A circular polarization filter antenna

Abstract

The embodiment of the present application provides a circular polarization filtering antenna, which relates to the field of antenna design technology. The antenna includes: a first dielectric substrate, a second dielectric substrate, a third dielectric substrate, a fourth dielectric substrate and a metal through-hole column; the first dielectric substrate, the second dielectric substrate, the third dielectric substrate and the fourth dielectric substrate are arranged in sequence from top to bottom; the metal through-hole column penetrates the first dielectric substrate, the second dielectric substrate, the third dielectric substrate and the fourth dielectric substrate in sequence from top to bottom; wherein the lower surface of the second dielectric substrate is provided with a strip line. The antenna provided by the present application can achieve a filtering effect without adding an additional feeding structure, significantly suppresses interference in non-target frequency bands, and has high manufacturing precision and low processing and device costs.

Description

Technical Field

[0001] The present application relates to the technical field of antenna design, and in particular to a circularly polarized filtering antenna. Background Art

[0002] With the development of modern wireless communication systems, the RF front-end structure is developing towards multi-function, miniaturization and integration. Antennas and filters are the two most important components of RF front-end circuits, and their size and performance are crucial to the quality of the overall system. The traditional design method designs the antenna and filter separately, which causes the two devices to have losses due to incomplete matching when cascaded. The filter antenna formed by integrating the antenna and the filter not only has both radiation characteristics and filtering characteristics, but also can greatly reduce the overall size of the circuit and unnecessary energy loss between devices. Therefore, the filter antenna has become a hot topic for domestic and foreign scholars. Compared with linearly polarized antennas, circularly polarized antennas have many advantages, such as being very effective in suppressing multipath interference and attenuation, and being able to reduce the Faraday glare effect caused by the ionosphere. In addition, circularly polarized antennas do not require strict directivity between the transmitting and receiving antennas, while linearly polarized antennas will experience polarization mismatch loss if any polarization misalignment occurs between the transmitting and receiving antennas. In addition, circularly polarized antennas also have excellent properties such as orthogonality of rotation and polarization rotation. These advantages make circularly polarized antennas increasingly valued in wireless communications. Summary of the invention

[0003] An embodiment of the present application provides a circularly polarized filtering antenna, which can achieve a filtering effect without adding an additional feeding structure, significantly suppresses interference in non-target frequency bands, and has high manufacturing precision and low processing and device costs.

[0004] Other features and advantages of the present application will become apparent from the following detailed description, or may be learned in part by the practice of the present application.

[0005] According to a first aspect of an embodiment of the present application, there is provided a circularly polarized filtering antenna, comprising: a first dielectric substrate, a second dielectric substrate, a third dielectric substrate, a fourth dielectric substrate and a metal through-hole column;

[0006] The first dielectric substrate, the second dielectric substrate, the third dielectric substrate and the fourth dielectric substrate are arranged in sequence from top to bottom;

[0007] The metal through-hole column sequentially penetrates the first dielectric substrate, the second dielectric substrate, the third dielectric substrate and the fourth dielectric substrate from top to bottom;

[0008] Wherein, a strip line is arranged on the lower surface of the second dielectric substrate.

[0009] In some embodiments of the present application, based on the aforementioned solution, a square radiation patch is provided on the upper surface of the first dielectric substrate.

[0010] In some embodiments of the present application, based on the aforementioned solution, a cut corner is provided at a diagonal position of the square radiation patch.

[0011] In some embodiments of the present application, based on the aforementioned solution, a U-shaped gap is provided on the square radiation patch.

[0012] In some embodiments of the present application, based on the aforementioned solution, a first metal layer is disposed on the lower surface of the first dielectric substrate.

[0013] In some embodiments of the present application, based on the above solution, a second metal layer is disposed on the upper surface of the fourth dielectric substrate, and a metal bottom plate is disposed on the lower surface.

[0014] In some embodiments of the present application, based on the aforementioned solution, an open resonant ring is provided on the second metal layer.

