A Ka-band circularly polarized array antenna based on substrate integrated waveguide

Abstract

The invention discloses a Ka-band circularly polarized array antenna based on substrate integrated waveguide, belonging to the field of antenna technology, which includes an antenna radiation layer and a feeding layer; wherein the antenna radiation layer includes a first dielectric plate and a second dielectric plate; a plurality of parasitic patches are arranged on the upper surface of the first dielectric plate, a plurality of radiation patches are arranged on the upper surface of the second dielectric plate, and the radiation patches and the parasitic patches are arranged one by one; a first metal grounding surface is arranged on the lower surface of the second dielectric plate; a plurality of through holes are arranged around each parasitic patch; the feeding layer includes a third dielectric plate with an input port on one side, a power divider connected to the input port is arranged on the lower surface of the third dielectric plate, and is used to feed the radiation patches; a second metal grounding surface is arranged on the upper surface of the third dielectric plate. The antenna has good performance and can emit radiation waves with excellent circular polarization performance and high gain in a wider frequency band of the Ka-band.

Description

Technical Field

[0001] The present invention relates to the field of antenna technology, and in particular to a Ka-band circularly polarized array antenna based on substrate integrated waveguide. Background Art

[0002] In recent years, with the rapid development of information technology, communication systems are gradually evolving towards higher frequency bands to cope with the growing communication needs and data transmission volume. In this trend, the Ka-band (26.5 GHz to 40 GHz), as part of the millimeter wave band, has attracted much attention for its large bandwidth and high frequency. It has broad application prospects in satellite communications, radar detection and other fields. Circular polarization technology has the advantages of less multipath interference and strong resistance to rain and fog interference, which can improve the transmission quality and stability of signals. In view of the defect of electromagnetic coupling of traditional microstrip antennas in the millimeter wave band, the substrate integrated waveguide (SIW) structure has the advantages of low loss, planarization and easy integration, and is widely used in the field of antenna design.

[0003] In summary, the Ka-band circularly polarized array antenna based on SIW technology can expand the application scenarios of communication systems, improve the performance of communication systems, and thus promote the advancement of communication technology.

[0004] In recent years, single-feed circularly polarized antennas have been widely studied due to their simple structure and easy processing. However, existing single-feed circularly polarized antennas still have problems such as narrow working bandwidth. Summary of the invention

[0005] The present invention provides a Ka-band circularly polarized array antenna based on substrate integrated waveguide, so as to solve the technical problem of narrow working bandwidth existing in the existing single-feed point circularly polarized antenna.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] A Ka-band circularly polarized array antenna based on a substrate integrated waveguide, the circularly polarized array antenna comprising an antenna radiation layer and a feeding layer stacked in layers; wherein:

[0008] The antenna radiation layer comprises a first dielectric plate and a second dielectric plate, the first dielectric plate and the second dielectric plate are stacked; a plurality of parasitic patches are arranged on a side of the first dielectric plate facing away from the second dielectric plate, a plurality of radiation patches for radiating circularly polarized waves, which are matched with the number of the parasitic patches, are arranged on a side of the second dielectric plate facing the first dielectric plate, the radiation patches are arranged one by one opposite to the parasitic patches, and a first metal grounding surface is arranged on a side of the second dielectric plate facing away from the first dielectric plate; a plurality of through holes are arranged around each parasitic patch, the through holes are arranged in a square shape at equal intervals to form a planar closed structure, thereby realizing a substrate integrated waveguide, each through hole penetrates the first dielectric plate and the second dielectric plate in a direction perpendicular to the first dielectric plate, and the inner wall of the through hole is metallized;

[0009] The feeding layer includes a third dielectric plate, one side of the third dielectric plate is provided with an input port for excitation input, the side of the third dielectric plate facing away from the second dielectric plate is provided with a power divider connected to the input port, and the power divider feeds the radiation patch through a coaxial cable; the side of the third dielectric plate facing the second dielectric plate is provided with a second metal grounding surface.

