Multi-antenna hybrid decoupling device and wireless communication system suitable for compact environment

Abstract

The present invention discloses a multi-antenna hybrid decoupling device and a wireless communication system suitable for a compact environment, the device comprising: first to third antenna units, a first decoupling structure, a second decoupling structure, a dielectric substrate and a metal floor; the first antenna unit, the second antenna unit and the third antenna unit are all located on the side of the dielectric substrate away from the metal floor and are distributed in an L shape; the first decoupling structure and the second decoupling structure are respectively connected to the metal floor, the first decoupling structure is arranged on the dielectric substrate and located between the first antenna unit and the second antenna unit to suppress the energy coupling between the first antenna unit and the second antenna unit; the second decoupling structure is arranged on the side of the metal floor away from the dielectric substrate and located between the second antenna unit and the third antenna unit to suppress the energy coupling between the second antenna unit and the third antenna unit. The present invention can achieve high isolation of an odd number of antennas in a very compact environment and improve the working performance of the system.

Description

Technical Field

[0001] The present invention relates to the field of microwave communication technology, and in particular to a multi-antenna hybrid decoupling device and a wireless communication system suitable for a compact environment. Background Art

[0002] With the rapid development of the fifth generation (5G) mobile communications, millimeter wave antennas are widely used in various wireless systems and radar sensors due to their advantages of low latency, high transmission rate and high access density. In the traditional millimeter wave radar sensor design, the antenna and chip are located on the same plane, which greatly increases the lateral size and link loss of the entire wireless communication system, resulting in reduced system integration and increased product costs.

[0003] Packaged antenna technology can overcome these technical pain points. It flips the chip under the antenna and then packages the two into a system, greatly reducing the size and cost of the entire system. However, the reduction in the overall board area will increase the energy coupling between antennas, deteriorate performance indicators such as isolation, and increase the difficulty of antenna design. Taking the 24GHz millimeter wave radar antenna as an example, in order to achieve precise positioning, it is necessary to design a transmitting antenna and two receiving antennas, and the isolation between the two antennas needs to be greater than 20dB. It is very difficult to achieve such high performance in a very compact environment. In addition, although the traditional MIMO antenna decoupling technology can effectively improve the isolation between the two antennas, most decoupling technologies are only designed for an even number of antennas. As we all know, the energy coupling relationship between odd-numbered antennas will be more complicated. Therefore, how to achieve high isolation performance between odd-numbered antennas in a very compact environment has become a technical problem that needs to be solved urgently in the industry.

[0004] In view of this, it is necessary to propose further improvements to the current decoupling structure of odd-numbered antennas. Summary of the invention

[0005] In order to solve at least one of the above technical problems, the main purpose of the present invention is to provide a multi-antenna hybrid decoupling device and a wireless communication system suitable for a compact environment.

[0006] To achieve the above-mentioned purpose, a technical solution adopted by the present invention is: to provide a multi-antenna hybrid decoupling device suitable for a compact environment, comprising: a first antenna unit, a second antenna unit, a third antenna unit, a first decoupling structure, a second decoupling structure, and a stacked dielectric substrate and a metal floor; the first antenna unit, the second antenna unit, and the third antenna unit are all located on a side of the dielectric substrate away from the metal floor and are distributed in an L shape; the first decoupling structure and the second decoupling structure are respectively connected to the metal floor, the first decoupling structure is arranged on a side of the dielectric substrate away from the metal floor and is located in the middle of the first antenna unit and the second antenna unit to suppress energy coupling between the first antenna unit and the second antenna unit; the second decoupling structure is arranged on a side of the metal floor away from the dielectric substrate and is located in the middle of the second antenna unit and the third antenna unit to suppress energy coupling between the second antenna unit and the third antenna unit.

[0007] Among them, the first decoupling structure includes three microstrip lines parallel to the first antenna unit and the second antenna unit respectively, and three corresponding short-circuit pins. The short-circuit pins are passed through one end of the microstrip line and connected to the metal floor. The adjacent short-circuit pins are distributed in reverse direction. The three microstrip lines and the short-circuit pins form an interdigital stopband filter structure.

[0008] Wherein, the length of the middle microstrip line is less than or equal to the length of the microstrip lines on both sides.

