A low profile reconfigurable antenna

Abstract

The present invention aims to provide a low-profile reconfigurable antenna, which belongs to the technical field of reconfigurable antennas. The design main body of the antenna is a dielectric disk loaded with a metal short circuit, a circular radiation patch is arranged on the upper surface of the dielectric disk, four square annular gaps are arranged on the radiation patch, a circular metal ground is arranged on the lower surface of the dielectric disk, a rectangular annular gap is arranged on the metal ground, a PIN diode is loaded on the gap, and the antenna pattern has a reconfigurable characteristic through the conduction and disconnection of the diode. At the same time, the dielectric disk is surrounded by a metal disk cavity, so that the overall structure of the antenna is stable, and the cross-sectional height of the entire antenna is only 0.125λ.

Description

Technical Field

[0001] The invention belongs to the technical field of reconfigurable antennas, and in particular relates to a low-profile directional pattern reconfigurable antenna. Background Art

[0002] At present, modern wireless communication technology is developing in the direction of multi-function and large capacity. Antennas, as an important part of wireless communication systems, are subject to increasingly higher requirements. Reconfigurable antennas reduce the volume and weight of communication systems, making their structures simpler and more compact, which is conducive to integration into current wireless communication equipment. According to different reconfigurable targets, reconfigurable antennas can be divided into frequency reconfigurable, polarization reconfigurable, and pattern reconfigurable antennas. Among them, pattern reconfigurable antennas have the advantages of flexible beam control and beam reconfigurability, which can effectively reduce the electronic interference of incident waves, improve the information receiving capability, and enhance the security of communication. Therefore, the research on pattern reconfigurable antennas has practical significance.

[0003] There are three main ways to realize the reconfigurable antenna with directivity pattern: the first is the mechanical control method, in which the antenna can change the structure required by the design by means of mechanical operation, thereby realizing the change of radiation direction; the second is the material property control method, by selecting and adding special materials such as liquid metal and water to change the size and shape of the antenna, and using the deformable characteristics to realize reconfiguration, the working state of the antenna can change with the deformation of the special material; the third is the electrical control method, loading variable capacitors, PIN tubes and other switching elements at the appropriate position of the antenna, and changing the current distribution of the antenna by controlling these adjustable devices, thereby realizing the switching of different performances. Among them, loading PIN diodes has become a research hotspot because of its simple and easy operation. In addition to the reconfigurable directivity pattern, antennas are now developing towards miniaturization in many fields such as drones. The lower the profile height, the higher the utilization rate of space. Wang Wenting et al. (Wang Wenting, Yin Xiaolei, Yan Denghui, et al. Design of broadband directional pattern reconfigurable circular monopole antenna [J]. Ship Electronic Engineering, 2024, 44(07): 68-71.) proposed a new type of printed Yagi structure reconfigurable antenna. The antenna adjusts the antenna direction by adjusting the conduction state of the PIN diode in the parasitic patch structure, so that it can be adjusted in S 11 It works from 3GHz to 4GHz with a power factor of less than -10dB, but its profile height is relatively high, about 0.5λ; Qin Shichuan (Qin Shichuan, Li Rongqiang. Design of a directional pattern reconfigurable monopole antenna [J]. Journal of Chengdu University of Information Technology, 2024, 39(01): 18-22.) proposed a miniaturized and highly efficient directional pattern reconfigurable antenna. By controlling the on and off states of the two PIN diodes on the parasitic strip, the antenna can achieve 3 directional pattern reconstruction modes with different beam pointing directions, but it cannot achieve 360° directional scanning of the antenna.

[0004] Therefore, how to design a reconfigurable antenna so that it has a 360° directional pattern scanning while also having a low profile height has become a key research direction. Summary of the invention

[0005] In view of the problems existing in the background technology, the purpose of the present invention is to provide a low-profile reconfigurable antenna. The design body of the antenna is a dielectric disk loaded with a metal short circuit, a circular radiation patch is arranged on the upper surface of the dielectric disk, four square annular gaps are arranged on the radiation patch, a circular metal ground is arranged on the lower surface of the dielectric disk, a rectangular annular gap is arranged on the metal ground, a PIN diode is loaded on the gap, and the antenna pattern has a reconfigurable characteristic through the conduction and disconnection of the diode. At the same time, the dielectric disk is surrounded by a metal disk cavity, so that the overall structure of the antenna is stable, and the cross-sectional height of the entire antenna is only 0.125λ.

