A wideband low-scattering microstrip array antenna based on phase cancellation mechanism

Abstract

A kind of wideband low scattering microstrip array antenna based on phase cancellation mechanism, the array antenna is formed by the chessboard arrangement of extended Jerusalem cross microstrip antenna unit and bent Jerusalem cross microstrip antenna unit with similar radiation characteristics and approximately 180° reflection phase difference in wide frequency band range;Two kinds of microstrip antenna unit are composed of metal radiation patch, L-shaped coupling feed structure, metal floor and dielectric substrate. Among them, the L-shaped coupling feed structure is composed of rectangular feed patch and metallized via, which can control the two kinds of microstrip antennas to have similar radiation characteristics. The present application can maintain the normal radiation performance of microstrip array antenna and realize the wideband low scattering characteristics without introducing additional low scattering design structure, which can meet the design and application requirements of wideband stealth antenna system.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of communication technology, and further relates to a kind of wideband low scattering microstrip array antenna design based on phase cancellation mechanism in electromagnetic field and microwave technology field, which can be used in stealth antenna system design of various platforms. BACKGROUND

[0002] The low scattering design of traditional microstrip array antenna mainly relies on the method of modifying shape. By comparing the induced electric field and induced current in the radiation and scattering states of microstrip antenna, the induced electric field and induced current in the scattering state are suppressed by etching slots and other methods under the premise that the induced electric field and induced current in the radiation state are not affected. However, this scheme can only achieve limited low scattering design in a relatively narrow frequency band. With the continuous development of electromagnetic metamaterial technology, various electromagnetic metamaterial structures with frequency selection characteristics, frequency selection wave absorption characteristics and polarization rotation characteristics are widely used in antenna system stealth design, greatly expanding the frequency band width and scattering suppression effect of effective low scattering design of antenna system. However, the antenna system stealth design method based on electromagnetic metamaterial structure loading has the following significant defects: first, various electromagnetic metamaterial structures need a certain loading space, which means that the low scattering design of microstrip array antenna inevitably needs to expand its metal floor area or load additional cover on top, which is contrary to the trend of miniaturization and integration of antenna system design, directly limiting the application of microstrip array antenna system in limited physical space. In addition, the former will also lead to the deterioration of the aperture efficiency of microstrip array antenna, and the latter will greatly increase the overall profile height of microstrip array antenna. Second, the loading of various electromagnetic metamaterial structures will inevitably affect the antenna system radiation electromagnetic wave while realizing the regulation or absorption of scattered electromagnetic wave, such as the loading of frequency selection structure or frequency selection wave absorber structure will inevitably introduce certain insertion loss, resulting in the decrease of array antenna gain. SUMMARY

[0003] In order to overcome the above-mentioned defects of the prior art, a wideband low scattering microstrip array antenna based on phase cancellation mechanism is proposed, which aims to realize wideband low scattering design while maintaining the gain of microstrip array antenna without introducing additional low scattering design structure, and can meet the design of various stealth antenna systems.

[0004] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is:

[0005] A wideband low scattering microstrip array antenna based on phase cancellation mechanism is composed of chessboard arranged extended Jerusalem cross microstrip antenna units and bent Jerusalem cross microstrip antenna units, characterized in that:

[0006] The extended Jerusalem cross microstrip antenna unit and the bent Jerusalem cross microstrip antenna unit have similar radiation characteristics, i.e., the same polarization mode, consistent central resonant frequency and less than 0.5 dB difference in radiation gain.

[0007] The extended Jerusalem cross microstrip antenna unit and the bent Jerusalem cross microstrip antenna unit have less than 0.5 dB difference in reflection amplitude and within 180°±37° in reflection phase difference in a wide frequency band range.

[0008] In one embodiment, the chessboard arrangement refers to that the array antenna is composed of four sub-arrays, i.e., a first sub-array A, a first sub-array B, a second sub-array A and a second sub-array B; the first sub-array A and the first sub-array B are each composed of n*n extended Jerusalem cross microstrip antenna units, the second sub-array A and the second sub-array B are each composed of n*n bent Jerusalem cross microstrip antenna units; the first sub-array A is symmetrical to the second sub-array A about a first symmetry axis, and symmetrical to the second sub-array B about a second symmetry axis; the first sub-array B is symmetrical to the second sub-array A about the second symmetry axis, and symmetrical to the first sub-array B about the first symmetry axis; the first sub-array A is symmetrical to the first sub-array B about the intersection of the first symmetry axis and the second symmetry axis; the second sub-array A is symmetrical to the second sub-array B about the intersection of the first symmetry axis and the second symmetry axis; and the first symmetry axis is perpendicular to the second symmetry axis.

