Circular polarized antenna based on artificial magnetic conductor and electronic equipment

Abstract

The invention provides a circularly polarized antenna based on an artificial magnetic conductor and electronic equipment, and relates to the technical field of wireless communication. The circularly polarized antenna is composed of a coaxial line, a first dielectric substrate, a second dielectric substrate and a grounding plate, the first dielectric substrate, the second dielectric substrate and the grounding plate are arranged from top to bottom, the first dielectric substrate, the second dielectric substrate and the grounding plate are parallel and mutually spaced, an upper-layer radiation unit is printed on the upper surface of the first dielectric substrate, and a lower-layer radiation unit is printed on the lower surface of the first dielectric substrate. An outer conductor of the coaxial line is connected with the lower-layer radiation unit, an inner conductor of the coaxial line penetrates through the first dielectric substrate and is connected with the upper-layer radiation unit, a plurality of rows and columns of metasurface units are printed on the upper surface of the second dielectric substrate, the metasurface units comprise multiple types, and the multiple types of metasurface units respectively have different shapes. Therefore, the bandwidth and the profile height of the circularly polarized antenna are well considered, and the performance of the circularly polarized antenna is better.

Description

Technical Field

[0001] The present application relates to the field of wireless communication technology, and in particular to a circularly polarized antenna and electronic equipment based on an artificial magnetic conductor. Background Art

[0002] An antenna is a converter that can transform a guided wave (an electromagnetic wave in which electromagnetic energy is confined within a limited cross-section and transmitted in a certain direction) into an electromagnetic wave that propagates in free space, or vice versa. Generally, compared with linearly polarized antennas, circularly polarized antennas have the ability to receive electromagnetic waves of arbitrary linear polarization, which can effectively avoid energy loss caused by polarization mismatch, and are not affected by the Faraday effect, which helps to reduce the multipath effect. This gives circularly polarized antennas excellent reliability and stability, making them widely used in satellite communications, radio frequency identification, radar and other fields.

[0003] In the related technology, it is simple to realize circular polarization with a cross-dipole antenna. It needs to maintain a distance of 1 / 4 wavelength from the reflector to ensure the in-phase superposition of the reflected wave and the forward radiated wave. The cross-dipole antenna profile height needs to be between 0.3 and 0.4λ. C Between (λ C The wavelength of the center frequency corresponding to the overlapping bandwidth of impedance and axial ratio) can achieve ultra-wideband, but 0.3~0.4λ C The cross-sectional height is very large, which will increase the size of the antenna, making it difficult to install and integrate the antenna, and even more difficult for it to conform to the carrier. Summary of the invention

[0004] The present application provides a circularly polarized antenna and electronic equipment based on an artificial magnetic conductor, aiming to solve the problem in the related art that the bandwidth and profile height of the circularly polarized antenna cannot be balanced.

[0005] In order to solve the above-mentioned drawbacks existing in the related art, the first aspect of the present application provides a circularly polarized antenna based on an artificial magnetic conductor, including a ground plate, a coaxial line, a first dielectric substrate and a second dielectric substrate, the ground plate is located below the first dielectric substrate, the second dielectric substrate is located between the first dielectric substrate and the ground plate, the first dielectric substrate, the second dielectric substrate and the ground plate are parallel and spaced from each other, an air layer is loaded between the second dielectric substrate and the ground plate, an upper radiation unit is printed on the upper surface of the first dielectric substrate, a lower radiation unit is printed on the lower surface of the first dielectric substrate, the outer conductor of the coaxial line is electrically connected to the lower radiation unit, the inner conductor of the coaxial line passes through the first dielectric substrate and is electrically connected to the upper radiation unit, and a plurality of rows and columns of super-surface units are printed on the upper surface of the second dielectric substrate, the super-surface units include multiple types, and the multiple super-surface units have different shapes.

