A hexagonal multi-frequency microstrip antenna combined with symmetrical split-ring slot and L-shaped coupling branch

Abstract

The application discloses a kind of symmetric split ring slot and L-shaped coupling branch combined hexagonal multi-frequency microstrip antenna, which can be applied to 5G mobile communication system;The antenna is composed of dielectric substrate, radiation patch and ground plate;Two split ring slot structures symmetric about the central axis of the patch are introduced in the upper half of the radiation patch, and two L-shaped coupling branches are added about the central axis of the feed line;The antenna uses embedded feed-in form, and the feed-in is inserted into the internal radiation patch;The antenna has simple structure, easy to process, resonant frequency is convenient to adjust, and has good passband matching characteristics;The application is designed to work in 28GHz, 37.5GHz, 44.5GHz and 50.5GHz frequency bands, and is suitable for 5G millimeter wave communication.

Description

Technical Field

[0001] This invention patent belongs to the field of wireless communication and designs a hexagonal multi-frequency microstrip antenna that combines symmetrical split-ring slotting with L-shaped coupling branches. Background Technology

[0002] With the explosive growth in the number of communication devices today, limited spectrum resources are extremely valuable. Meeting the needs of different fields across multiple frequency bands and maximizing frequency reuse is a persistent research topic in the field of wireless communication, and it's also one of the goals of multi-band antenna operation. Currently, with the deployment of 5G, various communication systems are deployed in the Sub-6GHz band, leading to spectrum congestion in the FR1 band. Therefore, research in wireless communication is increasingly shifting towards the millimeter-wave band. Antennas should be able to operate in multiple frequency bands, which can significantly reduce the number of modules required, shrink device size, and facilitate miniaturization.

[0003] In multi-frequency design, slot loading and multi-branch structures are commonly used. Slot loading of the radiating patch is simple, produces a small antenna, and is suitable for mass production. Slots can extend the current path to achieve multiple resonant points, but the gain is usually low. Multi-branch structures are more effective in two frequency bands. Parasitic branch structures are equivalent to adding capacitive-inductive coupling elements to the structure to achieve matching in the required frequency band, changing the current path to introduce new resonant frequencies and achieve multi-frequency operation. When there are more than three frequency bands or more than three branches of different lengths, the interference between branches increases, and the branches cause the performance of the antenna in each frequency band to deteriorate.

[0004] A hexagonal multi-frequency microstrip antenna combining symmetrical split-ring slotting and L-shaped coupling branches is proposed. By combining parasitic branching and slot loading, it achieves good matching performance in the four required frequency bands and optimizes antenna performance at high frequencies. Summary of the Invention

[0005] The purpose of this invention is to propose a hexagonal multi-frequency microstrip antenna that combines symmetrical split-ring slotting with L-shaped coupling branches. It achieves multi-frequency operation by combining slot loading and coupling branches. Furthermore, by adjusting the size and position of the split-ring slot and the length of the L-shaped branch, the four center frequencies can be adjusted to achieve multi-frequency operation.

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

[0007] A hexagonal multi-frequency microstrip antenna combining symmetrical split ring slotting and L-shaped coupling branches is structurally composed of three parts from top to bottom: a first layer of metal sheet (1), a second layer of dielectric substrate (2), and a third layer of metal sheet (3).

[0008] Furthermore, the first metal sheet (1) of a hexagonal multi-frequency microstrip antenna combining symmetrical split-ring slots and L-shaped coupling branches is composed of a radiating structure and a transmission structure; the radiating structure is formed by etching symmetrically distributed split-ring slots (103) and split-ring slots (104), as well as L-shaped metal lines (105) and L-shaped metal lines (106) in the hexagonal metal sheet (101); the transmission structure is composed of a rectangular metal sheet (102), which is connected to the radiating structure by an embedded feed to provide excitation to the radiating structure. The embedded feed can reduce the input impedance and adjust the input impedance to 50 ohms;

[0009] Furthermore, the second dielectric substrate (2) is made of Rogers RO3003 material, with a dielectric constant ε r =3.0, the thickness of the dielectric substrate is 0.25mm, and the length and width are 17.0mm×16.0mm; the first metal sheet (1) is on the top layer of the second dielectric substrate (2) and is used for the excitation and radiation of the microstrip antenna; the third metal sheet (3) is on the bottom layer of the second dielectric substrate (2), with the same length and width as the second dielectric substrate (2), and is used as a defect-free metal plate for grounding;

[0010] Furthermore, by loading the cracked ring groove (103) and cracked ring groove (104), the current distribution on the hexagonal metal sheet is changed, the current path is enriched, the resonance point is increased, and the electromagnetic field radiates outward along its edge. Its perimeter is close to the resonance wavelength λ. At the same time, the cracked ring groove can reduce the imaginary part of the input impedance, which is beneficial to achieving impedance matching.