[0010] Further, the plurality of through holes around each parasitic patch are evenly distributed around the corresponding parasitic patch;

[0011] The through hole has a height of 1.27 mm and a radius of 0.1 mm.

[0012] Furthermore, the dielectric constants of the first dielectric plate, the second dielectric plate and the third dielectric plate are all 2.2, and the loss tangents are all 0.0009;

[0013] The size of the first dielectric plate is: 10.4 mm×10.4 mm×0.762 mm;

[0014] The size of the second dielectric plate is: 10.4 mm×10.4 mm×0.508 mm;

[0015] The dimensions of the third dielectric plate are: 11.4 mm×11.4 mm×0.254 mm.

[0016] Furthermore, the number of the radiation patches is four, and the four radiation patches are arranged in a 2×2 array;

[0017] The number of the parasitic patches is also four, and the four parasitic patches are also arranged in a 2×2 array.

[0018] Furthermore, the radiation patch includes a radiation patch body; the radiation patch body is formed by respectively setting a first cut angle and a second cut angle at two opposite corners of a rectangular patch, and a first groove is opened in the middle of the radiation patch body; one end of the radiation patch body provided with the second cut angle extends outward along the longitudinal direction of the radiation patch body to form a first microstrip line, and the parts on both sides of the first microstrip line connected to the radiation patch body are respectively provided with second grooves along the longitudinal direction of the radiation patch.

[0019] Furthermore, the longitudinal side length of the rectangular patch is 2.69 mm;

[0020] The size of the first cutting angle is 1.06mm; the size of the second cutting angle is 0.49mm; the length and width of the first microstrip line are 0.51mm and 1.09mm respectively; the first groove is a square with a side length of 1.01mm; the second groove is a rectangle with a length and width of 0.36mm and 0.16mm respectively.

[0021] Furthermore, the parasitic patch is formed by respectively setting a third cut corner at two opposite corners of a square patch; wherein the side length of the square patch is 2.12 mm; and the size of the third cut corner is 0.5 mm.

[0022] Furthermore, the power divider includes an intermediate impedance converter, which is connected to the input port through a second microstrip line; the intermediate impedance converter is connected to two side impedance converters through a third microstrip line respectively, and the two side impedance converters are symmetrically distributed on both sides of the intermediate impedance converter, and each side impedance converter is connected to a feeding point branch through a fourth microstrip line respectively, and the two feeding point branches are symmetrically distributed on both sides of the intermediate impedance converter, and each feeding point branch includes two feeding points.

[0023] Furthermore, the distance between two opposite feeding points in the two feeding point branches is 5.4 mm; the width of the second microstrip line is 0.78 mm; the length and width of the third microstrip line are 1.45 mm and 0.95 mm respectively; the length of the fourth microstrip line is 0.7 mm; the length and width of the side impedance converter are 2 mm and 1.4 mm respectively; the length and width of the middle impedance converter are 1.8 mm and 1.5 mm respectively; and the side length of the metal surface at the feeding point is 0.9 mm.

[0024] Furthermore, the antenna has a Ka-band impedance matching relative bandwidth, a 3dB axial ratio relative bandwidth, and a 6dB axial ratio relative bandwidth of 8.40%, 6.31%, and 14.55% respectively, and a maximum gain of 11.1dB at 28GHz.