[0006] To achieve the above object, the technical solution of the present invention is as follows:

[0007] A low-profile reconfigurable antenna comprises a metal disc cavity 1, a dielectric disc 2, a circular radiation patch 3, a metal ground 4 and a coaxial line 5; wherein the metal disc cavity is stepped, and is composed of a first disc, a second disc and a third disc, all of which are annular; the outer diameter of the first disc is greater than the outer diameter of the second disc; the inner diameter of the first disc is equal to the inner diameter of the second disc and smaller than the outer diameter of the second disc; the outer diameter of the second disc is equal to the outer diameter of the third disc; and the inner diameter of the second disc is greater than the inner diameter of the third disc;

[0008] The diameter of the dielectric disk is equal to the inner diameter of the first disk, and the height is equal to the height of the first disk, and the dielectric disk is fixedly arranged in the metal disk cavity; a circular radiation patch is arranged on the upper surface of the dielectric disk, and a circular metal ground having the same size as the dielectric disk is arranged on the lower surface; the center of the dielectric disk, the center of the circular radiation patch, the center of the metal ground and the center of the metal disk cavity coincide;

[0009] A plurality of first square annular gaps 3-1 are evenly provided along the circumference of the circular radiation patch, and second rectangular annular gaps 4-1 equal in number to the first square annular gaps 3-1 are provided on the metal ground; wherein a PIN diode is provided on each second rectangular annular gap, and the PIN diode connects the metal 4-2 inside the second rectangular annular gap and the metal outside the second rectangular annular gap; the centers of the first square annular gap and the second rectangular annular gap are on the same vertical line, and all the second rectangular annular gaps are located inside the first square annular gap;

[0010] A plurality of metal short-circuit posts 2-1 penetrating the dielectric disc are evenly arranged along the circumference thereof, wherein four metal short-circuit posts are arranged at the center of the first square annular gap, and the metal in the first square annular gap and the metal in the second square annular gap are connected through the metal short-circuit posts;

[0011] The inner conductor of the coaxial line passes through the dielectric disk and is connected to the circular radiation patch, and the outer conductor is connected to the circular metal ground for antenna radiation feeding.

[0012] Furthermore, the number of the metal short-circuit posts will affect the resonant frequency of the antenna, and the number is preferably 4, 8, 12, and 16.

[0013] Furthermore, the size of the first square annular slot affects the gain of the antenna pattern, and the outer side length of the annular slot is 5.5-6.4 mm, and the slot width is 0.1-0.9 mm.

[0014] Furthermore, the number of the first square annular slots 3 - 1 is preferably 4, and the first square annular slots 3 - 1 cut the current on the circular radiation patch; if the number is too large or too small, the bandwidth and antenna gain of the antenna will be reduced.

[0015] Furthermore, the diameter of the circular radiation patch 3 should be smaller than the diameter of the dielectric disk 2 , so that the circular radiation patch 3 does not contact the metal disk cavity 1 .

[0016] The mechanism of the present invention is as follows: a metal short-circuit column is loaded in a dielectric disk. The introduction of the metal short-circuit column is equivalent to the introduction of a parallel inductor between the metal ground and the radiation patch. The inductor increases the inductive reactance of the antenna, thereby reducing the resonant frequency of the antenna, and then reducing the cross-sectional height of the antenna, thereby achieving the purpose of miniaturization and low profile; at the same time, by designing a specific radiation patch and coordinating the on and off of the PIN diode, the antenna can achieve 360° omnidirectional scanning.

[0017] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0018] 1. The antenna of the present invention has a lower profile height while realizing reconfigurable radiation pattern, and the profile height of the entire antenna can be as low as 0125λ.

[0019] 2. The antenna of the present invention controls the on / off state of the PIN diode through direct current feeding, thereby controlling the antenna's directional pattern, and can achieve 360° full coverage of the antenna directional pattern, and the implementation means are simple.

