Ultra-wideband single-pulse antenna based on compact coupled array and radiation method thereof

Abstract

The application discloses a kind of based on tight coupling array's ultra-wideband single pulse antenna and its radiation method, including first truncation, first tight coupling line array, second truncation, second tight coupling line array, third truncation, upper layer feed network and lower layer feed network, first truncation, first tight coupling line array, second truncation, second tight coupling line array and third truncation are sequentially connected from left to right, and its lower end is fixedly connected with lower layer feed network by passing through the fourth plug hole on upper layer feed network;Upper layer feed network and lower layer feed network are coupled connection, and lower layer feed network is electrically connected between first truncation, first tight coupling line array, second truncation, second tight coupling line array and third truncation;By exciting the first port of first feed network, and wave beam in xoz plane is generated;By exciting the second port of second feed network, difference wave beam in xoz plane is generated.The application has the advantages of compact structure, low profile and wide bandwidth, and can be used in ultra-wideband single pulse tracking system.

Description

Technical Field

[0001] This invention relates to antenna technology, specifically to an ultra-wideband monopulse antenna based on a tightly coupled array and its radiation method, which can be applied to ultra-wideband target tracking, detection, radar communication and other applications. Background Technology

[0002] Monopulse technology is a method that uses the echo of a single pulse to form the sum and difference signals required for direction finding. Due to its precise tracking performance, it is widely used in satellite tracking and target positioning systems. Compared to tracking techniques such as step tracking and conical scan tracking, monopulse technology offers higher sensitivity, accuracy, and efficiency. A monopulse antenna, as the front-end transceiver of a monopulse system, typically consists of two parts: a feed network and a radiating section. The feed network generates the sum and difference modes, while the radiating section performs the radiation.

[0003] With the development of modern technology, monopulse antennas can now be roughly divided into three categories. The first type is monopulse antennas based on horn antennas and reflectors. These monopulse antennas use waveguides as the feeding structure. Although they have good monopulse performance, the overall antenna is not only complex and bulky, but also difficult to integrate with other devices, and the manufacturing cost is high. The second type is planar microstrip monopulse antennas. Due to their advantages such as small size, low cost, and easy integration, they are widely used in monopulse radar systems. However, since microstrip lines themselves generate spurious radiation, it inevitably affects the antenna pattern. The third type is monopulse antennas based on substrate integrated waveguides. By etching metal vias on the substrate to confine electromagnetic waves, the influence of the feeding network on the pattern is greatly avoided. They also have advantages such as low profile and low cost. However, their operating bandwidth is generally narrow and cannot be used in ultra-wideband communication and tracking equipment.

[0004] The aforementioned monopulse antennas all possess excellent monopulse performance, but the vast majority of them are limited in application due to their narrow operating bandwidth. Although a few monopulse antennas have achieved ultra-wideband performance, they have not been widely used due to their high profile and complex feeding network. Summary of the Invention

[0005] Purpose of the invention: One objective of this invention is to provide an ultra-wideband monopulse antenna based on a tightly coupled array.

[0006] Another object of the present invention is to provide a radiation method for an ultra-wideband monopulse antenna based on a tightly coupled array.

[0007] Technical solution: The present invention provides an ultra-wideband monopulse antenna based on a tightly coupled array, comprising: a first truncation, a first tightly coupled linear array, a second truncation, a second tightly coupled linear array, a third truncation, an upper feed network, and a lower feed network, wherein the first truncation, the first tightly coupled linear array, the second truncation, the second tightly coupled linear array, and the third truncation are connected sequentially from left to right, and their lower ends all pass through a fourth connector on the upper feed network and are fixedly connected to the lower feed network;

[0008] The first tightly coupled linear array includes a first frequency selective patch unit, a first dipole unit array, a second dipole unit array, and a second dielectric layer arranged in an array. The first frequency selective patch unit is symmetrically disposed on the upper part of the front and rear sides of the second dielectric layer. The first dipole unit array and the second dipole unit array are respectively disposed on the front and rear sides of the second dielectric layer, both located below the first frequency selective patch unit. The array period of the first frequency selective patch unit is the same as the array period of the first dipole unit array and the second dipole unit array. The structure of the second tightly coupled linear array is the same as the structure of the first tightly coupled linear array.

[0009] The upper-layer feed network includes a sixth dielectric layer, and a first feed network and a fifth metal layer respectively disposed on the upper and lower surfaces of the sixth dielectric layer. The first feed network includes a first port and a first metal microstrip line. The fifth metal layer is provided with a first elliptical coupling slot and a second elliptical coupling slot that are coupled and connected to the first metal microstrip line.