[0025] The beneficial effects brought about by the technical solution provided by the present invention include at least:

[0026] 1. The Ka-band circularly polarized array antenna based on substrate integrated waveguide of the present invention can radiate Ka-band left-handed circularly polarized waves. When working, the excitation is fed into the power divider from the input port, and then the radiation patch is fed through the power divider and the coaxial cable, thereby emitting circularly polarized radiation waves;

[0027] 2. The Ka-band circularly polarized array antenna based on substrate integrated waveguide of the present invention combines the microstrip antenna with the substrate integrated waveguide technology, and on the basis of retaining the advantages of easy processing and low cost of the microstrip antenna, significantly broadens the working bandwidth and improves the circularly polarized radiation of the antenna;

[0028] 3. The Ka-band impedance matching relative bandwidth, 3dB axial ratio relative bandwidth and 6dB axial ratio relative bandwidth of the circularly polarized array antenna of the present invention are 8.40%, 6.31% and 14.55% respectively, and the maximum gain at 28GHz is 11.1dB. It has the characteristics of good impedance matching, wide working bandwidth, excellent circular polarization performance and high gain. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0030] Figure 1 1 is a schematic structural diagram of a Ka-band circularly polarized array antenna based on a substrate integrated waveguide provided in an embodiment of the present invention;

[0031] Figure 2 is a schematic structural diagram of a radiation patch provided by an embodiment of the present invention;

[0032] Figure 3 is a schematic diagram of electric field distribution of a radiation patch provided in an embodiment of the present invention;

[0033] Figure 4 is a schematic structural diagram of a parasitic patch provided by an embodiment of the present invention;

[0034] Figure 5 is a schematic diagram of the structure of a power distributor provided by an embodiment of the present invention;

[0035] Figure 6 is a schematic diagram of return loss after simulation of a power divider provided in an embodiment of the present invention;

[0036] Figure 7 is a schematic diagram of return loss after simulation of an array antenna provided in an embodiment of the present invention;

[0037] Figure 8 is a schematic diagram of the axial ratio of the array antenna after simulation provided by an embodiment of the present invention;

[0038] Fig. 9 It is the directional diagram of the total gain and left-handed circularly polarized wave gain at 28 GHz after simulation of the array antenna provided by an embodiment of the present invention;

[0039] Fig.10 It is a schematic diagram comparing the simulated return loss of the array antenna provided by an embodiment of the present invention with that of a 2×2 array antenna using a non-SIW structure and a traditional rectangular cut-corner radiation patch;

[0040] Fig.11 is a schematic diagram comparing the axial ratio of the array antenna after simulation provided by an embodiment of the present invention and a 2×2 array antenna using a non-SIW structure and a traditional rectangular cut-corner radiation patch;

[0041] Fig.12 It is a schematic diagram comparing the total gain at 28 GHz of the array antenna provided by an embodiment of the present invention after simulation with a 2×2 array antenna using a non-SIW structure and a traditional rectangular cut-corner radiation patch.

[0042] Description of reference numerals:

[0043] 1. dielectric plate; 101. first dielectric plate; 102. second dielectric plate; 103. third dielectric plate;

[0044] 2. Input port;

[0045] 3. Through hole; 4. Radiating patch; 5. Parasitic patch; 6. Coaxial cable; 7. Power divider;

[0046] 8. Metal grounding surface; 801. First metal grounding surface; 802. Second metal grounding surface. DETAILED DESCRIPTION

[0047] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0048] First of all, it should be noted that in the embodiments of the present invention, words such as "exemplarily" and "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "exemplary" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the word "exemplarily" is intended to present the concept in a concrete way. In addition, in the embodiments of the present invention, the meaning expressed by "and / or" can be both, or it can be either of the two.

[0049] This embodiment provides a Ka-band circularly polarized array antenna based on a substrate integrated waveguide operating at 28 GHz. The Ka-band circularly polarized array antenna based on a substrate integrated waveguide can radiate circularly polarized waves with 28 GHz as the center frequency, has a wide impedance matching bandwidth and circular polarization bandwidth, and has good gain performance. Specifically, Figure 1 As shown, the circularly polarized array antenna includes an antenna radiation layer and a feeding layer which are stacked; wherein,

[0050] The antenna radiation layer includes a first dielectric plate 101 and a second dielectric plate 102; the first dielectric plate 101 and the second dielectric plate 102 are stacked; the feeding layer includes a third dielectric plate 103; wherein the dielectric plate is a substrate of a printed circuit, which is used to bear the entire circuit; specifically, in this embodiment, the three dielectric plates are made of the same material, and the dielectric constants of the materials are all 2.2, and the loss tangents are all 0.0009; wherein the size of the first dielectric plate 101 is: 10.4mm×10.4mm×0.762mm; the size of the second dielectric plate 102 is: 10.4mm×10.4mm×0.508mm; the size of the third dielectric plate 103 is: 11.4mm×11.4mm×0.254mm.