[0006] In some implementation solutions, the metasurface units include three types, namely the first metasurface unit, the second metasurface unit, and the third metasurface unit. There is one first metasurface unit, and there are multiple second metasurface units and multiple third metasurface units. The first metasurface unit is located at the center of the second dielectric substrate. The multiple second metasurface units surround the first metasurface unit for at least one circle, and the multiple third metasurface units surround the second metasurface unit for at least one circle. As one or more implementation solutions, the first metasurface unit includes a square loop patch; the second metasurface unit includes a first cross-shaped patch and four square patches. The four square patches are respectively located at the four corners of the first cross-shaped patch and are all spaced apart from the first cross-shaped patch; the third metasurface unit includes a second cross-shaped patch.

[0007] In some implementation solutions, the upper radiation unit includes two upper dipole arms which are perpendicular to each other and are connected by an upper phase delay line; the lower radiation unit includes two lower dipole arms which are perpendicular to each other and are connected by a lower phase delay line. The size of the lower dipole arms is smaller than that of the upper dipole arms. The two lower dipole arms and the two upper dipole arms form a cross-shaped intersection structure, and the intersection point is located at the center of the first dielectric substrate. As one or more implementation solutions, the upper dipole arms and the lower dipole arms have the same profile, each including a semi-elliptical arc and two straight lines extending from both ends of the semi-elliptical arc towards each other until they meet, and the intersection of the two straight lines has a rounded corner.

[0008] In some implementation solutions, four parasitic units are also printed on the upper surface of the first dielectric substrate. The four parasitic units are respectively located at the four corners of the cross-shaped intersection structure, and each parasitic unit is spaced apart from the adjacent upper dipole arm or lower dipole arm. As one or more implementation solutions, the parasitic unit includes a triangular patch, and the vertex of the triangular patch faces the center of the first dielectric substrate.

[0009] In some implementation solutions, four metal sheet groups are erected on the upper surface of the ground plane. Each metal sheet group includes two metal sheets that are opposite and spaced apart from each other. The four metal sheet groups are respectively adjacent to the midpoints of the four sides of the ground plane, and each metal sheet is higher than the second dielectric substrate and lower than the first dielectric substrate.

[0010] The second aspect of this application provides an electronic device, which includes an electronic device body and the circularly polarized antenna provided in the first aspect of this application. The circularly polarized antenna is arranged on the electronic device body.

[0011] For the circularly polarized antenna provided in the first aspect of the present application, it is composed of a coaxial cable, a first dielectric substrate, a second dielectric substrate, and a ground plane arranged from top to bottom. The first dielectric substrate, the second dielectric substrate, and the ground plane are parallel and spaced apart from each other. An air layer is loaded between the second dielectric substrate and the ground plane. An upper radiation unit is printed on the upper surface of the first dielectric substrate, and a lower radiation unit is printed on the lower surface of the first dielectric substrate. The outer conductor of the coaxial cable is connected to the lower radiation unit, and the inner conductor passes through the first dielectric substrate and is connected to the upper radiation unit. Multiple rows and multiple columns of metasurface units are printed on the upper surface of the second dielectric substrate. There are multiple types of metasurface units, and the multiple types of metasurface units have different shapes respectively. It can be understood that the metasurface unit belongs to a specific implementation form of an artificial magnetic conductor. If only one type of metasurface unit is printed on the upper surface of the second dielectric substrate, then in order to cover a wider co-polarization reflection phase bandwidth of the artificial magnetic conductor, it is necessary to increase the height of the air layer (i.e., increase the distance between the second dielectric substrate and the ground plane), resulting in an increase in the profile height of the circularly polarized antenna. However, in the present application, multiple types of metasurface units with different shapes are printed on the upper surface of the second dielectric substrate. In this way, while ensuring a certain profile height of the circularly polarized antenna, by designing the shape of each metasurface unit and arranging all the metasurface units periodically on the upper surface of the second dielectric substrate, the co-polarization reflection phase bandwidth of the artificial magnetic conductor can cover different intervals, thereby expanding the co-polarization reflection phase bandwidth of the artificial magnetic conductor, and further broadening the impedance bandwidth and axial ratio bandwidth of the circularly polarized antenna. That is to say, the present application can reduce the profile height of the circularly polarized antenna while ensuring the impedance bandwidth and axial ratio bandwidth of the circularly polarized antenna. That is, the present application well balances the bandwidth and profile height of the circularly polarized antenna, and the performance of the circularly polarized antenna is better.