[0009] The length of the microstrip lines on both sides is between 1 / 8 wavelength and 1 / 2 wavelength of the working frequency of the antenna unit; the length of the microstrip line in the middle is between 1 / 8 wavelength and 1 / 2 wavelength of the working frequency of the antenna unit.

[0010] The second decoupling structure is two equal-length gaps etched on the metal floor and parallel to the second antenna unit and the third antenna unit respectively.

[0011] The two slots extend from the edge of the metal floor to the middle of the metal floor respectively, so as to suppress the energy coupling between the second antenna unit and the third antenna unit.

[0012] The length of the slot is between 1 / 8 wavelength and 1 / 2 wavelength of the working frequency of the antenna unit, and the width of the slot is less than 2 mm.

[0013] The first antenna unit, the second antenna unit and the third antenna unit all include an antenna patch and a feeding probe having one end connected to the antenna patch, and the other end of the feeding probe passes through the dielectric substrate and the metal floor in sequence and is used to connect to an external connector.

[0014] The metal floor and the dielectric substrate have the same area.

[0015] To achieve the above-mentioned purpose, another technical solution adopted by the present invention is: to provide a wireless communication system, including the above-mentioned multi-antenna hybrid decoupling device suitable for a compact environment.

[0016] The technical solution of the present invention can suppress the energy coupling between the first antenna unit and the second antenna unit through the first decoupling structure set on the dielectric substrate, and has a better coupling effect; on the other hand, the second decoupling structure set on the metal floor can suppress the energy coupling between the second antenna unit and the third antenna unit, and has a better coupling effect, which can solve the energy mutual coupling problem between the three antenna units, has better isolation, and can improve the working performance of the system. In addition, this solution also has the advantages of simple structure and convenient processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0018] Figure 1 It is a schematic diagram of the three-dimensional structure of a multi-antenna hybrid decoupling device according to an embodiment of the present invention;

[0019] Figure 2 It is a side view of a multi-antenna hybrid decoupling device according to an embodiment of the present invention;

[0020] Figure 3 A top view of a multi-antenna hybrid decoupling device according to an embodiment of the present invention;

[0021] Figure 4 It is a rear view of a multi-antenna hybrid decoupling device according to an embodiment of the present invention;

[0022] Figure 5 is a graph of scattering parameters of a conventional dual-antenna structure symmetrically placed along a non-radiating edge;

[0023] Figure 6 is a graph of the scattering parameters of the conventional dual antennas placed symmetrically along the radiation edge;

[0024] Figure 7 It is a curve diagram of the scattering parameters of the multi-antenna hybrid decoupling device according to an embodiment of the present invention.

[0025] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] It should be noted that the descriptions of "first", "second", etc. in the present invention are only for descriptive purposes and cannot be understood as indicating or implying their 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 at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0028] Different from the prior art in which the energy coupling relationship between odd-numbered antennas is more complicated and it is difficult to achieve high isolation between odd-numbered antennas in a very compact environment, the embodiment of the present invention provides a multi-antenna hybrid decoupling device suitable for a compact environment, aiming to solve the energy coupling between odd-numbered antennas and improve the working performance of the system. Please refer to the following embodiment for the specific structure of the multi-antenna hybrid decoupling device suitable for a compact environment.

[0029] Please refer to Figures 1 to 3 , Figure 1 It is a schematic diagram of the three-dimensional structure of a multi-antenna hybrid decoupling device according to an embodiment of the present invention; Figure 2 It is a side view of a multi-antenna hybrid decoupling device according to an embodiment of the present invention; Figure 3It is a top view of a multi-antenna hybrid decoupling device according to an embodiment of the present invention. In an embodiment of the present invention, the multi-antenna hybrid decoupling device suitable for compact environments is applied to a wireless communication system to improve the isolation between an odd number of antennas. The multi-antenna hybrid decoupling device includes: a first antenna unit 110, a second antenna unit 120, a third antenna unit 130, a first decoupling structure 150, a second decoupling structure 160, and a stacked dielectric substrate 140 and a metal floor 170; the first antenna unit 110, the second antenna unit 120, and the third antenna unit 130 are all located on a side of the dielectric substrate 140 away from the metal floor 170 and are distributed in an L shape; the first decoupling structure 150 and the second decoupling structure 160 are respectively connected to the metal floor 170, and the first decoupling structure 150 and the second decoupling structure 160 are respectively connected to the metal floor 170. The structure 150 is arranged on a side of the dielectric substrate 140 away from the metal floor 170 and is located in the middle of the first antenna unit 110 and the second antenna unit 120 to suppress energy coupling between the first antenna unit 110 and the second antenna unit 120; the second decoupling structure 160 is arranged on a side of the metal floor 170 away from the dielectric substrate 140 and is located in the middle of the second antenna unit 120 and the third antenna unit 130 to suppress energy coupling between the second antenna unit 120 and the third antenna unit 130.