[0051] A plurality of parasitic patches 5 are arranged on the side of the first dielectric plate 101 facing away from the second dielectric plate 102, and a plurality of radiation patches 4 for radiating circularly polarized waves matching the number of parasitic patches 5 are arranged on the side of the second dielectric plate 102 facing the first dielectric plate 101. The radiation patches 4 on the second dielectric plate 102 are arranged opposite to the parasitic patches 5 on the first dielectric plate 101. A first metal grounding surface 801 is arranged on the side of the second dielectric plate 102 facing away from the first dielectric plate 101. A plurality of through holes 3 are arranged around the first dielectric plate 101 and the second dielectric plate 102, and each through hole 3 penetrates the first dielectric plate 101 and the second dielectric plate 102 in a direction perpendicular to the first dielectric plate 101, and the inner wall of the through hole 3 is metallized. Specifically, in this embodiment, the height of the through hole 3 is 1.27 mm and the radius is 0.1 mm; multiple through holes 3 are evenly arranged around each parasitic patch 5, and these through holes are arranged in a square at equal intervals to form a planar closed structure. The metal through holes are inserted into the sides of the dielectric plate, thereby realizing the substrate integrated waveguide. An input port 2 for excitation input is provided on one side of the third dielectric plate 103, which is used to input energy; a power divider 7 connected to the input port 2 is provided on the side of the third dielectric plate 103 facing away from the second dielectric plate 102, and the power divider 7 feeds the radiation patch 4 through the coaxial cable 6; a second metal grounding surface 802 is provided on the side of the third dielectric plate 103 facing the second dielectric plate 102.

[0052] Specifically, in this embodiment, the number of radiation patches 4 is four, and the four radiation patches are arranged in a 2×2 array; the number of parasitic patches 5 is also four, and the four parasitic patches are also arranged in a 2×2 array; correspondingly, four coaxial cables 6 are provided, and their height is 1.462 mm and their radius is 0.1 mm.

[0053] The following is an introduction to the roles and functions of the above components:

[0054] The first dielectric plate 101, the second dielectric plate 102, and the third dielectric plate 103 are substrates for printed circuits, which are used to support the entire circuit; the input port 2 is used to input energy; the through hole 3 constitutes a substrate integrated waveguide structure, which can reduce losses; the radiation patch 4 is used to radiate circularly polarized waves; the parasitic patch 5 is used to improve the circular polarization performance; the coaxial cable 6 is used to connect the radiation patch 4 and the power divider 7; the power divider 7 is used to feed the radiation patch 4; the first metal ground plane 801 and the second metal ground plane 802 constitute the reflection surface of the antenna.

[0055] Furthermore, if Figure 2 As shown, the radiation patch 4 includes a radiation patch body; the radiation patch body is formed by respectively setting a first cut angle and a second cut angle at two opposite corners of a rectangular patch, and a first groove is provided in the middle of the radiation patch body; one end of the radiation patch body provided with the second cut angle extends outward along the longitudinal direction of the radiation patch body to form a first microstrip line, and the parts on both sides of the first microstrip line connected to the radiation patch body are respectively provided with second grooves along the longitudinal direction of the radiation patch. Specifically, in this embodiment, the longitudinal side length lx1 of the rectangular patch is 2.69mm; the first cut angle size ds1 is 1.06mm; the second cut angle size ds2 is 0.49mm; the length ax and width ay of the microstrip line are 0.51mm and 1.09mm respectively; the first groove is a square, and its side length bx is 1.01mm; the second groove is a rectangle, and its length cx and width cy are 0.36mm and 0.16mm respectively.

