Broadband two-dimensional eight-beam switchable annular magnetoelectric dipole array antenna and design method therefor

Abstract

The present invention relates to the technical field of radio frequency communications. Disclosed are a broadband two-dimensional eight-beam switchable annular magnetoelectric dipole array antenna and a design method therefor. The broadband two-dimensional eight-beam switchable annular magnetoelectric dipole array antenna comprises a first four-beam unit and a second four-beam unit which form an eight-beam array antenna; array antennas in the four-beam units are both located on a same horizontal plane and arranged on dielectric substrates, are both in a four-leaf clover shape and differ by 45°, two dielectric substrates are connected, and the bottoms of the dielectric substrates are provided with metal ground planes; shorting pins are provided at the top ends of leaves of the array antennas, and sequentially pass through the array antennas and the dielectric substrates to be connected to the metal ground planes; and coaxial inner conductor metal columns are provided at the junctions of the leaves of the array antennas, pass through the array antennas, the dielectric substrates and the metal ground planes, and are connected to feed ports. The present invention provides a beam switching antenna which is small, has a wider overlapping bandwidth during multi-beam switching, and has more switching states.

Description

A broadband two-dimensional eight-beam switchable ring magnetoelectric dipole array antenna and its design method Technical Field

[0001] This invention relates to the field of radio frequency communication technology, and more specifically to a broadband two-dimensional eight-beam switchable ring magnetoelectric dipole array antenna and its design method. Background Technology

[0002] Currently, beam-switching antennas have received widespread attention in recent years due to their ability to switch multiple beams, improve channel capacity, and enhance communication link stability. These antennas improve antenna utilization efficiency by reconfiguring directional beams to the desired angle, and are therefore widely used in radar systems, satellite communications, vehicle communications, tracking systems, and more.

[0003] However, existing beam-switching or scanning antennas generally employ phased array antennas or beamforming network (BFN) based antennas for beam steering. However, phased array antennas inevitably require expensive transceiver components and complex radiating element design and arrangement. Furthermore, the unavoidable large size and complexity of beamforming networks limit their applications. To meet this need, many compact beam-guided antennas have been researched and reported over the past few decades, such as square loop antennas, quad-arm helical antennas, patch array antennas without beamforming networks, low-profile pattern reconfigurable antennas with short leads, and diode-loaded pattern reconfigurable antennas. With the development of 5G and 6G, broadband characteristics have become a fundamental requirement for modern wireless communication. However, most of the aforementioned antennas operate in narrowbands, typically less than 25% of their bandwidth. Moreover, existing beam-switching antennas offer limited beam-switching states, which may be insufficient for some communication systems requiring high beam accuracy.

[0004] Therefore, how to provide a compact beam-switching antenna with a wider overlap bandwidth and more switching states during multi-beam switching is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides a broadband two-dimensional eight-beam switchable ring magnetoelectric dipole array antenna and its design method to solve the problems existing in the background art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A broadband two-dimensional eight-beam switchable ring magnetoelectric dipole array antenna includes: a first four-beam element and a second four-beam element, which together form an eight-beam array antenna. The first four-beam element includes a first four-beam switchable ring magnetoelectric dipole array, a coaxial inner conductor metal pillar, a short-circuit pin, a dielectric substrate, a metal ground plane, and a feed port. The second four-beam element includes a second four-beam switchable ring magnetoelectric dipole array, a coaxial inner conductor metal pillar, a short-circuit pin, a dielectric substrate, a metal ground plane, and a feed port. The first four-beam switchable ring magnetoelectric dipole array and the second four-beam switchable ring magnetoelectric dipole array are on the same horizontal plane and disposed on the antenna. On a dielectric substrate, two dielectric substrates are connected together, and a metal ground plane is provided at the bottom end of the dielectric substrate; the first four-beam switchable annular magnetoelectric dipole array and the second four-beam switchable annular magnetoelectric dipole array are both clover-shaped and 45° apart; the short-circuit pin is provided at the top of the blade of the four-beam switchable annular magnetoelectric dipole array, passes through the four-beam switchable annular magnetoelectric dipole array and the dielectric substrate in sequence, and is connected to the metal ground plane; the coaxial inner conductor metal pillars are respectively provided at the junction of the blades of the same four-beam switchable annular magnetoelectric dipole array, and pass through the four-beam switchable annular magnetoelectric dipole array, the dielectric substrate and the metal ground plane in sequence, and are connected to the feed port.