[0015] In some embodiments of the present application, based on the aforementioned solution, the open resonant ring is a U-shaped gap, a T-shaped gap or an L-shaped gap.

[0016] In some embodiments of the present application, based on the above-mentioned solution, the strip line is a cross strip line, a square strip line, a rectangular strip line or a circular strip line.

[0017] In some embodiments of the present application, based on the above solution, prepregs are disposed between each of the first dielectric substrate, the second dielectric substrate, the third dielectric substrate, and the fourth dielectric substrate.

[0018] The technical solution of this application has the following technical effects:

[0019] (1) High flatness of the in-band gain curve;

[0020] (2) It has good filtering response and achieves broadband filtering;

[0021] (3) The overall structure is simple, without any special processing technology, and the cross-sectional height is 1.314 mm, which is smaller than that of most cavity filter antennas.

[0022] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings herein are incorporated into the specification and constitute a part of the specification, showing embodiments consistent with the present application, and together with the specification, are used to explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0024] Figure 1 An exploded schematic diagram of a circular polarization filtering antenna according to an embodiment of the present application is shown;

[0025] Figure 2 A schematic diagram of S parameter test results of a circularly polarized filter antenna according to an embodiment of the present application is shown;

[0026] Figure 3 A schematic diagram showing test results of axial ratio variation with frequency of a circularly polarized filter antenna according to an embodiment of the present application is shown;

[0027] Figure 4 A schematic diagram showing test results of gain variation with frequency of a circularly polarized filter antenna according to an embodiment of the present application is shown;

[0028] Figure 5 A schematic diagram showing the directional test results of a circularly polarized filter antenna at 25 GHz according to an embodiment of the present application is shown;

[0029] Figure 6 A schematic diagram of axial ratio directivity test results of a circularly polarized filter antenna at 25 GHz according to an embodiment of the present application is shown.

[0030] Description of reference numerals:

[0031] 1-first dielectric substrate; 2-second dielectric substrate; 3-third dielectric substrate; 4-fourth dielectric substrate; 5-prepreg; 6-square radiation patch; 7-metal through hole; 11-first metal layer; 41-second metal layer; 411-open resonant ring; 42-metal bottom plate; 61-U-shaped gap. DETAILED DESCRIPTION

[0032] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this application will be more comprehensive and complete and fully convey the concept of the example embodiments to those skilled in the art.

[0033] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present application. However, those skilled in the art will appreciate that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps, etc. can be adopted. In other cases, known methods, devices, realizations or operations are not shown or described in detail to avoid blurring the various aspects of the application.

[0034] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the objects used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those shown or described.

[0035] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all the embodiments. Based on the embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] Some embodiments of the present application will be described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments may be combined with each other.

[0037] In order to solve the technical problems existing in the prior art, an embodiment of the present application provides a circularly polarized filtering antenna, which can achieve a filtering effect without adding an additional feeding structure and can suppress interference in non-target frequency bands.

[0038] Specifically, the antenna includes: a first dielectric substrate, a second dielectric substrate, a third dielectric substrate, a fourth dielectric substrate and a metal through-hole column;

[0039] The first dielectric substrate, the second dielectric substrate, the third dielectric substrate and the fourth dielectric substrate are arranged in sequence from top to bottom;

[0040] The metal through-hole column sequentially penetrates the first dielectric substrate, the second dielectric substrate, the third dielectric substrate and the fourth dielectric substrate from top to bottom;

[0041] Wherein, a strip line is arranged on the lower surface of the second dielectric substrate.

[0042] In some feasible embodiments, based on the above solution, a square radiation patch is provided on the upper surface of the first dielectric substrate.

[0043] It will be appreciated that a square radiating patch is used to achieve circular polarization performance.

[0044] In some feasible embodiments, based on the above solution, corner cuts are provided at diagonal positions of the square radiation patch.

