Method for determining shaping area and low-scattering Vivaldi array antenna based on scattering separation

Abstract

The present invention discloses a method for determining a modified area, comprising: obtaining a first current distribution, a second current distribution, and a third current distribution; the first current distribution, the second current distribution, and the third current distribution are scattering currents at various positions on the surface of a metal radiation patch of a Vivaldi array antenna obtained by simulation when a port of a Vivaldi array antenna incident with a co-polarized wave in an end-fire direction is connected to a short-circuit load, an open-circuit load, and a matching load, respectively; determining a structural term scattering current distribution of the metal radiation patch based on the first current distribution and the second current distribution; determining a mode term scattering current distribution of the metal radiation patch based on the third current distribution and the structural term scattering current distribution; obtaining a reduced field distribution of metal radiation based on the structural term scattering current distribution and the mode term scattering current distribution; and determining a modified area of the metal radiation patch based on the reduced field currents at various positions on the surface of the metal radiation patch and a preset current threshold.

Description

Technical Field

[0001] The present invention belongs to the field of communication technology, and in particular relates to a method for determining a modified area and a low-scattering Vivaldi array antenna based on scattering separation. Background Art

[0002] The Radar Cross Section (RCS) is a key metric that can quantitatively represent a target's stealth capabilities, measuring the strength of its scattering. Antennas, as key components of wireless electronic systems, are essential devices for converting the guided current within them into electromagnetic waves in free space. Compared to individual antennas, array antennas composed of multiple antennas arranged in a desired manner offer better directivity and higher gain. At the same time, the low-scattering properties of array antennas are becoming increasingly important. The most commonly used methods for reducing antenna RCS include shape design and absorbing material technology, but these techniques are not applicable to applications requiring in-band RCS reduction under co-polarized wave incidence. Loading an antenna with a low-scattering metasurface can achieve simultaneous in-band and out-of-band RCS reduction while maintaining essentially unchanged antenna radiation performance. However, loading the antenna with a metasurface increases the overall size of the antenna, making it unsuitable for antenna arrays.

[0003] Antenna shaping technology is an effective method for reducing antenna RCS, especially for Vivaldi array antennas. It can reduce both in-band and out-of-band RCS without increasing antenna size. The location and size of antenna shaping are typically selected based on the overall antenna radiation current and scattering current. However, because the distribution of antenna radiation current and scattering current differ significantly, typically under oblique incidence conditions, traditional shaping methods are effective in angular regions other than endfire, but are generally less effective in reducing scattering in the endfire direction of array antennas. Therefore, research on methods for reducing scattering in the endfire direction of Vivaldi array antennas is of great significance.

[0004] Existing shaping schemes for the low-scattering shape of the Vivaldi array are all based on the current distribution of the antenna radiation current and scattered current areas to guide the shaping design. The difference between the antenna radiation current distribution and the scattered current distribution is generally when the condition of oblique incidence is large. Therefore, traditional shaping methods are only effective in other angular regions outside the non-end-fire direction, and have no effect in the end-fire direction. Summary of the Invention

[0005] To address the aforementioned issues in related technologies, the present invention provides a method for determining a modified region and a low-scattering Vivaldi array antenna based on scattering separation to reduce antenna scattering in the co-polarized end-fire direction. The technical problems to be solved by the present invention are achieved through the following technical solutions:

[0006] The present invention provides a method for determining a modified area of a Vivaldi array antenna, wherein the Vivaldi array antenna includes a metal radiation patch and a microstrip line-to-stripline conversion method. The method includes:

[0007] Obtaining a first current distribution, a second current distribution, and a third current distribution; the first current distribution, the second current distribution, and the third current distribution are scattered currents at various positions on the surface of the metal radiation patch obtained by simulation when a Vivaldi array antenna port with a co-polarized wave incident in an end-fire direction is connected to a short-circuit load, an open-circuit load, and a matched load, respectively;

[0008] Determining a structural scattered current distribution of the metal radiation patch according to the first current distribution and the second current distribution; the structural scattered current distribution is the structural scattered current at each position on the surface of the metal radiation patch;

[0009] Determining a mode term scattering current distribution of the metal radiation patch according to the third current distribution and the structural term scattering current distribution; the mode term scattering current distribution is the mode term scattering current at each position on the surface of the metal radiation patch;

[0010] According to the structural scattered current distribution and the mode scattered current distribution, the reduced field distribution of the metal radiation is obtained; the reduced field distribution is the reduced field current at each position on the surface of the metal radiation patch;

[0011] The trimming area of the metal radiation patch is determined according to the reduced field current at various positions on the surface of the metal radiation patch and a preset current threshold.