[0008] Preferably, the dielectric substrates used in the first four-beam unit and the second four-beam unit are cuboid in shape, and both are chamfered along with the metal floor.

[0009] Preferably, a gap is provided between the metal floor corresponding to the first four-beam unit and the second four-beam unit.

[0010] Preferably, in the chamfering process, the right-angled side of the chamfer is 15mm long.

[0011] Preferably, the width of the gap is 2 mm.

[0012] Preferably, the dielectric substrate is made of F4BM320 material, has a dielectric constant of 3.2, and a dielectric loss of 0.0015.

[0013] A design method for a broadband two-dimensional eight-beam switchable ring magnetoelectric dipole array antenna includes:

[0014] S01: Determine the operating frequency band of the antenna, design a broadband four-beam switchable ring magnetoelectric dipole array of the corresponding size in the required frequency band, introduce four short-circuit pins, and use the magnetic current source mode to extend the bandwidth of the antenna.

[0015] S02: Keep the first four-beam switchable ring magnetoelectric dipole array unchanged, and add a second four-beam switchable ring magnetoelectric dipole array, which is 45 degrees out of phase with the first four-beam switchable ring magnetoelectric dipole array.

[0016] S03: In order to obtain a beam with higher directivity and lower sidelobes, a chamfered design is adopted for the dielectric substrate;

[0017] S04: Slotting the metal floor to improve isolation between the two multi-beam array ports.

[0018] As can be seen from the above technical solutions, compared with the prior art, the present invention discloses a broadband two-dimensional eight-beam switchable ring magnetoelectric dipole array antenna and its design method. By adding short-circuit pins to the ring four-leaf clover antenna to introduce a magnetic current source mode, the bandwidth of the antenna is expanded, thereby designing a broadband beam-switching array unit, solving the problem of narrow overlapping bandwidth. At the same time, the method of reconfigurable unit integration is used to expand the number of beams. This can increase the number of beams without significantly increasing the size of the antenna. Furthermore, the method of floor gaps is used to reduce the coupling between ports. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0020] Figure 1 is a perspective view of the broadband eight-beam switchable magnetoelectric dipole array antenna provided by the present invention.

[0021] Figure 2 is a top view of the broadband eight-beam switchable magnetoelectric dipole array antenna provided by the present invention.

[0022] Figure 3 is a bottom view of the broadband eight-beam switchable magnetoelectric dipole array antenna provided by the present invention.

[0023] Figure 4 is a schematic diagram of beam switching in eight states of the broadband eight-beam switchable magnetoelectric dipole array antenna provided by the present invention.

[0024] Figure 5 shows the reflection coefficients of each port of the broadband eight-beam switchable magnetoelectric dipole array antenna provided by the present invention with and without short-circuit pins, where a represents without short-circuit pins and b represents with short-circuit pins.

[0025] Figure 6 is a design flowchart of the broadband eight-beam switchable magnetoelectric dipole array antenna provided by the present invention.

[0026] Figure 7 is a schematic diagram of beam switching in eight states of the broadband eight-beam switchable magnetoelectric dipole array antenna provided by the present invention.

