A plastic electromagnetic band gap structure and an antenna having the same

Abstract

The present application relates to the field of communication technology. Please provide a plastic electromagnetic bandgap structure and an antenna with the plastic electromagnetic bandgap structure. The antenna with the plastic electromagnetic bandgap structure includes a reflector and a plastic substrate. A plurality of columns of antenna radiators are arranged on the plastic substrate. A decoupling device is arranged between the coupling feed lines of two adjacent columns of antenna radiators, and the decoupling device is arranged on the plane of the plastic substrate; the decoupling device includes a plurality of metal patches with continuous I-shaped structures, and a through hole is arranged on the I-shaped structure; the distance between two adjacent columns of antenna radiators is less than or equal to 1 / 10λ. In practical applications, the decoupling device provided in the present application is a planar structure arranged between two columns of antenna radiators. The planar structure has obvious advantages over the traditional decoupling structure in terms of processing and weight control, thereby ensuring that the antenna with the plastic electromagnetic bandgap structure has a smaller volume and weight on the basis of meeting the antenna isolation.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a plastic electromagnetic band gap structure and an antenna having the plastic electromagnetic band gap structure. Background Art

[0002] As the mobile communications industry transitions from the 4G era to the 5G era, the mobile communications frequency band is gradually advancing from low frequency to high frequency band, and the size of antennas in mobile communications devices is continuously reduced. However, since the attenuation effect of high frequency bands is stronger than that of low frequency bands, in order to compensate for the negative effects of low radiation efficiency caused by attenuation when high frequency signals propagate in the air, Massive MIMO Antenna technology will become an inevitable trend in the future 5G communications field. However, for compact antennas or close-range MIMO antennas, isolation is an important criterion for measuring whether crosstalk occurs between radiating units and affects the communication quality of the entire antenna. Therefore, it is of great importance to improve the isolation of MIMO antennas in the field of 5G mobile communications.

[0003] At present, the mainstream methods to improve the isolation of MIMO antennas are: increasing the spacing between antennas from a physical level; using characteristic mode analysis to arrange the antennas in perpendicular polarization directions; adding metal isolation baffles between antennas, or even loading metasurfaces above the antennas to prevent the propagation of surface waves, thereby improving isolation.

[0004] As for the method of increasing the antenna spacing on the physical level, the space of the antenna itself is extremely limited, and in the era of 5G mobile communications that constantly requires miniaturization, simply increasing the antenna spacing from the physical level is undoubtedly contrary to the mainstream miniaturization antenna design requirements. For the characteristic mode analysis method, the isolation is improved by designing the radiation units in the form of perpendicular polarization directions. However, like the above-mentioned method of increasing the antenna spacing on the physical level, this solution also requires a large area of ​​antenna layout space. Therefore, this method does not have a high practical value in the application of 5G antennas. As for the method of adding a metal isolation baffle between antennas, this method is currently the most commonly used. However, under the condition that the spacing between the radiation units is very narrow, firstly, the metal isolation baffle is also difficult to effectively improve its isolation. Secondly, the addition of the metal isolation baffle is bound to bring a burden to the processing cost and the weight of the entire antenna. Therefore, in the 5G era that constantly requires lightweight, this method will also bring potential high-load problems. Regarding the method of loading a metamaterial surface isolation plate above the radiation unit, in order for the metamaterial surface isolation plate to effectively prevent the propagation of surface waves, its height must reach at least 0.25λ wavelength from the ground. This invisibly increases the overall height of the antenna, which is also contrary to the mainstream miniaturized antenna design requirements.

[0005] In summary, how to provide an antenna with smaller mass and volume while meeting the antenna isolation requirements is a technical problem that needs to be urgently solved by those skilled in the art. Summary of the invention

[0006] The present application provides a plastic electromagnetic band gap structure and an antenna having the plastic electromagnetic band gap structure, so as to provide an antenna with smaller mass and volume while meeting the antenna isolation requirements.