[0012] In some embodiments, determining the modified area of the metal radiation patch according to the reduced field current at each position on the surface of the metal radiation patch and a preset current threshold includes:

[0013] Screening out the reduced field currents greater than or equal to the preset current threshold from the reduced field currents at various locations on the surface of the metal radiation patch;

[0014] taking an area formed by positions corresponding to a reduced field current greater than or equal to the preset current threshold as a candidate area;

[0015] The area of the selected area except the area corresponding to the microstrip line to stripline conversion and the slot area of the Vivaldi array antenna is used as the shaping area of the metal radiation patch.

[0016] In some embodiments, the calculation formula of the structural scattered current distribution is as follows:

[0017] Jstr =(J tot (∞)+J tot (0)) / 2;

[0018] Among them, J str is the structural scattered current distribution, J tot (∞) is the second current distribution, J tot (0) is the first current distribution.

[0019] In some embodiments, the calculation formula of the mode term scattered current distribution is as follows:

[0020] J ant (load) = J tot (load)-J str ;

[0021] Among them, J ant (load) is the mode term scattered current distribution, J tot (load) is the third current distribution, J str is the structural scattered current distribution.

[0022] In some embodiments, the calculation formula of the reduced field distribution is as follows:

[0023] J cut (load) = J str -2*J ant (load);

[0024] Among them, J cut (load) is the reduced field distribution, J str is the structural scattered current distribution, J ant (load) is the mode term scattered current distribution.

[0025] The present invention also provides a low-scattering Vivaldi array antenna based on scattering separation, comprising:

[0026] A plurality of horizontally arranged array elements (2);

[0027] Each array element (2) comprises: a metal radiation patch (21), a first dielectric substrate (22), a second dielectric substrate (23) and a microstrip line-to-strip line (24);

[0028] The first dielectric substrate (22) and the second dielectric substrate (23) are arranged vertically up and down;

[0029] The microstrip line-to-stripline (24) is arranged between the first dielectric substrate (22) and the second dielectric substrate (23);

[0030] The metal radiation patch (21) is respectively arranged on the upper surface of the first dielectric substrate (22) and the lower surface of the second dielectric substrate (23) in a vertical direction, and hollow grooves (25) are engraved in the trimming areas on both sides of the index groove line center line of the metal radiation patch (21).

[0031] In some embodiments, a plurality of hollow grooves (25) of different sizes are engraved in the shaping area on each side of the midline of the index groove line, and the hollow grooves (25) in the shaping areas on both sides of the midline of the index groove line are symmetrical along the midline of the index groove line.

[0032] In some embodiments, in the modified areas on both sides of the midline of the index slot line of the metal radiation patch (21), the number of hollow slots (25) in the modified area on the side where the fan-shaped component of the microstrip line to stripline (24) is located is greater than the number of hollow slots (25) in the modified area on the other side.

[0033] In some embodiments, the hollow groove (25) is an elliptical groove, and the ratio between the major axis and the minor axis of each elliptical groove is 2:1.

[0034] In some embodiments, the shaping region on one side where the fan-shaped component of the microstrip line to stripline (24) is located includes four elliptical grooves of different sizes, and the shaping region on the other side includes three elliptical grooves of different sizes.

[0035] The present invention has the following beneficial technical effects:

[0036] The method for determining the shaping area of the Vivaldi array antenna proposed in this invention breaks through the shackles of traditional shaping based on the distribution of scattered current and radiation current. By separating the distribution of the scattered current of the antenna mode item and the scattered current of the antenna structure item through the scattering separation method, the shaping area is determined to guide the antenna shaping. This can reduce the scattering of the antenna in the co-polarization end-fire direction, providing a new idea for reducing the RCS of the Vivaldi array antenna.