[0010] The lower-layer feed network includes a seventh dielectric layer, a sixth metal layer, and a second feed network disposed on the upper and lower surfaces of the seventh dielectric layer, respectively. The second feed network includes a second port, a second metal microstrip line, a third metal microstrip line, a first 1-to-4 power divider, and a second 1-to-4 power divider. The second port is connected to the input terminal of the first 1-to-4 power divider via the second metal microstrip line. The four first output ports of the first 1-to-4 power divider are respectively connected to the second dipole element array. The third metal microstrip line is connected to the input terminal of the second 1-to-4 power divider. The four second output ports of the second 1-to-4 power divider are respectively connected to the fourth dipole element array of the second tightly coupled linear array. The sixth metal layer is provided with a third elliptical coupling slot and a fourth elliptical coupling slot that are respectively coupled to the second metal microstrip line and the third metal microstrip line. The first elliptical coupling slot and the third elliptical coupling slot are spatially aligned and correspond to each other. The second elliptical coupling slot and the fourth elliptical coupling slot are spatially aligned and correspond to each other.

[0011] The first, second, and third cutoffs direct the current on the first and second tightly coupled linear arrays to the sixth metal layer of the lower-level feed network.

[0012] Preferably, the first cut includes a first dielectric layer and a first metal layer attached to one side of the first dielectric layer near the first tightly coupled linear array; the second cut includes a third dielectric layer and a second metal layer and a third metal layer respectively attached to the left and right sides of the third dielectric layer; the third cut includes a fifth dielectric layer and a fourth metal layer attached to one side of the fifth dielectric layer near the second tightly coupled linear array.

[0013] Preferably, the first segment is provided with a first connector hole for insertion and fixing to the first tightly coupled linear array, the second segment is provided with a second connector hole for insertion and fixing to the first tightly coupled linear array and the second tightly coupled linear array, and the third segment is provided with a third connector hole 53 for insertion and fixing to the second tightly coupled linear array. The lower end faces of the first segment, the second segment and the third segment are respectively provided with a first connector post, a fifth connector post and a ninth connector post for insertion and fixing to the lower layer power supply network.

[0014] Preferably, the first dipole unit array includes arrayed first dipole units, each including a first dipole and a first balun ground; the second dipole unit array includes arrayed second dipole units, each including a second dipole and a first balun microstrip line; the first balun ground and the first balun microstrip line extend taperedly from spatially adjacent ends of the first and second dipoles toward the lower end of the second dielectric layer, respectively, and the tapered width of the first balun ground is larger than the tapered width of the first balun microstrip line; the first output port of the first 1-to-4 power divider is connected to the lower end of the first balun microstrip line, and the second output port of the second 1-to-4 power divider is connected to the lower end of the second balun microstrip line of the fourth dipole unit.

[0015] Preferably, the first frequency selection patch unit includes four sequentially connected first frequency selection patches, and the second frequency selection patch unit includes four sequentially connected second frequency selection patches.

[0016] Preferably, the second dielectric layer has a second connector and a third connector that are fixed to the first cut-off and the second cut-off on its left and right sides, respectively. The fourth dielectric layer has a sixth connector and a seventh connector that are fixed to the second cut-off and the third cut-off on its left and right sides, respectively. The lower end surfaces of the second dielectric layer and the fourth dielectric layer have a fourth connector and an eighth connector 47 that are fixed to the lower feed network, respectively.

[0017] Preferably, the upper-layer power supply network and the lower-layer power supply network are respectively provided with a first fixing hole and a second fixing hole.

[0018] Preferably, the lower-level power supply network also includes six resistors, which are respectively set at the branch ports of the 1-to-4 power divider to improve the isolation of the output ports.

[0019] Preferably, the lower-level feed network also has a fifth connector that runs vertically through the first, second, and third cut-off sections and is fixed to them, and a sixth connector that is fixed to the first and second tightly coupled linear arrays.

[0020] The present invention provides a radiation method for an ultra-wideband monopulse antenna based on a tightly coupled array, comprising:

[0021] The first port is excited, and current flows through the first metal microstrip line. One path is coupled to the first 1-to-4 power divider of the second feed network through the first and third elliptical coupling slots, and then splits into four outputs to the first tightly coupled linear array; the other path is coupled to the second 1-to-4 power divider of the second feed network through the second and fourth elliptical coupling slots, and then splits into four outputs to the second tightly coupled linear array; this makes the first and second dipole unit arrays phase with the third and fourth dipole unit arrays, forming a beam.

[0022] The second port is excited, and one current flows through the second metal microstrip line to the first 1-to-4 power divider, which splits into four outputs to the first tightly coupled linear array; another current flows through the third elliptical coupling slot and the first elliptical coupling slot, coupled to the first metal microstrip line, and then through the second elliptical coupling slot and the fourth elliptical coupling slot, coupled to the second 1-to-4 power divider of the second feed network, which then splits into four outputs to the second tightly coupled linear array; this makes the first and second dipole unit arrays out of phase with the third and fourth dipole unit arrays, forming a difference beam.