[0007] In a first aspect, the present application provides an antenna with a plastic electromagnetic bandgap structure, comprising a reflector and a plastic substrate arranged on the reflector, wherein a plurality of columns of antenna radiators are arranged on the plastic substrate, a decoupling device is arranged between coupling feed lines of two adjacent columns of antenna radiators, and the decoupling device is arranged on the plane of the plastic substrate; the decoupling device comprises a plurality of metal patches with continuous I-shaped structures, and a through hole is arranged on the I-shaped structure;

[0008] The distance between two adjacent columns of antenna radiators is less than or equal to 1 / 10λ, where λ is the wavelength of the waves radiated by the antenna radiators.

[0009] Optionally, the metal patch is directly disposed on the upper surface of the plastic substrate.

[0010] Optionally, the plastic substrate is further provided with a placement groove, wherein the placement groove is located between the coupling feed lines of two adjacent columns of antenna radiators (3).

[0011] Optionally, the decoupling device further comprises a plastic carrier, the plastic carrier is arranged in the placement groove, and a metal patch is arranged on the plastic carrier.

[0012] Optionally, the metal patch is integrally formed on the modified plastic by laser engraving and chemical gold plating technology.

[0013] Optionally, the metal patch is formed on the modified plastic by selective electroplating.

[0014] Optionally, the material of the plastic substrate is modified plastic, the relative dielectric constant of the plastic substrate is 4, and the tangent loss is 0.003.

[0015] A second aspect of the present application provides a plastic electromagnetic bandgap structure, which is a decoupling device arranged between coupling feed lines of two adjacent columns of antenna radiators. The decoupling device includes a plastic carrier and a metal patch arranged on the plastic carrier.

[0016] Optionally, the metal patch is a plurality of continuous I-shaped structures, and the I-shaped structures are provided with through holes.

[0017] It can be seen from the above technical scheme that the present application provides a plastic electromagnetic band gap structure and an antenna with a plastic electromagnetic band gap structure, the antenna with a plastic electromagnetic band gap structure includes a reflector and a plastic substrate arranged on the reflector, a plurality of columns of antenna radiators are arranged on the plastic substrate, a decoupling device is arranged between the coupling feed lines of two adjacent columns of antenna radiators, and the decoupling device is arranged on the plane of the plastic substrate; the decoupling device includes a plurality of metal patches with continuous I-shaped structures, and a through hole is arranged on the I-shaped structure; the distance between two adjacent columns of antenna radiators is less than or equal to 1 / 10λ, where λ is the wavelength of the radiation wave of the antenna radiator.

[0018] In practical applications, the decoupling device provided in the embodiment of the present application is a planar structure arranged between two columns of antenna radiators. The planar structure has obvious advantages in processing and weight control over the traditional decoupling structure, thereby ensuring that the antenna with a plastic electromagnetic band gap structure has a smaller volume and weight while meeting the antenna isolation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the embodiments are briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0020] Figure 1 A schematic diagram of the overall structure of an antenna with a plastic electromagnetic band gap structure provided in an embodiment of the present application;

[0021] Figure 2 A schematic diagram of the metal patch structure provided in an embodiment of the present application;

[0022] Figure 3 A schematic diagram of the structure of a decoupling device provided in an embodiment of the present application;

[0023] Figure 4 It is a schematic diagram of the structure of a dual-patch MIMO antenna without any isolation measures;

[0024] Figure 5 A schematic diagram of the structure of a dual-patch MIMO antenna with a planar metal isolation strip added;

[0025] Figure 6 Schematic diagram of S11 parameters of a dual-patch MIMO antenna without any isolation measures, with a planar metal isolation strip, and with a decoupling device;

[0026] Figure 7 Schematic diagram of S21 parameters of a dual-patch MIMO antenna without any isolation measures, with a planar metal isolation strip, and with a decoupling device;

[0027] Figure 8 Schematic diagram of current distribution before decoupling of dual-patch MIMO antenna;

[0028] Fig. 9 A schematic diagram of current distribution after decoupling of the dual-patch MIMO antenna provided in an embodiment of the present application.

[0029] Illustration Description:

[0030] Among them, 1 is a reflector, 2 is a plastic substrate, 3 is an antenna radiator, 4 is a coupling feed line, 5 is a decoupling device, 51 is a metal patch, 52 is a plastic carrier, and 6 is a planar metal isolation strip. DETAILED DESCRIPTION

[0031] The following embodiments are described in detail, and examples thereof are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations described in the following embodiments do not represent all implementations consistent with the present application. They are only examples of systems and methods consistent with some aspects of the present application as detailed in the claims.

