Frequency reconfigurable room division antenna

Abstract

The application relates to the technical field of communication, in particular to a frequency reconfigurable indoor distributed antenna. The application provides a frequency reconfigurable indoor distributed antenna, which comprises a dielectric plate, a radiation structure, a feeding structure, a metal floor and a metal column, the dielectric plate is made of flexible material; the radiation structure comprises a plurality of radiation units, the plurality of radiation units are arranged by being separated by the dielectric plate; the feeding structure is used for feeding the radiation structure; the metal floor is arranged on the dielectric plate, the metal floor comprises a first metal strip, and the radiation structure is symmetrically arranged relative to the first metal strip; the metal column is connected with different radiation units; the radiation unit, the feeding structure and the metal floor are composite conductive ink. The frequency reconfigurable indoor distributed antenna provided by the application has a wide bandwidth and can realize double-frequency continuous reconfiguration.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a frequency-reconfigurable indoor antenna. Background Technology

[0002] In modern IoT, smart homes, and enterprise-level wireless networks, indoor wireless communication environments are becoming increasingly complex. In large commercial complexes, smart offices, and high-density residential areas, signals need to remain stable in the propagation environment created by concrete walls, metal frames, and complex indoor layouts. Multiple communication systems, such as Wi-Fi, Bluetooth, and 4G / 5G indoor distribution systems, coexist in limited frequency bands like 2.4GHz and 5GHz, leading to fierce competition for spectrum resources and prominent issues of co-channel and adjacent-channel interference. Traditional antennas (such as monopole antennas or microstrip patch antennas) employ fixed frequencies and fixed radiation modes, making it difficult to adapt to the dynamic characteristics of indoor channels. This easily creates coverage blind spots and capacity bottlenecks, limiting the performance improvement of modern high-density, high-capacity indoor communication systems. Furthermore, emerging application scenarios such as flexible wearable devices and smart textiles place higher demands on the flexibility, stretchability, and wideband characteristics of antennas, which traditional rigid antenna structures struggle to meet.

[0003] In the prior art, some antennas use flexible PDMS as the dielectric substrate and liquid metal EGaIn as the radiating material, wrapping EGaIn in a microfluidic channel formed by PDMS, thereby enabling operation in two frequency bands: 2.4 GHz and 5.8 GHz.

[0004] However, existing frequency-reconfigurable antennas have narrow bandwidths, and their structures still need optimization. Summary of the Invention

[0005] This application provides a frequency-reconfigurable indoor distributed antenna to solve the technical problem of narrow bandwidth in current frequency-reconfigurable antennas.

[0006] This application provides a frequency-reconfigurable indoor distributed antenna, including a dielectric substrate, a radiating structure, a feeding structure, a metal ground plane, and metal pillars. The dielectric substrate is made of a flexible material. The radiating structure includes multiple radiating elements, which are separated by the dielectric substrate. The feeding structure is used to feed power to the radiating structure. The metal ground plane is disposed on the dielectric substrate and includes a first metal strip. The radiating structure is symmetrically arranged with respect to the first metal strip. The metal pillars connect different radiating elements. The radiating elements, the feeding structure, and the metal ground plane are made of composite conductive ink.

[0007] The frequency-reconfigurable indoor distributed antenna provided in this application achieves flexible and stretchable characteristics by using a flexible dielectric substrate and a liquid conductive material. Simultaneously, the radiating structure includes multiple radiating elements symmetrically arranged relative to a first metal strip on a metal ground plane. This prevents mutual coupling of the radiating structures, adjusts the antenna matching, and thus broadens the bandwidth, achieving continuous reconfigurability across dual frequency bands. Furthermore, the multiple radiating elements are connected by metal pillars, further increasing the bandwidth. In addition, the symmetrical arrangement of the multiple radiating elements gives the antenna excellent omnidirectional radiation characteristics.

[0008] As an optional implementation, the dielectric substrate includes a first dielectric substrate, and a plurality of radiating units include a first radiating unit and a second radiating unit. The first radiating unit and the second radiating unit are disposed on both sides of the first dielectric substrate and form two folded dipoles symmetrical along a first direction.