[0037] The Vivaldi array antenna with a low-scattering shape based on scattering separation proposed in the present invention directly optimizes the array antenna according to the determined shaping area. Compared with the unit shaping and then applying it to the array, it takes into account the coupling and edge effects of the array antenna, which is more effective for actual array applications.

[0038] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 A schematic diagram of the structure of a Vivaldi array antenna provided in an embodiment of the present invention;

[0040] Figure 2 A flowchart of a method for determining a modified area of a Vivaldi array antenna provided in an embodiment of the present invention;

[0041] Figure 3 A schematic diagram of an exemplary total scattered field current distribution provided by an embodiment of the present invention;

[0042] Figure 4 A schematic diagram of an exemplary structural scattered field current distribution provided by an embodiment of the present invention;

[0043] Figure 5 A schematic diagram of an exemplary mode item scattered field current distribution provided by an embodiment of the present invention;

[0044] Figure 6 A schematic diagram of an exemplary structural item reduction field current distribution provided by an embodiment of the present invention;

[0045] Figure 7 A schematic structural diagram of an exemplary low-scattering Vivaldi array antenna based on scattering separation provided in an embodiment of the present invention;

[0046] Figure 8 A schematic diagram of the standing wave ratio of each port of an exemplary reference array antenna provided in an embodiment of the present invention;

[0047] Figure 9 A schematic diagram of an exemplary design of the standing wave ratio of each port of an array antenna provided in an embodiment of the present invention;

[0048] Figure 10 A comparison chart of the actual gain of an exemplary reference array antenna and a designed array antenna provided in an embodiment of the present invention;

[0049] Figure 11 A comparison diagram of the single-station RCS in the co-polarization end-fire direction of the exemplary reference array antenna and the designed array antenna provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0050] The present invention will be further described in detail below with reference to specific examples, but the embodiments of the present invention are not limited thereto.

[0051] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0052] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification.

[0053] Although the present invention is described herein in conjunction with various embodiments, in the process of implementing the claimed invention, those skilled in the art can understand and implement other variations of the disclosed embodiments by reviewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple situations. A single processor or other unit can implement several functions listed in the claims. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0054] Currently, existing Vivaldi antenna optimization solutions include: the patent "A Vivaldi Antenna," which reduces the RCS of the Vivaldi antenna unit by digging rectangular grooves on the edge based on the antenna's radiation current distribution and scattered current distribution; and the patent "A Low RCS Ultra-Wideband Vivaldi Antenna Based on Differential Evolution Algorithm," which proposes a differential evolution algorithm to optimize the antenna's radiating patch structure, which has a certain effect on reducing the Vivaldi antenna's RCS. However, the structure proposed in "A Vivaldi Antenna" is a low-RCS antenna structure, and the low RCS angular domain is the oblique incidence angle domain of the plane wave; the patent "A Low RCS Ultra-Wideband Vivaldi Antenna Based on Differential Evolution Algorithm," which proposes a differential evolution algorithm to optimize the antenna's radiating patch structure, still has a certain effect on reducing the RCS of the antenna when the plane wave is obliquely incident, but does not provide any information on the RCS reduction effect in the end-fire direction.

[0055] Figure 1 is a structural diagram of the Vivaldi array antenna, as shown in Figure 1As shown, the Vivaldi array antenna includes a plurality of horizontally arranged array elements (1); each array element (1) includes: a metal radiation patch (11), a first dielectric substrate (12), a second dielectric substrate (13) and a microstrip line-to-stripline (14); the first dielectric substrate (12) and the second dielectric substrate (13) are arranged vertically up and down; the microstrip line-to-stripline (14) is arranged between the first dielectric substrate (12) and the second dielectric substrate (13); and the metal radiation patch (11) is respectively arranged vertically on the upper surface of the first dielectric substrate (12) and the lower surface of the second dielectric substrate (13).