[0027] Figure 8 shows the simulated current at 5.8 GHz on the ground plane when the four-beam unit antenna provided by the present invention is designed with different side length chamfers on the dielectric substrate;

[0028] Figure 9 is a schematic diagram of the influence between each element and port in the two four-port elements provided by the present invention;

[0029] Figure 10 shows the selection of the floor width for the broadband eight-beam switchable magnetoelectric dipole array antenna provided by the present invention, where a is the Ce5 variation curve for different floor widths, and b is the |S| curve for different floor widths. 55 |Change curve;

[0030] Figure 11 shows the measured |S| of the broadband eight-beam switchable magnetoelectric dipole array antenna provided by the present invention. 11 |-|S 88 |Image;

[0031] Figure 12 shows a simulation of the broadband eight-beam switchable magnetoelectric dipole array antenna provided by the present invention. 11 |-|S 88 |Image;

[0032] Figure 13 is a simulation curve of the gain of the broadband eight-beam switchable magnetoelectric dipole array antenna provided by the present invention.

[0033] Figure 14 is a measured curve of the broadband eight-beam switchable magnetoelectric dipole array antenna provided by the present invention.

[0034] Figure 15 shows the simulated and measured radiation patterns of the broadband eight-beam switchable magnetoelectric dipole array antenna provided by the present invention in the plane phi = 45° when port 1 is excited at 4.75 GHz.

[0035] Figure 16 shows the simulated and measured radiation patterns of the broadband eight-beam switchable magnetoelectric dipole array antenna provided by the present invention in the plane phi = 45° when port 1 is excited at 5.2 GHz;

[0036] Figure 17 shows the simulated and measured radiation patterns of the broadband eight-beam switchable magnetoelectric dipole array antenna provided by the present invention in the plane phi = 45° when port 1 is excited at 5.65 GHz.

[0037] Figure 18 shows the simulated and measured radiation patterns of the broadband eight-beam switchable magnetoelectric dipole array antenna provided by the present invention in the plane phi = 45° when port 1 is excited at 6.1 GHz;

[0038] In the figure: 1 First four-beam switchable ring magnetoelectric dipole array; 2 Second four-beam switchable ring magnetoelectric dipole array; 3 Coaxial inner conductor metal pillar; 4 Short-circuit pin; 5 Dielectric substrate; 6 Gap; 7 Feed port; 8 Metal ground plane. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] This invention discloses a broadband two-dimensional eight-beam switchable ring magnetoelectric dipole array antenna, as shown in Figure 1. It includes a first four-beam unit and a second four-beam unit, which together form an eight-beam array antenna. The first four-beam unit includes a first four-beam switchable ring magnetoelectric dipole array 1, a coaxial inner conductor metal pillar 3, a short-circuit pin 4, a dielectric substrate 5, a metal ground plane 8, and a feed port 7. The second four-beam unit includes a second four-beam switchable ring magnetoelectric dipole array 2, a coaxial inner conductor metal pillar 3, a short-circuit pin 4, a dielectric substrate 5, a metal ground plane 8, and a feed port 7. The first four-beam switchable ring magnetoelectric dipole array 1 and the second four-beam switchable ring magnetoelectric dipole array 2... Column 2 is on the same horizontal plane and is set on dielectric substrate 5. The two dielectric substrates 5 are connected together, and a metal ground plate 8 is set at the bottom of the dielectric substrate 5. The first four-beam switchable annular magnetoelectric dipole array 1 and the second four-beam switchable annular magnetoelectric dipole array 2 are both clover-shaped and 45° apart. The short-circuit pin 4 is set at the top of the blade of the four-beam switchable annular magnetoelectric dipole array, passes through the four-beam switchable annular magnetoelectric dipole array and the dielectric substrate 5 in sequence, and is connected to the metal ground plate 8. The coaxial inner conductor metal pillar 3 is respectively set at the junction of the blade of the same four-beam switchable annular magnetoelectric dipole array, and passes through the four-beam switchable annular magnetoelectric dipole array, the dielectric substrate 5 and the metal ground plate 8 in sequence, and is connected to the feed port 7.