[0009] In one embodiment, the extended Jerusalem cross microstrip antenna unit is composed of an L-shaped coupling feeding structure A, a metal ground plate A, a second layer dielectric substrate A, a first layer dielectric substrate A and an extended Jerusalem cross structure metal radiation patch arranged in sequence.

[0010] The bent Jerusalem cross microstrip antenna unit is composed of an L-shaped coupling feeding structure B, a metal ground plate B, a second layer dielectric substrate B, a first layer dielectric substrate B and a bent Jerusalem cross structure metal radiation patch arranged in sequence.

[0011] In one embodiment, the metal ground plate A and the metal ground plate B, the second layer dielectric substrate A and the second layer dielectric substrate B, and the first layer dielectric substrate A and the first layer dielectric substrate B are respectively in the same plane.

[0012] In an embodiment, the extended Jerusalem cross structure metal radiation patch is a central symmetric structure, printed on the upper layer of the first layer dielectric substrate A, composed of a square metal patch A, a first metal rectangular patch A, a second metal rectangular patch A and a third metal rectangular patch A, and the edges of each patch are only in vertical or parallel relationship; the square metal patch A is located at the center, and one end of each of the four metal rectangular patches A is vertically connected to the midpoint of each edge of the square metal patch A; one second metal rectangular patch A is connected to the other end of one metal rectangular patch A and one third metal rectangular patch A, forming a branch, and the centers of each patch on one branch are located on the same straight line.

[0013] In an embodiment, on one branch, the length of the second metal rectangular patch A is greater than the length of the third metal rectangular patch A, and the width is less than the width of the third metal rectangular patch A; wherein the length refers to the size in the direction perpendicular to the straight line, and the width refers to the size in the direction parallel to the straight line.

[0014] In an embodiment, the L-shaped coupling feeding structure A is composed of a rectangular feeding patch A and a metalized via A; the rectangular feeding patch A is printed on the upper layer of the second layer dielectric substrate A, and the metalized via A penetrates the second layer dielectric substrate A; the metal ground plate A is printed on the lower layer of the second layer dielectric substrate A; the metal ground plate A is etched with a circular aperture whose center coincides with the metalized via A and whose radius is greater than that of the metalized via A.

[0015] In an embodiment, the extended Jerusalem cross structure metal radiation patch is a central symmetric structure, printed on the upper layer of the first layer dielectric substrate A, composed of a square metal patch A, a first metal rectangular patch A, a second metal rectangular patch A and a third metal rectangular patch A, and the edges of each patch are only in vertical or parallel relationship; the square metal patch A is located at the center, and one end of each of the four metal rectangular patches A is vertically connected to the midpoint of each edge of the square metal patch A; one second metal rectangular patch A is connected to the other end of one metal rectangular patch A and one third metal rectangular patch A, forming a branch, and the centers of each patch on one branch are located on the same straight line.

[0016] In an embodiment, the L-shaped coupling feeding structure B is composed of a rectangular feeding patch B and a metalized via B; the rectangular feeding patch B is printed on the upper layer of the second layer dielectric substrate B, and the metalized via B penetrates the second layer dielectric substrate B; the metal ground plate B is printed on the lower layer of the second layer dielectric substrate B; the metal ground plate B is etched with a circular aperture whose center coincides with the metalized via B and whose radius is greater than that of the metalized via B.

[0017] In an embodiment, the unit size P of the extended Jerusalem cross type microstrip antenna unit is 15mm, the thickness of the first layer dielectric substrate A is 0.75mm, the side length L of the square metal patch A is 7.5mm, the length of the first metal rectangular patch A is 7.5mm, the length of the second metal rectangular patch A is 9mm, the length of the third metal rectangular patch A is 6mm, the length of the rectangular feeding patch B is 7.5mm, the length of the metalized via B is 0.5mm, the length of the metal ground plate B is 7.5mm, and the radius of the circular aperture is 0.5mm. a =15mm, the thickness of the first layer dielectric substrate A is 0.75mm, the side length La = 3 mm, length L of the first metal rectangular patch A a1 = 0.8 mm, width W a1 = 0.6 mm, length L of the second metal rectangular patch A a2 = 3 mm, width W a2 = 0.75 mm, length L of the third metal rectangular patch A a3 = 2.5 mm, width W a3 = 0.7 mm, length L of the rectangular feed patch A fa = 0.9 mm, width W fa = 0.8 mm, thickness of the second layer dielectric substrate A is 3.75 mm;

