Cube structure based electrically small antenna
By using a three-dimensional orthogonal folded metal ring with a cube structure and a multi-substrate splicing design, the omnidirectional radiation and dual polarization functions of the electrically small antenna in miniaturized devices are achieved, improving radiation efficiency and providing electromagnetic isolation characteristics.
Patent Information
- Application Number
- CN202511476668.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-16
- Publication Date
- 2026-02-27
- Estimated Expiration
- 2045-10-16
AI Technical Summary
Existing electrically small antennas struggle to balance performance improvement and structural complexity in miniaturized devices, and are also limited in achieving multi-functional switching, especially in terms of functional requirements such as omnidirectional radiation and dual polarization.
The design employs a three-dimensional orthogonal folded metal ring based on a cube structure and a splicing design of multiple substrates. By using single-feed or double-feed methods to excite the combination of multiple magnetic dipole rings and electric dipoles, a multi-loop coupling path is formed to achieve omnidirectional radiation or dual polarization functions. The current distribution is controlled by the difference in the dielectric properties of the substrates.
It achieves omnidirectional radiation and dual polarization functions in a small electrical size, enhances radiation efficiency, has electromagnetic isolation characteristics, and requires no additional packaging.
Smart Images
Figure CN120955352B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of wireless communication, in particular to an electrically small antenna based on a magic cube structure. BACKGROUND
[0002] In the field of wireless communication technology, electrically small antennas have a wide application prospect in miniaturized devices due to their size far smaller than the working wavelength (satisfying the electrically small size parameter ka 1 <1, where k is the wave number, a 1 is the smallest spherical radius surrounding the antenna).
[0003] However, traditional electrically small antennas face a contradiction between performance improvement and structural complexity: on the one hand, existing technologies mostly focus on improving the performance of a single antenna (such as increasing gain, bandwidth or tuning range) through independent complex structures, but such designs are difficult to meet the needs of miniaturization and functional diversification; on the other hand, modern radio frequency communication systems have higher requirements for antennas to achieve multi-function switching on the basis of miniaturization, such as realizing different functions such as omnidirectional radiation and dual polarization in the same structure to adapt to complex communication scenarios (such as multi-band communication, anti-interference transmission, etc.).
[0004] In existing technologies, a magnetic dipole loop antenna can be compressed in size through three-dimensional folding, but a single folding structure can only realize fixed functions and needs to rely on complex feeding or additional elements to switch modes. For example, traditional single-polarized antennas cannot meet the demand for orthogonal polarization communication, and dual-polarized antennas often result in size exceeding the limit or insufficient isolation due to complex structures. In addition, the limitations of substrate combination methods also restrict the expansion of functions: existing designs mostly use a single type of substrate, making it difficult to achieve topology reconstruction through simple splicing.
[0005] Therefore, how to realize functional diversification through modular structure design under the constraint of electrically small size has become a technical problem to be solved. SUMMARY
[0006] Therefore, the present application provides an electrically small antenna based on a magic cube structure to solve the problem of how to realize functional diversification through modular structure design under the constraint of electrically small size.
[0007] The present application provides an electrically small antenna based on a magic cube structure, comprising:
[0008] a metal ring structure formed by three-dimensional orthogonal folding;
[0009] a cubic magic cube structure formed by splicing at least three different types of substrates, and the number of the three substrates is not equal;
[0010] the metal ring structure is printed on six substrates of the cubic magic cube structure by a microstrip line;
[0011] The metal ring structure is excited by single or double feeding to realize omni-directional radiation or dual-polarization function in small electric size through the combination of multi-magnetic dipole ring and electric dipole.
[0012] The electrically small antenna based on the magic cube structure forms a multi-loop coupling path through the three-dimensional orthogonal folded metal ring structure, and an asymmetric electromagnetic environment is constructed in the cubic assembly by using three substrates with different dielectric constants. The microstrip line of the metal ring is continuously printed along the six substrate surfaces to form a closed conductive loop across the three-dimensional orthogonal surface. The single feeding mode excites the metal ring segments on different substrates through a single feeding point to generate a phase difference along the folded path, thereby synchronously exciting the mixed radiation mode of the multi-magnetic dipole ring and the electric dipole. The double feeding mode drives the vertical and horizontal metal ring branches through two groups of orthogonally distributed feeding points, and adjusts the current distribution by using the dielectric property difference of the substrates to decouple the two polarization components in space. The three-dimensional orthogonal folded structure enhances the radiation efficiency through the inter-ring coupling of the magnetic dipole ring, and the electric dipole component compensates for the pattern distortion in small electric size through the substrate asymmetry, thereby realizing omni-directional radiation or dual-polarization function in small electric size (ka 1 <1) and the cubic frame formed by self-assembly of the substrates has electromagnetic isolation characteristics without additional packaging.
