Wide-axial-ratio circularly polarized patch antenna based on hybrid electromagnetic coupling technology

Abstract

The invention discloses a wide-axial-ratio circularly polarized patch antenna based on a hybrid electromagnetic coupling technology, and relates to the technical field of wireless communication. The antenna is composed of a probe, a radiation patch, a trapezoidal patch and a cavity. The radiation patch is located in the cavity, a radiation patch metal column is arranged in the center of the bottom of the radiation patch, the upper end of the radiation patch metal column is connected with the radiation patch, and the lower end of the radiation patch metal column is connected with the bottom of the cavity; the trapezoidal patch is arranged above the radiation patch, the middle part and the tail part of the trapezoidal patch are provided with trapezoidal patch metal columns, the upper ends of the trapezoidal patch metal columns are connected with the trapezoidal patch, and the lower ends of the trapezoidal patch metal columns penetrate through the bottom of the cavity; a feed structure is arranged below the bottom of the cavity, one end of the probe penetrates through the bottom of the cavity and is connected with the radiation patch, and the other end of the probe is connected with the feed structure. The antenna has a wide axial ratio bandwidth and a high gain, is simple in structure, is easy to process, and is suitable for a base station antenna in mobile communication.

Description

Technical Field

[0001] The invention relates to the technical field of wireless communication, in particular to a wide-axis ratio circularly polarized patch antenna based on hybrid electromagnetic coupling technology. Background Art

[0002] With the development of human society, people's requirements for communication quality are constantly increasing. Antennas, as devices for transmitting and receiving electromagnetic waves, play a vital role in communication systems. Nowadays, antennas are widely used in mobile communications, navigation, radar and other fields, and people's lives are inseparable from antennas. However, traditional linear polarization antennas have poor receiving capabilities and are easily interfered with, and can no longer meet people's needs. Compared with traditional linear polarization antennas, circular polarization antennas have the advantages of orthogonality, the ability to receive signals from all directions, strong ability to penetrate the ionosphere, strong anti-interference ability, etc., which can ensure the stability of signal transmission between the transmitter and the receiver.

[0003] An important measure of circular polarization performance is the axial ratio, which represents the purity of circular polarization. Antennas with high circular polarization purity can better receive signals from all directions in practical applications. Modern communications have put forward higher requirements for data transmission rate and signal transmission stability. Summary of the invention

[0004] The purpose of the present invention is to propose a wide-axis ratio circularly polarized patch antenna based on hybrid electromagnetic coupling technology, which is used to solve the problem that traditional linearly polarized antennas have poor receiving ability and are easily interfered with, and ensure the stability of signal transmission between the transmitting end and the receiving end.

[0005] To achieve the above-mentioned objectives, the present invention proposes a wide-axis ratio circularly polarized patch antenna based on hybrid electromagnetic coupling technology, comprising: a probe, a radiating patch, a trapezoidal patch, a feeding structure and a cavity; the radiating patch is located inside the cavity, and a radiating patch metal column is provided at the bottom center thereof, the upper end of the radiating patch metal column is connected to the radiating patch, and the lower end of the radiating patch metal column is connected to the bottom of the cavity for supporting the radiating patch; the trapezoidal patch is arranged above the radiating patch; the feeding structure is arranged below the bottom of the cavity.

[0006] Preferably, the probe is a feeding device, one end of which passes through the bottom of the cavity to be connected to the radiation patch, and the other end is connected to the feeding structure, and the radiation patch is differentially fed by two probes.

[0007] Preferably, the feeding structure comprises an upper cylindrical conductor and a lower cylindrical conductor, the upper cylindrical conductor covers the upper surface of the lower cylindrical conductor, and the upper cylindrical conductor wraps the probe.

[0008] Preferably, the lower surface of the upper cylindrical conductor is provided with a circular feeding surface having the same area as the lower surface thereof, which is directly connected to the probe.

[0009] Preferably, the radiation patch is located below the trapezoidal patch, with an air layer of a certain height between the two, and they do not touch each other; one set of diagonals of the radiation patch is cut off with triangles of the same size to achieve circular polarization; and the other set of diagonals is provided with feeding points.

[0010] Preferably, the feeding point is provided with an embedded microstrip line to achieve impedance matching.