[0030] In this embodiment, the multi-antenna hybrid decoupling device specifically includes three antenna units, namely a first antenna unit 110, a second antenna unit 120 and a third antenna unit 130. The three antenna units are roughly distributed in an L shape, wherein the first antenna unit 110 is adjacent to the second antenna unit 120, and the second antenna unit 120 is adjacent to the third antenna unit 130. Since the three antenna units are not symmetrically distributed, the decoupling structure using a traditional even number of antennas cannot achieve high isolation of the overall antenna. To this end, the present solution designs a first decoupling structure 150 for solving the energy coupling between the first antenna unit 110 and the second antenna unit 120, and a second decoupling structure 160 for solving the energy coupling between the second antenna unit 120 and the third antenna unit 130. Specifically, the first decoupling structure 150 is located on a side of the dielectric substrate 140 away from the metal floor 170, and the first decoupling structure 150 is located between the first antenna unit 110 and the second antenna unit 120; the second decoupling structure 160 is located on a side of the metal floor 170 away from the dielectric substrate 140, and the second decoupling structure 160 is located between the second antenna unit 120 and the third antenna unit 130. The first decoupling structure 150 and the second decoupling structure 160 are arranged in back-to-back orientation to avoid interference caused by mixed decoupling of the two.

[0031] In order to explain this scheme more clearly, the following will continue with the accompanying drawings. Figure 1 and Figure 2The specific structures of the first decoupling structure 150 and the second decoupling structure 160 are described in detail.

[0032] Specifically, the first decoupling structure 150 includes three microstrip lines 151 parallel to the first antenna unit 110 and the second antenna unit 120, and three corresponding short-circuit pins 152. The short-circuit pins 152 are arranged at one end of the microstrip line 151 and connected to the metal floor 170. The adjacent short-circuit pins 152 are distributed in reverse direction. The three microstrip lines 151 and the short-circuit pins 152 form an interdigital stopband filter structure. The length of the microstrip line 151 is less than or equal to the side length of the antenna unit. The middle microstrip line 151 is located between the first antenna unit 110 and the second antenna unit 120, and the microstrip lines 151 on both sides are symmetrically arranged about the middle microstrip line 151. The three microstrip lines 151 are arranged in parallel, and the length of the middle microstrip line 151 is less than or equal to the length of the microstrip lines 151 on both sides. A gap is formed between the three microstrip lines 151 , and the distance of the gap is less than 1 / 8 wavelength, so as to better suppress the energy coupling between the first antenna unit 110 and the second antenna unit 120 .

[0033] Furthermore, the operating frequencies of the first antenna unit 110, the second antenna unit 120 and the third antenna unit 130 are all close to 24 GHz, and the lengths of the microstrip lines 151 on both sides are between 1 / 8 wavelength and 1 / 2 wavelength of the operating frequency of the antenna unit; the length of the microstrip line 151 in the middle is between 1 / 8 wavelength and 1 / 2 wavelength of the operating frequency of the antenna unit. The first antenna unit 110, the second antenna unit 120 and the third antenna unit 130 can meet the requirements of the radar sensor. Specifically, the operating frequencies of the first antenna unit 110, the second antenna unit 120 and the third antenna unit 130 are between 23.5-24.5 GHz, and the specific values ​​can be adjusted according to actual requirements. The length of the above-mentioned microstrip line 151 is between 1 / 8 wavelength and 1 / 2 wavelength of the operating frequency of the antenna unit. Preferably, the length of the microstrip line 151 can be 1 / 8 wavelength, 1 / 6 wavelength, 1 / 4 wavelength, and 1 / 2 wavelength, etc., and can be flexibly selected according to actual requirements.