[0056] Figure 2 is a flow chart of a method for determining a shaping area provided by an embodiment of the present invention. Figure 2 As shown, the method includes the following steps:

[0057] S101. Obtain a first current distribution, a second current distribution, and a third current distribution; the first current distribution, the second current distribution, and the third current distribution are the scattered currents at various positions on the surface of the metal radiation patch obtained by simulation when the port of the Vivaldi array antenna with the same polarized wave incident in the end-fire direction is connected to a short-circuit load, an open-circuit load, and a matched load, respectively.

[0058] For example, full-wave simulation software can be used to obtain the scattered current distribution on the surface of the metal radiation patch when the Vivaldi array antenna port is connected to a short-circuit load, an open-circuit load, and a matched load in the end-fire direction. tot (0), J tot (∞), J tot (load), J tot The distribution of (load) is as follows Figure 3 shown.

[0059] Here, J tot (0), J tot (∞) and J tot (load) is a three-dimensional matrix. For example, for J tot (0), the matrix includes the scattering currents at various locations on the surface of the metal radiation patch of the Vivaldi array antenna obtained by simulation when the ports of the Vivaldi array antenna are connected to short-circuit loads with the same polarized wave incident in the end-fire direction; for J tot (∞), which includes the scattering currents at various locations on the surface of the metal radiation patch of the Vivaldi array antenna obtained by simulation when the ports of the Vivaldi array antenna are connected to open-circuit loads with the incident polarized wave in the end-fire direction; tot(load), which includes the scattering current at each position on the surface of the metal radiation patch of the Vivaldi array antenna obtained by simulation when the ports of the Vivaldi array antenna are respectively connected to matching loads with the incident polarized wave in the end-fire direction.

[0060] S102 . Determine a structural scattering current distribution of the metal radiation patch according to the first current distribution and the second current distribution; the structural scattering current distribution is the structural scattering current at each position on the surface of the metal radiation patch.

[0061] Specifically, the calculation formula for the structural scattered current distribution is as follows:

[0062] J str =(J tot (∞)+J tot (0)) / 2 (1);

[0063] Among them, J str is the structural scattered current distribution, that is, formula (1) is the calculation formula for the structural scattered current at each position on the surface of the metal radiation patch.

[0064] For example, J str The distribution of Figure 4 shown.

[0065] S103 . Determine a mode-term scattered current distribution of the metal radiation patch according to the third current distribution and the structure-term scattered current distribution; the mode-term scattered current distribution is the mode-term scattered current at each position on the surface of the metal radiation patch.

[0066] Specifically, the calculation formula for the mode term scattered current distribution is as follows:

[0067] J ant (load) = J tot (load)-J str (2);

[0068] Among them, J ant (load) is the mode item scattered current distribution, that is, formula (2) is the calculation formula for the mode item scattered current at each position on the surface of the metal radiation patch.

[0069] For example, J ant The distribution of (load) is as follows Figure 5 shown.

[0070] Here, formula (1) can be obtained according to formulas (3) and (4), and formula (2) can be obtained according to formulas (3) and (5):

[0071] E=-jωμ∮ S G.J. SdS (3);

[0072] Wherein, formula (3) is the relationship between current and scattered field, J S is the current, jω is the complex angular frequency, and μ is the relative magnetic permeability.

[0073]

[0074] Among them, E str is the scattered electric field of the structural term, E s (0) is the simulation J tot (0) The J obtained by simulation tot (0) The corresponding electric field, E s (∞) is the simulation J tot (∞) The J obtained by simulation tot (∞)The corresponding electric field.

[0075] E ant =E tot -E str (5);

[0076] Among them, E ant is the scattered electric field of the mode term, E tot The electric field on the surface of the metal radiation patch obtained by simulation when the port of the Vivaldi array antenna is connected to a load with a co-polarized wave incident in the end-fire direction.

[0077] S104. Obtain the reduced field distribution of metal radiation according to the structural scattered current distribution and the mode scattered current distribution; the reduced field distribution is the reduced field current at each position on the surface of the metal radiation patch.