[0020] 3. The antenna structure of the present invention has strong stability, small size and light weight, and is suitable for communication systems such as drones. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is the overall structural diagram of the low-profile directional pattern reconfigurable antenna of the present invention.

[0022] Figure 2 It is a schematic structural diagram of the metal disk cavity in the low-profile directional pattern reconfigurable antenna of the present invention.

[0023] Figure 3 It is a side view of the metal disk cavity in the low-profile directional pattern reconfigurable antenna of the present invention.

[0024] Figure 4 It is a schematic diagram of the overall structure of the low-profile directional pattern reconfigurable antenna of the present invention excluding the metal disk cavity.

[0025] Figure 5 This is a top view of the dielectric disk in the low-profile directional pattern reconfigurable antenna of the present invention.

[0026] Figure 6 This is a bottom view of the dielectric disk in the low-profile directional pattern reconfigurable antenna of the present invention.

[0027] Figure 7 When all four diodes of the low-profile directional pattern reconfigurable antenna of Embodiment 1 of the present invention are turned on, S 11 Parameter curve graph.

[0028] Figure 8 This is the directional pattern when all four diodes of the low-profile directional pattern reconfigurable antenna according to Embodiment 1 of the present invention are turned on.

[0029] Fig. 9 This is the directional pattern when the first PIN diode 4-3 and the second PIN diode 4-4 in the low-profile directional pattern reconfigurable antenna of the present invention are turned on, and the third PIN diode 4-5 and the fourth PIN diode 4-6 are turned off.

[0030] Fig.10 is the S of the reconfigurable antenna of the present invention and the reconfigurable antenna of comparative example 1 11 Parameter comparison chart.

[0031] Fig.11 This is a comparison chart of the directional pattern gain results of the reconfigurable antenna of the present invention and the reconfigurable antenna of comparative example 1.

[0032] Fig.12 is the S of the reconfigurable antenna of the present invention and the reconfigurable antenna of comparative example 2 11 Parameter comparison chart.

[0033] Fig.13 This is a comparison chart of the directional pattern gain results of the reconfigurable antenna of the present invention and the reconfigurable antenna of comparative example 2.

[0034] Figure numerals: 1 is a metal disc cavity, 2 is a dielectric disc, 3 is a circular radiation patch, 4 is a metal ground, 5 is a coaxial line, 2-1 is a metal short-circuit column, 3-1 is a first square ring gap, 4-1 is a second rectangular ring gap, 4-2 is the inner metal of the second rectangular ring gap, 4-3 is a first PIN diode, 4-4 is a second PIN diode, 4-5 is a third PIN diode, and 4-6 is a fourth PIN diode. DETAILED DESCRIPTION

[0035] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with the implementation modes and the accompanying drawings.

[0036] A low-profile reconfigurable antenna, the overall structure diagram of which is shown in Figure 1 As shown, it includes a metal disc cavity 1, a dielectric disc 2, a circular radiation patch 3, a metal ground 4 and a coaxial line 5; wherein the structural schematic diagram of the metal disc cavity is as shown Figure 2 As shown, the side view is Figure 3 As shown, the whole is in a stepped shape, and is composed of a first disk, a second disk, and a third disk, all of which are annular. The outer diameter of the first disk is larger than the outer diameter of the second disk, the inner diameter of the first disk is equal to the inner diameter of the second disk and smaller than the outer diameter of the second disk, the outer diameter of the second disk is equal to the outer diameter of the third disk, and the inner diameter of the second disk is larger than the inner diameter of the third disk;

[0037] The diameter of the medium disc is equal to the inner diameter of the first disc, and the height is equal to the height of the first disc, and the medium disc is fixedly arranged in the metal disc cavity;

[0038] The overall structure diagram excluding the metal disc cavity is as follows Figure 4 The top view of the dielectric disk is shown in Figure 5 As shown, the bottom view of the dielectric disk is as follows Figure 6 As shown, a circular radiation patch 3 is arranged on the upper surface of the dielectric disk 2, and a circular metal ground 4 having the same size as the dielectric disk is arranged on the lower surface; the center of the dielectric disk 2, the center of the circular radiation patch 3, the center of the metal ground 4 and the center of the metal disk cavity 1 coincide with each other;