[0018] The unit size P of the bent Jerusalem cross microstrip antenna unit b = 15 mm, length L of the square metal patch B of the first layer dielectric substrate B is 2 mm b = 6.7 mm, overall length L of the S-shaped bent metal strip b1 = 3.25 mm, overall width H b1 = 1.9 mm, line width W b1 = 0.25 mm, length L of the rectangular metal patch B b2 = 2 mm, width W b2 = 0.5 mm, length L of the rectangular feed patch B fb = 3.5 mm, width W fb = 0.1 mm, thickness of the second layer dielectric substrate B is 2 mm.

[0019] Compared with the prior art, the beneficial effects of the present application are:

[0020] First, no additional low-scattering design structure is needed, avoiding the deterioration of the aperture efficiency of the microstrip array antenna or the increase of the profile height, which has broad application prospects in low-scattering antenna system design in limited space; avoiding various losses caused by additional structures, greatly reducing the gain loss of the array antenna in the radiation state.

[0021] Second, due to the central symmetry of the extended Jerusalem cross microstrip antenna unit and the bent Jerusalem cross microstrip antenna unit structure involved in the present application, the present application has super wideband and high efficiency scattering suppression effect under the irradiation of cross-polarized incident wave and co-polarized incident wave. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a wideband low-scattering microstrip array antenna overall structure based on the phase cancellation mechanism.

[0023] Figure 2is a structural schematic diagram (perspective view) of the extended Jerusalem cross microstrip antenna unit of the present application.

[0024] Figure 3 is a structural schematic diagram (top view) of the extended Jerusalem cross microstrip antenna unit of the present application.

[0025] Figure 4 is a structural schematic diagram (perspective view) of the bent Jerusalem cross microstrip antenna unit of the present application.

[0026] Figure 5 is a structural schematic diagram (top view) of the bent Jerusalem cross microstrip antenna unit of the present application.

[0027] Figure 6 is a structural schematic diagram of the extended Jerusalem cross microstrip antenna unit of the present application, wherein (a) is a top view and (b) is a perspective view.

[0028] Figure 7 is a structural schematic diagram of the bent Jerusalem cross microstrip antenna unit of the present application, wherein (a) is a top view and (b) is a perspective view.

[0029] Figure 8 is a radiation characteristic curve diagram of the extended Jerusalem cross microstrip antenna unit and the bent Jerusalem cross microstrip antenna unit in the simulation experiment of the embodiment of the present application. Wherein, (a) is a working frequency band characteristic curve diagram, and (b) is a central resonant frequency gain direction diagram characteristic curve diagram.

[0030] Figure 9 is a scattering characteristic curve diagram of the extended Jerusalem cross microstrip antenna unit and the bent Jerusalem cross microstrip antenna unit in the simulation experiment of the embodiment of the present application. Wherein, (a) is a reflection amplitude and reflection phase curve diagram with frequency variation under cross-polarized incident wave irradiation, and (b) is a reflection amplitude and reflection phase curve diagram with frequency variation under co-polarized incident wave irradiation.

[0031] Figure 10 is a single station radar scattering cross section curve diagram of the embodiment of the present application and the same size ordinary microstrip array antenna under cross-polarized incident wave and co-polarized incident wave irradiation in the simulation experiment. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0033] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0034] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0035] In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the product of the invention is usually placed when in use. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be understood as a limitation on the present invention.

[0036] In addition, the terms "first", "second", etc., if used, are merely used to distinguish and describe, and should not be understood as indicating or implying relative importance.

[0037] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.

[0038] Reference Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 and Figure 5 , the broadband low-scattering microstrip array structure based on the phase cancellation mechanism of the present invention is further described in detail.

[0039] In an embodiment of the present invention, a broadband low-scattering microstrip array antenna based on a phase cancellation mechanism is composed of a plurality of extended Jerusalem cross-type microstrip antenna units 1 and a plurality of bent Jerusalem cross-type microstrip antenna units 2 arranged in a checkerboard pattern. It is easy to understand that the number of extended Jerusalem cross-type microstrip antenna units 1 and bent Jerusalem cross-type microstrip antenna units 2 should generally be equal.