[0012] For the electronic device provided in the second aspect of the present application, since it includes the circularly polarized antenna provided in the first aspect of the present application, it has all the advantages of this circularly polarized antenna. Description of the Drawings

[0013] In order to more clearly illustrate the related art or the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required to be used in the description of the related art or the embodiments of the present application. Obviously, the drawings in the following description are only some embodiments of the present application, rather than all embodiments. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0014] Figure 1 It is a schematic structural diagram of the circularly polarized antenna provided by the embodiment of the present application;

[0015] Figure 2 It is a side view of the circularly polarized antenna provided by the embodiment of the present application;

[0016] Figure 3 Exploded schematic diagram of the circularly polarized antenna provided by the embodiment of the present application;

[0017] Figure 4 Top view of the first dielectric substrate provided by the embodiment of the present application;

[0018] Figure 5 Top view of the circularly polarized antenna provided by the embodiment of the present application;

[0019] Figure 6 Top view of the second dielectric substrate provided by the embodiment of the present application;

[0020] Figure 7 Structural schematic diagrams of three kinds of metasurface units provided by the embodiment of the present application;

[0021] Figure 8 In-phase reflection phase diagrams of the second and third metasurface units provided by the embodiment of the present application;

[0022] Figure 9 Reflection coefficient diagram of the circularly polarized antenna provided by the embodiment of the present application;

[0023] Figure 10 Axial ratio and gain diagrams of the circularly polarized antenna provided by the embodiment of the present application;

[0024] Figure 11 Radiation pattern of the circularly polarized antenna at 1.6 GHz provided by the embodiment of the present application;

[0025] Figure 12 Radiation pattern of the circularly polarized antenna at 2.2 GHz provided by the embodiment of the present application;

[0026] Figure 13 Radiation pattern of the circularly polarized antenna at 3.0 GHz provided by the embodiment of the present application.

[0027] The markings in each of the above figures represent respectively: 1 - first dielectric substrate, 2 - second dielectric substrate, 3 - ground plane, 4 - coaxial cable, 5 - air layer, 6 - metal sheet group, 7 - upper radiation unit, 8 - lower radiation unit, 9 - metasurface unit, 10 - parasitic unit, 100 - upper phase delay line, 21 - via hole, 41 - outer conductor, 42 - inner conductor, 61 - metal sheet, 71 - upper dipole arm, 81 - lower dipole arm, 91 - first metasurface unit, 92 - second metasurface unit, 93 - third metasurface unit, 911 - square ring patch, 921 - first cross-shaped patch, 922 - square patch, 931 - second cross-shaped patch, 101 - triangular patch. Detailed implementation manners

[0028] In the related art, a crossed dipole antenna can achieve circular polarization more simply. A quarter-wavelength distance needs to be maintained between it and the reflector to ensure in-phase superposition of the reflected wave and the forward radiation wave. Moreover, the profile height of many crossed dipole antennas needs to be between 0.3 and 0.4λ C (λ C is the wavelength corresponding to the center frequency of the overlapping bandwidth of the impedance and the axial ratio) to achieve ultra-wideband. However, the profile height of 0.3 to 0.4λ C is very large, which will increase the size of the antenna, is not conducive to the installation and integration of the antenna, and is even less conducive to its conformal with the carrier. In view of this, the present application proposes a circularly polarized antenna and an electronic device based on an artificial magnetic conductor in the following embodiments to solve the above-mentioned drawbacks existing in the related art.