[0023] Beneficial effects: Compared with the prior art, the significant technical effects of the present invention are as follows:

[0024] The antenna of this invention has a simple feeding method and an extremely low profile. By using a tightly coupled array with a truncation, a continuous current is formed on the dipole arm, and ultra-wideband single-pulse performance is achieved. While maintaining ultra-wideband and low profile, the antenna of this invention has the advantages of high radiation efficiency, easy integration and low cost. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the antenna structure of the present invention;

[0026] Figure 2 This is a schematic diagram of the layered antenna structure of the present invention, wherein (a) is a first view and (b) is a second view;

[0027] Figure 3 This is a schematic diagram of the first and third truncations of the antenna of the present invention, wherein (a) is a side view and (b) is a front view;

[0028] Figure 4This is a schematic diagram of the second truncated section of the antenna of the present invention, wherein (a) is a side view and (b) is a front view;

[0029] Figure 5 This is a schematic diagram of the first tightly coupled array of the antenna of the present invention, wherein (a) is a side view, (b) is a front view, and (c) is a rear view;

[0030] Figure 6 This is a schematic diagram of the second tightly coupled antenna array of the present invention, wherein (a) is a side view, (b) is a front view, and (c) is a rear view;

[0031] Figure 7 This is a schematic diagram of the first feed network layer of the antenna of the present invention, wherein (a) is a side view and (b) is a front view;

[0032] Figure 8 This is a schematic diagram of the second feed network layer of the antenna of the present invention, wherein (a) is a side view and (b) is a front view;

[0033] Figure 9 The diagram shows the antenna S-parameters, gain, and zero depth of the present invention, where (a) is the antenna S-parameters diagram and (b) is the antenna gain and zero depth diagram.

[0034] Figure 10 The radiation pattern of the antenna of the present invention is shown in the diagram, where (a) is the sum beam at 5.5 GHz, (b) is the difference beam at 5.5 GHz, (c) is the sum beam at 8.5 GHz, (d) is the difference beam at 8.5 GHz, (e) is the sum beam at 11.5 GHz, and (f) is the difference beam at 11.5 GHz. Detailed Implementation

[0035] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0036] The present invention provides a monopulse antenna based on a tightly coupled array, which adopts a 7-block structure. Two layers of feed network form the antenna feed network to generate the sum and difference modes of the monopulse antenna. A pair of tightly coupled arrays serve as the radiating part of the antenna. Three blocks of truncated continuous current are used to form a dipole array to achieve the ultra-wideband performance of the antenna.

[0037] like Figure 1 and Figure 2As shown in (a) and (b), the ultra-wideband monopulse antenna based on a tightly coupled array comprises, from left to right and from top to bottom: a first truncation 1, a first tightly coupled linear array 2, a second truncation 3, a second tightly coupled linear array 4, a third truncation 5, an upper feed network 6, and a lower feed network 7. The left side of the first tightly coupled linear array 2 is connected to the first truncation 1, and the right side is connected to the second truncation 3. The left side of the second tightly coupled linear array 4 is connected to the second truncation 3, and the right side is connected to the third truncation 5. 4. After the third segments 5 are interconnected, their lower ends all pass through the fourth connector 65 on the upper feed network 6 and are fixedly connected to the lower feed network 7. The upper feed network and the lower feed network are fixedly connected by plastic nuts passing through fixing holes 64 and 74. There is also an electrical connection between the lower feed network and the first segment, the first tightly coupled linear array, the second segment, the second tightly coupled linear array, and the third segment. By exciting the first port of the first feed network, an xoz plane sum beam is generated. By exciting the second port of the second feed network, an xoz plane difference beam is generated.

[0038] like Figure 3 As shown in (a) and (b), the first section 1 and the third section 5 have completely identical structures. The first section 1 includes a first metal layer 11 and a first dielectric layer 12. The first metal layer 11 is attached to one side of the first dielectric layer 12 near the first tightly coupled linear array 2 and is in contact with the first tightly coupled linear array 2. The first section 1 is provided with a first through-hole 13 extending from left to right. The lower end face of the first section 1 is provided with a first through-hole 14. The first through-hole 13 and the first through-hole 14 are used for fixing the plates. The third section 5 includes a fourth metal layer 51 and a fifth dielectric layer 52. The fourth metal layer 51 is attached to one side of the fifth dielectric layer 52 near the second tightly coupled linear array 4 and is in contact with the second tightly coupled linear array 4. The third section is provided with a third through-hole 53 extending from left to right. The lower end face of the third section 5 is provided with a ninth through-hole 54. The third through-hole 53 and the ninth through-hole 54 are used for fixing the plates.

[0039] like Figure 4 As shown in (a) and (b), the second section 3 includes a second metal layer 31, a third dielectric layer 32, and a third metal layer 33. The second metal layer 31 and the third metal layer 33 are respectively attached to the left and right sides of the third dielectric layer 32. The second section 3 is provided with a second insertion hole 34 that runs through the left and right sides. The lower end face of the second section 3 is provided with a fifth insertion post 35. The second insertion hole 34 and the fifth insertion post 35 are used for fixing between the plates.