[0032] like Figure 1As shown, it is a schematic diagram of the overall structure of an antenna with a plastic electromagnetic band gap structure provided in an embodiment of the present application. In a first aspect, an embodiment of the present application provides an antenna with a plastic electromagnetic band gap structure, comprising a reflector 1, and a plastic substrate 2 arranged on the reflector 1, a plurality of columns of antenna radiators 3 are arranged on the plastic substrate 2, a decoupling device 5 is arranged between the coupling feed lines 4 of two adjacent columns of antenna radiators 3, and the decoupling device 5 is arranged on the plane of the plastic substrate 2; the decoupling device 5 is a plurality of metal patches 51 with continuous I-shaped structures, and a through hole is arranged on the I-shaped structure; the distance between two adjacent columns of antenna radiators 3 is less than or equal to 1 / 10λ, where λ is the wavelength of the radiation wave of the antenna radiator 3.

[0033] It should be noted that the antenna provided in the embodiment of the present application is a single-patch MIMO antenna, but is not limited to a dual-patch MIMO antenna and can also be used in other dual-patch MIMO antennas. The antenna provided this time is probe-coupled fed and can also be connected using a direct feeding method.

[0034] The metal patch 51 provided in the embodiment of the present application is a periodic electromagnetic bandgap structure based on the laser engraving and chemical plating process, including multiple continuous I-shaped structures, forming a periodic electromagnetic bandgap structure, the periodic electromagnetic bandgap structure is equivalent to a parallel LC circuit, and the parallel LC circuit near the resonant frequency will form an infinite impedance characteristic. Therefore, the periodic electromagnetic bandgap structure can be similar to a band-stop filter, thereby preventing the current from flowing on the conductor surface, or changing the current flow direction on the conductor, suppressing the propagation of surface waves, thereby forming a frequency bandgap of the surface wave. The center frequency of the surface wave is the resonant frequency of the parallel LC circuit, and the equivalent capacitance and inductance estimated from this can obtain the resonant frequency of the electromagnetic bandgap structure:

[0035]

[0036] L=ε eff h

[0037]

[0038] Its resonant frequency Where ε0 is the dielectric constant of air, p is the period length of the periodic electromagnetic bandgap structure, l is the length unit of the I-shaped patch, d is the patch spacing, h is the thickness of the plastic substrate, and ε r is the relative dielectric constant of the plastic substrate, and ε eff By appropriately changing the length and spacing of the periodic electromagnetic bandgap structure, the characteristic of suppressing the propagation of surface waves at a specific frequency can be obtained.

[0039] In some embodiments of the present application, the metal patch 51 is directly processed on the plastic substrate 2 by laser engraving and chemical gold plating technology, but it is not limited to being directly processed on the plastic substrate 2. The decoupling device 5 can also be designed as an independent structure and installed in conjunction with the plastic substrate 2. For example, the plastic substrate 2 is also provided with a placement groove, and the placement groove is located between the coupling feed lines 4 of two adjacent columns of antenna radiators 3. The decoupling device 5 also includes a plastic carrier 52, which is arranged in the placement groove, and the plastic carrier 52 is provided with a metal patch 51. By setting the decoupling device 5 as an independent structure, it is ensured that the decoupling device 5 can be plug-and-play, so that the decoupling device 5 with different isolation can be replaced according to different antenna design requirements.

[0040] Furthermore, the material of the plastic substrate 2 is modified plastic, the relative dielectric constant of the plastic substrate 2 is 4, and the tangent loss is 0.003. The plastic substrate 2 can also be made of materials with other relative dielectric constants according to actual design requirements.

[0041] The periodic electromagnetic bandgap structure provided in the embodiment of the present application can not only reduce the weight problem of large-scale antennas, but also solve the problem of low isolation in low-frequency bands at extremely close distances. Taking the dual-patch MIMO antenna as an example, the periodic electromagnetic bandgap structure can increase the isolation of 3.4GHz-3.7GHz in the 6GHz band to more than 20dB.