[0029] In order to make the purpose, technical solution and advantages of the present application more obvious and understandable, the present application will be clearly and completely described below in conjunction with the embodiments of the present application and the corresponding drawings, wherein the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. It should be understood that the various embodiments of the present application described below are only used to explain the present application and are not used to limit the present application. That is, based on the various embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application. In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0030] Please refer to Figures 1 to 5 , Figure 1 which shows a schematic structural diagram of the circularly polarized antenna, Figure 2 which shows a side view of the circularly polarized antenna, Figure 3 which shows an exploded schematic diagram of the circularly polarized antenna, Figure 4 which shows a top view of the first dielectric substrate, Figure 5A top view of a circularly polarized antenna is shown. This embodiment provides a circularly polarized antenna based on an artificial magnetic conductor, which includes a ground plane 3, a coaxial cable 4, a first dielectric substrate 1 and a second dielectric substrate 2. The ground plane 3 is located below the first dielectric substrate 1 to achieve in-phase superposition of the forward radiation wave and the reflected wave. The second dielectric substrate 2 is located between the first dielectric substrate 1 and the ground plane 3. The first dielectric substrate 1, the second dielectric substrate 2 and the ground plane 3 are parallel and spaced from each other. An air layer 5 is loaded between the second dielectric substrate 2 and the ground plane 3. An upper radiation unit 7 is printed on the upper surface of the first dielectric substrate 1, and a lower radiation unit 8 is printed on the lower surface of the first dielectric substrate 1. The outer conductor 41 of the coaxial cable 4 is connected to the lower radiation unit 8, and the inner conductor 42 of the coaxial cable 4 passes through the first dielectric substrate 1 and is connected to the upper radiation unit 7. Multiple rows and columns of metasurface units 9 are printed on the upper surface of the second dielectric substrate 2. The metasurface units 9 include multiple types, and the multiple types of metasurface units 9 have different shapes respectively. In addition, it should be noted that the circularly polarized antenna can be applied to any electronic device in the field that has the need to transmit and receive electromagnetic waves, such as satellite communication devices, intelligent transportation devices, aerospace devices, etc., and can be specifically selected according to actual needs. This embodiment does not make a unique limitation on this; among them, an electronic device applying the circularly polarized antenna usually includes an electronic device body, and the circularly polarized antenna needs to be provided on the electronic device body.

[0031] Exemplarily, the length×width of the first dielectric substrate 1 is 88×88 mm, the thickness is 1.6 mm, the material is FR-4 (a composite material composed of glass fiber and flame-retardant epoxy resin), and the relative dielectric constant is 4.4; the length×width of the second dielectric substrate 2 is 117×117 mm, the thickness is 0.8 mm, the relative dielectric constant is 4.4, and the material is FR-4; the second dielectric substrate 2 is located at a position 9 mm below the first dielectric substrate 1; the distance between the ground plane 3 and the second dielectric substrate 2 is 14.2 mm, and the length×width of the ground plane 3 is 142×142 mm; the ground plane 3 is located at a position 24 mm below the first dielectric substrate 1 (the distance between the first dielectric substrate 1 and the second dielectric substrate 2 is 9 mm + the distance between the second dielectric substrate 2 and the ground plane 3 is 14.2 mm + the thickness of the second dielectric substrate 2 is 0.8 mm); the multiple rows and columns of metasurface units 9 on the second dielectric substrate 2 are spaced from each other, and the spacing is 1 mm; the coaxial cable 4 is 50 Ω.

[0032] It can be understood that the metasurface unit 9 belongs to a specific implementation form of an artificial magnetic conductor. If only one type of metasurface unit 9 is printed on the upper surface of the second dielectric substrate 2, then in order to cover a wider in-phase reflection phase bandwidth of the artificial magnetic conductor, it is necessary to increase the height of the air layer 5 (i.e., increase the distance between the second dielectric substrate 2 and the ground plane 3), resulting in an increase in the profile height of the circularly polarized antenna. However, in this embodiment, multiple metasurface units 9 with different shapes are printed on the upper surface of the second dielectric substrate 2. Thus, while ensuring a certain profile height of the circularly polarized antenna, by designing the shape of each metasurface unit 9 and periodically arranging all the metasurface units 9 on the upper surface of the second dielectric substrate 2, the in-phase reflection phase bandwidth of the artificial magnetic conductor can cover different intervals, thereby expanding the in-phase reflection phase bandwidth of the artificial magnetic conductor, and further broadening the impedance bandwidth and axial ratio bandwidth of the circularly polarized antenna.

[0033] As can be seen from the above, this embodiment can reduce the profile height of the circularly polarized antenna while ensuring the impedance bandwidth and axial ratio bandwidth of the circularly polarized antenna. That is, this embodiment well balances the bandwidth and profile height of the circularly polarized antenna, can reduce the size of the circularly polarized antenna, is beneficial to the installation and integration of the circularly polarized antenna, and is more beneficial to the conformal shaping of the circularly polarized antenna with the carrier, ultimately greatly improving the performance of the circularly polarized antenna.