[0040] The first cutoff 1, the second cutoff 3, and the third cutoff 5 respectively use the first metal layer 11, the second metal layer 31, the third metal layer 33, and the fourth metal layer 51 to guide the current of the dipole arms 22, 24, 42, and 44 connected to the cutoff to the sixth metal layer, which is equivalent to the current continuity effect in an infinitely large tightly coupled array.

[0041] like Figure 5 As shown in (a), (b), and (c), the first tightly coupled linear array 2 includes a first frequency selective patch unit 21, a first dipole unit array, a second dipole unit array, and a second dielectric layer 23 arranged in an array. The first frequency selective patch unit is used to improve the impedance matching of the dipole unit array, which serves as a radiating component. The second dielectric layer 23 has a second connector 25 and a third connector 26 on its left and right sides, respectively, and a fourth connector 27 on its lower end face. The first frequency selective patch unit 21 is symmetrically arranged on the upper part of the front and rear sides of the second dielectric layer 23. Each first frequency selective patch unit 21 includes four sequentially connected first frequency selective patches. In this embodiment, eight first frequency selective patch units 21 are symmetrically arranged on the front and rear sides of the second dielectric layer 23, with 16 first frequency selective patches on each side. The first dipole unit array is disposed on the front side of the second dielectric layer 23, below the first frequency selection patch unit 21; the second dipole unit array is disposed on the rear side of the second dielectric layer 23, below the first frequency selection patch unit 21; the array period of the first frequency selection patch unit 21 is the same as the array period of the first dipole unit array and the second dipole unit array; in this embodiment, the first dipole unit array includes four first dipole units arranged in an array, and the second dipole unit array includes four second dipole units arranged in an array.

[0042] The first dipole unit includes a first dipole arm 22 and a first balun ground 28, and the second dipole unit includes a second dipole arm 24 and a first balun microstrip line 29. The first balun ground 28 and the first balun microstrip line 29 extend taperedly from the spatially adjacent ends of the first dipole arm 22 and the second dipole arm 24 toward the lower end of the second dielectric layer 23, and the tapered width of the first balun ground 28 is larger than the tapered width of the first balun microstrip line 29.

[0043] In this embodiment, the width of the second connector 25 is greater than the width of the third connector 26, and the fourth connector 27 is disposed between two adjacent first dipole units.

[0044] like Figure 6As shown in (a), (b), and (c), the second tightly coupled linear array 4 includes a second frequency selective patch unit 41, a third dipole unit array, a fourth dipole unit array, and a fourth dielectric layer 43 arranged in an array. The second frequency selective patch unit is used to improve the impedance matching of the dipole unit array, which serves as a radiating component. The fourth dielectric layer 43 has a sixth connector 45 and a seventh connector 46 on its left and right sides, respectively, and an eighth connector 47 on its lower surface. The second frequency selective patch unit 41 is symmetrically arranged on the upper part of the front and rear sides of the fourth dielectric layer 43. Each second frequency selective patch unit 41 includes four sequentially connected second frequency selective patches. In this embodiment, 16 second frequency selective patch units 41 are symmetrically arranged on the upper part of the front and rear sides of the fourth dielectric layer 43, with 16 second frequency selective patches on each side. The third dipole unit array is disposed on the front side of the fourth dielectric layer 43, below the second frequency selection patch unit 41; the fourth dipole unit array is disposed on the rear side of the fourth dielectric layer 43, below the second frequency selection patch unit 41; the array period of the second frequency selection patch unit 41 is the same as the array period of the third dipole unit array and the fourth dipole unit array; in this embodiment, the third dipole unit array includes four third dipole units arranged in an array, and the fourth dipole unit array includes four fourth dipole units arranged in an array.

[0045] The third dipole unit includes a third dipole arm 42 and a second balun ground 48. The fourth dipole unit includes a fourth dipole arm 44 and a second balun microstrip line 49. The second balun ground 48 and the second balun microstrip line 49 extend taperedly from the spatially adjacent ends of the third dipole arm 42 and the fourth dipole arm 44 toward the lower end of the fourth dielectric layer 43, respectively. The tapered width of the second balun ground 48 is larger than the tapered width of the second balun microstrip line 49.

[0046] In this embodiment, the width of the seventh connector 46 is greater than the width of the sixth connector 45, and the eighth connector 47 is disposed between two adjacent third dipole units.

[0047] The second connector 25 of the first tightly coupled linear array 2 is the same as the seventh connector 46 of the second tightly coupled linear array 4, the third connector 26 of the first tightly coupled linear array 2 is the same as the sixth connector 45 of the second tightly coupled linear array 4, and the rest of the structures are exactly the same.

[0048] like Figure 7As shown in (a) and (b), the upper-layer power supply network 6 includes a first power supply network 63, a sixth dielectric layer 62, and a fifth metal layer 61. The first power supply network 63 and the fifth metal layer 61 are respectively disposed on the upper and lower surfaces of the sixth dielectric layer 62. The first power supply network 63 includes a first port 68 and a first metal microstrip line 69. The fifth metal layer 61 is provided with a first elliptical coupling slot 66 and a second elliptical coupling slot 67, which are coupled to the first metal microstrip line 69 of the first power supply network 63. The upper-layer power supply network 6 also has a fourth through-hole 65 and several first fixing holes 64.