[0040] In the present invention, the extended Jerusalem cross microstrip antenna unit 1 and the bent Jerusalem cross microstrip antenna unit 2 have similar radiation characteristics, that is, the polarization mode is the same, the central resonant frequency is consistent, and the radiation gain and radiation pattern within the working frequency band are similar. Specifically, similarity here means that the radiation gain difference is less than 0.5dB;

[0041] In the present application, the extended Jerusalem cross microstrip antenna unit 1 and the bent Jerusalem cross microstrip antenna unit 2 have similar radiation characteristics, so that the extended Jerusalem cross microstrip antenna unit 1 and the bent Jerusalem cross microstrip antenna unit 2 have normal radiation performance at the center resonance frequency point. For the scattering state, since the reflection amplitude difference of the extended Jerusalem cross microstrip antenna unit 1 and the bent Jerusalem cross microstrip antenna unit 2 is less than 0.5dB and the reflection phase difference is within 180°±37°, the energy cancellation condition proposed in the passive cancellation basic theory is met, so the chessboard distribution structure can be used without increasing additional low scattering design structure, and the wideband low scattering characteristic is realized.

[0042] In the present application, the extended Jerusalem cross microstrip antenna unit 1 and the bent Jerusalem cross microstrip antenna unit 2 have similar radiation characteristics, so that the extended Jerusalem cross microstrip antenna unit 1 and the bent Jerusalem cross microstrip antenna unit 2 have normal radiation performance at the center resonance frequency point. For the scattering state, since the reflection amplitude difference of the extended Jerusalem cross microstrip antenna unit 1 and the bent Jerusalem cross microstrip antenna unit 2 is less than 0.5dB and the reflection phase difference is within 180°±37°, the energy cancellation condition proposed in the passive cancellation basic theory is met, so the chessboard distribution structure can be used without increasing additional low scattering design structure, and the wideband low scattering characteristic is realized.

[0043] The "chessboard arrangement" described in the present application refers to that the antenna units in the array antenna can be divided into four sub-arrays, i.e., a first sub-array A, a first sub-array B, a second sub-array A and a second sub-array B. The first sub-array A and the first sub-array B are both composed of n*n extended Jerusalem cross microstrip antenna units 1, and the second sub-array A and the second sub-array B are both composed of n*n bent Jerusalem cross microstrip antenna units 2. The first sub-array A is symmetrical to the second sub-array A about a first symmetry axis, and the second sub-array B is symmetrical to the first sub-array B about a second symmetry axis. The first sub-array B is symmetrical to the second sub-array A about the second symmetry axis, and the first sub-array B is symmetrical to the second sub-array B about the first symmetry axis. The four sub-arrays are simultaneously distributed in a central symmetry, and the center is the intersection of the first symmetry axis and the second symmetry axis, the first symmetry axis is perpendicular to the second symmetry axis, and each antenna unit in each sub-array is arranged in a regular row-column arrangement. For example, taking the first symmetry axis as the Y axis and the second symmetry axis as the X axis, the four sub-arrays fall into four quadrants, so that the first sub-array A, the first sub-array B, the second sub-array A and the second sub-array B of the present application are located in the fourth, second, first and third quadrants, respectively. Based on the passive cancellation basic theory, the scattering energy can be changed from being concentrated to the center to being dispersed to four directions by using the above chessboard arrangement.

[0044] Reference Figure 2 and Figure 3As shown in the drawings, in one embodiment of the present application, the extended Jerusalem cross microstrip antenna unit 1 is composed of an extended Jerusalem cross structure metal radiation patch 11, an L-shaped coupling feed structure A 12, a metal ground plate A 13, a first layer dielectric substrate A 14 and a second layer dielectric substrate A 15. The metal ground plate A 13, the second layer dielectric substrate A 15 and the first layer dielectric substrate A 14 are arranged in order from bottom to top, the L-shaped coupling feed structure A 12 is a feed unit, and the extended Jerusalem cross structure metal radiation patch 11 is printed on the upper layer of the first layer dielectric substrate A 14.

[0045] Reference Figure 4 And Figure 5 As shown in the drawings, in one embodiment of the present application, the extended Jerusalem cross microstrip antenna unit 1 is composed of an extended Jerusalem cross structure metal radiation patch 11, an L-shaped coupling feed structure A 12, a metal ground plate A 13, a first layer dielectric substrate A 14 and a second layer dielectric substrate A 15. The metal ground plate A 13, the second layer dielectric substrate A 15 and the first layer dielectric substrate A 14 are arranged in order from bottom to top, the L-shaped coupling feed structure A 12 is a feed unit, and the extended Jerusalem cross structure metal radiation patch 11 is printed on the upper layer of the first layer dielectric substrate A 14.