[0034] In some embodiments, please refer to Figure 6 and Figure 7 , Figure 6 is a top view of the second dielectric substrate, Figure 7 is a schematic structural diagram of three types of metasurface units. There are three types of metasurface units 9, and the three types of metasurface units 9 have different shapes respectively. The three types of metasurface units 9 are the first metasurface unit 91, the second metasurface unit 92, and the third metasurface unit 93 respectively. The first metasurface unit 91 includes one, and both the second metasurface unit 92 and the third metasurface unit 93 include multiple. The first metasurface unit 91 is located at the center of the second dielectric substrate 2. Multiple second metasurface units 92 surround the first metasurface unit 91 for at least one circle, and multiple third metasurface units 93 surround the second metasurface unit 92 for at least one circle. Exemplarily, when 9 rows and 9 columns of metasurface units 9 (i.e., 81 metasurface units 9) are printed on the upper surface of the second dielectric substrate 2, multiple second metasurface units 92 surround the first metasurface unit 91 for two circles. There are 8 second metasurface units 9 in the first circle and 16 second metasurface units 9 in the second circle. Correspondingly, multiple third metasurface units 93 surround the second metasurface unit 92 for two circles. There are 24 third metasurface units 93 in the first circle and 32 third metasurface units 93 in the second circle.

[0035] As at least one of the embodiments, the first metasurface unit 91 includes a square loop patch 911. The square loop patch 911 is located at the center of the second dielectric substrate 2. A through hole 21 is provided at the center of the second dielectric substrate 2. The square loop patch 911 encloses the through hole 21. The coaxial line 4 can pass through the second dielectric substrate 2 through the through hole 21. That is, the main purpose of adopting the ring structure for the first metasurface unit 91 is to facilitate the coaxial line 4 to pass through the second dielectric substrate 2 so as to feed the upper radiation unit 7 and the lower radiation unit 8. The second metasurface unit 92 includes a first cross-shaped patch 921 and four square patches 922. The four square patches 922 are respectively located at the four corners of the first cross-shaped patch 921 and are all spaced from the first cross-shaped patch 921. The third metasurface unit 93 includes a second cross-shaped patch 931. Exemplarily, the inner ring of the square loop patch 911 is 5 mm, and the outer ring is 12 mm; the long side of the first cross-shaped patch 921 is 4.8 mm, and the short side is 2.4 mm; the side length of the square patch 922 is 4.4 mm, and the distance from the long side of the first cross-shaped patch 921 is 0.4 mm; the size of the second cross-shaped patch 931 is the same as that of the first cross-shaped patch 921.

[0036] In some embodiments, please refer to Figure 4 and Figure 5 , the upper radiation unit 7 includes two upper dipole arms 71. The two upper dipole arms 71 are perpendicular to each other. The two upper dipole arms 71 are connected by an upper phase delay line 100. Similarly, the lower radiation unit 8 includes two lower dipole arms 81. The two lower dipole arms 81 are perpendicular to each other. The two lower dipole arms 81 are connected by a lower phase delay line (not shown in the figure). Specifically, the size of the lower dipole arm 81 is smaller than that of the upper dipole arm 71. The two lower dipole arms 81 and the two upper dipole arms 71 form a cross-shaped intersection structure, and the intersection point is located at the center of the first dielectric substrate 1. It can be understood that the sizes of the upper dipole arm 71 and the lower dipole arm 81 are different, which means that they are asymmetric. Then, compared with the symmetric upper radiation unit 7 and lower radiation unit 8 in the traditional solution, this asymmetry in the present application can effectively expand the impedance bandwidth and axial ratio bandwidth of the circularly polarized antenna.