[0039] A plurality of first square annular gaps 3-1 are evenly provided along the circumference of the circular radiation patch 3, and a number of second rectangular annular gaps 4-1 equal to the number of the first square annular gaps 3-1 are provided on the metal ground 4; wherein a PIN diode is provided on each second rectangular annular gap, and the PIN diode connects the metal 4-2 inside the second rectangular annular gap and the metal outside the second rectangular annular gap; the centers of the first square annular gap 3-1 and the second rectangular annular gap 4-1 are on the same vertical line, and all the second rectangular annular gaps are located inside the first square annular gap;

[0040] A plurality of metal short-circuit posts 2-1 penetrating the dielectric disc are evenly arranged along the circumference thereof, wherein four metal short-circuit posts are arranged at the center of the first square annular gap 3-1, and the metal in the first square annular gap and the metal in the second square annular gap are connected through the metal short-circuit posts 2-1;

[0041] The inner conductor of the coaxial line 5 passes through the dielectric disk 2 and is connected to the circular radiation patch 3, and the outer conductor is connected to the circular metal ground 4, which is used for antenna radiation feeding. Example 1

[0042] The structure of the metal disc cavity 1 is in a stepped shape, and is composed of a first disc, a second disc and a third disc, all of which are annular; the first disc has an outer radius of 66 mm, an inner radius of 33 mm and a thickness of 3 mm, the second disc has an outer radius of 36 mm, an inner radius of 33 mm and a thickness of 1.5 mm, and the third disc has an outer radius of 36 mm, an inner radius of 30 mm and a thickness of 3 mm;

[0043] The circular dielectric plate is made of Rogers 5880, with a relative dielectric constant of 2.2, a radius of 33 mm, and a height of 3 mm. Sixteen metal short-circuit posts 2-1 are loaded inside the plate, with a radius of 0.3 mm and a height of 3 mm. A coaxial line is used for feeding at the bottom center of the dielectric disc 2.

[0044] The radius of the circular radiation patch set on the upper surface of the dielectric disk is 20.9mm. Four first square ring gaps 3-1 are evenly opened along the circumference of the circular radiation patch. The outer side length of the square ring gap is 6.4mm, and the inner side length is 6mm; the gaps are used to cut the DC bias current.

[0045] A circular metal ground 4 is arranged on the lower surface of the dielectric disk, and its radius is 33mm; four second rectangular annular gaps 4-1 are arranged on the metal ground, and the long side of the outer side of the rectangular annular gap is 3.5mm and the wide side is 1.9mm, and the long side of the inner side is 2.5mm and the wide side is 0.9mm; a PIN diode is arranged on the rectangular annular gap, and the change of the antenna radiation pattern is controlled by controlling the conduction and disconnection of the diode.

[0046] Comparative Example 1

[0047] The antenna is arranged according to the structure of Example 1, and only the first square annular gap is adjusted to a rectangular annular gap, that is, the inner side length is adjusted from the original 6 mm to 5 mm in length and 4 mm in width, and the rest remains unchanged.

[0048] Comparative Example 2

[0049] The antenna is arranged according to the structure of Embodiment 1, and only the number of the first square annular slots 3-1 and the second rectangular annular slots is adjusted to eight, while the rest remain unchanged.

[0050] The overall structure of the antenna is simulated and optimized in the electromagnetic simulation software Ansys HFSS, and the simulation result diagram of the low-profile directional pattern reconfigurable antenna is obtained. Figure 7 When all four diodes of the low-profile directional pattern reconfigurable antenna of Embodiment 1 of the present invention are turned on, S 11 Parameter curve diagram, where S 11The parameter is the reflection coefficient. When all four diodes are turned on, it can be seen from the figure that the center frequency of the antenna is 5.2GHz and the bandwidth is about 0.7GHz. The antenna H-plane radiation pattern results are as follows Figure 8 As shown in the figure, it can be seen that when all four diodes are turned on, the antenna's directional pattern is omnidirectional. By changing the on and off of the diodes, the antenna's directional pattern can be changed. When the first PIN diode 4-3 and the second PIN diode 4-4 are turned on, and the third PIN diode 4-5 and the fourth PIN diode 4-6 are turned off, the antenna H-plane directional pattern at the center frequency of 5.2 GHz is as follows Fig. 9 The reconfigurable antenna of the present invention can achieve full coverage of 360° of the antenna pattern.