[0041] In one specific embodiment, there are eight feed ports 7. The first four-beam switchable ring magnetoelectric dipole array 1 can generate four tilted beams pointing at 45 degrees, 135 degrees, 225 degrees, and 315 degrees. Similarly, the second four-beam switchable ring magnetoelectric dipole array 2 can be regarded as the first four-beam switchable ring magnetoelectric dipole array 1 translated and rotated 45 degrees around the center, and can generate four tilted beams pointing at 0 degrees, 90 degrees, 180 degrees, and 270 degrees. The coaxial inner conductor metal pillar can feed the radio frequency signal into the array element to be excited in the ring array to obtain the tilted beam pointing to the desired beam. The short-circuit pin 4 is an introduced magnetic current short-circuit pin used to increase the bandwidth of the ring antenna array.

[0042] The top and bottom views of the antenna involved in this invention are shown in Figures 2 and 3. Figure 3 shows the naming of the eight ports as 7-1 to 7-8. When ports 7-5, 7-6, 7-7, and 7-8 are activated respectively, tilted beams pointing at 0 degrees, 90 degrees, 180 degrees, and 270 degrees can be generated. When ports 7-1, 7-2, 7-3, and 7-4 are activated respectively, tilted beams pointing at 45 degrees, 135 degrees, 225 degrees, and 315 degrees can be generated. In this way, by switching ports, eight radiation beams pointing in different azimuth planes can be generated, thereby covering users in different areas. The effect is shown in Figure 4.

[0043] Figure 5(a) and (b) show the reflection coefficients |S| of the eight ports of the antenna with and without the short-circuit pin 4. 11 |-|S 88As can be seen, the addition of the short-circuit pin introduces a new low-frequency mode, thereby extending the -10dB impedance bandwidth and enabling the design of a broadband four-beam switchable ring magnetoelectric dipole array, as shown in step 1 of Figure 6. Based on this, by rotating the four-beam magnetoelectric dipole array antenna 1 around its center by 45 degrees and then translating it, a broadband eight-beam magnetoelectric dipole array antenna can be obtained, as shown in step 2 of Figure 6. However, for a ring magnetoelectric dipole array antenna capable of generating four beams pointing at 45°, 135°, 225°, and 315°, if a cuboid dielectric substrate is still used, its radiation pattern will deteriorate. In this invention, the dielectric substrate of the array antenna element adopts a beveled cut design, resulting in a better radiation pattern. Taking the state of port 1 (7-1) with the mechanism (beam pointing phi = 45°) as an example, the two-dimensional radiation pattern in the phi = 45° plane when the chamfer changes at the 5.8GHz frequency point is shown in Figure 7. As shown in Figure 7, when the two right-angled sides of the chamfer are 15mm, a tilted beam with better gain and sidelobe level can be obtained. This is because the effect of a finite ground plane with different tilt angles on the multi-beam magnetoelectric dipole array is different. At 5.8GHz, as shown in Figure 8, the ground current distribution is more uniform when the right-angled sides of the chamfer are 15mm compared to other parameters. The final designed array antenna size is 100mm × 50mm × 8mm. Thus, the multi-beam switching array antenna not only achieves better radiation characteristics but is also lighter, making it more suitable for applications in lightweight wireless systems. Finally, we use a method of opening slots in the ground plane to optimize the isolation between the two multi-beam elements, as shown in step 4 of Figure 6.

[0044] In one specific embodiment, the dielectric substrate 5 used in the first four-beam unit and the second four-beam unit is rectangular in shape, and both the substrate and the metal ground plate 8 are chamfered.

[0045] In one specific embodiment, a gap 6 is provided between the metal floor 8 corresponding to the first four-beam unit and the second four-beam unit to improve the isolation between the ports.