[0037] As at least one of the embodiments, the contour of the upper dipole arm 71 is the same as that of the lower dipole arm 81, both including a semi-elliptical arc and two straight lines extending from both ends of the semi-elliptical arc towards each other until they meet, and the junction of the two straight lines is rounded. That is to say, for the upper dipole arm 71 and the lower dipole arm 81, although their sizes are different, they are both composed of a semi-elliptical patch and a triangular patch, and the apex angle of the triangular patch is rounded; preferably, the shape of the triangular patch is an isosceles triangle. Exemplarily, in the upper dipole arm 71, the major axis of the semi-elliptical patch is 15 mm, the minor axis is 10 mm, and the height of the triangular patch (isosceles triangle) is 18.9 mm; in the lower dipole arm 81, the major axis of the semi-elliptical patch is 12 mm, the minor axis is 8 mm, and the height of the triangular patch (isosceles triangle) is 14.4 mm.

[0038] In some embodiments, referring to Figure 4 and Figure 5 , four parasitic elements 10 are also printed on the upper surface of the first dielectric substrate 1. The four parasitic elements 10 are respectively located at the four corners of the cross-shaped structure, and each parasitic element 10 is spaced from the adjacent upper dipole arm 71 or lower dipole arm 81. It can be understood that the parasitic elements 10 can be electromagnetically coupled with the radiation elements (i.e., the upper radiation element 7 and the lower radiation element 8), thereby changing the current distribution, enabling the antenna to generate an additional circular polarization mode, and further expanding the axial ratio bandwidth of the antenna. As at least one of the embodiments, the parasitic element 10 includes a triangular patch 101, and the apex angle of the triangular patch 101 faces the center of the first dielectric substrate 1. Exemplarily, the triangular patch 101 is an isosceles triangle, the base length and height of the triangular patch 101 are both 14.1 mm, and the vertex of the triangular patch 101 is 13.2 mm away from the center of the first dielectric substrate 1.

[0039] In some embodiments, referring to Figures 1 to 3 , four metal sheet groups 6 are erected on the upper surface of the ground plane 3. Each metal sheet group 6 includes two relatively spaced metal sheets 61. The four metal sheet groups 6 are respectively adjacent to the midpoints of the four sides of the ground plane 3. Each metal sheet 61 is higher than the second dielectric substrate 2 and lower than the first dielectric substrate 1. The function of these metal sheet groups 6 is to reduce the axial ratio of the circular polarization antenna at low frequencies and improve its radiation pattern. Exemplarily, the distance between the two metal sheets 61 in the same metal sheet group 6 is 10 mm, and the length × width × height of the metal sheet 61 is 1 mm × 10 mm × 24 mm.

[0040] The above embodiments are only the preferred implementations of the present application, and they are not the only limitations on the circularly polarized antenna based on artificial magnetic conductor and related electronic devices; in this regard, those skilled in the art can flexibly set according to the actual application scenarios on the basis of the above embodiments. It can be understood that through the implementation of the above embodiments of the present application, the coaxial cable 4 and the first dielectric substrate 1, the second dielectric substrate 2 and the ground plane 3 arranged from top to bottom together constitute a circularly polarized antenna. The first dielectric substrate 1, the second dielectric substrate 2 and the ground plane 3 are parallel and spaced from each other. An air layer 5 is loaded between the second dielectric substrate 2 and the ground plane 3. The upper surface of the first dielectric substrate 1 is printed with an upper radiation unit 7, and the lower surface is printed with a lower radiation unit 8. The outer conductor 41 of the coaxial cable 4 is connected to the lower radiation unit 8, and the inner conductor 42 passes through the first dielectric substrate 1 and is connected to the upper radiation unit 7. The upper surface of the second dielectric substrate 2 is printed with multiple rows and multiple columns of metasurface units 9. The metasurface units 9 include multiple types, and the multiple metasurface units 9 have different shapes respectively. It can be understood that the metasurface unit 9 belongs to a specific implementation form of the artificial magnetic conductor. If only one type of metasurface unit 9 is printed on the upper surface of the second dielectric substrate 2, then in order to cover a wider co-polarization reflection phase bandwidth of the artificial magnetic conductor, it is necessary to increase the height of the air layer 5 (that is, increase the distance between the second dielectric substrate 2 and the ground plane 3), which leads to an increase in the profile height of the circularly polarized antenna; however, in the present application, multiple metasurface units 9 with different shapes are printed on the upper surface of the second dielectric substrate 2. In this way, while ensuring a certain profile height of the circularly polarized antenna, by designing the shape of each metasurface unit 9 and arranging all the metasurface units 9 periodically on the upper surface of the second dielectric substrate 2, the co-polarization reflection phase bandwidth of the artificial magnetic conductor can cover different intervals, thereby expanding the co-polarization reflection phase bandwidth of the artificial magnetic conductor, and further broadening the impedance bandwidth and axial ratio bandwidth of the circularly polarized antenna; that is to say, the present application can reduce the profile height of the circularly polarized antenna while ensuring the ultra-wideband of the circularly polarized antenna, that is, the present application well balances the bandwidth and profile height of the circularly polarized antenna.