[0013] In an alternative embodiment, the substrate includes a first structure feeding substrate, a second structure feeding substrate, and a non-feeding substrate.
[0014] The substrate is provided with a clamping groove around the periphery, and adjacent substrates are spliced by the clamping groove.
[0015] In this embodiment, the first structure feeding substrate and the second structure feeding substrate are vertically interlocked with the non-feeding substrate through the clamping grooves, forming three-dimensional orthogonal supports of the cubic frame; the clamping groove depth of the first structure feeding substrate is greater than that of the second structure feeding substrate, so that a stepped contact surface is formed when the non-feeding substrate is embedded, ensuring the isolation of the feeding path and the non-feeding substrate. The microstrip line of the first structure feeding substrate extends along the edge of the clamping groove to the surface of the adjacent substrate, directly forming a coplanar feeding coupling with the metal ring segment of the second structure feeding substrate; the inner wall of the clamping groove of the non-feeding substrate is covered with an insulating layer to suppress the parasitic current between adjacent metal rings. By adjusting the clamping groove spacing of the first and second structure feeding substrates, the feeding coupling strength is controlled, and the clamping groove of the non-feeding substrate is used to limit the folding angle of the metal ring, so that the three-dimensionally orthogonal spliced metal ring produces a multi-loop phase-synchronized magnetic dipole-electric dipole composite radiation under single / double feeding excitation.
[0016] In an alternative embodiment, the microstrip line of the metal ring structure is printed on the inner surface of the substrate, and the width of the microstrip line is adjusted according to the surface of the feeding substrate to achieve impedance matching.
[0017] In this embodiment, the first structure feeding substrate and the second structure feeding substrate are respectively vertically interlocked with the non-feeding substrate through the clamping slot, forming a three-dimensional orthogonal support of the cubic frame; the clamping slot depth of the first structure feeding substrate is greater than that of the second structure feeding substrate, so that the non-feeding substrate forms a stepped contact surface when embedded, ensuring that the feeding path is isolated from the non-feeding substrate. The microstrip line of the first structure feeding substrate extends along the edge of the clamping slot to the surface of the adjacent substrate, directly forming a coplanar feeding coupling with the metal ring segment of the second structure feeding substrate; the inner wall of the clamping slot of the non-feeding substrate is covered with an insulating layer to suppress the parasitic current between adjacent metal rings. By adjusting the clamping slot spacing of the first and second structure feeding substrates, the feeding coupling strength is controlled, and at the same time, the clamping slot of the non-feeding substrate is used to limit the folding angle of the metal ring, so that the metal ring after three-dimensional orthogonal splicing produces a multi-loop phase-synchronized magnetic dipole-electric dipole composite radiation under single / dual feeding excitation.
[0018] In an alternative embodiment, the single-feed structure includes a metal ring formed by three-dimensional orthogonal folding of two straight metal strips and a bent metal strip, and the ends of the two straight metal strips are connected with metal pads for exciting multiple magnetic dipole rings and electric dipoles to achieve 45-degree omnidirectional radiation.
[0019] In an alternative embodiment, the dual-feed structure includes two orthogonally symmetric metal rings, any of which is composed of two straight metal strips and a bent metal strip, and the ends of the two straight metal strips are connected with metal pads to form orthogonal feeding ports for exciting horizontal polarization and vertical polarization respectively.
[0020] In an alternative embodiment, the isolation between the two metal rings of the dual-feed structure is greater than 38 dB, and the 10 dB bandwidth of the operating frequency band is not less than 5%.
[0021] In an alternative embodiment, the material of the substrate is Rogers4003c, with a relative dielectric constant of 3.38 and a tangent loss angle of 0.0027;
[0022] The side length a of the cubic Rubik's structure is 19-21 mm, the substrate thickness t is 0.8-0.9 mm, and the clamping slot splicing length is 4-6 mm.
[0023] In an alternative embodiment, the electrical size of the cubic Rubik's structure satisfies ka 1 <1, where k is the wave number, a 1 is the minimum spherical radius enclosing the antenna, and the operating frequency band covers 1.21-1.22 GHz or 2.39-2.52 GHz. BRIEF DESCRIPTION OF DRAWINGS
[0024] In order to more clearly illustrate the technical solutions in the specific embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or prior art description. Obviously, the drawings described below are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative effort based on these drawings.