[0045] It can be understood that the cut angles set at the diagonal positions of the square radiation patch are used to form left-handed / right-handed circularly polarized waves.

[0046] In some feasible embodiments, based on the above-mentioned solution, a U-shaped gap is provided on the square radiation patch.

[0047] It can be understood that the U-shaped gap is used to achieve impedance matching.

[0048] In some feasible embodiments, based on the above solution, a first metal layer is disposed on the lower surface of the first dielectric substrate.

[0049] It can be understood that the first metal layer is used as a reflective ground layer for the square radiation patch, which is different from the traditional grounding concept.

[0050] In some feasible embodiments, based on the above solution, a second metal layer is disposed on the upper surface of the fourth dielectric substrate, and a metal bottom plate is disposed on the lower surface.

[0051] It can be understood that the second metal layer is used to achieve low-frequency filtering performance and the metal base plate is used for grounding.

[0052] In some feasible embodiments, based on the above solution, an open resonant ring is provided on the second metal layer.

[0053] It can be understood that the open resonant ring can cause electromagnetic waves of corresponding frequencies to form a reverse current at the open resonant ring, thereby generating a radiation zero point of the corresponding frequency.

[0054] In some feasible embodiments, based on the above solution, prepregs are disposed between each of the first dielectric substrate, the second dielectric substrate, the third dielectric substrate, and the fourth dielectric substrate.

[0055] It can be understood that the prepreg sheet disposed between the dielectric substrates is used to bond the dielectric substrates.

[0056] For example, see Figure 1 , shows an exploded schematic diagram of a circular polarization filtering antenna according to an embodiment of the present application.

[0057] like Figure 1As shown, the antenna includes a first dielectric substrate 1, a second dielectric substrate 2, a third dielectric substrate 3, a fourth dielectric substrate 4 and a metal through-hole column; the lower surface of the first dielectric substrate 1 is provided with a first metal layer 11 used as a reflective stratum of a square radiation patch; the upper surface of the fourth dielectric substrate 4 is provided with a second metal layer 41; the lower surface of the fourth dielectric substrate 4 is provided with a metal bottom plate 42.

[0058] The first dielectric substrate 1 , the second dielectric substrate 2 , the third dielectric substrate 3 and the fourth dielectric substrate 4 are arranged in sequence from top to bottom.

[0059] Prepreg sheets 5 for bonding the dielectric substrates are disposed between the first dielectric substrate 1 , the second dielectric substrate 2 , the third dielectric substrate 3 and the fourth dielectric substrate 4 .

[0060] A square radiation patch 6 for achieving circular polarization performance is provided on the upper surface of the first dielectric substrate 1. A U-shaped slot 61 is provided on the square radiation patch 6, and a cut corner is provided at the diagonal position. The square radiation patch 6 forms a left-handed / right-handed circularly polarized wave in the form of a cut corner and achieves impedance matching through the U-shaped slot 61.

[0061] A plurality of metal through holes 7 are arranged at the same position on the first dielectric substrate 1, the second dielectric substrate 2, the third dielectric substrate 3 and the fourth dielectric substrate 4, and the metal through hole column passes through the first dielectric substrate 1, the second dielectric substrate 2, the third dielectric substrate 3 and the fourth dielectric substrate 4 from top to bottom. The metal through hole column, the first metal layer 11 and the metal bottom plate 42, and the second dielectric substrate 2, the third dielectric substrate 3 and the fourth dielectric substrate 4 form a substrate integrated waveguide cavity. The substrate integrated waveguide cavity can make electromagnetic waves of a specific frequency resonate in the cavity to generate a radiation zero point of the corresponding frequency. A stripline is arranged on the lower surface of the second dielectric substrate 2, which cooperates with the substrate integrated waveguide cavity to achieve filtering.

[0062] An open resonant ring 411 is disposed on the second metal layer 41 . The open resonant ring 411 on the second metal layer 41 can cause electromagnetic waves of corresponding frequencies to form a reverse current at the open resonant ring 411 , thereby generating a radiation zero point of the corresponding frequency.