[0011] Preferably, there are two groups of trapezoidal patches, two in each group and symmetrical about the center, arranged above the radiating patch, and the radiating patch generates coupled feeding. This arrangement makes the antenna more compact and achieves miniaturization; four rectangles of the same size are arranged at the tail of each trapezoidal patch to increase the axial ratio bandwidth, and trapezoidal patch metal columns are also arranged in the middle and tail.

[0012] Preferably, the number of the trapezoidal patch metal columns is 8, the upper ends of which are connected to the trapezoidal patch and the lower ends pass through the bottom of the cavity.

[0013] Preferably, the lower end of the trapezoidal patch metal column in the middle of the trapezoidal patch also passes through the radiation patch.

[0014] Preferably, the cavity is a cuboid with the upper surface removed, the bottom of which is located below the radiation patch and above the feeding structure, and the four surrounding surfaces surround the entire antenna structure. This cavity structure increases the radiation efficiency of the antenna.

[0015] Therefore, the present invention proposes a wide-axis ratio circularly polarized patch antenna based on hybrid electromagnetic coupling technology, which has the following beneficial effects:

[0016] (1) The present invention completes the design of the antenna only in one cavity, has a low profile, and uses hybrid electromagnetic coupling technology, which meets the communication system's requirements for antenna miniaturization and high performance. The antenna as a whole has the advantages of simple structure and easy processing;

[0017] (2) The present invention uses an embedded microstrip line at the feeding position of the radiation patch to achieve impedance matching and increase the bandwidth of the antenna; and a differential feeding method is used when feeding the radiation patch. The differential feeding method can more accurately control the polarization characteristics of the circular polarization antenna, reduce cross-polarization interference, and improve polarization purity, which can significantly improve the signal coverage and quality, reduce interference, and improve user experience;

[0018] (3) The present invention cuts off four rectangles of the same size at the end of each trapezoidal patch. This design is to increase the axial ratio bandwidth. The introduction of the trapezoidal patch can also improve the gain of the antenna; and the two groups of trapezoidal patches are arranged symmetrically about the center. This arrangement makes the antenna more compact and achieves miniaturization.

[0019] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of a wide-axis ratio circularly polarized patch antenna based on hybrid electromagnetic coupling technology of the present invention;

[0021] Figure 2 It is a schematic diagram of the bottom structure of a wide-axis ratio circularly polarized patch antenna based on hybrid electromagnetic coupling technology of the present invention;

[0022] Figure 3 It is a schematic diagram of dimension marking in a top view of an embodiment of a wide-axis ratio circularly polarized patch antenna based on a hybrid electromagnetic coupling technology of the present invention;

[0023] Figure 4 It is a schematic diagram of dimension marking in a front-view state of an embodiment of a wide-axis ratio circularly polarized patch antenna based on a hybrid electromagnetic coupling technology of the present invention;

[0024] Figure 5 This is a simulation result diagram of the reflection coefficient of a wide-axis ratio circularly polarized patch antenna based on a hybrid electromagnetic coupling technology of the present invention;

[0025] Figure 6 This is a simulation result diagram of the gain of a wide-axis ratio circularly polarized patch antenna based on a hybrid electromagnetic coupling technology of the present invention;

[0026] Figure 7 This is a simulation result diagram of the axial ratio of a wide axial ratio circularly polarized patch antenna based on a hybrid electromagnetic coupling technology of the present invention;

[0027] Figure 8 The present invention discloses a radiation pattern of a wide-axis ratio circularly polarized patch antenna based on a hybrid electromagnetic coupling technology at 4900 MHz.

[0028] Reference numerals

[0029] 1. Cavity; 2. Trapezoidal patch; 3. Radiating patch; 4. Feeding point; 5. Trapezoidal patch metal column; 6. Lower cylindrical conductor; 7. Upper cylindrical conductor; 8. Radiating patch metal column; 9. Probe; 10. Feeding structure. DETAILED DESCRIPTION

[0030] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0031] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0032] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0033] In the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] like Figure 1 and Figure 2 As shown, the present invention provides a wide-axis ratio circularly polarized patch antenna based on hybrid electromagnetic coupling technology, including a probe 9, a radiation patch 3, a trapezoidal patch 2, a feeding structure 10 and a cavity 1 surrounding the above structure; there are two probes 9, one end of each of which is connected to the corresponding coaxially arranged feeding structure 10 below the bottom of the cavity 1, and the other end passes through the bottom of the cavity 1 to be connected to the radiation patch 3; the radiation patch 3 is differentially fed by the two probes 9.