[0046] The extended Jerusalem cross structure metal radiation patch 11 can be equivalent to an LC series structure under plane wave illumination, so the equivalent impedance of the extended Jerusalem cross microstrip antenna unit 1 at the center resonance presents inductance. The bent Jerusalem cross structure metal radiation patch 21 can be equivalent to an LC parallel structure under plane wave illumination, so the equivalent impedance of the bent Jerusalem cross microstrip antenna unit 2 at the center resonance presents capacitance. Based on the equivalent transmission line principle, the capacitive equivalent impedance and the inductive equivalent impedance can achieve an effective 180° reflection phase difference in an ideal state, so the extended Jerusalem cross microstrip antenna unit 1 and the bent Jerusalem cross microstrip antenna unit 2 proposed in the present application have a reflection phase difference of 180°±37° in a wide frequency band.

[0047] In the present application, the metal ground plate A 13 and the metal ground plate B 23, the second layer dielectric substrate A 15 and the second layer dielectric substrate B 25, and the first layer dielectric substrate A 14 and the first layer dielectric substrate B 24 can be in the same plane, respectively, or can be described as each substrate can have different thicknesses, which can be designed as needed.

[0048] Further, the extended Jerusalem cross structure metal radiation patch 11 is a center-symmetrical structure, which is composed of a square metal patch A111, a first metal rectangular patch A112, a second metal rectangular patch A113 and a third metal rectangular patch A114, and the edges of each patch are only in vertical or parallel relationship. The square metal patch A111 is located at the center, and one end of each of the four metal rectangular patches A112 is connected to the midpoint of each edge of the square metal patch A111, which can also be understood as that the metal rectangular patch A112 is an extension in the vertical direction from the midpoint of each edge of the square metal patch A111; one second metal rectangular patch A113 is connected to the other end of one first metal rectangular patch A112 and one third metal rectangular patch A114, thereby forming a branch, and the centers of the patches on one branch are located on the same straight line. Apparently, in the present application, the side length of the square metal patch A111 should be the aforementioned X-axis direction or Y-axis direction.

[0049] On one branch, the length of the second metal rectangular patch A113 is greater than the length of the third metal rectangular patch A114, and the width of the second metal rectangular patch A113 is less than the width of the third metal rectangular patch A114; wherein the length refers to the size in the direction perpendicular to the straight line, and the width refers to the size in the direction parallel to the straight line.

[0050] Further, the L-shaped coupling feeding structure A12 is composed of a rectangular feeding patch A121 and a metalized via A122; the rectangular feeding patch A121 is printed on the upper layer of the second layer dielectric substrate A15, and the metalized via A122 penetrates the second layer dielectric substrate A15 to realize feeding; the metal ground plate A13 is printed on the lower layer of the second layer dielectric substrate A15; the metal ground plate A13 is etched with a circular aperture with a center coinciding with the metalized via A122 and a radius slightly larger than the metalized via A122.

[0051] Further, the bent Jerusalem cross structure metal radiation patch 21 is a center-symmetrical structure, which is composed of a square metal patch B211, four S-shaped bent metal strips 212 and a rectangular metal patch B213, and the edges of each patch are only in vertical or parallel relationship; the square metal patch B211 is located at the center, and one end of each of the four S-shaped bent metal strips 212 is connected to the midpoint of each edge of the square metal patch B211; one rectangular metal patch B213 is connected to the other end of one S-shaped bent metal strip 212, thereby forming a branch, and the centers of the patches on one branch are located on the same straight line. Apparently, in the present application, the side length of the square metal patch B211 should be the aforementioned X-axis direction or Y-axis direction.

[0052] Furthermore, the L-shaped coupled feeding structure B22 of the present invention is composed of a rectangular feeding patch B221 and a metallized via B222; the rectangular feeding patch B221 is printed on the upper layer of the second-layer dielectric substrate B25, and the metallized via B222 passes through the second-layer dielectric substrate B25 to achieve feeding; the metal floor B23 is printed on the lower layer of the second-layer dielectric substrate B25; a circular gap is etched in the metal floor B23, the center of which coincides with the metallized via B222 and the radius is slightly larger than the metallized via B222.