[0051] Fig.10 and Fig.11 are respectively the S of the reconfigurable antenna of Embodiment 1 of the present invention and the reconfigurable antenna of Comparative Example 1 11 Parameter and pattern gain result comparison diagram. As can be seen from the figure, after the square ring gap is replaced by the rectangular ring gap, when the second PIN diode 4-4 and the third PIN diode 4-5 are turned on, and the first PIN diode 4-3 and the fourth PIN diode 4-6 are turned off, it can be seen from the figure that its bandwidth is seriously affected, from the original 0.7GHz to 0.2GHz bandwidth, and the gain is also reduced by about one dB.

[0052] Fig.12 and Fig.13 is the S of the reconfigurable antenna of embodiment 1 of the present invention and the reconfigurable antenna of comparative example 2 11 Comparison of parameters and pattern gain results. As can be seen from the figure, after increasing the number of square patches, when all diodes are turned on, the gain and bandwidth of the antenna will decrease.

[0053] The above description is only a specific implementation mode of the present invention. Any feature disclosed in this specification, unless otherwise stated, can be replaced by other alternative features that are equivalent or have similar purposes; all the disclosed features, or all the steps in the methods or processes, except for mutually exclusive features and / or steps, can be combined in any way.

Claims

1. A low-profile reconfigurable antenna, characterized in that: It comprises a metal disc cavity, a dielectric disc, a circular radiation patch, a metal ground and a coaxial line; wherein the metal disc cavity is in a stepped shape, and is composed of a first disc, a second disc and a third disc which are connected in sequence and are all in annular shapes, the outer diameter of the first disc is larger than the outer diameter of the second disc, the inner diameter of the first disc is equal to the inner diameter of the second disc and smaller than the outer diameter of the second disc, the outer diameter of the second disc is equal to the outer diameter of the third disc, and the inner diameter of the second disc is larger than the inner diameter of the third disc; The diameter of the dielectric disk is equal to the inner diameter of the first disk, and the height is equal to the height of the first disk, and the dielectric disk is fixedly arranged in the metal disk cavity; a circular radiation patch is arranged on the upper surface of the dielectric disk, and a circular metal ground having the same size as the dielectric disk is arranged on the lower surface; the center of the dielectric disk, the center of the circular radiation patch, the center of the metal ground and the center of the metal disk cavity coincide; A plurality of first square annular gaps are evenly provided along the circumference of the circular radiation patch, and second rectangular annular gaps equal in number to the first square annular gaps are provided on the metal ground; wherein a PIN diode is provided on each second rectangular annular gap, and the PIN diode connects the metal inside the second rectangular annular gap and the metal outside the second rectangular annular gap; and the centers of the first square annular gap and the second rectangular annular gap are on the same vertical line; A plurality of metal short-circuit posts are evenly arranged along the circumference of the dielectric disc and penetrate the dielectric disc, wherein four metal short-circuit posts are arranged at the center of the first square annular gap, and the metal in the first square annular gap and the metal in the second square annular gap are connected through the metal short-circuit posts; The inner conductor of the coaxial line passes through the dielectric disk and is connected to the circular radiation patch, and the outer conductor is connected to the circular metal ground for antenna radiation feeding.

2. The low-profile reconfigurable antenna according to claim 1, characterized in that: The number of metal shorting posts is 4, 8, 12 or 16.

3. The low-profile reconfigurable antenna according to claim 1, characterized in that: The outer side length of the first square annular gap is 5.5-6.4 mm, and the gap width is 0.1-0.9 mm.

4. The low-profile reconfigurable antenna according to claim 1, characterized in that: The number of the first square annular gaps is 4, and the first square annular gaps cut the current on the circular radiation patch.

5. The low-profile reconfigurable antenna according to claim 1, characterized in that: The diameter of the circular radiating patch is smaller than the diameter of the dielectric disk.

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