monopulse slot antenna, characterized in that, The frequency-scanned single-pulse slot antenna includes: A waveguide is hollow inside, with both its left and right end faces open. Multiple arrayed slot groups are evenly arranged on the upper surface of the waveguide; each arrayed slot group contains two arrayed slots arranged in a figure-eight shape. Multiple slots are provided on the lower surface of the waveguide; these slots include a first slot, a second slot, and a third slot; the first slot is located on the lower surface of the left end of the waveguide; the second slot is located on the lower surface of the middle section of the waveguide; and the third slot is located on the lower surface of the right end of the waveguide. Multiple flanges are provided, including a first flange sleeved upward from the lower surface of the left end of the waveguide, a second flange sleeved upward from the lower surface of the middle part of the waveguide, and a third flange sleeved upward from the lower surface of the right end of the waveguide; and the distance from the center of the first flange to the center of the second flange is equal to the distance from the center of the second flange to the center of the third flange; each slot is respectively provided with one flange. The upper surface of the first flange is provided with a first U-shaped groove, and the center of the bottom surface of the first U-shaped groove is provided with a first waveguide opening. Multiple pairs of first through holes are provided on the two opposite sides of the first U-shaped groove. The first waveguide opening and the first groove hole are provided in correspondence with each other, and the first waveguide opening and the first groove hole are coaxial. The upper surface of the third flange is provided with a third U-shaped groove, and the center of the bottom surface of the third U-shaped groove is provided with a third waveguide opening. Multiple pairs of third through holes are provided on the two opposite sides of the third U-shaped groove. The third waveguide opening and the third groove hole are provided in correspondence with each other, and the third waveguide opening and the third groove hole are coaxial. Multiple closures are provided at the openings on the left and right end faces of the waveguide, and the multiple closures are used to seal the left and right end faces of the waveguide, respectively. An isolator that vertically divides the frequency-scanning monopulse slot antenna into left and right parts along the central axis of the waveguide; The upper surface of the second flange is provided with a second U-shaped groove, and the center of the bottom surface of the second U-shaped groove is provided with a second waveguide opening. Multiple pairs of second through holes are provided on the two opposite sides of the second U-shaped groove. The second waveguide opening and the second groove hole are provided in correspondence with each other, and the second waveguide opening and the second groove hole are coaxial. The isolating member divides the second flange into an equal second left flange and a second right flange along the central axis of the waveguide, and also divides the second waveguide opening and the second slot into two symmetrical parts along the central axis of the waveguide. The second slot and the second waveguide port are divided into left and right parts by an isolator. Electromagnetic waves are fed in from the first slot through the first waveguide port and radiated out from multiple array gaps between the left part of the first waveguide port and the second waveguide port. Excess electromagnetic waves are absorbed by the absorption load connected to the left part of the second waveguide port. At the same time, electromagnetic waves are fed in from the right part of the second waveguide port and radiated out from multiple array gaps between the right part of the second waveguide port and the third waveguide port. Excess electromagnetic waves are absorbed by the absorption load connected to the third waveguide port.

2. The frequency-scanned monopulse slot antenna according to claim 1, characterized in that, Multiple pairs of reinforcing members are respectively provided on the front and rear sides of the waveguide between the first flange and the second flange, and on the front and rear sides of the waveguide between the second flange and the third flange.

3. The frequency-scanning monopulse slot antenna according to claim 1, characterized in that, Multiple countersunk holes are provided below each of the second through holes near the second waveguide opening on the second left flange and the second right flange, and an inductor pin is provided in each of the countersunk holes.

4. The frequency-scanning monopulse slot antenna according to any one of claims 1 to 3, characterized in that, The closure includes interconnected connecting plates and connecting blocks; wherein... One end face of the connecting plate is a free end face, which facilitates the insertion or removal of the closure member from the end face opening of the waveguide; the other end face of the connecting plate is a connecting end face, which is fastened to the connecting block, and the area of ​​the connecting end face of the connecting plate is larger than the area of ​​the contact surface between the connecting plate and the connecting block. The connecting block is stepped and includes a first connecting block and a second connecting block connected in sequence. One end face of the first connecting block is fastened to the connecting plate, and the other end face of the first connecting block is fastened to one end face of the second connecting block. The height of the first connecting block is greater than the height of the second connecting block. When the closure is inserted into the end face opening of the waveguide, the connecting plate is located outside the waveguide and closes the end face opening of the waveguide; the connecting block is located inside the waveguide and is adapted to the waveguide; the length of the first connecting block is equal to the distance from the end face opening of the waveguide to the inlet surface of the first waveguide port or the third waveguide port; the second connecting block is located below the first waveguide port or the third waveguide port, and the length of the second connecting block is not greater than the length of the first waveguide port or the third waveguide port.