[0049] like Figure 8 As shown in (a) and (b), the lower-layer feed network 7 includes a sixth metal layer 73, a seventh dielectric layer 72, and a second feed network 71. The sixth metal layer 73 and the second feed network 71 are respectively disposed on the upper and lower surfaces of the seventh dielectric layer 72. The second feed network 71 includes six resistors 75, a second port 78, a second metal microstrip line 711, a third metal microstrip line 712, a first 1-to-4 power divider 713, and a second 1-to-4 power divider 714. The second port 78 is connected to the input terminal of the first 1-to-4 power divider through the second metal microstrip line 711. The first 1-to-4 power divider includes four first output ports 715. The third metal microstrip line is connected to the input terminal of the second 1-to-4 power divider. The second 1-to-4 power divider includes four first output ports 715. Two output ports 716; six resistors are respectively set at the branch ports of the two 1-to-4 power dividers to improve the isolation of the output terminals; the sixth metal layer 73 is provided with a third elliptical coupling gap 76 and a fourth elliptical coupling gap 77; the lower feed network 7 is also provided with three vertically penetrating fifth connectors 79, eight sixth connectors 710 and several second fixing holes 74, and the positions of the fifth connectors 79 and the sixth connectors 710 correspond to the fourth connectors 65 on the upper feed network 6, and the positions of the second fixing holes 74 correspond one-to-one with the first fixing holes 64, for fixing the upper feed network 6 and the lower feed network 7; four first output ports 715 and four second output ports 716 are respectively located on the eight sixth connectors 710.

[0050] In this embodiment, the six resistors 75 in the second feed network are all 200Ω in value, which is intended to improve the isolation of the output port. The first elliptical coupling slot and the third elliptical coupling slot are spatially corresponding and fit together, and the second elliptical coupling slot and the fourth coupling slot are spatially corresponding and fit together; this is used for phase modulation in a wide bandwidth.

[0051] The first and third cut-off sections have the same structure, each consisting of a metal layer and a dielectric layer; the first and third dipole arrays have the same structure, as do the second and fourth dipole arrays, each consisting of metal dipole arms; the first and second frequency selection patches have the same structure, each consisting of metal patches located on the front and back sides of the dielectric substrate, with the same number on both sides.

[0052] During antenna installation, the first connector 13 corresponds to the second connector 25; the third connector 26 and the sixth connector 45 correspond to the second connector 34; the seventh connector 46 corresponds to the third connector 53; the fourth connector 27 and the eighth connector 47 both pass through the fourth connector 65 of the upper feed network 6 and correspond to the sixth connector 710 of the lower feed network 7; the first connector 14, the fifth connector 35, and the ninth connector 54 all pass through the fourth connector 65 of the upper feed network 6 and correspond to the fifth connector 79 of the lower feed network 7. The first elliptical coupling slot 66 corresponds spatially to the third elliptical coupling slot 76; the second elliptical coupling slot 67 corresponds spatially to the fourth elliptical coupling slot 77. The 16 fixing holes 64 and 74 on the upper feed network 6 and the lower feed network 7 respectively correspond spatially. The second feed network 71 has six 200Ω resistors 75 to improve the isolation of the output ports. The first and third dipole unit arrays are grounded, and the second and fourth dipole unit arrays are connected to the eight output ports of the two 1-to-4 power dividers of the second feed network 71.

[0053] When the antenna is operational, the first port 68 is excited, and current flows through the first metallic microstrip line 69. One path is coupled through the first elliptical coupling slot 66 and the third elliptical coupling slot 76 to the first 1-to-4 power divider 713 of the second feed network 71, and then splits into four outputs to the first tightly coupled linear array 2; another path is coupled through the second elliptical coupling slot 67 and the fourth elliptical coupling slot 77 to the second 1-to-4 power divider 714 of the second feed network 71, and then splits into four outputs to the second tightly coupled linear array 4; this makes the first dipole element array 22 and the second dipole element array 24 phase with the third dipole element array 42 and the fourth dipole element array 44, forming a phase relationship with the second dipole element array 22 and the second dipole element array 24. The beam is excited at the second port 78, and the current flows through the second metal microstrip line 711 to the first 1-to-4 power divider 713, which splits the current into four paths and outputs them to the first tightly coupled linear array 2. Another path is coupled to the first metal microstrip line (69) through the third elliptical coupling slot 76 and the first elliptical coupling slot 66, and then coupled to the second 1-to-4 power divider 714 of the second feed network 71 through the second elliptical coupling slot 67 and the fourth elliptical coupling slot 77, and then splits the current into four paths and outputs them to the second tightly coupled linear array 4. This makes the first dipole unit array 22 and the second dipole unit array 24 out of phase with the third dipole unit array 42 and the fourth dipole unit array 44, forming a difference beam.