[0011] Furthermore, the L-shaped metal wire (105) and L-shaped metal wire (106) change the current path and reduce the imaginary part of the input impedance by means of coupling feeding, thereby introducing a new resonant point. The length of the L-shaped metal wire (105) and L-shaped metal wire (106) is slightly greater than λ / 4.

[0012] Furthermore, the microstrip antenna has dimensions of 17mm × 16mm × 0.32mm and employs a combination of slot loading and coupling branching to achieve multi-frequency operation. The frequency range with return loss below -10dB is 27.3-27.9GHz, 37.4-37.9GHz, 44-44.8GHz, and 50.1-52.1GHz. The gain is 7.2dBi at 27.6GHz, 8.1dBi at 37.6GHz, 8.9dBi at 44.4GHz, and 7.5dBi at 50.7GHz.

[0013] Compared with the prior art, the present invention has the following advantages:

[0014] 1. The present invention proposes a hexagonal multi-frequency microstrip antenna that combines symmetrical split ring slotting with L-shaped coupling branches. It has the characteristic of multi-frequency operation. By combining split ring slot loading with L-shaped coupling branches, the current distribution in the metal sheet is changed, the current path on the metal sheet is enriched, and a new resonant frequency is introduced, thereby realizing multi-frequency operation. At the same time, the slot loading reduces the imaginary part of the input impedance, which is beneficial to achieving impedance matching in the required frequency band.

[0015] 2. The present invention proposes a hexagonal multi-frequency microstrip antenna that combines symmetrical split-ring slotting with L-shaped coupling branches. It adopts an embedded feeding method, which effectively avoids the high impedance caused by direct feeding.

[0016] 3. The present invention proposes a hexagonal multi-frequency microstrip antenna that combines symmetrical split-ring slotting with L-shaped coupling branches, with four adjustable center frequencies: the resonant frequency can be adjusted by adjusting the size of the radiating patch, the size and position of the split-ring slot, and the size of the L-shaped coupling branch to achieve good impedance matching. Attached Figure Description

[0017] Figure 1 This invention relates to the overall structure of a hexagonal multi-frequency microstrip antenna that combines symmetrical split-ring slotting with L-shaped coupling branches.

[0018] Figure 2 This invention relates to a patch structure for a hexagonal multi-frequency microstrip antenna that combines symmetrical split-ring slotting with L-shaped coupling branches.

[0019] Figure 3 The reflection coefficient of the hexagonal multi-frequency microstrip antenna combining symmetrical split-ring slotting and L-shaped coupling branches of this invention.

[0020] Figure 4 The voltage standing wave ratio (VSWR) of the hexagonal multi-frequency microstrip antenna combining symmetrical split-ring slotting and L-shaped coupling branches of this invention.

[0021] Figure 5 The radiation pattern of the hexagonal multi-frequency microstrip antenna at 27.6 GHz, which combines symmetrical split-ring slotting with L-shaped coupling branches according to the present invention.

[0022] Figure 6 The radiation pattern of the hexagonal multi-frequency microstrip antenna at 37.6 GHz, which combines symmetrical split-ring slotting with L-shaped coupling branches according to the present invention.

[0023] Figure 7 The radiation pattern of the hexagonal multi-frequency microstrip antenna at 44.4 GHz, which combines symmetrical split-ring slotting with L-shaped coupling branches according to the present invention.

[0024] Figure 8 The radiation pattern of the hexagonal multi-frequency microstrip antenna combining symmetrical split-ring slotting and L-shaped coupling branches of this invention at 50.7 GHz. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings.

[0026] See Figure 1 As shown in the overall structural diagram, a hexagonal multi-frequency microstrip antenna combining symmetrical split-ring slots and L-shaped coupling branches consists of a radiating structure and a transmission structure. From top to bottom, it consists of three parts: a first layer metal sheet (1), a second layer dielectric substrate (2), and a third layer metal sheet (3). The first layer metal sheet (1) is on the top layer of the second layer dielectric substrate (2) and is used for the excitation and radiation of the microstrip antenna. The third layer metal sheet (3) is on the bottom layer of the second layer dielectric substrate (2) and its size is the same as that of the second layer dielectric substrate (2), which is a defect-free ground plane. The radiating structure is formed by etching symmetrically distributed split-ring slots (103) and split-ring slots (104) and symmetrically distributed L-shaped metal lines (105) and L-shaped metal lines (106) in the hexagonal metal sheet (101). The side length d of the split-ring slots (103) and (104) is 0.7 mm, the slot width w1 is 0.1 mm, and the center distance yc between the two slots is 0. 5mm, by loading a cracked ring groove, the current distribution on the hexagonal metal sheet can be changed, which can increase the resonance point. The electromagnetic field radiates outward along its edge. Its perimeter is close to the resonance wavelength λ. At the same time, the cracked ring groove can reduce the imaginary part of the input impedance, which is beneficial to achieving impedance matching. Among them, the L-shaped metal lines (105) and L-shaped metal lines (106) symmetrically distributed on both sides of the rectangular metal sheet (102) change the current path and reduce the imaginary part of the input impedance through coupling branches, thereby introducing a new resonance point. The length of the L-shaped coupling branch is slightly greater than λ / 4. The transmission structure is composed of a rectangular metal sheet (102) with a size of 10.3mm×0.54mm. It adopts embedded feeding with a feeding depth Li of 1.3mm and a width wi of 0.3mm to avoid the high impedance caused by direct feeding, which is beneficial to impedance matching. Its input impedance is set to 50 ohms. The second layer dielectric substrate (2) is made of Rogers RO3003 material with a dielectric constant ε. r =3.0, the dielectric substrate thickness is 0.25mm, and the length and width are 17.0mm×16.0mm.