[0034] Please refer to Figure 4 , Figure 4The figure is a rear view of a multi-antenna hybrid decoupling device according to an embodiment of the present invention. The second decoupling structure 160 is two equal-length slots 161 etched on the metal floor 170 and parallel to the second antenna unit 120 and the third antenna unit 130, respectively. The second decoupling structure 160 is used to suppress the energy coupling between the second antenna unit 120 and the third antenna unit 130 without affecting the original isolation of the first antenna unit 110 and the second antenna unit 120. The second decoupling structure 160 and the first decoupling structure 150 work together to achieve a hybrid decoupling effect.

[0035] Specifically, the two slots 161 extend from the edge of the metal floor 170 to the middle of the metal floor 170 respectively to suppress the energy coupling between the second antenna unit 120 and the third antenna unit 130, and have a better isolation effect. Further, the operating frequencies of the first antenna unit 110, the second antenna unit 120 and the third antenna unit 130 are all close to 24GHz, the length of the slot 161 is between 1 / 8 wavelength and 1 / 2 wavelength of the operating frequency of the antenna unit, and the width of the slot 161 is less than 2mm. Specifically, the operating frequencies of the first antenna unit 110, the second antenna unit 120 and the third antenna unit 130 are between 23.5-24.5GHz, and the specific value can be adjusted according to actual requirements. The length of the slot 161 is between 1 / 8 wavelength and 1 / 2 wavelength of the operating frequency of the antenna unit. Preferably, the length of the slot 161 can be 1 / 8 wavelength, 1 / 6 wavelength, 1 / 4 wavelength, and 1 / 2 wavelength, etc., which can be flexibly selected according to actual requirements. The width of the gap 161 is less than 2 mm, specifically 0.5 mm, 1 mm, 1.5 mm, 2 mm, etc.

[0036] Specifically, the first antenna unit 110, the second antenna unit 120 and the third antenna unit 130 each include an antenna patch 111, and a feeding probe 112 connected to the antenna patch 111 at one end, and the other end of the feeding probe 112 passes through the dielectric substrate 140 and the metal floor 170 in sequence and is used to connect to an external connector. The antenna patch 111 can be designed as a transmitting antenna, a receiving antenna or a transceiver antenna according to actual design requirements. Each antenna patch 111 is connected to a microstrip line through a feeding probe 112, and then connected to an external connector through a microstrip line to facilitate further processing of the received signal. Furthermore, the metal floor 170 has the same area as the dielectric substrate 140. In this embodiment, the dielectric substrate 140 uses a Rogers 4003 substrate with a thickness of 0.508 mm and a length and width of 8 mm×8 mm. It should be noted that other parameter substrates can also be selected according to actual requirements.

[0037] In order to more clearly illustrate the present solution, a scattering parameter curve of a conventional dual-antenna structure is compared with a scattering parameter curve of the present solution.

[0038] Please refer to Figure 5 and Figure 6 , Figure 5 is a graph of the scattering parameters of the traditional dual antenna structure placed symmetrically along the non-radiating edge. Figure 5 It can be seen that the operating frequency of the two antennas is around 24GHz, and good impedance matching is achieved. Since the two antennas are too close, their spacing is less than half a wavelength, so there is a strong energy coupling between the two antennas, and the isolation is only about 9dB, which is far from meeting the isolation requirements of radar sensor antennas. Figure 6 This is a graph of the scattering parameters of the traditional dual antennas placed symmetrically along the radiation edge. Figure 6 It can be seen that the two antennas achieve good impedance matching at an operating frequency of around 24 GHz. However, since the two antennas are too close, their spacing is less than half a wavelength, so there is strong energy coupling between the two antennas, and the isolation is only about 12 dB, which is slightly better than the result of the antenna placed along the non-radiating edge, but it also cannot meet the isolation requirements of the radar sensor antenna.