[0078] Specifically, the calculation formula for the reduced field distribution is as follows:

[0079] J cut (load) = J str -2*J ant (load) (6);

[0080] Among them, J cut (load) is the reduced field distribution, that is, formula (6) is the calculation formula for the reduced field current at each position on the surface of the metal radiation patch.

[0081] For example, J cut The distribution of (load) is as follows Figure 6 shown.

[0082] S105 , determining a trimming area of the metal radiation patch according to the reduced field current at each position on the surface of the metal radiation patch and a preset current threshold.

[0083] Specifically, the reduced field currents greater than or equal to a preset current threshold can be screened out from the reduced field currents at various positions on the surface of the metal radiation patch; the area formed by the positions corresponding to the reduced field currents greater than or equal to the preset current threshold is used as the selected area; and the area in the selected area except the area corresponding to the microstrip line to stripline conversion and the slot line area of the Vivaldi array antenna is used as the shaping area of the metal radiation patch.

[0084] The following specific example is used to illustrate the above method.

[0085] S1. First, in the process of separating antenna mode item scattering and structural item scattering, it is necessary to obtain a relationship for separating the antenna surface scattered current. This relationship is based on the scattering matrix method to separate the antenna mode item scattering and the structural item scattering field. First, how to obtain the relationship between the scattered electric fields, specifically as shown in the above formulas (4) and (5); since the relationship between current and field is linear, this relationship is also applicable to the scattered field. Therefore, the relationship between the scattered field and current can be expressed as the above formula (3).

[0086] S2. According to the above formula (3) and the above formula (4), as well as the above formula (3) and the above formula (5), respectively determine the array antenna structure item scattering surface current expression (the above formula (1)) and the array antenna pattern item scattering surface current expression (the above formula (2)).

[0087] S3. Use full-wave simulation software to obtain the scattered current distribution on the metal radiation patch surface when the Vivaldi array antenna port is connected to a short-circuit load, an open-circuit load, and a matched load with the incident polarized wave in the end-fire direction. tot (0), J tot (∞), J tot (load);

[0088] S4. Use the above formulas (1) and (2) to obtain the surface current distribution of the antenna structure item scattering field and the mode item scattering field respectively; then, use the above formula (6) to calculate the reduced field based on the obtained surface current distribution of the antenna structure item scattering field and the mode item scattering field.

[0089] S5. The area where the intensity of the field current of the metal radiation patch is relatively large is selected as the candidate area, and the area except the corresponding area of the microstrip line to stripline conversion and the slot line area of the Vivaldi array antenna in the candidate area is used as the shaping area of the metal radiation patch, so as to design the array antenna by setting a hollow slot in the shaping area.

[0090] The present invention provides a low-scattering Vivaldi array antenna based on scattering separation. The low-scattering Vivaldi array antenna based on scattering separation comprises a plurality of horizontally arranged array elements (2); each array element (2) comprises: a metal radiation patch (21), a first dielectric substrate (22), a second dielectric substrate (23) and a microstrip line-to-stripline (24); the first dielectric substrate (22) and the second dielectric substrate (23) are arranged vertically up and down; the microstrip line-to-stripline (24) is arranged between the first dielectric substrate (22) and the second dielectric substrate (23); the metal radiation patch (21) is respectively arranged on the upper surface of the first dielectric substrate (22) and the lower surface of the second dielectric substrate (23) in the vertical direction, and hollow grooves (25) are engraved in the modified areas on both sides of the center line of the index groove line of the metal radiation patch (21).

[0091] In some embodiments, a plurality of hollow grooves (25) of different sizes are engraved in the modified area on each side of the index groove line midline, and the hollow grooves (25) in the modified areas on both sides of the index groove line midline are symmetrical along the index groove line midline.

[0092] In some embodiments, in the modified areas on both sides of the midline of the index slot line of the metal radiation patch (21), the number of hollow slots (25) in the modified area on the side where the fan-shaped component of the microstrip line to stripline (24) is located is greater than the number of hollow slots (25) in the modified area on the other side.

[0093] In some embodiments, the hollow grooves (25) are elliptical grooves, and the ratio between the major axis and the minor axis of each elliptical groove is 2:1.