[0054] Specifically: The first port 68 is excited, and current flows through the first metal microstrip line 69. One path leads to the second metal microstrip line of the second feed network 71 via the first elliptical coupling slot 66 and the third elliptical coupling slot 76. The current flowing through the second metal microstrip line is then output from the four first output ports of the first tightly coupled linear array 2 to the four first balun microstrip lines 29. These lines are coupled together via the first dipole arm 22 and the second dipole arm 24, and finally through the first metal layer 11 of the first cutoff 1 and the second metal layer of the second cutoff 3. Layer 31 flows to the sixth metal layer 73; another path is coupled to the third metal microstrip line of the second feed network 71 through the second elliptical coupling slot 67 and the fourth elliptical coupling slot 77. The current flowing through the third metal microstrip line is output to the four second balun microstrip lines 49 of the second tightly coupled linear array 4 through the second one-to-four power divider. The current is coupled to each other through the third dipole arm 42 and the fourth dipole arm 44, and finally flows to the sixth metal layer 73 through the third metal layer 3 of the second cut-off 3 and the fourth metal layer 51 of the third cut-off 5.

[0055] The second port 78 is excited, and current flows through the second metal microstrip line 711. One path flows into the first 1-to-4 power divider 713 and is then output from the four first output ports to the four first balun microstrip lines 29 of the first tightly coupled linear array 2. They are coupled to each other through the first dipole arm 22 and the second dipole arm 24, and finally flow to the sixth metal layer 73 through the first metal layer 11 of the first cut-off 1 and the second metal layer 31 of the second cut-off 3. The other path flows through the third elliptical coupling slot 76 and the first elliptical coupling slot 66 and then couples to... The first feed network 63 is then coupled to the third metal microstrip line 712 of the second feed network 71 via the second elliptical coupling slot 67 and the fourth elliptical coupling slot 77. After passing through the second one-to-four power divider 714, the power is output to the four second balun microstrip lines 49 of the second tightly coupled linear array 4 via the four second output ports. The power is then coupled to each other via the third dipole arm 42 and the fourth dipole arm 44. Finally, the power flows to the sixth metal layer 73 via the third metal layer 33 of the second cut-off 3 and the fourth metal layer 51 of the third cut-off 5.

[0056] The first dielectric layer 12, the second dielectric layer 23, the third dielectric layer 32, the fourth dielectric layer 43, the fifth dielectric layer 52, the sixth dielectric layer 62, and the seventh dielectric layer 72 are all made of F4B material with a relative permittivity of 2.65 and a loss tangent of 0.001. The first dielectric layer 12, the third dielectric layer 32, and the fifth dielectric layer 52 are 1 mm thick, and the second dielectric layer 23, the fourth dielectric layer 43, the sixth dielectric layer 62, and the seventh dielectric layer 72 are 0.5 mm thick. The first dipole arrays 22 and 24, the second dipole arrays 42 and 44, the first frequency selective patch array 21 and the second frequency selective patch array 41, the first feed network 63 and the second feed network 71, the first metal layer 11, the second metal layer 31, the third metal layer 33, the fourth metal layer 51, the fifth metal layer 61, and the sixth metal layer 73 are all made of copper with a thickness of 0.035 mm.

[0057] The above-mentioned radiation method for an ultra-wideband monopulse antenna based on a tightly coupled array is as follows:

[0058] Excitement at the first port 68 causes current to flow through the first metal microstrip line 69. One path couples through the first elliptical coupling slot 66 and the third elliptical coupling slot 76 to the first 1-to-4 power divider 713 of the second feed network 71, and then splits into four outputs to the first tightly coupled linear array 2. Another path couples through the second elliptical coupling slot 67 and the fourth elliptical coupling slot 77 to the second 1-to-4 power divider 714 of the second feed network 71, and then splits into four outputs to the second tightly coupled linear array 4. This ensures that the first dipole element array 22 and the second dipole element array 24 are in phase with the third dipole element array 42 and the fourth dipole element array 44, forming a beam. The second port 78 is excited, and the current flows through the second metal microstrip line 711 to the first 1-to-4 power divider 713, which splits the current into four outputs to the first tightly coupled linear array 2. Another output is coupled to the first metal microstrip line 69 through the third elliptical coupling slot 76 and the first elliptical coupling slot 66, and then coupled to the second 1-to-4 power divider 714 of the second feed network 71 through the second elliptical coupling slot 67 and the fourth elliptical coupling slot 77, which then splits the current into four outputs to the second tightly coupled linear array 4. This makes the first dipole unit array 22 and the second dipole unit array 24 out of phase with the third dipole unit array 42 and the fourth dipole unit array 44, forming a difference beam.

[0059] Figure 9 (a) shows the S-parameter curve of the antenna of the present invention. It can be seen that the two ports of the antenna of the present invention operate at the same frequency band. The simulated and measured return loss is less than -10dB in the range of 5-12GHz, and the isolation is better than 16dB.