[0041] In addition, in order to enable those skilled in the art to more clearly understand the advantages of the circularly polarized antenna described in the above embodiments, the applicant has carried out experimental verification, and the results are as follows.

[0042] Please refer to Figure 8 , Figure 8 which is the co-polarization reflection phase diagram of the second and third metasurface units, Figure 8 The dotted line in Figure 8It can be seen that the in-phase reflection phase bandwidth of the second metasurface unit 92 is 1.56 - 3.05 GHz, and the in-phase reflection phase bandwidth of the third metasurface unit 93 is 1.78 - 3.83 GHz. By printing the second metasurface unit 92 and the third metasurface unit 93 on the upper surface of the second dielectric substrate 2 simultaneously, the working bandwidth of the circularly polarized antenna in the traditional solution can be covered (in the traditional circularly polarized antenna, the second dielectric substrate 2 and several metasurface units 9 thereon are not provided, the ground plane 3 is placed 36.2 mm below the first dielectric substrate 1, and no metal sheet group 6 is loaded on the ground plane 3). Imagine that if only the second metasurface unit 92 or the third metasurface unit 93 is printed on the upper surface of the second dielectric substrate 2, then to cover the working bandwidth of the circularly polarized antenna in the traditional solution, the height of the air layer 5 needs to be increased, which will inevitably increase the profile height of the circularly polarized antenna.

[0043] Please refer to Figure 9 , Figure 9 which is the reflection coefficient diagram of the circularly polarized antenna. Figure 9 In Figure 9 , the dashed line represents the circularly polarized antenna in the traditional solution, and the solid line represents the circularly polarized antenna of the present application. It can be seen from 11 that for the circularly polarized antenna in the traditional solution, the operating frequency band with S 11 (the reflection coefficient of the input port of the circularly polarized antenna) < -10 dB is 1.55 - 4.84 GHz (103%), while for the circularly polarized antenna of the present application, the operating frequency band with S

[0044] Please refer to Figure 10 , Figure 10 which shows the axial ratio and gain diagram of the circularly polarized antenna. Figure 10 In

[0045] Please refer to Figures 11 to 13 , Figure 11 is the radiation pattern of the circularly polarized antenna at 1.6 GHz. Figure 12It is the radiation pattern of the circularly polarized antenna at 2.2 GHz. Figure 13 It is the radiation pattern of the circularly polarized antenna at 3.0 GHz. Figures 11 to 13 In [the figure], the solid line represents the right-handed circular polarization and the dashed line represents the left-handed circular polarization. From Figures 11 to 13 it can be seen that the circularly polarized antenna of this application is right-handed and has good directional radiation.

[0046] Based on the results of the above experimental verification, for the circularly polarized antenna of this application, its profile height is 0.22λ C , the impedance bandwidth is 103%, the axial ratio bandwidth is 78.2%, and within the entire operating frequency band, the gain is greater than 7 dBic, the peak gain is 9.1 dBic, and the gain fluctuation is 2 dB. That is to say, the circularly polarized antenna of this application has the advantages of low profile height, wide operating frequency band, and high gain.

[0047] It should be noted that several embodiments shown in the above text of this application are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts among the various embodiments can be referred to each other. It should also be noted that in the text description of this application, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of such an actual relationship or order between these entities or operations. Further, the terms "include", "comprise" or any other corresponding variant are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes these elements, but may also include other elements not explicitly listed, or may also include elements inherent to this process, method, article or device; and, without more limitations, the element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, article or device including the said element.