[0009] With this configuration, a folded dipole is formed through the first and second radiating units, achieving a dual-frequency continuously reconfigurable characteristic.

[0010] As an optional implementation, the first radiation unit includes two U-shaped metal strips, which are symmetrically arranged along a second direction; the second radiation unit includes two straight metal strips, which are symmetrically arranged along a first direction.

[0011] This configuration, with two symmetrically arranged U-shaped metal strips, can enhance signal coverage quality, anti-interference capability, and communication reliability. The two symmetrically arranged straight metal strips can generate new resonant modes near the fundamental mode, thereby expanding the bandwidth.

[0012] As an optional implementation, the U-shaped metal strip includes two radiating arms, which are symmetrically arranged along a first direction; the two radiating arms of the two U-shaped metal strips located on the same side are connected to the same straight metal strip through a metal column.

[0013] With this configuration, the two radiating arms and the straight metal strip are connected by metal pillars to form a folded dipole, which can create a current loop and enable dual-band operation.

[0014] As an optional implementation, there are multiple metal pillars, which are disposed through the dielectric plate and form multiple metal pillar arrays; along the first direction, each metal pillar array includes multiple columns of metal pillars; one end of the straight metal strip is connected to a radial arm of a U-shaped metal strip through a set of metal pillar arrays, and the other end of the straight metal strip is connected to a radial arm of another U-shaped metal strip through a set of metal pillar arrays.

[0015] This configuration allows for the expansion of antenna bandwidth through the metal pillar array.

[0016] As an alternative implementation, the power supply structure is a microstrip line, which is connected to one of two U-shaped metal strips, while the other of the two U-shaped metal strips is disconnected and connected to a metal ground plane via a metal post.

[0017] This configuration creates a short-circuit structure, which is beneficial for antenna miniaturization and expanding the overall impedance bandwidth of the antenna.

[0018] As an optional implementation, the metal floor also includes a second metal strip and a third metal strip, the first metal strip extending along a first direction, and the second and third metal strips extending along a second direction; one end of the first metal strip is connected to the middle of the second metal strip, and the other end of the first metal strip is connected to the middle of the third metal strip.

[0019] The third metal strip has metal extensions at both ends, which extend toward the second metal strip.

[0020] This configuration allows for a reduction in the overall size of the antenna and miniaturization through the design of the metal ground plane structure. At the same time, the metal extension section can extend the path of the metal ground plane and reduce impedance.

[0021] As an optional implementation, the second radiating unit and the metal floor are located on the same side of the dielectric plate; along the X direction, a straight metal strip is disposed between the first metal strip and the metal extension, and the two straight metal strips are symmetrically disposed relative to the first metal strip.

[0022] This design optimizes the overall structure and reduces the size of the antenna.

[0023] As an alternative implementation, the dielectric substrate is made of styrene-ethylene-butene-styrene; the composite conductive ink includes gallium-indium alloy and styrene-ethylene-butene-styrene.

[0024] This configuration enables the antenna to be fully flexible and cyclically stretchable through a gallium-indium alloy and a styrene-ethylene-butene-styrene mixture.

[0025] As an optional implementation, the dielectric substrate further includes a second dielectric substrate and a third dielectric substrate, which are disposed on both sides of the first dielectric substrate in the thickness direction; the thickness of the second dielectric substrate and the thickness of the third dielectric substrate are less than the thickness of the first dielectric substrate.

[0026] The first radiating unit and the feeding structure are disposed on the upper surface of the first dielectric substrate, and the second radiating unit and the metal ground are disposed on the lower surface of the first dielectric substrate.

[0027] This configuration allows for optimized impedance matching through a thicker first dielectric substrate, while the thinner second and third dielectric substrates provide protection for the conductive structure.

