Antenna decoupling method of aperiodic 3D folded metamaterial combined with defected ground structure

Abstract

The invention provides an antenna decoupling method for combining a non-periodic 3D folded metamaterial with a defected ground structure, and relates to the technical field of antenna decoupling. An original double-helix metamaterial structure is bent along a transverse center line to obtain a 3D folded metamaterial structure, the 3D folded metamaterial is printed on the upper face and the lower face of a dielectric substrate according to the designed structure, the whole 3D folded metamaterial is embedded into the dielectric substrate, and the upper face and the lower face are connected through a via hole; and designing a defected ground structure in the middle of the MIMO antenna, debugging, and organically combining the non-periodic arrangement of the 3D folded metamaterial with the defected ground structure to realize antenna decoupling. The method provided by the invention has relatively strong decoupling property, can effectively solve the problem of mutual coupling of MIMO antennas, does not need extra space or complex process, and is beneficial to realizing antenna miniaturization.

Description

Technical Field

[0001] The present invention relates to the field of antenna decoupling technology, and in particular to an antenna decoupling method of a non-periodic 3D folded metamaterial combined with a defective ground structure. Background Art

[0002] In recent years, the rapid development of integrated circuits has put forward higher requirements for the miniaturization and integration of antenna systems. When placing antenna units in close proximity, MIMO antennas will produce serious inter-line coupling, which will interfere with signal transmission and is not conducive to the integration of MIMO antenna systems. Therefore, the decoupling method for miniaturization of MIMO antenna systems has also become a hot research topic. Common decoupling methods include adding decoupling networks, adding polarization converters, adding coupling resonators, adding electromagnetic band gaps, introducing defective ground structures, using antenna units with orthogonal polarization ports, and using mushroom-type metamaterial structures. However, the method of adding decoupling networks often requires the arrangement of decoupling networks outside the original antenna system, which greatly increases the complexity of the system; using orthogonal polarization ports and adding polarization converters to antenna units is not conducive to the miniaturization of the antenna system as a whole; adding a single electromagnetic band gap or defective ground structure often does not achieve a good decoupling effect; and the high-density periodically arranged mushroom-type metamaterial structure greatly increases the complexity and cost of the antenna system. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide an antenna decoupling method of a non-periodic 3D folded metamaterial combined with a defective ground structure in view of the deficiencies of the above-mentioned prior art, so as to solve the problem that MIMO antennas cannot be miniaturized due to mutual coupling between lines.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0005] A method for antenna decoupling of a non-periodic 3D folded metamaterial combined with a defective ground structure, wherein a plurality of groups of 3D folded metamaterial structures with different central resonance frequencies are designed by adjusting the length of the thin wire of the bent 3D folded metamaterial according to the required antenna operating frequency; then the 3D folded metamaterial is printed on the upper and lower surfaces of a dielectric substrate according to the designed structure, the whole is embedded in the dielectric substrate and the upper and lower surfaces are connected through vias; then a defective ground structure is designed in the middle of a MIMO antenna and debugged, the non-periodic arrangement of the 3D folded metamaterial is organically combined with the defective ground structure to achieve antenna decoupling;

[0006] The design of the 3D folded metamaterial structure is to bend the original double helix metamaterial structure along the horizontal center line, and the end face after bending is a right-angle C shape; during the printing process, the vertical structure part at the bend is replaced by a through-hole structure that is easy to embed into the dielectric substrate; the 3D folded metamaterial structure introduces a new electromagnetic circuit while retaining the equivalent capacitance and inductance of the original double helix metamaterial structure, so that its resonant center frequency is shifted to the left.

[0007] Furthermore, the width of the defective ground structure can be appropriately adjusted to utilize the defective structure to regulate the electromagnetic coupling effect between antennas and further optimize the antenna system.

[0008] The beneficial effect of adopting the above technical solution is that the antenna decoupling method of the non-periodic 3D folded metamaterial combined with the defective ground structure provided by the present invention has a strong decoupling property, can effectively solve the MIMO antenna mutual coupling problem, does not require additional space or complex processes, and is conducive to realizing antenna miniaturization. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 A schematic diagram of the evolution steps of a 3D folded metamaterial structure provided by an embodiment of the present invention;

[0010] Figure 2 A three-dimensional diagram of the antenna system structure that organically combines a 3D folded metamaterial with a defective ground structure provided by an embodiment of the present invention;

[0011] Figure 3 The embodiment of the present invention provides Figure 2 The main view of

[0012] Figure 4 The embodiment of the present invention provides Figure 2 Bottom view of

[0013] Figure 5 An overall dimensioning diagram of a MIMO antenna system operating at a 5.5 GHz frequency band provided by an embodiment of the present invention;

[0014] Figure 6 A dimensioned diagram of a defective structure of a MIMO antenna system operating at a 5.5 GHz frequency band provided by an embodiment of the present invention;

[0015] Figure 7 Partial dimension annotation diagram of two groups of 3D folded metamaterials for a MIMO antenna system operating at 5.5 GHz frequency band provided in an embodiment of the present invention; wherein, Figure (7a) is group A metamaterial, and Figure (7b) is group B metamaterial.