[0094] In some embodiments, the modified area on one side of the microstrip line to stripline (24) where the fan-shaped component is located includes four elliptical grooves of different sizes, and the modified area on the other side includes three elliptical grooves of different sizes.

[0095] For example, Figure 7 A schematic structural diagram of a low-scattering Vivaldi array antenna based on scattering separation provided by the present invention; Figure 7 As shown, the shaping area on one side where the fan-shaped component of the microstrip line to stripline (24) is located includes four elliptical grooves (211), (212), (213) and (214) of different sizes, and the other side includes elliptical grooves (211), (212) and (213). Figure 7 The low scattering Vivaldi array antenna based on scattering separation is shown in FIG. Figure 1 The difference between the Vivaldi array antenna shown is that the elliptical slots of different sizes are set in the modified area, and the other parameters are the same. Figure 1The Vivaldi array antenna shown has a cross-sectional height of l1 = 32.5 mm, coupling slot lengths l2 = 5 mm, l3 = 5.95 mm, microstrip length l4 = 3 mm, element spacing w1 = 25 mm, maximum taper slot width w2 = 24.5 mm, minimum taper slot width w3 = 0.6 mm, circular resonant cavity diameter w4 = 2 mm, microstrip width t1_w = 1.158 mm, stripline-microstrip transition width t2_w = 0.85 mm, stripline-slot transition width t3_w = 0.5 mm, and sector radius r1 = 3 mm. For example, Figure 7 In the low-scattering Vivaldi array antenna based on scattering separation shown, the short axes of the elliptical slots (211), (212), (213) and (214) are d1=2mm, d2=3.5mm, d3=4mm, d4=4.5mm, respectively, and the distances between the elliptical center points of the elliptical slots (211), (212), (213) and (214) and the center of the antenna are x1=8mm, x2=9mm, x3=7mm, x4=9mm, respectively.

[0096] The method for determining the shaping area of the Vivaldi array antenna proposed in this invention breaks through the shackles of traditional shaping based on the distribution of scattered current and radiation current. By separating the distribution of the scattered current of the antenna mode item and the scattered current of the antenna structure item through the scattering separation method, the shaping area is determined to guide the antenna shaping. This can reduce the scattering of the antenna in the co-polarization end-fire direction, providing a new idea for reducing the RCS of the Vivaldi array antenna.

[0097] The low-scattering Vivaldi array antenna based on scattering separation proposed in the present invention directly optimizes the array antenna according to the determined shaping area. Compared with the unit shaping and then applying it to the array, it takes into account the coupling and edge effects of the array antenna, which is more effective for actual array applications.

[0098] The technical effects of the present invention are further illustrated below through experimental simulation.

[0099] The full-wave simulation software is used to simulate the design antenna (the low-scattering Vivaldi array antenna based on scattering separation proposed in this invention) and the reference antenna ( Figure 1 The radiation and scattering characteristics of the Vivaldi array antenna shown in FIG. 1 are simulated, and the simulation results are compared.

[0100] like Figure 8 and Figure 9As shown in the figure, the active standing wave ratio of the designed array is lower than that of the reference antenna at 10 GHz, but the active standing wave ratio is higher than 2.5 at 11.5 GHz, indicating that the shaping method inevitably affects the impedance matching of the antenna, but is generally within an acceptable range. Figure 10 Comparing the gain comparison charts of the designed array antenna and the reference array antenna reveals that gain is closely related to the active standing wave ratio (ASWR). The designed array antenna's gain is lower than the reference antenna's around the frequency point where standing waves are deteriorating (11.5 GHz), but the gain difference is similar at other frequencies. This analysis indicates that the designed array antenna affects the antenna's radiation to some extent, but this effect is within the acceptable range. Therefore, we next analyze the scattering performance of the designed array antenna. Figure 11 A comparison of the frequency-varying single-station RCS of the designed antenna array and the reference antenna array under perpendicular incidence main polarization is presented. It is found that the RCS increases near the frequency point where standing waves deteriorate (11.5 GHz), which also reflects that the shaping method will affect the coupling of the array. Except for a slight increase in the single-station RCS in the 11.25-11.65 GHz frequency band, the designed array antenna has a certain RCS reduction effect in the entire frequency band of 8-11.25 GHz, with a maximum reduction of 8 dB and an average reduction of 3.7 dB.