[0035] The feeding structure 10 includes an upper cylindrical conductor 7 and a lower cylindrical conductor 6. The upper cylindrical conductor 7 covers the upper surface of the lower cylindrical conductor 6. The upper cylindrical conductor 7 wraps the probe 9, and its lower surface is also provided with a circular feeding surface with the same area as its lower surface, which is directly connected to the probe 9.

[0036] The radiation patch 3 is arranged inside the cavity 1, and a radiation patch metal column 8 is provided at the bottom center thereof. The upper end of the radiation patch metal column 8 is connected to the radiation patch 3, and the lower end of the radiation patch metal column 8 is connected to the bottom of the cavity 1, which is used to support the radiation patch 3; a group of diagonals of the radiation patch 3 are cut off with triangles of the same size to achieve circular polarization; another group of diagonals are provided with a feeding point 4, and the feeding point 4 is provided with an embedded microstrip line to achieve impedance matching.

[0037] There are two groups of trapezoidal patches 2, two in each group and symmetrical about the center, which are arranged above the radiation patch 3, and the radiation patch 3 generates coupled feed. This arrangement makes the antenna more compact and realizes miniaturization; four rectangles of the same size are arranged at the tail of each trapezoidal patch 2 to increase the axial ratio bandwidth, and trapezoidal patch metal columns 5 are also arranged in the middle and tail; there are 8 trapezoidal patch metal columns 5, the upper ends of which are connected to the trapezoidal patch 2, and the lower ends pass through the bottom of the cavity 1; the lower end of the trapezoidal patch metal column 5 located in the middle of the trapezoidal patch 2 also passes through the radiation patch 3.

[0038] The cavity 1 is a cuboid with the upper surface removed, and its bottom is located below the radiation patch 3 and above the feeding structure 10. The entire antenna structure is arranged above the bottom of the cavity 1, and the four surfaces around the cavity 1 surround the entire antenna structure.

[0039] The following is a further explanation of the characteristics of the circularly polarized patch antenna combined with experiments.

[0040] like Figure 3 and Figure 4As shown, in the experiment, taking the impedance bandwidth of 3346-5054MHz as an example, the optimal dimensions are optimized as follows: the length and width of the bottom of cavity 1 are Lg=85mm, Wg=85mm, and the height is Hg=12mm. The overall thickness of cavity 1 and the thickness of radiation patch 3 are both Ts=1mm; a set of diagonal corners of radiation patch 3 are cut off to form a triangle with a height of Ht=19.2mm and a base of Wt=19.2mm, and the remaining side length is L s=24.8mm, and a microstrip line with a length of L1=12.8mm and a width of W1=2.5mm is set at the other diagonal point, and the edge at d=2.35mm away from the microstrip line is trimmed into an arc. The height of the bent part of the microstrip line is Hga=1.8mm, and the radiation patch metal column 8 supporting the radiation patch 3 is H1=2.5mm high and has a radius of R1=2.5mm; the trapezoidal patch 2 was originally a rectangle with a length of Lu=23.9mm and a width of Wu=23.7mm, two triangles with height Ht1=10mm and base Wt1=16mm are cut off from the head, four rectangles with length L2=5mm and width W2=3mm are cut off from the tail, the distance between two adjacent rectangles is d1=0.95mm, there are eight trapezoidal patch metal pillars 5 supporting the trapezoidal patch 2, these eight metal pillars have the same size, height H3=12mm, radius R3=1.5mm, radiating patch 3 and the interval between the trapezoidal patch 2 is Hj=6.5mm; the radius of the probe 9 is 0.65mm, and the length is Hz=5.5mm; the feeding structure 10 is composed of an upper cylindrical conductor 7 wrapping the probe 9 and a lower cylindrical conductor 6 thereunder, and is coaxial with the probe 9 and located below the ground plane, the upper cylindrical conductor 7 wrapping the probe 9 has a radius of R4=2mm and a height of H4=2mm, and the lower cylindrical conductor 6 has a radius of R5=4mm and a height of H5=2mm.