[0016] In the figure: 1. MIMO antenna; 2. Group A 3D folded metamaterial; 3. Group B 3D folded metamaterial; 4. Defective ground structure; 5. Dielectric substrate; 6. GND; 7. Through-hole structure. DETAILED DESCRIPTION

[0017] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0018] In order to solve the inter-wire coupling problem of MIMO antennas, this embodiment designs a miniaturized new type of non-periodic 3D metamaterial and a defective ground structure combined antenna decoupling method, which is composed of a non-periodic 3D folded metamaterial and a defective ground structure. According to the required antenna operating frequency, several groups of 3D folded metamaterial structures with different central resonant frequencies are designed by adjusting the length of the thin wire of the bent 3D folded metamaterial; then, the 3D folded metamaterial is printed on the upper and lower surfaces of the dielectric substrate 5 according to the designed structure, and the whole is embedded in the dielectric substrate 5 and the upper and lower surfaces are connected through vias; then, a defective ground structure 4 is designed in the middle of the MIMO antenna 1, and debugging is performed to organically combine the non-periodic arrangement of the 3D folded metamaterial with the defective ground structure 4 to achieve antenna decoupling.

[0019] The novel non-periodic 3D folded metamaterial structure designed in this embodiment is as follows Figure 1 As shown. The original double helix metamaterial structure is bent along the horizontal midline, and the end face after bending is a right-angle C shape. When printing on the dielectric substrate, the vertical structure part at the bend is replaced by a through-hole structure 7 that is easy to embed into the dielectric substrate. The 3D folded metamaterial structure retains the equivalent capacitance and inductance of the original double helix metamaterial structure while introducing a new electromagnetic loop, so that its resonant center frequency shifts to the left.

[0020] like Figure 2 As shown, the method of this embodiment is a MIMO antenna working at the 5.5GHz frequency band. According to the required antenna working frequency 5.5GHz frequency band, two groups of 3D folded metamaterial structures with different central resonant frequencies are designed by adjusting the length of the thin wire of the bent 3D metamaterial, namely, group A 3D folded metamaterial 2 and group B 3D folded metamaterial 3, and then the two groups of metamaterial structures are embedded in the dielectric substrate 5 in the middle of the MIMO antenna 1, and then a defective ground structure 4 is designed in the middle of the MIMO antenna 1, and debugging is performed to organically combine the 3D folded metamaterial structure with the defective ground structure 4 and play the effect of improving the isolation of the MIMO antenna. Figure 3 Said, for Figure 2 The front view shows that two groups of 3D folded metamaterial structures 2 and 3 are embedded in the dielectric substrate 5 in the middle of the MIMO antenna 1 and combined with the defective ground structure 4 in the middle. The defective ground structure 4 is a vacant part in the middle of the GND 6. Figure 3The 3D metamaterial structure in FIG is the upper part of the 3D folded metamaterial structure. Figure 4 As shown, Figure 2 Bottom view of Figure 4 The 3D metamaterial structure in FIG. 1 is the lower half of the 3D folded metamaterial structure, and the upper and lower parts are connected by a through-hole structure 7 .

[0021] The dimensions of the two groups A and B 3D folded metamaterial structures and the defect ground structure are designed according to the antenna operating frequency 5.5 GHz band. The dimensions designed in this embodiment are marked as follows Figure 5 , Figure 6 and Figure 7 The specific sizes are shown in Table 1.

[0022] Table 1 Antenna system dimensions (unit: mm)

[0023] <![CDATA[l1]]> <![CDATA[l2]]> <![CDATA[l3]]> <![CDATA[l4]]> <![CDATA[l5]]> <![CDATA[l6]]> <![CDATA[l7]]> <![CDATA[l8]]> <![CDATA[l9]]> <![CDATA[l 10 ]]> <![CDATA[l 11 ]]> 40 15.6 12.18 6 2.7 14.18 3.89 4.9 1.35 4.5 1.35

[0024] In the design of this embodiment, the metamaterial structure can be designed to have different operating frequencies to widen the overall effective decoupling frequency band width. At the same time, by adjusting the width of the defect ground structure, the defect structure can be used to control the electromagnetic coupling effect between antennas to further optimize the antenna system.

[0025] Compared with the conventional technology, firstly, the method of this embodiment has a stronger decoupling property and can effectively solve the mutual coupling problem of MIMO antennas. Secondly, the method of this embodiment does not require additional space or complex processes, which is conducive to miniaturization of antennas.

[0026] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope defined by the claims of the present invention.

Claims

1. An antenna decoupling method for a non-periodic 3D folded metamaterial combined with a defective ground structure, characterized in that: According to the required antenna operating frequency, several groups of 3D folded metamaterial structures with different central resonance frequencies are designed by adjusting the length of the thin wire of the bent 3D folded metamaterial; then, the 3D folded metamaterial is printed on the upper and lower surfaces of the dielectric substrate (5) according to the designed structure, and the whole is embedded in the dielectric substrate (5) and the upper and lower surfaces are connected through vias; Then, a defective ground structure (4) is designed in the middle of the MIMO antenna (1), and debugging is performed to organically combine the non-periodic arrangement of the 3D folded metamaterial with the defective ground structure (4) to achieve antenna decoupling; The design of the 3D folded metamaterial structure is to bend the original double helix metamaterial structure along the transverse midline, and the end surface after bending is a right-angle C shape; During the printing process, the vertical structure part at the bend is replaced by a through-hole structure (7) that is easy to embed into the dielectric substrate (5); the 3D folded metamaterial structure introduces a new electromagnetic loop while retaining the equivalent capacitance and inductance of the original double-helix metamaterial structure, so that its resonant center frequency is shifted to the left.

2. The antenna decoupling method of the non-periodic 3D folded metamaterial combined with defective ground structure according to claim 1, characterized in that: The width of the defective ground structure (4) can be appropriately adjusted, so as to utilize the defective structure to regulate the electromagnetic coupling effect between antennas and further optimize the antenna system.

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