[0025] Figure 1 is a first structure folding schematic diagram of an electrically small antenna based on a magic cube structure provided in the embodiments of the present application;
[0026] Figure 2 is a second structure folding schematic diagram of an electrically small antenna based on a magic cube structure provided in the embodiments of the present application;
[0027] Figure 3 is a first structure feeding substrate schematic diagram of an electrically small antenna based on a magic cube structure provided in the embodiments of the present application;
[0028] Figure 4 is a second structure feeding substrate schematic diagram of an electrically small antenna based on a magic cube structure provided in the embodiments of the present application;
[0029] Figure 5 is a non-feeding substrate schematic diagram of an electrically small antenna based on a magic cube structure provided in the embodiments of the present application;
[0030] Figure 6 is a simulation S11 diagram of a first structure of an electrically small antenna based on a magic cube structure provided in the embodiments of the present application;
[0031] Figure 7 is a 45-degree omnidirectional simulation E-plane pattern of a first structure of an electrically small antenna based on a magic cube structure provided in the embodiments of the present application;
[0032] Figure 8 is a 45-degree omnidirectional simulation H-plane pattern of a first structure of an electrically small antenna based on a magic cube structure provided in the embodiments of the present application;
[0033] Figure 9 is a simulation S parameter diagram of a second structure of an electrically small antenna based on a magic cube structure provided in the embodiments of the present application;
[0034] Figure 10 is a horizontal polarization simulation E-plane pattern of a second structure of an electrically small antenna based on a magic cube structure provided in the embodiments of the present application;
[0035] Figure 11 is a horizontal polarization simulation H-plane pattern of a second structure of an electrically small antenna based on a magic cube structure provided in the embodiments of the present application;
[0036] Figure 12is a vertical polarization simulation E-plane pattern of a second structure in the electrically small antenna based on a Rubik's structure provided in the embodiments of the present application;
[0037] Figure 13 is a vertical polarization simulation H-plane pattern of a second structure in the electrically small antenna based on a Rubik's structure provided in the embodiments of the present application.
[0038] Reference numerals:
[0039] 1, first structure feeding substrate; 2, second structure feeding substrate; 3, non-feeding substrate. DETAILED DESCRIPTION
[0040] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.
[0041] In the field of wireless communication technology, electrically small antennas have wide application prospects in miniaturized devices due to their size far smaller than the working wavelength (satisfying the electrically small size parameter ka 1 <1, where k is the wave number, a 1 is the smallest spherical radius surrounding the antenna).
[0042] However, traditional electrically small antennas face a contradiction between performance improvement and structural complexity: on the one hand, existing technologies mostly focus on improving the performance of a single antenna (such as increasing gain, bandwidth or tuning range) through independent complex structures, but such designs are difficult to meet the needs of miniaturization and functional diversification; on the other hand, modern radio frequency communication systems have higher requirements for antennas to realize multi-function switching on the basis of miniaturization, such as realizing different functions such as omnidirectional radiation and dual polarization in the same structure to adapt to complex communication scenarios (such as multi-band communication, anti-interference transmission, etc.).
[0043] In existing technologies, a magnetic dipole loop antenna can be compressed in size through three-dimensional folding, but a single folding structure can only realize a fixed function and needs to rely on complex feeding or additional elements to switch modes. For example, traditional single-polarized antennas cannot meet the demand for orthogonal polarization communication, and dual-polarized antennas often result in size exceeding the limit or insufficient isolation due to complex structures. In addition, the limitations of substrate combination methods also restrict functional expansion - existing designs mostly use a single type of substrate, making it difficult to achieve topology reconstruction through simple splicing.
[0044] Therefore, how to realize functional diversification through modular structure design under the constraint of electrically small size has become a technical problem to be solved at present.
[0045] Embodiments of the present application are described below in conjunction with Figures 1 to 13
[0046] According to an embodiment of the present application, in one aspect, an electrically small antenna based on a Rubik's structure is provided, including a metal ring structure formed by three-dimensional orthogonal folding, a cubic Rubik's structure formed by splicing at least three different types of substrates, and the three substrates are of different quantities; the metal ring structure is printed on the six substrates of the cubic Rubik's structure by a microstrip line; wherein the metal ring structure excites a combination of multiple magnetic dipole rings and electric dipoles through single or double feeding modes, realizing omnidirectional radiation or dual-polarization function under small electric size.