[0053] In the extended Jerusalem cross microstrip antenna unit 1 and the bent Jerusalem cross microstrip antenna unit 2 proposed in the present invention, the extended Jerusalem cross structure metal radiating patch 11 and the bent Jerusalem cross structure metal radiating patch 21 are both centrosymmetrical structures. Both exhibit the same electromagnetic response under cross-polarized electromagnetic waves and co-polarized electromagnetic waves. That is, the extended Jerusalem cross microstrip antenna unit 1 exhibits inductive response under both cross-polarized electromagnetic waves and co-polarized electromagnetic waves, while the bent Jerusalem cross microstrip antenna unit 2 exhibits capacitive response under both cross-polarized electromagnetic waves and co-polarized electromagnetic waves. Therefore, both antennas can achieve a reflection phase difference of 180°±37° under both cross-polarized electromagnetic waves and co-polarized electromagnetic waves, thereby achieving broadband low-scattering characteristics based on a phase cancellation mechanism.

[0054] Combine Figure 1 and Figure 6 As shown in (a) and (b), the unit size P of the extended Jerusalem cross microstrip antenna unit 1 is a =15mm, the extended Jerusalem cross structure metal radiation patch 11 is a central symmetrical structure, printed on a thickness of 0.75mm, with a relative dielectric constant ε r =3.55, the upper layer of the first dielectric substrate A14 is composed of a side length L a =3mm square metal patch A111 in the center, the length and width extending vertically from the midpoint of each side of the square metal patch A111 in the center are L a1 =0.8mm, W a1 =0.6mm first metal rectangular patch A112, the length and width of the first metal rectangular patch A112 extending horizontally are L a2 =3mm, W a2 =0.75mm second metal rectangular patch A113, and the length and width of the second metal rectangular patch A113 extending horizontally are L a3 =2.5mm, W a3 =0.7mm third metal rectangular patch A114. The L-shaped coupled feeding structure A12 is composed of a rectangular feeding patch A121 and a metalized via A122, wherein the length and width of the rectangular feeding patch A121 are L fa =0.9mm, Wfa = 0.8 mm, printed on the upper layer of the second layer dielectric substrate A15 with a thickness of 3.75 mm and a relative dielectric constant ε r = 3.55, the metalized via hole A122 penetrates the second layer dielectric substrate A15 with a hole diameter of 0.7 mm. The metal ground plate A13 is printed on the lower layer of the second layer dielectric substrate A15, and the metal ground plate A13 is etched with a circular hole with a center coinciding with the metalized via hole A122 and a hole diameter of 0.8 mm.

[0055] In combination Figure 1 and Figure 7 As shown in (a) and (b), the unit size P of the bent Jerusalem cross microstrip antenna unit 2 is b = 15 mm, the bent Jerusalem cross structure metal radiation patch 21 is a center-symmetric structure, printed on the upper layer of the first layer dielectric substrate B24 with a thickness of 2 mm and a relative dielectric constant ε r = 3.55, composed of a square metal patch B211 with a side length L b = 6.7 mm, a whole length L b1 = 3.25 mm, a whole width H b1 = 1.9 mm, a line width W b1 = 0.25 mm, and an S-shaped bent metal strip 212 connected with the S-shaped bent metal strip 212 and extending horizontally with a length L b2 = 2 mm and a width W b2 = 0.5 mm. The L-shaped coupling feed structure B22 is composed of a rectangular feed patch B221 and a metalized via hole B222; wherein the rectangular feed patch B221 has a length L fb = 3.5 mm and a width W fb = 0.1 mm, printed on the upper layer of the second layer dielectric substrate B25 with a thickness of 2 mm and a relative dielectric constant ε r = 3.55, the metalized via hole B222 penetrates the second layer dielectric substrate B25 with a hole diameter of 1.1 mm. The metal ground plate B23 is printed on the lower layer of the second layer dielectric substrate B25, and the metal ground plate B23 is etched with a circular gap with a center coinciding with the metalized via hole B222 and a hole diameter of 1.2 mm.

[0056] The following simulation experiment is used to further illustrate the technical effects of the present application:

[0057] The radiation characteristic curves of the extended Jerusalem cross microstrip antenna unit and the bent Jerusalem cross microstrip antenna unit are obtained by modeling and simulating the embodiments of the present application using the commercial simulation software CST Studio Suite 2020, as shown in Figure 8are shown. Among them, (a) is the working frequency band characteristic curve, (b) is the central resonant frequency gain direction characteristic curve. It can be seen that the extended Jerusalem cross microstrip antenna unit and the bent Jerusalem cross microstrip antenna unit have a common working frequency band of 9.72-10.85GHz, and have similar gain direction characteristic at the central resonant frequency point 10.3GHz.