[0027] In this embodiment, a hexagonal multi-frequency microstrip antenna patch structure combining symmetrical split-ring slotting and L-shaped coupling branches is described below. Figure 2 The dimensions are shown in Table 1:

[0028] Table 1. Parameter settings for a hexagonal multi-frequency microstrip antenna combining symmetrical split-ring slotting and L-shaped coupling branches.

[0029]

[0030] Figure 3The study presents the reflection coefficient curve of a hexagonal multi-frequency microstrip antenna combining symmetrical split-ring slotting and L-shaped coupling branches, as a function of frequency. The four-band antenna exhibits return loss less than -10dB in the 27.3-27.9GHz, 37.4-37.9GHz, 44-44.8GHz, and 50.1-52.1GHz frequency bands, and the return loss at 27.6GHz, 37.6GHz, 44.4GHz, and 50.6GHz is all near or below -20dB. These results verify that the invention possesses multi-frequency operating characteristics.

[0031] Figure 5-8 These are the radiation patterns of this embodiment at frequencies of 27.6 GHz, 37.6 GHz, 44.4 GHz, and 50.6 GHz. The gain is 7.2 dBi at 27.6 GHz, 8.1 dBi at 37.6 GHz, 8.9 dBi at 44.4 GHz, and 7.5 dBi at 50.7 GHz. This invention uses a combination of slot loading and coupling branching to achieve multi-frequency operation of the microstrip antenna, and it has a certain directivity in each frequency band, thus exhibiting multi-band operation characteristics.

Claims

1. A hexagonal multi-frequency microstrip antenna combining symmetrical split-ring slotting and L-shaped coupling branches, characterized in that: It consists of three parts from top to bottom: a first metal sheet (1), a second dielectric substrate (2), and a third metal sheet (3). The first metal sheet (1) is composed of a radiation structure and a transmission structure. The radiation structure is composed of a hexagonal metal sheet (101), and etched with symmetrically distributed first and second annular grooves (103) and second annular grooves (104), and loaded with symmetrically distributed first and second L-shaped metal lines (105) and second L-shaped metal lines (106). The transmission structure is composed of a rectangular metal sheet (102) with dimensions of 10.3 mm × 0.54 mm. An embedded feed is used to reduce the input impedance of the transmission structure. The feed depth Li is 1.3 mm and the width wi is 0.3 mm. The input impedance of the transmission structure is set to 50 ohms. The third metal sheet (3) is a seamless metal sheet used for grounding; The second dielectric substrate (2) is made of Rogers RO3003, with a dielectric constant εr=3.0, a thickness of 0.25 mm, and a length and width of 17.0 mm × 16.0 mm; The length and width of the third metal sheet (3) are the same as those of the second dielectric substrate (2); The first split-ring groove (103) and the second split-ring groove (104) both have a side length d of 0.7 mm and a groove width w1 of 0.1 mm. The center distance yc between the two grooves is 0.5 mm. By loading the split-ring groove, the current distribution on the hexagonal metal sheet can be changed, which can increase the resonant point. At the same time, the split-ring groove can reduce the imaginary part of the input impedance, which is beneficial to achieving impedance matching. The first L-shaped metal line (105) and the second L-shaped metal line (106) symmetrically distributed on both sides of the rectangular metal sheet (102) change the current path and reduce the imaginary part of the input impedance through coupling branches, thereby introducing a new resonant point.

2. The hexagonal multi-frequency microstrip antenna combining symmetrical split-ring slotting and L-shaped coupling branches according to claim 1, characterized in that: The resonant frequency is adjusted by modifying the size of the radiating patch, the size and position of the split ring groove, and the size of the L-shaped coupling branch, enabling independent adjustment of the four center frequencies. The antenna dimensions are 17 mm × 16 mm × 0.32 mm, and the frequency range with return loss below -10 dB is 27.3-27.9 GHz, 37.4-37.9 GHz, 44-44.8 GHz, and 50.1-52.1 GHz. The gain is 7.2 dBi at 27.6 GHz, 8.1 dBi at 37.6 GHz, 8.9 dBi at 44.4 GHz, and 7.5 dBi at 50.7 GHz.

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