[0056] Based on the above, the electric field distribution of the radiation patch 4 at 28 GHz is as follows Figure 3 As shown by Figure 3 It can be seen that the radiation patch 4 of this embodiment is mainly distributed with electric field vectors oriented toward the upper left and upper right directions, which are 90° apart, so that it radiates circularly polarized waves.

[0057] Furthermore, if Figure 4 As shown, the parasitic patch 5 is formed by respectively setting third cut corners at two opposite corners of the square patch; wherein the side length lx2 of the square patch is 2.12 mm; and the size dss of the third cut corner is 0.5 mm.

[0058] Furthermore, if Figure 5As shown, the power divider 7 serves as the feeding network of the array antenna, which includes an intermediate impedance converter, which is connected to the input port 2 through a second microstrip line; the intermediate impedance converter is connected to the two side impedance converters through a third microstrip line respectively, and the two side impedance converters are symmetrically distributed on both sides of the intermediate impedance converter, and each side impedance converter is connected to a feed point branch through a fourth microstrip line respectively, and the two feed point branches are symmetrically distributed on both sides of the intermediate impedance converter, and each feed point branch includes two feed points. Specifically, in this embodiment, the spacing d between two opposite feed points in the two feed point branches is 5.4mm; the width w of the second microstrip line is 0.78mm; the length bl and width bw of the third microstrip line are 1.45mm and 0.95mm respectively; the length al of the fourth microstrip line is 0.7mm; the length cl and width cw of the side impedance converter are 2mm and 1.4mm respectively; the length dl and width dw of the intermediate impedance converter are 1.8mm and 1.5mm respectively; the side length el of the metal surface at the feed point is 0.9mm.

[0059] Based on the above structure, the Ka-band circularly polarized array antenna of this embodiment combines the microstrip antenna structure with the substrate integrated waveguide structure, and emits left-handed circularly polarized radiation waves in the Ka-band. Its Ka-band impedance matching relative bandwidth, 3dB axial ratio relative bandwidth and 6dB axial ratio relative bandwidth are 8.40%, 6.31% and 14.55% respectively, and the maximum gain at 28GHz is 11.1dB. It has a wide working bandwidth, excellent circular polarization performance and high gain.

[0060] Specifically, the working principle of the Ka-band circularly polarized array antenna of this embodiment is:

[0061] The current excitation is input from the input port 2 to the power divider 7, and then the excitation is transmitted to the four radiating patches 4 in equal phases via the coaxial cable 6. The electric field vector on the radiating patch 4 changes due to geometric perturbations such as cutting angles and digging grooves, forming two electric field vectors with a 90° difference in direction, so that the radiating patch 4 radiates circularly polarized radiation. The circularly polarized bandwidth of the radiated circularly polarized wave is further widened due to the reflection of the substrate integrated waveguide structure and the parasitic patch 5. At the same time, the 2×2 array composed of the four radiating patches 4 greatly improves the gain of the antenna.

[0062] The circularly polarized array antenna of this embodiment has been subjected to multiple simulation experiments, and the experimental results are briefly described below:

[0063] Figure 6 The schematic diagram of the return loss after simulation of the power divider in the circularly polarized array antenna of this embodiment is shown. Figure 6It can be seen that the center frequency of the power divider is around 28 GHz, the -10 dB return loss frequency range is 26.83-28.56 GHz, and the relative bandwidth is 6.25%, which meets the requirements of the Ka-band 2×2 array antenna for the feeding network.

[0064] Figure 7 The schematic diagram of return loss after simulation of the circularly polarized array antenna of this embodiment is shown. Figure 7 It can be seen that the impedance matching center frequency of the array antenna is around 28 GHz, the -10 dB return loss frequency range is 27.03-29.40 GHz, the relative bandwidth is 8.40%, and the impedance matching performance is good.