[0060] Figure 9 (b) shows the gain and zero depth curves of the antenna of the present invention. It can be seen that within the operating frequency band, the simulated and measured gain of the antenna is greater than 7.4 dBi, and the zero depth is less than -19 dB.

[0061] Figure 10 The sum and difference radiation pattern of the antenna of this invention shows that it has a stable sum and difference beam, wherein:

[0062] Figure 10 (a) is the beam pattern of the antenna of the present invention at 5.5 GHz;

[0063] Figure 10 (b) is the differential beam pattern of the antenna of the present invention at 5.5 GHz;

[0064] Figure 10 (c) is the beam pattern of the antenna of the present invention at 8.5 GHz;

[0065] Figure 10 (d) is the differential beam pattern of the antenna of the present invention at 8.5 GHz;

[0066] Figure 10 (e) is the beam pattern of the antenna of the present invention at 11.5 GHz;

[0067] Figure 10 (f) is the differential beam pattern of the antenna of the present invention at 11.5 GHz;

[0068] This invention relates to a monopulse antenna based on a tightly coupled array, belonging to the field of antenna technology. This novel monopulse antenna with a dipole array utilizes the advantage of current continuity in the tightly coupled mode, greatly widening the antenna's operating frequency band. By employing a compactly designed feed network and a miniaturized tightly coupled array, the entire antenna structure is compact, significantly reducing antenna profile and manufacturing costs. This invention's monopulse antenna achieves ultra-wideband performance while maintaining a low antenna profile, and also possesses advantages such as high gain and low null depth, making it suitable for ultra-wideband monopulse tracking systems.

Claims

1. A compact ultra-wideband single-pulse antenna based on a tightly coupled array, characterized by, include: The first cut-off (1), the first tightly coupled linear array (2), the second cut-off (3), the second tightly coupled linear array (4), the third cut-off (5), the upper feed network (6), and the lower feed network (7) are connected sequentially from left to right. Their lower ends pass through the fourth connector (65) on the upper feed network (6) and are fixedly connected to the lower feed network (7). The first tightly coupled linear array (2) includes a first frequency selection patch unit (21), a first dipole unit array, a second dipole unit array, and a second dielectric layer (23) arranged in an array. The first frequency selection patch unit (21) is symmetrically arranged on the upper part of the front and rear sides of the second dielectric layer (23). The first dipole unit array and the second dipole unit array are respectively arranged on the front and rear sides of the second dielectric layer (23), both located below the first frequency selection patch unit (21). The array period of the first frequency selection patch unit (21) is the same as the array period of the first dipole unit array and the second dipole unit array. The structure of the second tightly coupled linear array (4) is the same as the structure of the first tightly coupled linear array (2). The upper-layer power supply network (6) includes a sixth dielectric layer (62), and a first power supply network (63) and a fifth metal layer (61) respectively disposed on the upper and lower surfaces of the sixth dielectric layer (62). The first power supply network (63) includes a first port (68) and a first metal microstrip line (69). The fifth metal layer (61) is provided with a first elliptical coupling slot (66) and a second elliptical coupling slot (67) coupled to the first metal microstrip line (69). The lower-level feed network (7) includes a seventh dielectric layer (72), a sixth metal layer (73) disposed on the upper and lower surfaces of the seventh dielectric layer (72), and a second feed network (71). The second feed network (71) includes a second port (78), a second metal microstrip line (711), a third metal microstrip line (712), a first 1-to-4 power divider (713), and a second 1-to-4 power divider (714). The second port (78) is connected to the input terminal of the first 1-to-4 power divider (713) through the second metal microstrip line (711). The four first output ports (715) of the first 1-to-4 power divider are respectively connected to the second dipole single-phase power divider. The array is connected; the third metal microstrip line (712) is connected to the input terminal of the second 1-to-4 power divider (714), and the four second output ports (716) of the second 1-to-4 power divider are respectively connected to the fourth dipole unit array of the second tightly coupled linear array (4); the sixth metal layer (73) is provided with a third elliptical coupling slot (76) and a fourth elliptical coupling slot (77) respectively coupled to the second metal microstrip line and the third metal microstrip line; the first elliptical coupling slot (66) and the third elliptical coupling slot (76) are spatially fitted and correspond to each other, and the second elliptical coupling slot (67) and the fourth elliptical coupling slot (77) are spatially fitted and correspond to each other; The first, second and third cut-offs (1, 3, 5) direct the currents on the first and second tightly coupled linear arrays (2, 4) to the sixth metal layer (73) of the lower layer feeding network (7).

2. The ultra-wideband single-pulse antenna based on a tightly coupled array according to claim 1, characterized in that, The first cut-off (1) comprises a first dielectric layer (12) and a first metal layer (11) attached to one side of the first dielectric layer (12) close to the first tightly coupled linear array (2); the second cut-off (3) comprises a third dielectric layer (32) and a second metal layer (31) and a third metal layer (33) attached to the left and right sides of the third dielectric layer (32) respectively; and the third cut-off (5) comprises a fifth dielectric layer (52) and a fourth metal layer (51) attached to one side of the fifth dielectric layer (52) close to the second tightly coupled linear array (4).