[0047] The electrically small antenna based on the Rubik's structure forms a multi-loop coupling path through the three-dimensional orthogonal folded metal ring structure, uses different quantities of three substrates (dielectric constant difference) to construct an asymmetric electromagnetic environment in cubic splicing, and the microstrip line of the metal ring is continuously printed along the six substrate surfaces to form a closed conductive loop across the three-dimensional orthogonal surface. The single feeding mode excites different substrate metal ring segments through a single feeding point, so that the current generates a phase difference along the folded path, and simultaneously excites a mixed radiation mode of multiple magnetic dipole rings and electric dipoles; the double feeding mode drives the vertical and horizontal metal ring branches through two groups of orthogonally distributed feeding points, and uses the dielectric property difference of the substrates to control the current distribution, so that the two groups of polarization components are spatially decoupled. The three-dimensional orthogonal folded structure enhances the radiation efficiency through the inter-ring coupling of the magnetic dipole ring, and the electric dipole component compensates for the pattern distortion under small electric size through the substrate asymmetry, finally realizes omnidirectional radiation or dual-polarization function under small electric size (ka 1 <1) and the cubic frame formed by self-splicing of the substrate has electromagnetic isolation characteristics without additional packaging.
[0048] In one embodiment, the substrate includes a first structure feeding substrate 1, a second structure feeding substrate 2, and a non-feeding substrate 3; the substrate is provided with a clamping groove around, and adjacent substrates are spliced by the clamping groove.
[0049] In this embodiment, the first structure feeding substrate 1 and the second structure feeding substrate 2 are respectively vertically interlocked with the non-feeding substrate 3 through the clamping slots, forming a three-dimensional orthogonal support of the cubic frame; the clamping slot depth of the first structure feeding substrate 1 is greater than that of the second structure feeding substrate 2, so that the non-feeding substrate 3 forms a stepped contact surface when embedded, ensuring that the feeding path is isolated from the non-feeding substrate 3. The microstrip line of the first structure feeding substrate 1 extends along the edge of the clamping slot to the surface of the adjacent substrate, directly forming a coplanar feeding coupling with the metal ring segment of the second structure feeding substrate 2; the inner wall of the clamping slot of the non-feeding substrate 3 is covered with an insulating layer to suppress parasitic current between adjacent metal rings. By adjusting the clamping slot spacing of the first and second structure feeding substrates 2, the feeding coupling strength is controlled, and at the same time, the clamping slot of the non-feeding substrate 3 is used to limit the folding angle of the metal ring to achieve precise constraint, so that the metal ring after three-dimensional orthogonal splicing produces multi-loop phase-synchronized magnetic dipole-electric dipole composite radiation under single / dual feeding excitation.
[0050] In one embodiment, the microstrip line of the metal ring structure is printed on the inner surface of the substrate, and the microstrip line width is adjusted according to the feeding substrate surface to achieve impedance matching.
[0051] In this embodiment, the microstrip line of the metal ring structure is printed on the inner surface of the substrate, and the microstrip line width is adjusted according to the feeding substrate surface to achieve impedance matching.
[0052] In one embodiment, as shown in the structure Figure 1 , the single-feed structure includes a metal ring formed by three-dimensional orthogonal folding of two straight metal strips a1, b1 and a bent metal strip, and the ends of the two straight metal strips a1, b1 are connected with metal pads c1, d1 for exciting multiple magnetic dipole rings and electric dipoles to achieve 45-degree omnidirectional radiation. Figure 3 is a schematic diagram of the first structure feeding substrate 1 in the magic cube structure-based electrically small antenna provided in this embodiment, and metal through holes are provided on the two metal pads for feeding. The radius of the metal pad is r3, and the radii of the metal through holes on the metal pad for feeding are r1 and r2, respectively.
[0053] In one embodiment, such as Figure 2 In the structure shown, the doubly fed structure includes two orthogonally symmetrical metal rings. Each of the metal rings is composed of two straight metal strips and a bent metal strip. The ends of the two straight metal strips are connected to metal pads to form orthogonal feeding ports, which respectively excite horizontal polarization and vertical polarization. Figure 4 This is a schematic diagram of the second structure feed substrate 2 in the electrically small antenna based on the Rubik's Cube structure provided in this embodiment. Each of the two metal pads connecting the ends of the two straight metal strips of any metal ring has a metal via at the feed point. The radius of the metal pad is r3, and the radii of the metal vias at the feed point on the metal pads are r1 and r2, respectively.