[0028] This application provides a frequency-reconfigurable indoor distributed antenna, including a dielectric substrate, a radiating structure, a feeding structure, a metal ground plane, and metal pillars. The dielectric substrate is made of a flexible material. The radiating structure includes multiple radiating elements, which are separated by the dielectric substrate. The feeding structure feeds power to the radiating structure. The metal ground plane is disposed on the dielectric substrate and includes a first metal strip. The radiating structure is symmetrically arranged with respect to the first metal strip. The metal pillars connect different radiating elements. The radiating elements, the feeding structure, and the metal ground plane are made of composite conductive ink. The frequency-reconfigurable indoor distributed antenna provided by this application has a wide bandwidth and can achieve dual-frequency continuous reconfiguration.

[0029] In addition to the technical problems solved by the embodiments of this application, the technical features constituting the technical solutions, and the beneficial effects brought about by the technical features of these technical solutions described above, other technical problems that can be solved by the frequency reconfigurable indoor distributed antenna provided by this application, other technical features included in the technical solutions, and the beneficial effects brought about by these technical features will be further explained in detail in the specific implementation. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the structure of a frequency-reconfigurable indoor distributed antenna provided in an embodiment of this application;

[0032] Figure 2 A side view of a frequency-reconfigurable indoor distributed antenna provided in an embodiment of this application;

[0033] Figure 3 A schematic diagram of the first radiating element and the feeding structure provided in the embodiments of this application;

[0034] Figure 4 A schematic diagram of the second radiating unit and the metal floor provided in an embodiment of this application;

[0035] Figure 5 A schematic diagram illustrating the change in antenna performance due to the number of metal pillars provided in the embodiments of this application;

[0036] Figure 6 A schematic diagram illustrating the changes in antenna performance caused by loading straight metal strips on both sides of a metal ground plane, as provided in an embodiment of this application.

[0037] Figure 7A comparison diagram of S-parameters of a frequency-reconfigurable indoor antenna under different degrees of stretching along the Y direction, as provided in the embodiments of this application;

[0038] Figure 8 Comparison of E-plane radiation directions of the frequency reconfigurable indoor antenna provided in this application embodiment under different degrees of stretching along the Y direction;

[0039] Figure 9 A comparison diagram of the H-plane radiation direction of the frequency reconfigurable indoor antenna provided in this application embodiment under different degrees of stretching along the Y direction.

[0040] Explanation of reference numerals in the attached figures:

[0041] 10-Frequency reconfigurable indoor antenna;

[0042] 100 - Dielectric substrate; 110 - First dielectric substrate; 120 - Second dielectric substrate; 130 - Third dielectric substrate;

[0043] 200 - Radiation structure; 210 - First radiation unit; 211 - U-shaped metal strip; 2111 - Radiation arm; 220 - Second radiation unit; 221 - Straight metal strip;

[0044] 300-feed structure;

[0045] 400 - Metal floor; 410 - First metal strip; 420 - Second metal strip; 430 - Third metal strip; 431 - Metal extension section;

[0046] 500-Metal column array; 510-Metal column. Detailed Implementation

[0047] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an indirect connection through an intermediate medium, or the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0048] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0049] The terms "first," "second," and "third" (if any) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein.

[0050] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, such as a process, method, system, product, or maintenance tool that includes a series of steps or units, not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or maintenance tool.

[0051] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0052] In modern IoT, smart homes, and enterprise-level wireless networks, indoor wireless communication environments are becoming increasingly complex. In large commercial complexes, smart offices, and high-density residential areas, signals need to remain stable in the propagation environment created by concrete walls, metal frames, and complex indoor layouts. Multiple communication systems, such as Wi-Fi, Bluetooth, and 4G / 5G indoor distribution systems, coexist in limited frequency bands like 2.4GHz and 5GHz, leading to fierce competition for spectrum resources and prominent issues of co-channel and adjacent-channel interference. Traditional antennas (such as monopole antennas or microstrip patch antennas) employ fixed frequencies and fixed radiation modes, making it difficult to adapt to the dynamic characteristics of indoor channels. This easily creates coverage blind spots and capacity bottlenecks, limiting the performance improvement of modern high-density, high-capacity indoor communication systems. Furthermore, emerging application scenarios such as flexible wearable devices and smart textiles place higher demands on the flexibility, stretchability, and wideband characteristics of antennas, which traditional rigid antenna structures struggle to meet.