[0058] The scattering characteristic curves of the extended Jerusalem cross microstrip antenna unit and the bent Jerusalem cross microstrip antenna unit are obtained by modeling and simulating the embodiments of the application by using the commercial simulation software CST Studio Suite 2020, as shown in Figure 9 . Among them, (a) is the reflection amplitude and reflection phase curve with frequency variation under cross-polarized incident wave irradiation, (b) is the reflection amplitude and reflection phase curve with frequency variation under co-polarized incident wave irradiation. It can be seen that the extended Jerusalem cross microstrip antenna unit and the bent Jerusalem cross microstrip antenna unit have full reflection within 5.48-11.91GHz under cross-polarized incident wave while maintaining a phase difference of 180°±37°; within 5.44-9.51GHz under co-polarized incident wave while maintaining a phase difference of 180°±37°.

[0059] The monostatic radar scattering cross section curves of the embodiments of the application and the same size ordinary microstrip array antenna under cross-polarized incident wave and co-polarized incident wave irradiation in simulation experiments are obtained by modeling and simulating the embodiments of the application by using the commercial simulation software CST Studio Suite 2020, as shown in Figure 10 . It can be seen that the embodiments of the application achieve a monostatic radar scattering cross section reduction of more than 10dB within 5.5-11.9GHz under cross-polarized incident wave; the embodiments of the application achieve a monostatic radar scattering cross section reduction of more than 10dB within 5.4-11.1GHz under co-polarized incident wave.

[0060] Although the specific embodiments of the application are described in detail with reference to the accompanying drawings, it should not be understood as limiting the protection scope of the patent. Various modifications and variations made by those skilled in the art within the scope described in the claims are still within the protection scope of the patent.

[0061] The above is only the preferred embodiments of the application, and does not limit the application in any form. Any simple modification and equivalent change made according to the technical essence of the application to the above embodiments also falls within the protection scope of the application.

Claims

1. A wideband low-scattering microstrip array antenna based on phase cancellation mechanism, which is composed of extended Jerusalem cross microstrip antenna units (1) and bent Jerusalem cross microstrip antenna units (2) arranged in a chessboard pattern, characterized in that: the extended Jerusalem cross microstrip antenna units (1) and the bent Jerusalem cross microstrip antenna units (2) have similar radiation characteristics, i.e. the same polarization mode, consistent central resonance frequency and a radiation gain difference less than 0.5 dB; the extended Jerusalem cross microstrip antenna units (1) and the bent Jerusalem cross microstrip antenna units (2) have a reflection amplitude difference less than 0.5 dB and a reflection phase difference within 180°±37° in a wide frequency band; the chessboard arrangement refers to that the array antenna is composed of four sub-arrays, i.e. a first sub-array A, a first sub-array B, a second sub-array A and a second sub-array B; the first sub-array A and the first sub-array B are each composed of n*n extended Jerusalem cross microstrip antenna units (1), and the second sub-array A and the second sub-array B are each composed of n*n bent Jerusalem cross microstrip antenna units (2); the first sub-array A is symmetrical to the second sub-array A about a first symmetry axis, and symmetrical to the second sub-array B about a second symmetry axis; the first sub-array B is symmetrical to the second sub-array A about the second symmetry axis, and symmetrical to the first sub-array B about the first symmetry axis; the first sub-array A is symmetrical to the first sub-array B about the intersection of the first symmetry axis and the second symmetry axis; the second sub-array A is symmetrical to the second sub-array B about the intersection of the first symmetry axis and the second symmetry axis; and the first symmetry axis is perpendicular to the second symmetry axis. The extended Jerusalem cross microstrip antenna unit (1) is composed of an L-shaped coupling feeding structure A (12) and sequentially arranged metal ground plate A (13), second layer dielectric substrate A (15), first layer dielectric substrate A (14) and extended Jerusalem cross structure metal radiation patch (11). The bent Jerusalem cross microstrip antenna unit (2) is composed of an L-shaped coupling feeding structure B (22) and sequentially arranged metal ground plate B (23), second layer dielectric substrate B (25), first layer dielectric substrate B (24) and bent Jerusalem cross structure metal radiation patch (21). The metal ground plate A (13) and the metal ground plate B (23), the second layer dielectric substrate A (15) and the second layer dielectric substrate B (25), and the first layer dielectric substrate A (14) and the first layer dielectric substrate B (24) are respectively in the same plane. ​ 2. The wideband low-scattering microstrip array antenna based on phase cancellation mechanism according to claim 1, characterized in that, ​ ​ 3. The wideband low-scattering microstrip array antenna based on phase cancellation mechanism according to claim 2, characterized in that, ​ 4. The wideband low-scattering microstrip array antenna based on phase cancellation mechanism according to claim 2, characterized in that, The extended Jerusalem cross structure metal radiation patch (11) is a central symmetric structure printed on the upper layer of the first layer dielectric substrate A (14), which is composed of a square metal patch A (111), a first metal rectangular patch A (112), a second metal rectangular patch A (113) and a third metal rectangular patch A (114), and the edges of each patch are only vertically or horizontally related; the square metal patch A (111) is located at the center, and the four metal rectangular patches A (112) are vertically connected to the midpoint of each edge of the square metal patch A (111) respectively; one second metal rectangular patch A (113) is connected to the other end of one metal rectangular patch A (112) and one third metal rectangular patch A (114), forming a branch, and the centers of each patch on one branch are located on the same straight line.