5. A method for fabricating a frequency-scanning monopulse slot antenna, characterized in that, The production method includes: According to the electrical process design requirements, the size and specifications of multiple flanges on the waveguide are determined, multiple installation positions of the flanges are preset on the waveguide, and a slot is set at each installation position. Process a plurality of flanges and install the plurality of flanges at a plurality of preset mounting positions on the waveguide respectively; Multiple uniformly arranged array slot groups are machined on the upper surface of the waveguide; corresponding pairs of reinforcing members are respectively provided on the front and rear sides of the waveguide; A sealing component adapted to the flange is provided on both end faces of the waveguide; and an isolating component is inserted along the central axis of the waveguide to assemble the frequency-scanning monopulse slot antenna. Each of the slots is respectively provided with one of the flange components; The isolator vertically divides the frequency-scanning monopulse slot antenna into left and right parts along the central axis of the waveguide.

6. The method for manufacturing a frequency-scanned monopulse slot antenna according to claim 5, characterized in that, The steps of determining the dimensions and specifications of multiple flanges on the waveguide according to electrical process design requirements, pre-setting the installation positions of multiple flanges on the waveguide, and setting a corresponding slot at each installation position include: The plurality of flanges include a first flange sleeved upward from the lower surface of the left end of the waveguide, a second flange sleeved upward from the lower surface of the middle portion of the waveguide, and a third flange sleeved upward from the lower surface of the right end of the waveguide; and the distance from the center of the first flange to the center of the second flange is equal to the distance from the center of the second flange to the center of the third flange; Multiple pairs of reinforcing members are respectively provided on the front and rear sides of the waveguide between the first flange and the second flange, and on the front and rear sides of the waveguide between the second flange and the third flange; The plurality of slots include a first slot, a second slot, and a third slot; the first slot is disposed on the lower surface of the left end of the waveguide; the second slot is disposed on the lower surface of the middle part of the waveguide; and the third slot is disposed on the lower surface of the right end of the waveguide.

7. The method for manufacturing a frequency-scanned monopulse slot antenna according to claim 6, characterized in that, The step of processing multiple flanges and installing the multiple flanges at multiple preset installation positions on the waveguide includes: The upper surface of the first flange is provided with a first U-shaped groove, and the center of the bottom surface of the first U-shaped groove is provided with a first waveguide opening. Multiple pairs of first through holes are provided on the two opposite sides of the first U-shaped groove. The first waveguide opening and the first groove hole are provided in correspondence with each other, and the first waveguide opening and the first groove hole are coaxial. The upper surface of the second flange is provided with a second U-shaped groove, and the center of the bottom surface of the second U-shaped groove is provided with a second waveguide opening. Multiple pairs of second through holes are provided on the two opposite sides of the second U-shaped groove. The second waveguide opening and the second groove hole are provided in correspondence with each other, and the second waveguide opening and the second groove hole are coaxial. The isolating member divides the second flange into an equal second left flange and a second right flange along the central axis of the waveguide, and also divides the second waveguide opening and the second slot into two symmetrical parts along the central axis of the waveguide. Multiple countersunk holes are provided below each of the second through holes near the second waveguide opening on the second left flange and the second right flange, and an inductor pin is provided in each of the countersunk holes; The upper surface of the third flange is provided with a third U-shaped groove, and the center of the bottom surface of the third U-shaped groove is provided with a third waveguide opening. Multiple pairs of third through holes are provided on the two opposite sides of the third U-shaped groove. The third waveguide opening and the third groove hole are provided in correspondence with each other, and the third waveguide opening and the third groove hole are coaxial.

8. The method for manufacturing a frequency-scanned monopulse slot antenna according to claim 7, characterized in that, Multiple uniformly arranged array slot groups are processed on the upper surface of the waveguide; The step of setting corresponding pairs of reinforcing members on the front and rear sides of the waveguide includes: The waveguide is hollow inside, and both the left and right end faces of the waveguide are open; Each of the array slot groups comprises two array slots arranged in a figure-eight shape; and the middle array slot group on the waveguide is divided into two symmetrical parts by the isolator.

9. The method for manufacturing a frequency-scanned monopulse slot antenna according to claim 8, characterized in that, The waveguide is provided with closures that are adapted to the flange on both end faces; The steps of assembling the frequency-scanning monopulse slot antenna by inserting isolators along the central axis of the waveguide include: The closure includes interconnected connecting plates and connecting blocks; wherein... One end face of the connecting plate is a free end face, which facilitates the insertion or removal of the closure member from the end face opening of the waveguide. The other end face of the connecting plate is a connecting end face. The connecting end face of the connecting plate is tightly connected to the connecting block, and the area of ​​the connecting end face of the connecting plate is larger than the area of ​​the contact surface between the connecting plate and the connecting block. The connecting block is stepped and includes a first connecting block and a second connecting block connected in sequence. One end face of the first connecting block is fastened to the connecting plate, and the other end face of the first connecting block is fastened to one end face of the second connecting block. The height of the first connecting block is greater than the height of the second connecting block. When the closure is inserted into the end face opening of the waveguide, the connecting plate is located outside the waveguide and closes the end face opening of the waveguide; the connecting block is located inside the waveguide and is adapted to the waveguide; the length of the first connecting block is equal to the distance from the end face opening of the waveguide to the inlet surface of the first waveguide port or the third waveguide port; the second connecting block is located below the first waveguide port or the third waveguide port, and the length of the second connecting block is not greater than the length of the first waveguide port or the third waveguide port.

Images