[0065] Figure 8 The figure shows the axial ratio diagram of the circularly polarized array antenna after simulation in this embodiment. Figure 8 It can be seen that the circular polarization center frequency of the array antenna is around 28 GHz, the 3dB and 6dB axial ratio frequency ranges are 27.15-28.92 GHz and 26.58-30.75 GHz respectively, the relative bandwidth reaches 6.31% and 14.55%, and the circular polarization bandwidth is wide, indicating that its circular polarization performance is excellent.

[0066] Fig. 9 The total gain and the directional pattern of the left-handed and right-handed circularly polarized wave gain at 28 GHz after simulation of the circularly polarized array antenna of this embodiment are shown. Fig. 9 It can be seen that the maximum gain of the array antenna in the maximum radiation direction Theta = 0° is 11.1dB, which is a relatively high gain. At the same time, from the similarity between the total gain image of the array antenna and the left-handed circularly polarized wave gain image, it can be seen that the circularly polarized wave radiated by the array antenna is a left-handed circularly polarized wave.

[0067] Figures 10 to 12 A schematic diagram showing the comparison of the simulated performance of the circularly polarized array antenna of this embodiment with a 2×2 array antenna using a non-SIW structure and a traditional rectangular cut-corner radiating patch is shown. Fig.10 is a schematic diagram comparing the return loss of the two antennas. Fig.10 It can be seen that their -10dB return loss bandwidth is similar and their impedance matching performance is relatively good. Fig.11 is a schematic diagram for comparing the axial ratios of the two antennas. Fig.11 It can be seen that, compared with the array antenna without SIW structure, the 3dB axial ratio bandwidth of the array antenna of this embodiment in the Ka band is nearly doubled, and the circular polarization performance of the array antenna of this embodiment is better. Fig.12 This is a schematic diagram comparing the total gain of the two antennas at 28 GHz. Fig.12 It can be seen that the maximum gain of the array antenna of the present invention is higher than that of the array antenna without the SIW structure, and the power directional radiation capability of the array antenna of the present invention is stronger.

[0068] In addition, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. The terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "comprises a..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements.

[0069] Finally, it should be noted that the above is only a preferred embodiment of the present invention. It should be pointed out that although the preferred embodiment of the present invention has been described, for ordinary technicians in this technical field, once the basic creative concept of the present invention is known, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention. Therefore, the attached claims are intended to be interpreted as including the preferred embodiment and all changes and modifications that fall within the scope of the embodiments of the present invention.

Claims

1. A Ka-band circularly polarized array antenna based on substrate integrated waveguide, characterized in that: The circularly polarized array antenna comprises an antenna radiation layer and a feeding layer which are stacked; wherein, The antenna radiation layer comprises a first dielectric plate and a second dielectric plate, the first dielectric plate and the second dielectric plate are stacked; a plurality of parasitic patches are arranged on a side of the first dielectric plate facing away from the second dielectric plate, a plurality of radiation patches for radiating circularly polarized waves, which are matched with the number of the parasitic patches, are arranged on a side of the second dielectric plate facing the first dielectric plate, the radiation patches are arranged opposite to the parasitic patches one by one, and a first metal grounding surface is arranged on a side of the second dielectric plate facing away from the first dielectric plate; a plurality of through holes are arranged around each parasitic patch, each through hole penetrates the first dielectric plate and the second dielectric plate in a direction perpendicular to the first dielectric plate, and the inner wall of the through hole is metallized; The feeding layer comprises a third dielectric plate, one side of the third dielectric plate is provided with an input port for excitation input, a side of the third dielectric plate facing away from the second dielectric plate is provided with a power divider connected to the input port, and the power divider feeds the radiation patch through a coaxial cable; a side of the third dielectric plate facing the second dielectric plate is provided with a second metal grounding surface; The radiation patch includes a radiation patch body; the radiation patch body is formed by respectively setting a first cut angle and a second cut angle at two opposite corners of a rectangular patch, and a first groove is opened in the middle of the radiation patch body; one end of the radiation patch body provided with the second cut angle extends outward along the longitudinal direction of the radiation patch body to form a first microstrip line, and the parts on both sides of the first microstrip line connected to the radiation patch body are respectively provided with second grooves along the longitudinal direction of the radiation patch.