[0039] Please refer to Figure 7 , Figure 7 FIG. 1 is a graph showing the scattering parameters of a multi-antenna hybrid decoupling device according to an embodiment of the present invention. Figure 7 It can be seen that the three antennas all achieve good matching near 24GHz. Compared with the traditional antenna without decoupling structure, this design effectively solves the energy coupling problem between the three antennas through two different decoupling structures. The results show that the isolation between the three antennas in this design is improved to more than 22dB, and the improvement effect is very obvious, which fully meets the isolation performance requirements of the radar sensor.

[0040] In an embodiment of the present invention, the wireless communication system includes the above-mentioned multi-antenna hybrid decoupling device suitable for a compact environment. The specific structure of the multi-antenna hybrid decoupling device suitable for a compact environment is referred to the above-mentioned embodiment, which will not be described in detail here. Since the wireless communication system of this solution applies the above-mentioned multi-antenna hybrid decoupling device suitable for a compact environment, it has all the advantages and effects of the multi-antenna hybrid decoupling device for a compact environment.

[0041] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical solution of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A multi-antenna hybrid decoupling device suitable for compact environments, characterized in that: include: A first antenna unit, a second antenna unit, a third antenna unit, a first decoupling structure, a second decoupling structure, and a stacked dielectric substrate and a metal floor; The first antenna unit, the second antenna unit, and the third antenna unit are all located on a side of the dielectric substrate away from the metal floor and are distributed in an L shape; the first decoupling structure and the second decoupling structure are respectively connected to the metal floor, the first decoupling structure is arranged on a side of the dielectric substrate away from the metal floor and located in the middle of the first antenna unit and the second antenna unit to suppress energy coupling between the first antenna unit and the second antenna unit, the second decoupling structure is arranged on a side of the metal floor away from the dielectric substrate, and the second decoupling structure is located in the middle of the second antenna unit and the third antenna unit to suppress energy coupling between the second antenna unit and the third antenna unit.

2. The multi-antenna hybrid decoupling device suitable for compact environments as claimed in claim 1, characterized in that: The first decoupling structure includes three microstrip lines respectively parallel to the first antenna unit and the second antenna unit, and three corresponding short-circuit pins. The short-circuit pins are passed through one end of the microstrip line and connected to the metal floor. Adjacent short-circuit pins are distributed in opposite directions. The three microstrip lines and the short-circuit pins form an interdigital stopband filter structure.

3. The multi-antenna hybrid decoupling device suitable for compact environments as claimed in claim 2, characterized in that: The length of the middle microstrip line is less than or equal to the length of the microstrip lines on both sides.

4. The multi-antenna hybrid decoupling device suitable for compact environments as claimed in claim 2, characterized in that: The length of the microstrip lines on both sides is between 1 / 8 wavelength and 1 / 2 wavelength of the working frequency of the antenna unit; the length of the microstrip line in the middle is between 1 / 8 wavelength and 1 / 2 wavelength of the working frequency of the antenna unit.

5. The multi-antenna hybrid decoupling device suitable for compact environments as claimed in claim 2, characterized in that: The second decoupling structure is two equal-length slots etched on the metal floor and parallel to the second antenna unit and the third antenna unit respectively.

6. The multi-antenna hybrid decoupling device suitable for compact environments as claimed in claim 5, characterized in that: The two slots extend from the edge of the metal floor to the middle of the metal floor respectively, so as to suppress the energy coupling between the second antenna unit and the third antenna unit.

7. The multi-antenna hybrid decoupling device suitable for compact environments as claimed in claim 5, characterized in that: The length of the slot is between 1 / 8 wavelength and 1 / 2 wavelength of the working frequency of the antenna unit, and the width of the slot is less than 2 mm.

8. The multi-antenna hybrid decoupling device suitable for compact environments as claimed in claim 1, characterized in that: The first antenna unit, the second antenna unit and the third antenna unit all include an antenna patch and a feeding probe having one end connected to the antenna patch, and the other end of the feeding probe passes through the dielectric substrate and the metal floor in sequence and is used to connect to an external connector.

9. The multi-antenna hybrid decoupling device suitable for compact environments as claimed in claim 1, characterized in that: The metal floor has the same area as the dielectric substrate.

10. A wireless communication system, characterized in that: The wireless communication system comprises the multi-antenna hybrid decoupling device suitable for a compact environment as claimed in any one of claims 1 to 9.

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