[0048] In addition, by implementing several embodiments shown in the above text of this application, those skilled in the art can implement or use this application. For the several embodiments shown in the above text of this application, various modifications will be obvious to those skilled in the art. The general principles defined in this application can be implemented in other embodiments not shown without departing from the spirit or scope of this application. Therefore, this application will not be limited to the several embodiments shown above, but will conform to the widest scope consistent with the principles and novel features disclosed in this application.

Claims

1. A circularly polarized antenna based on an artificial magnetic conductor, characterized in that: The invention comprises a ground plate, a coaxial line, a first dielectric substrate and a second dielectric substrate, wherein the ground plate is located below the first dielectric substrate, the second dielectric substrate is located between the first dielectric substrate and the ground plate, the first dielectric substrate, the second dielectric substrate and the ground plate are spaced apart from each other, an air layer is loaded between the second dielectric substrate and the ground plate, an upper radiation unit is printed on the upper surface of the first dielectric substrate, and a lower radiation unit is printed on the lower surface, the outer conductor of the coaxial line is connected to the lower radiation unit, the inner conductor passes through the first dielectric substrate and is connected to the upper radiation unit, and a plurality of rows and columns of super surface units are printed on the upper surface of the second dielectric substrate, the super surface units include multiple types, and the multiple super surface units have different shapes respectively.

2. The circularly polarized antenna according to claim 1, characterized in that: The super-surface units include three types, which are a first super-surface unit, a second super-surface unit and a third super-surface unit. The first super-surface unit includes one, the second super-surface unit and the third super-surface unit each include a plurality, the first super-surface unit is located at the center of the second dielectric substrate, a plurality of the second super-surface units surround the first super-surface unit at least one circle, and a plurality of the third super-surface units surround the second super-surface unit at least one circle.

3. The circularly polarized antenna according to claim 2, characterized in that: The first super surface unit includes a square ring patch; the second super surface unit includes a first cross-shaped patch and four square patches, the four square patches are respectively located at the four corners of the first cross-shaped patch and are spaced apart from the first cross-shaped patch; the third super surface unit includes a second cross-shaped patch.

4. The circularly polarized antenna according to claim 1, characterized in that: The upper radiation unit comprises two upper dipole arms, the two upper dipole arms are perpendicular to each other, and the two upper dipole arms are connected via an upper phase delay line.

5. The circularly polarized antenna according to claim 4, characterized in that: The lower radiation unit includes two lower dipole arms, which are perpendicular to each other and connected through a lower phase delay line. The size of the lower dipole arm is smaller than that of the upper dipole arm. The two lower dipole arms and the two upper dipole arms form a cross-shaped structure, and the intersection is located at the center of the first dielectric substrate.

6. The circularly polarized antenna according to claim 5, characterized in that: The contours of the upper dipole arm and the lower dipole arm both include a semi-elliptical arc and two straight lines extending from two ends of the semi-elliptical arc toward each other until they are connected, and the connection between the two straight lines is rounded.

7. The circularly polarized antenna according to claim 5, characterized in that: Four parasitic units are printed on the upper surface of the first dielectric substrate and are respectively located at the four corners of the cross-shaped structure. Each of the parasitic units is spaced apart from the adjacent upper dipole arm or the lower dipole arm.

8. The circularly polarized antenna according to claim 7, characterized in that: The parasitic unit includes a triangular patch, and the vertex of the triangular patch faces the center of the first dielectric substrate.

9. The circularly polarized antenna according to claim 1, characterized in that: Four metal sheet groups are vertically arranged on the upper surface of the grounding plate, each of the metal sheet groups includes two metal sheets that are opposite and spaced from each other, the four metal sheet groups are respectively adjacent to the midpoints of the four sides of the grounding plate, and each of the metal sheets is higher than the second dielectric substrate and lower than the first dielectric substrate.

10. An electronic device, characterized in that: The invention comprises an electronic device body and the circularly polarized antenna according to any one of claims 1 to 9, wherein the circularly polarized antenna is arranged on the electronic device body.

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