[0046] Specifically, to improve the mutual influence between two multi-port components, this invention employs a floor gapping method to enhance the isolation between the components and ports. To further clarify this issue, this invention redefines a method for coupling between multi-port integrated networks. It is generally considered that the influence between ports 1 and 8 can be represented by |S... 18 |or|S 81| is used to characterize, however, for two multi-port elements, it is not enough to only look at the influence of one port on the other port; we should look at the influence of all ports of one multi-port element on the other port. Therefore, we define the influence of one multi-port element on a certain port of another element as a new coupling coefficient Cei (i = 1, 2, 3, ..., n). In this invention, n = 8. As a representative example, taking Figure 9 as an example, the normalized influence of element 1 on port 5 can be expressed as C e5 =(|S 15 |+|S 25 |+|S 35 |+|S 45 |) / 4;

[0047] Furthermore, if it is necessary to understand the sum of the normalized effects of one multi-port element on another multi-port element, it can be defined as the sum of the effects of all ports of one element on all ports of another element, and then averaged, defined as Coupling_ele12 = (C e5+ C e6+ C e7+ C e8 ) / 4; Coupling_ele21=(C e1+ C e2+ C e3+ C e4 ) / 4;

[0048] To investigate the effect of floor gaps on isolation, we selected port 5 (7-5) as the research object because it is closer to part 1 and more easily affected by element 1. Figure 10(a) shows the curves of Ce5 as a function of frequency when the floor width is selected for different values, and Figure 10(b) shows the curves of |S| when the floor width is selected for different values. 55 From this, we can see that the wider the gap, the smaller the in-band impact of element 1 on port 5. However, the gap width also affects the return loss of port 5. An excessively large gap width will cause the -10dB bandwidth of port 5 to narrow. Therefore, the wider the gap width is within a certain range, the better. Finally, as a compromise, the gap width is chosen to be 2mm in this invention.

[0049] In one specific embodiment, during the chamfering process, the length of the right-angled side of the chamfer is 15mm.

[0050] In one specific embodiment, the width of the gap 6 is 2 mm.

[0051] In one specific embodiment, the dielectric substrate 5 is made of F4BM320 material, has a dielectric constant of 3.2, and a dielectric loss of 0.0015.

[0052] A design method for a broadband two-dimensional eight-beam switchable ring magnetoelectric dipole array antenna, as shown in Figure 6, includes:

[0053] S01: Determine the operating frequency band of the antenna, design a broadband four-beam switchable ring magnetoelectric dipole array of the corresponding size in the required frequency band, introduce four short-circuit pins 4, and use the magnetic current source mode to extend the bandwidth of the antenna.

[0054] S02: Keep the first four-beam switchable ring magnetoelectric dipole array 1 unchanged, and add a second four-beam switchable ring magnetoelectric dipole array 2, which is 45 degrees out of phase with the first four-beam switchable ring magnetoelectric dipole array 1.

[0055] S03: In order to obtain a beam with higher directivity and lower sidelobes, the dielectric substrate 5 is designed with a chamfered corner.

[0056] S04: Add 8 slots to the metal floor to improve isolation between the two multi-beam array ports.

[0057] To validate the proposed antenna design, the proposed broadband eight-beam switchable array antenna was designed, fabricated, and measured. Manufacturing was performed using standard multilayer printed circuit board (PCB) technology.

[0058] Figures 11 and 12 show the simulated and measured |S11|-|S88| of the broadband eight-beam switchable magnetoelectric dipole array antenna involved in this invention, respectively. It can be seen that the simulation and measurement results are in good agreement. When the basic reflection coefficient is less than -10dB, the common simulation bandwidth of the eight states is 32.5% (4.44GHz~6.16GHz), and the measured bandwidth is 29.9% (4.52GHz~6.11GHz).

[0059] Figures 13 and 14 show the simulated and measured gain curves of the broadband eight-beam switchable magnetoelectric dipole array antenna involved in this invention, respectively. The simulation results agree well with the experimental results, and the error between the simulation results and the actual measured values ​​is less than 2 dB. The peak gains of the simulation and measured results are 8.25 dBi and 8.02 dBi, respectively, verifying the effectiveness of the antenna.