[0042] The region between two columns of antenna radiators 3 that is less than a quarter of a wavelength is called a strong mutual coupling region. In the antenna with a plastic electromagnetic band gap structure provided in the embodiment of the present application, the distance between two adjacent columns of antenna radiators 3 is less than or equal to 1 / 10λ. To further illustrate the effectiveness of the technical solution of the embodiment of the present application, Figure 4 As shown in FIG. 1 , it is a schematic diagram of the structure of a dual-patch MIMO antenna without any isolation measures; Figure 5 The figure shows a schematic diagram of a dual-patch MIMO antenna structure with a planar metal isolation strip. By removing any isolation measures, adding a planar metal isolation strip 6 and adding the decoupling device 5 of the present application, the changes of S parameters (including S11 parameters and S21 parameters) are observed.

[0043] like Figure 6 As shown, it is a schematic diagram of the S11 parameters of a dual-patch MIMO antenna without any isolation measures, with a planar metal isolation strip, and with a decoupling device. The S11 parameter is the reflection coefficient. Figure 6 It can be seen that the S11 parameters in the three cases are relatively stable, almost unaffected by the decoupling structure, and all meet the industry requirement of -14dB or less.

[0044] like Figure 7 As shown in the figure, the S21 parameters are respectively when no isolation measures are added, when a planar metal isolation strip 6 is added, and when a plastic electromagnetic bandgap decoupling structure is added. The S21 parameter is a transmission coefficient or a characterization of isolation, that is, an isolation characteristic. Figure 7 It can be seen that without any isolation measures, the isolation in the low frequency band can only be maintained below -15dB. Figure 7 Although the planar metal isolation strip 6 is added, the effect of improving the isolation in the low frequency band is still not obvious. However, the periodic plastic electromagnetic bandgap decoupling structure provided in the embodiment of the present application significantly improves the isolation in the low frequency band to below -20dB, so that the dual-patch MIMO antenna system maintains a good isolation state at the operating frequency.

[0045] like Figure 8 , which is a schematic diagram of the current distribution of the dual-patch MIMO antenna before decoupling, is used to more intuitively demonstrate the working principle of the present application. Figure 8 It can be seen that without adding any decoupling structure, the current excited by the feed port Port 2 tends to enter the feed port Port 1 horizontally, as shown in Fig. 9 As shown, it is a schematic diagram of the current distribution after the dual-patch MIMO antenna is decoupled according to an embodiment of the present application. Fig. 9 It can be seen that after adding the plastic electromagnetic bandgap structure provided in the embodiment of the present application, the current excited by the Port 2 feeding port flows vertically, so the plastic electromagnetic bandgap structure of the present application can significantly improve the isolation of the MIMO antenna in the strong mutual coupling area.

[0046] A second aspect of the present application provides a plastic electromagnetic bandgap structure, such as Figure 1 and Figure 3 As shown, the plastic electromagnetic bandgap structure is a decoupling device 5 arranged between the coupling feed lines 4 of two adjacent columns of antenna radiators 3, such as Fig. 9 As shown, the decoupling device 5 includes a plastic carrier 52 and a metal patch 51 disposed on the plastic carrier 52. The metal patch 51 is a plurality of continuous I-shaped structures, and the I-shaped structure is provided with a through hole. The specific embodiment of the plastic electromagnetic band gap structure is a periodic structure. The periodic metal patch 51 provided in the embodiment of the present application is an I-shaped structure, but is not limited to the I-shaped structure. Other forms of periodic structure units can be designed according to actual production to achieve frequency selection and improve isolation.

[0047] It can be seen from the above technical scheme that the embodiment of the present application provides a plastic electromagnetic bandgap structure and an antenna with a plastic electromagnetic bandgap structure, the antenna with a plastic electromagnetic bandgap structure comprises a reflector 1 and a plastic substrate 2 arranged on the reflector 1, a plurality of columns of antenna radiators 3 are arranged on the plastic substrate 2, a decoupling device 5 is arranged between the coupling feed lines 4 of two adjacent columns of antenna radiators 3, and the decoupling device 5 is arranged on the plane of the plastic substrate 2; the decoupling device 5 comprises a plurality of metal patches 51 with continuous I-shaped structures, and a through hole is arranged on the I-shaped structure; the distance between two adjacent columns of antenna radiators 3 is less than or equal to 1 / 10λ, where λ is the wavelength of the radiation wave of the antenna radiator 3.