2. The Ka-band circularly polarized array antenna based on substrate integrated waveguide according to claim 1, characterized in that: The plurality of through holes around each parasitic patch are evenly distributed around the corresponding parasitic patch; The through hole has a height of 1.27 mm and a radius of 0.1 mm.

3. The Ka-band circularly polarized array antenna based on substrate integrated waveguide according to claim 1, characterized in that: The dielectric constants of the first dielectric plate, the second dielectric plate and the third dielectric plate are all 2.2, and the loss tangents are all 0.0009; The size of the first dielectric plate is: 10.4 mm×10.4 mm×0.762 mm; The size of the second dielectric plate is: 10.4 mm×10.4 mm×0.508 mm; The dimensions of the third dielectric plate are: 11.4 mm×11.4 mm×0.254 mm.

4. The Ka-band circularly polarized array antenna based on substrate integrated waveguide according to claim 1, characterized in that: The number of the radiation patches is four, and the four radiation patches are arranged in a 2×2 array; The number of the parasitic patches is also four, and the four parasitic patches are also arranged in a 2×2 array.

5. The Ka-band circularly polarized array antenna based on substrate integrated waveguide according to claim 1, characterized in that: The longitudinal side length of the rectangular patch is 2.69 mm; The size of the first cutting angle is 1.06mm; the size of the second cutting angle is 0.49mm; the length and width of the first microstrip line are 0.51mm and 1.09mm respectively; the first groove is a square with a side length of 1.01mm; the second groove is a rectangle with a length and width of 0.36mm and 0.16mm respectively.

6. The Ka-band circularly polarized array antenna based on substrate integrated waveguide according to claim 1, characterized in that: The parasitic patch is formed by respectively setting a third cut corner at two opposite corners of a square patch; wherein the side length of the square patch is 2.12 mm; and the size of the third cut corner is 0.5 mm.

7. The Ka-band circularly polarized array antenna based on substrate integrated waveguide according to claim 1, characterized in that: The power divider includes an intermediate impedance converter, which is connected to the input port through a second microstrip line; the intermediate impedance converter is connected to two side impedance converters through a third microstrip line respectively, the two side impedance converters are symmetrically distributed on both sides of the intermediate impedance converter, each side impedance converter is connected to a feeding point branch through a fourth microstrip line, the two feeding point branches are symmetrically distributed on both sides of the intermediate impedance converter, and each feeding point branch includes two feeding points.

8. The Ka-band circularly polarized array antenna based on substrate integrated waveguide according to claim 7, characterized in that: The distance between two opposite feeding points in the two feeding point branches is 5.4 mm; the width of the second microstrip line is 0.78 mm; the length and width of the third microstrip line are 1.45 mm and 0.95 mm respectively; the length of the fourth microstrip line is 0.7 mm; the length and width of the side impedance converter are 2 mm and 1.4 mm respectively; the length and width of the middle impedance converter are 1.8 mm and 1.5 mm respectively; the side length of the metal surface at the feeding point is 0.9 mm.

9. The Ka-band circularly polarized array antenna based on substrate integrated waveguide according to claim 1, characterized in that: The Ka-band impedance matching relative bandwidth, 3dB axial ratio relative bandwidth and 6dB axial ratio relative bandwidth of the circularly polarized array antenna are 8.40%, 6.31% and 14.55% respectively, and the maximum gain at 28GHz is 11.1dB.

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