[0054] In one embodiment, the isolation between the two metal rings of the doubly fed structure is greater than 38dB, and the 10dB bandwidth of the operating frequency band is not less than 5%.
[0055] In one embodiment, the substrate is made of Rogers 4003c material, with a relative permittivity of 3.38 and a tangent loss angle of 0.0027. The side length 'a' of the cube structure is 19-21 mm, the substrate thickness 't' is 0.8-0.9 mm, and the slot splicing length 'l' is 4-6 mm. Preferably, the side length 'a' of the cube structure is 20 mm, the substrate thickness 't' is 0.813 mm, and the slot splicing length 'l' is 5 mm. The overall dimensions of the substrate are a × a × t, and the slot dimensions are l × t × t.
[0056] In one embodiment, the microstrip width of the metal ring is 0.4 mm (w1) or 1.5 mm (w2), and the gap g of the bent metal strip is 4 mm.
[0057] In one embodiment, the electrical dimensions of the cube structure satisfy ka. 1 <1, where k is the wave number, a 1 The minimum sphere radius required to surround the antenna is specified, and the operating frequency band covers 1.21-1.22GHz or 2.39-2.52GHz.
[0058] The electrically small antenna based on the Rubik's Cube structure in the embodiment of the present invention was simulated using the software HFSS.
[0059] Table 1 shows the parameters of the electric small antenna based on the Rubik's Cube structure.
[0060] Table 1
[0061] Parameter a t l w1 w2 g [r1] [r2] [r3] Dimensions / mm 20 0.813 5 0.4 1.5 4 0.65 0.2 1
[0062] The first structure of the embodiment works at 1.21-1.22 GHz, and the simulated 10 dB bandwidth is 0.8%. The highest simulated gain reaches 1.6 dBi, as shown in Figure 6 , Figure 7 and Figure 8 .
[0063] The second structure works at 2.39-2.52 GHz and 2.39-2.51 GHz, and the simulated 10 dB bandwidth is 5.3% and 5%. The highest simulated gain reaches 2.8 dBi and 2.7 dBi, and the isolation is greater than 38 dB, as shown in Figure 9 , Figure 10 , Figure 11 , Figure 12 and Figure 13 .
[0064] Although the embodiments of the present application are described in conjunction with the accompanying drawings, various modifications and changes can be suggested by those skilled in the art without departing from the spirit and scope of the present application, and such modifications and changes are intended to fall within the scope of the appended claims.
Claims
1. A small electric antenna based on a Rubik's structure, characterized in that, Comprise: A metal ring structure formed by three-dimensional orthogonal folding; A cubic Rubik's structure formed by splicing three different types of substrates, and the number of the three substrates is different; The metal ring structure is printed on six substrates of the cubic Rubik's structure by microstrip lines; Wherein, the metal ring structure is formed by continuous metal strips through three-dimensional orthogonal folding to form a closed loop; horizontal polarization and vertical polarization are excited by two orthogonally symmetric metal rings through double-fed mode; The substrate comprises a first structure feed substrate, a second structure feed substrate and a non-feed substrate; The substrate is provided with a clamping groove around, and adjacent substrates are spliced by the clamping groove; The microstrip line of the metal ring structure is printed on the inner surface of the substrate, and the width of the microstrip line is adjusted according to the surface of the feed substrate to realize impedance matching.
2. The cube-structure-based electrically small antenna according to claim 1, wherein, The double-fed structure comprises two orthogonally symmetric metal rings, any of which is composed of two flat metal strips and a bent metal strip, and the end of the two flat metal strips is connected with a metal pad to form an orthogonal feed port to excite horizontal polarization and vertical polarization respectively.
3. The cube structure based electrically small antenna of claim 2, wherein, The isolation between the two metal rings of the double-fed structure is greater than 38dB, and the 10dB bandwidth of the working frequency band is not less than 5%.
4. The cube structure based electrically small antenna of claim 1, wherein, The material of the substrate is Rogers4003c, the relative dielectric constant is 3.38, and the tangent loss angle is 0.0027; The side length a of the cubic Rubik's structure is 19-21mm, the substrate thickness t is 0.8-0.9mm, and the clamping groove splicing length is 4-6mm.
5. The cube-structure-based electrically small antenna according to claim 1, wherein, The electrical size of the cube Rubik's structure satisfies ka 1 <1, where k is the wave number, a 1 is the minimum spherical radius enclosing the antenna, and the operating frequency band covers 1.21-1.22 GHz or 2.39-2.52 GHz.