[0048] In practical applications, the decoupling device 5 provided in the embodiment of the present application is a planar structure arranged between two columns of antenna radiators 3. The planar structure has obvious advantages in processing and weight control compared to the traditional decoupling structure, thereby ensuring that the antenna with a plastic electromagnetic band gap structure has a smaller volume and weight while meeting the antenna isolation.

[0049] Similar parts between the embodiments provided in this application can be referenced to each other. The specific implementation methods provided above are only a few examples under the general concept of this application and do not constitute a limitation on the protection scope of this application. For those skilled in the art, any other implementation methods expanded based on the scheme of this application without creative work belong to the protection scope of this application.

Claims

1. An antenna having a plastic electromagnetic band gap structure, characterized in that: The invention comprises a reflector (1), and a plastic substrate (2) arranged on the reflector (1), wherein a plurality of columns of antenna radiators (3) are arranged on the plastic substrate (2), a decoupling device (5) is arranged between coupling feed lines (4) of two adjacent columns of antenna radiators (3), and the decoupling device (5) is arranged on the plane of the plastic substrate (2); the decoupling device (5) comprises a plurality of metal patches (51) with continuous I-shaped structures, and the I-shaped structures are provided with through holes to form a periodic electromagnetic bandgap structure, and the periodic electromagnetic bandgap structure is equivalent to a parallel LC circuit; The resonant frequency of the periodic electromagnetic bandgap structure is calculated by the following formula: ； ； ； Its resonant frequency , where is the dielectric constant of air, is the period length of the periodic electromagnetic bandgap structure, is the length unit of the I-shaped patch, is the patch spacing, is the thickness of the plastic substrate, is the relative dielectric constant of the plastic substrate, and is the equivalent dielectric constant; The distance between two adjacent columns of antenna radiators (3) is less than or equal to 1 / 10λ, where λ is the wavelength of the radiation wave of the antenna radiator (3); The plastic substrate (2) is also provided with a placement groove, wherein the placement groove is located between the coupling feed lines (4) of two adjacent columns of antenna radiators (3); The decoupling device (5) further comprises a plastic carrier (52), wherein the plastic carrier (52) is arranged in the placement groove, and a metal patch (51) is arranged on the plastic carrier (52).

2. The antenna with a plastic electromagnetic band gap structure according to claim 1, characterized in that: The metal patch (51) is directly arranged on the upper surface of the plastic substrate (2).

3. The antenna with a plastic electromagnetic band gap structure according to claim 1 or 2, characterized in that: The metal patch is integrally formed on the modified plastic by laser engraving and chemical gold plating technology.

4. The antenna with a plastic electromagnetic band gap structure according to claim 1 or 2, characterized in that: The metal patch is formed on the modified plastic by selective electroplating.

5. The antenna with a plastic electromagnetic band gap structure according to claim 1, characterized in that: The material of the plastic substrate (2) is modified plastic, the relative dielectric constant of the plastic substrate (2) is 4, and the tangent loss is 0.

003.

6. A plastic electromagnetic bandgap structure, characterized in that: The plastic electromagnetic bandgap structure is a decoupling device (5) arranged between coupling feed lines (4) of two adjacent columns of antenna radiators (3), the decoupling device (5) comprising a plastic carrier (52) and a metal patch (51) arranged on the plastic carrier (52); the metal patch (51) is a plurality of continuous I-shaped structures, and the I-shaped structures are provided with through holes to form a periodic electromagnetic bandgap structure, the periodic electromagnetic bandgap structure is equivalent to a parallel LC circuit; and the I-shaped structures are provided with through holes; The resonant frequency of the periodic electromagnetic bandgap structure is calculated by the following formula: ； ； ； Its resonant frequency , where is the dielectric constant of air, is the period length of the periodic electromagnetic bandgap structure, is the length unit of the I-shaped patch, is the patch spacing, is the thickness of the plastic substrate, is the relative dielectric constant of the plastic substrate, and is the equivalent dielectric constant; The plastic substrate (2) is also provided with a placement groove, wherein the placement groove is located between the coupling feed lines (4) of two adjacent columns of antenna radiators (3); The decoupling device (5) further comprises a plastic carrier (52), wherein the plastic carrier (52) is arranged in the placement groove, and a metal patch (51) is arranged on the plastic carrier (52).

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