[0063] It should be noted that the formed substrate integrated waveguide cavity can be a square cavity, a rectangular cavity or a circular cavity.

[0064] In some feasible embodiments, based on the above-mentioned solution, the open resonant ring is a U-shaped gap, a T-shaped gap or an L-shaped gap.

[0065] For example, see Figure 1 ,exist Figure 1 In the open resonant ring, a U-shaped gap is used.

[0066] In some feasible embodiments, based on the above-mentioned solution, the strip line is a cross strip line, a square strip line, a rectangular strip line or a circular strip line.

[0067] Figures 2 to 6 A schematic diagram of simulation results of a K-band circularly polarized microstrip antenna according to an embodiment of the present application is shown.

[0068] like Figure 2 As shown, the input port return loss S11 of the broadband circularly polarized antenna according to the embodiment of the present application is better than 10dB in the frequency band from 24GHz to 25.9GHz. Figure 3 As shown in the figure, it can be seen from the curve of axial ratio AR (Axial Ratio) changing with frequency that the axial ratio is less than 3dB in the frequency band from 24.8GHz to 25.2GHz. Figure 4 As shown in the figure, the gain versus frequency curve shows that the gain changes flat in the 24.2GHz to 25.8GHz frequency band, and there is a radiation zero point near the 22GHz and 30GHz frequency points, and the gain is lower than -10dB in the 10GHz to 23.2GHz and 28.2GHz to 40GHz frequency bands, achieving broadband filtering. Figure 5 As shown in the figure, it can be seen from the power pattern at 25 GHz that the gain direction of the left-hand circular polarization LHCP at the intermediate frequency 25 GHz has a 3 dB beam width greater than 90°; the cross polarization is less than 50 dB; and the front-to-back ratio is less than 50 dB. Figure 6 As shown, it can be seen from the axial ratio radiation pattern at 25 GHz that the 3 dB beam width of the axial ratio direction at the middle frequency point 25 GHz is greater than 100°.

[0069] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the embodiments disclosed herein. The present application is intended to cover any variations, uses or adaptations of the present application, which follow the general principles of the present application and include common knowledge or customary techniques in the art that are not disclosed in the present application. It should be understood that the present application is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A circular polarization filtering antenna, characterized in that: include: A first dielectric substrate, a second dielectric substrate, a third dielectric substrate, a fourth dielectric substrate and a metal through-hole column; The first dielectric substrate, the second dielectric substrate, the third dielectric substrate and the fourth dielectric substrate are arranged in sequence from top to bottom; The metal through-hole column sequentially penetrates the first dielectric substrate, the second dielectric substrate, the third dielectric substrate and the fourth dielectric substrate from top to bottom; A square radiation patch is provided on the upper surface of the first dielectric substrate; The square radiation patch is provided with a cut corner at a diagonal position; The square radiation patch is provided with a U-shaped gap; A first metal layer is provided on the lower surface of the first dielectric substrate; The upper surface of the fourth dielectric substrate is provided with a second metal layer, and the lower surface is provided with a metal bottom plate; An open resonant ring is provided on the second metal layer; The metal through-hole column, the first metal layer, the metal bottom plate, the second dielectric substrate, the third dielectric substrate and the fourth dielectric substrate form a substrate-integrated waveguide cavity; The lower surface of the second dielectric substrate is provided with a stripline, which cooperates with the substrate integrated waveguide cavity to achieve filtering.

2. The antenna according to claim 1, characterized in that The open resonant ring is a U-shaped gap, a T-shaped gap or an L-shaped gap.

3. The antenna according to claim 1, characterized in that The strip line is a cross strip line, a square strip line, a rectangular strip line or a circular strip line.

4. The antenna according to any one of claims 1 to 3, characterized in that: A prepreg is disposed between each of the first dielectric substrate, the second dielectric substrate, the third dielectric substrate and the fourth dielectric substrate.

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