5. The wideband low-scattering microstrip array antenna based on phase cancellation mechanism according to claim 4, characterized in that, On one branch, the length of the second metal rectangular patch A (113) is greater than the length of the third metal rectangular patch A (114), and the width is less than the width of the third metal rectangular patch A (114); wherein the length refers to the size perpendicular to the direction of the straight line, and the width refers to the size parallel to the direction of the straight line.

6. The wideband low-scattering microstrip array antenna based on phase cancellation mechanism according to claim 4, characterized in that, The L-shaped coupling feeding structure A (12) is composed of a rectangular feeding patch A (121) and a metalized via A (122); the rectangular feeding patch A (121) is printed on the upper layer of the second layer dielectric substrate A (15), and the metalized via A (122) penetrates the second layer dielectric substrate A (15); the metal ground plate A (13) is printed on the lower layer of the second layer dielectric substrate A (15); the metal ground plate A (13) is etched with a circular aperture with a center coinciding with the metalized via A (122) and a radius greater than the metalized via A (122).

7. The wideband low-scattering microstrip array antenna based on phase cancellation mechanism according to claim 4, characterized in that, The bending type Jerusalem cross structure metal radiation patch (21) is a central symmetric structure printed on the upper layer of the first layer dielectric substrate B (24), which is composed of a square metal patch B (211), an S-shaped bending metal strip (212) and a rectangular metal patch B (213), and the edges of each patch are only vertically or horizontally related; the square metal patch B (211) is located at the center, and the four S-shaped bending metal strips (212) are vertically connected to the midpoint of each edge of the square metal patch B (211) respectively; one rectangular metal patch B (213) is connected to the other end of one S-shaped bending metal strip (212), forming a branch, and the centers of each patch on one branch are located on the same straight line.

8. The wideband low-scattering microstrip array antenna based on phase cancellation mechanism according to claim 7, characterized in that, The L-shaped coupling feeding structure B (22) is composed of a rectangular feeding patch B (221) and a metalized via B (222); the rectangular feeding patch B (221) is printed on the upper layer of the second layer dielectric substrate B (25), and the metalized via B (222) penetrates the second layer dielectric substrate B (25); the metal ground plate B (23) is printed on the lower layer of the second layer dielectric substrate B (25); the metal ground plate B (23) is etched with a circular aperture with a center coinciding with the metalized via B (222) and a radius greater than the metalized via B (222).

9. The wideband low-scattering microstrip array antenna based on phase cancellation mechanism according to claim 8, characterized in that, The unit size P of the extended Jerusalem cross microstrip antenna unit (1) a =15mm, the thickness of the first dielectric substrate A (14) is 0.75mm, and the side length L of the square metal patch A (111) is a =3mm, the length L of the first metal rectangular patch A(112) a1 =0.8mm, width W a1 =0.6mm, the length L of the second metal rectangular patch A(113) a2 =3mm, width W a2 =0.75mm, the length L of the third metal rectangular patch A (114) a3 =2.5mm, width W a3 =0.7mm, the length L of the rectangular feed patch A(121) fa =0.9mm, width W fa =0.8mm, the thickness of the second dielectric substrate A (15) is 3.75mm; The unit size P of the bent Jerusalem cross microstrip antenna unit (2) b = 15 mm, the thickness of the first layer dielectric substrate B (24) is 2 mm, the side length L of the square metal patch B (211) b = 6.7 mm, the overall length L of the S-shaped bent metal strip (212) b1 = 3.25 mm, the overall width H b1 = 1.9 mm, the line width W b1 = 0.25 mm, the length L of the rectangular metal patch B (213) b2 = 2 mm, the width W b2 = 0.5 mm, the length L of the rectangular feed patch B (221) fb = 3.5 mm, the width W fb = 0.1 mm, the thickness of the second layer dielectric substrate B (25) is 2 mm.

Images