[0041] like Figure 5 As shown, it can be seen from the simulation results in the figure that the antenna works in a range of 3346-5054 MHz and has an absolute bandwidth of 1708 MHz. It has broadband characteristics and can meet the needs of multi-band communications.

[0042] like Figure 6 As shown in the figure, it can be seen from the results that the gain of the antenna in the 3346-5054MHz frequency band is above 9.15dB, and can reach up to 11.68dB, which has a high gain characteristic.

[0043] like Figure 7-8 As shown in the figure, it can be seen from the results that the axial ratio of the antenna in the 3373-4970MHz frequency band is less than 3dB, and it has a high axial ratio bandwidth.

[0044] Therefore, the present invention proposes a wide-axis ratio circularly polarized patch antenna based on hybrid electromagnetic coupling technology. The proposed wide-axis ratio circularly polarized patch antenna based on hybrid electromagnetic coupling technology adopts a differential feeding method to achieve high-purity circular polarization while having a wider bandwidth compared to traditional mobile communication base stations. It also has the advantages of simple structure and easy processing.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A wide-axis ratio circularly polarized patch antenna based on hybrid electromagnetic coupling technology, characterized in that: include: A probe, a radiation patch, a trapezoidal patch, a feeding structure and a cavity, wherein the radiation patch is located inside the cavity, a radiation patch metal column is provided at the bottom center thereof, the upper end of the radiation patch metal column is connected to the radiation patch, and the lower end of the radiation patch metal column is connected to the bottom of the cavity; the trapezoidal patch is arranged above the radiation patch; and the feeding structure is arranged below the bottom of the cavity.

2. The wide-axis ratio circularly polarized patch antenna based on hybrid electromagnetic coupling technology according to claim 1, characterized in that: The probe is a feeding device, one end of which passes through the bottom of the cavity and is connected to the radiation patch, and the other end of which is connected to the feeding structure.

3. The wide-axis ratio circularly polarized patch antenna based on hybrid electromagnetic coupling technology according to claim 2, characterized in that: The feeding structure comprises an upper cylindrical conductor and a lower cylindrical conductor, wherein the upper cylindrical conductor covers the upper surface of the lower cylindrical conductor, and the upper cylindrical conductor wraps the probe.

4. The wide-axis ratio circularly polarized patch antenna based on hybrid electromagnetic coupling technology according to claim 3, characterized in that: The lower surface of the upper cylindrical conductor is provided with a circular feeding surface with the same area as the lower surface thereof.

5. The wide-axis ratio circularly polarized patch antenna based on hybrid electromagnetic coupling technology according to claim 2, characterized in that: The radiation patches are located below the trapezoidal patches and do not contact each other; triangles of the same size are cut off from one set of diagonals of the radiation patches, and feeding points are arranged at the other set of diagonals.

6. The wide-axis ratio circularly polarized patch antenna based on hybrid electromagnetic coupling technology according to claim 5, characterized in that: The feeding point is provided with an embedded microstrip line.

7. The wide-axis ratio circularly polarized patch antenna based on hybrid electromagnetic coupling technology according to claim 1, characterized in that: There are two groups of trapezoidal patches, each group has two patches and are symmetrical about the center, and are arranged above the radiation patch; four rectangles of the same size are arranged at the tail of each trapezoidal patch, and trapezoidal patch metal columns are also arranged in the middle and tail.

8. The wide-axis ratio circularly polarized patch antenna based on hybrid electromagnetic coupling technology according to claim 7, characterized in that: The number of the trapezoidal patch metal columns is 8, the upper ends of which are connected to the trapezoidal patch and the lower ends pass through the bottom of the cavity.

9. The wide-axis ratio circularly polarized patch antenna based on hybrid electromagnetic coupling technology according to claim 8, characterized in that: The lower end of the trapezoidal patch metal column in the middle of the trapezoidal patch also passes through the radiation patch.

10. The wide-axis ratio circularly polarized patch antenna based on hybrid electromagnetic coupling technology according to claim 1, characterized in that: The cavity is a cuboid with the upper surface removed, and the bottom of the cavity is located below the radiation patch and above the feeding structure.

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