3. A compact ultra-wideband single-pulse antenna based on a tightly coupled array according to claim 2, characterized in that, The first cut-off (1) is provided with a first connector hole (13) for plugging and fixing the first tightly coupled linear array (2), the second cut-off (3) is provided with a second connector hole (34) for plugging and fixing the first and second tightly coupled linear arrays (2, 4), and the third cut-off (5) is provided with a third connector hole (53) for plugging and fixing the second tightly coupled linear array (4). The lower end surfaces of the first, second and third cut-offs (1, 3, 5) are respectively provided with a first, fifth and ninth connector column (14, 35, 54) for plugging and fixing the lower layer feeding network (7).

4. The ultra-wideband single-pulse antenna based on a tightly coupled array of claim 1, wherein, The first dipole unit array comprises arrayed first dipole units, each of which comprises a first dipole (22) and a first balun ground (28); the second dipole unit array comprises arrayed second dipole units, each of which comprises a second dipole (24) and a first balun microstrip line (29); the first balun ground (28) and the first balun microstrip line (29) are respectively tapered and extended from the spatially adjacent end of the first dipole (22) and the second dipole (24) to the lower end of the second dielectric layer (23), and the tapered width of the first balun ground (28) is greater than that of the first balun microstrip line (29); the first output port (715) of the first 1-to-4 power divider is connected to the lower end of the first balun microstrip line (29), and the second output port (716) of the second 1-to-4 power divider is connected to the lower end of the second balun microstrip line (49) of the fourth dipole unit.

5. The ultra-wideband single-pulse antenna based on a tightly coupled array of claim 1, wherein, The first frequency selective patch unit (21) comprises four sequentially connected first frequency selective patches, and the second frequency selective patch unit (41) comprises four sequentially connected second frequency selective patches.

6. The ultra-wideband single-pulse antenna based on a tightly coupled array of claim 1, wherein, The left and right sides of the second dielectric layer (23) are respectively provided with a second connector column (25) and a third connector column (26) for plugging and fixing the first and second cut-offs (1, 3); the left and right sides of the fourth dielectric layer (43) are respectively provided with a sixth connector column (45) and a seventh connector column (46) for plugging and fixing the second and third cut-offs (3, 5); and the lower end surfaces of the second and fourth dielectric layers (23, 43) are respectively provided with a fourth connector column (27) and an eighth connector column (47) for plugging and fixing the lower layer feeding network (7).

7. The ultra-wideband single-pulse antenna based on a tightly coupled array of claim 1, wherein, The first fixed hole (64) and the second fixed hole (74) are respectively arranged on the upper layer feeding network (6) and the lower layer feeding network (7).

8. The ultra-wideband single-pulse antenna based on a tightly coupled array of claim 1, wherein, The lower layer feeding network (7) further comprises six resistors (75) arranged at branch outlets of a one-to-four power divider, for improving the isolation of the output port.

9. The ultra-wideband single-pulse antenna based on a tightly coupled array of claim 1, wherein, The fifth connector hole (79) is arranged on the lower layer feeding network (7) and penetrates the first cutoff (1), the second cutoff (3) and the third cutoff (5) to be inserted and fixed, and the sixth connector hole (710) is arranged on the lower layer feeding network (7) and penetrates the first tightly coupled linear array (2) and the second tightly coupled linear array (4) to be inserted and fixed.

10. A method of radiating for a super wideband single-pulse antenna based on a tightly coupled array according to any one of claims 1-9, characterized in that, Comprise: The first port (68) is excited, and the current flows through the first metal microstrip line (69), is coupled to the first one-to-four power divider (713) of the second feeding network (71) through the first elliptical coupling slot (66) and the third elliptical coupling slot (76), and is then divided into four paths and output to the first tightly coupled linear array (2); another path is coupled to the second one-to-four power divider (714) of the second feeding network (71) through the second elliptical coupling slot (67) and the fourth elliptical coupling slot (77), and is then divided into four paths and output to the second tightly coupled linear array (4); so that the first dipole unit array and the second dipole unit array have the same phase as the third dipole unit array and the fourth dipole unit array, and a sum beam is formed; The second port (78) is excited, and one path of current passes through the second metal microstrip line (711) to the first one-to-four power divider (713) and is divided into four paths and output to the first tightly coupled linear array (2); Another path passes through the third elliptical coupling slot (76) and the first elliptical coupling slot (66) to be coupled to the first metal microstrip line (69), and then passes through the second elliptical coupling slot (67) and the fourth elliptical coupling slot (77) to be coupled to the second one-to-four power divider (714) of the second feeding network (71), and is then divided into four paths and output to the second tightly coupled linear array (4); so that the first dipole unit array and the second dipole unit array have opposite phases with the third dipole unit array and the fourth dipole unit array, and a difference beam is formed.

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