[0060] Figures 15-18 show the simulated and measured radiation patterns of the broadband eight-beam switchable magnetoelectric dipole array antenna of the present invention in the plane phi = 45° when port 1 is excited at 4.75, 5.2, 5.65 and 6.1 GHz, respectively. It can be seen that the simulation and the measured results are in good agreement.

[0061] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section.

[0062] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A broadband two-dimensional eight-beam switchable annular magnetoelectric dipole array antenna, characterized in that, include: A first four-beam unit and a second four-beam unit, together forming an eight-beam array antenna; the first four-beam unit includes a first four-beam switchable ring magnetoelectric dipole array, a coaxial inner conductor metal pillar, a short-circuit pin, a dielectric substrate, a metal ground plane, and a feed port; the second four-beam unit includes a second four-beam switchable ring magnetoelectric dipole array, a coaxial inner conductor metal pillar, a short-circuit pin, a dielectric substrate, a metal ground plane, and a feed port; the first four-beam switchable ring magnetoelectric dipole array and the second four-beam unit... Four-beam switchable annular magnetoelectric dipole arrays are located on the same horizontal plane and disposed on the dielectric substrate. The two dielectric substrates are connected together, and the bottom end of the dielectric substrate is provided with the metal ground plate. The first four-beam switchable annular magnetoelectric dipole array and the second four-beam switchable annular magnetoelectric dipole array are both clover-shaped and 45° apart. The short-circuit pin is disposed at the top of the blade of the four-beam switchable annular magnetoelectric dipole array, passes through the four-beam switchable annular magnetoelectric dipole array and the dielectric substrate in sequence, and is connected to the metal ground plate. The coaxial inner conductor metal pillars are respectively disposed at the junction of the blades of the same four-beam switchable annular magnetoelectric dipole array, and sequentially penetrate the four-beam switchable annular magnetoelectric dipole array, the dielectric substrate and the metal ground plane, and are connected to the feed port.

2. The wideband two-dimensional eight-beam switchable annular magnetoelectric dipole array antenna according to claim 1, characterized in that, The dielectric substrates used in the first four-beam unit and the second four-beam unit are cuboid in shape, and both are chamfered along with the metal floor.

3. The wideband two-dimensional eight-beam switchable annular magnetoelectric dipole array antenna according to claim 1, characterized in that, A gap is provided between the metal floor corresponding to the first four-beam unit and the second four-beam unit.

4. The wideband two-dimensional eight-beam switchable annular magnetoelectric dipole array antenna according to claim 2, characterized in that, In the chamfering process, the length of the right-angled side of the chamfer is 15mm.

5. The wideband two-dimensional eight-beam switchable annular magnetoelectric dipole array antenna according to claim 3, characterized in that, The width of the gap is 2mm.

6. The wideband two-dimensional eight-beam switchable annular magnetoelectric dipole array antenna according to claim 1, characterized in that, The dielectric substrate is made of F4BM320 material, with a dielectric constant of 3.2 and a dielectric loss of 0.0015.

7. A method for designing a wideband two-dimensional eight-beam switchable loop-shaped magneto-electric dipole array antenna, applied to the wideband two-dimensional eight-beam switchable loop-shaped magneto-electric dipole array antenna of any one of claims 1-6, characterized in that, include: S01: Determine the operating frequency band of the antenna, design a broadband four-beam switchable ring magnetoelectric dipole array of the corresponding size in the required frequency band, introduce four short-circuit pins, and use the magnetic current source mode to extend the bandwidth of the antenna. S02: Keep the first four-beam switchable ring magnetoelectric dipole array unchanged, and add a second four-beam switchable ring magnetoelectric dipole array, which is 45 degrees out of phase with the first four-beam switchable ring magnetoelectric dipole array. S03: In order to obtain a beam with higher directivity and lower sidelobes, a chamfered design is adopted for the dielectric substrate; S04: Slotting the metal floor to improve isolation between the two multi-beam array ports.

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