[0101] The above is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention should not be considered to be limited to these descriptions. For those skilled in the art of the present invention, without departing from the concept of the present invention, several simple deductions or substitutions can be made, which should be considered to fall within the scope of protection of the present invention.

Claims

1. A method for determining a shaping region, applied to a Vivaldi array antenna, the Vivaldi array antenna comprising: The metal radiation patch and the microstrip line to stripline conversion method include: Obtaining a first current distribution, a second current distribution, and a third current distribution; the first current distribution, the second current distribution, and the third current distribution are scattered currents at various positions on the surface of the metal radiation patch obtained by simulation when a Vivaldi array antenna port with a co-polarized wave incident in an end-fire direction is connected to a short-circuit load, an open-circuit load, and a matched load, respectively; Determining a structural scattered current distribution of the metal radiation patch according to the first current distribution and the second current distribution; the structural scattered current distribution is the structural scattered current at each position on the surface of the metal radiation patch; Determining a mode term scattering current distribution of the metal radiation patch according to the third current distribution and the structural term scattering current distribution; the mode term scattering current distribution is the mode term scattering current at each position on the surface of the metal radiation patch; According to the structural scattered current distribution and the mode scattered current distribution, the reduced field distribution of the metal radiation is obtained; the reduced field distribution is the reduced field current at each position on the surface of the metal radiation patch; the calculation formula of the reduced field distribution is as follows: ,in, To reduce the field distribution, is the structural scattered current distribution, is the mode scattered current distribution; The calculation formula is: ,in, For the second current distribution, is the first current distribution; The calculation formula is: ,in, is the third current distribution; Determining a trimming area of the metal radiation patch according to the reduced field current at various locations on the surface of the metal radiation patch and a preset current threshold value, specifically comprising: Screening out the reduced field currents greater than or equal to the preset current threshold from the reduced field currents at various locations on the surface of the metal radiation patch; taking an area formed by positions corresponding to a reduced field current greater than or equal to the preset current threshold as a candidate area; The area of the selected area except the area corresponding to the microstrip line to stripline conversion and the slot area of the Vivaldi array antenna is used as the shaping area of the metal radiation patch.

2. The method for determining a shaping area according to claim 1, wherein: The Vivaldi array antenna includes: A plurality of horizontally arranged array elements (2); Each array element (2) includes: a metal radiation patch (21), a first dielectric substrate (22), a second dielectric substrate (23), and a microstrip line-to-stripline (24); The first dielectric substrate (22) and the second dielectric substrate (23) are arranged vertically up and down; The microstrip line-to-stripline (24) is arranged between the first dielectric substrate (22) and the second dielectric substrate (23); The metal radiation patch (21) is respectively arranged on the upper surface of the first dielectric substrate (22) and the lower surface of the second dielectric substrate (23) in a vertical direction, and hollow grooves (25) are engraved in the trimming areas on both sides of the index groove line centerline of the metal radiation patch (21).

3. The method for determining a shaping area according to claim 2, wherein: A plurality of hollow grooves (25) of different sizes are engraved in the shaping area on each side of the index groove line midline, and the hollow grooves (25) in the shaping area on both sides of the index groove line midline are symmetrical left and right along the index groove line midline.

4. The method for determining a shaping area according to claim 3, wherein: In the shaping areas on both sides of the index slot line midline of the metal radiation patch (21), the number of hollow slots (25) in the shaping area on one side where the fan-shaped component of the microstrip line to stripline (24) is located is greater than the number of hollow slots (25) in the shaping area on the other side.

5. The method for determining a shaping area according to claim 2, wherein: The hollow grooves (25) are elliptical grooves, and the ratio between the major axis and the minor axis of each elliptical groove is 2:

1.

6. The method for determining a shaping area according to claim 2, wherein: The shaping area on one side where the fan-shaped component of the microstrip line to stripline (24) is located includes four elliptical grooves of different sizes, and the shaping area on the other side includes three elliptical grooves of different sizes.

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