[0053] In existing technologies, some antennas use flexible PDMS as the dielectric substrate and liquid metal EGaIn as the radiating material, encapsulating EGaIn within a microfluidic channel formed by PDMS to achieve operation in both 2.4 GHz and 5.8 GHz frequency bands (e.g., CN222282223U). However, existing frequency-reconfigurable antennas have narrow bandwidths and poor signal omnidirectionality.

[0054] To address the aforementioned technical problems, this application provides a frequency-reconfigurable indoor distributed antenna. It achieves flexible and stretchable characteristics by using a flexible dielectric substrate and a liquid conductive material. Simultaneously, the radiating structure includes multiple radiating elements, which form two symmetrical folded dipoles along a first direction, expanding the bandwidth and enabling continuous dual-frequency reconfiguration when stretched. Furthermore, the multiple radiating elements are connected by metal pillars, further increasing the bandwidth. In addition, the symmetrical arrangement of the multiple radiating elements ensures stable signal in all directions within the continuously tuned frequency band.

[0055] Figure 1 This is a schematic diagram of the structure of a frequency-reconfigurable indoor distributed antenna provided in an embodiment of this application; Figure 2 A side view of a frequency-reconfigurable indoor distributed antenna provided in an embodiment of this application; Figure 3 A schematic diagram of the first radiating element and the feeding structure provided in the embodiments of this application; Figure 4 A schematic diagram of the second radiating unit and the metal floor provided in an embodiment of this application; Figure 5 A schematic diagram illustrating the change in antenna performance due to the number of metal pillars provided in the embodiments of this application; Figure 6 A schematic diagram illustrating the changes in antenna performance caused by loading straight metal strips on both sides of a metal ground plane, as provided in an embodiment of this application. Figure 7 A comparison diagram of S-parameters of a frequency-reconfigurable indoor antenna under different degrees of stretching along the Y direction, as provided in the embodiments of this application; Figure 8 Comparison of E-plane radiation directions of the frequency reconfigurable indoor antenna provided in this application embodiment under different degrees of stretching along the Y direction; Figure 9 A comparison diagram of the H-plane radiation direction of the frequency reconfigurable indoor antenna provided in this application embodiment under different degrees of stretching along the Y direction.

[0056] Reference Figures 1 to 8 As shown, this application provides a frequency-reconfigurable indoor distributed antenna 10, including a dielectric substrate 100, a radiating structure 200, a feeding structure 300, a metal ground plane 400, and metal pillars 510. The dielectric substrate 100 is made of a flexible material; the radiating structure 200 includes multiple radiating elements, which are separated by the dielectric substrate 100; the feeding structure 300 is used to feed power to the radiating structure; the metal ground plane 400 is disposed on the dielectric substrate 100, and the metal ground plane 400 includes a first metal strip 410. The radiating structure 200 is symmetrically arranged with respect to the first metal strip 410; the metal pillars 510 connect different radiating elements; the radiating elements, the feeding structure 300, and the metal ground plane 400 are made of composite conductive ink.

[0057] It is understandable that the dielectric substrate 100, as the main carrier, supports the radiating structure 200, the feeding structure 300, the metal ground plate 400, and the metal pillar 510. The dielectric substrate 100 is a flexible material that can be stretched or compressed. At the same time, since the conductive materials of the radiating unit, the feeding structure 300, and the metal ground plate 400 are liquid metal, i.e. composite conductive ink, the conductive materials also change when the dielectric substrate 100 is stretched or compressed, so that the antenna frequency can change continuously and smoothly.

[0058] It should be noted that the radiating structure 200 includes multiple radiating elements, which form two folded dipoles. These two folded dipoles are symmetrical with respect to the first metal strip 410 of the metal ground plane 400, preventing mutual coupling. When the dielectric substrate 100 is stretched or compressed, the antenna can continuously adjust its operating frequency across multiple frequency bands. Furthermore, the metal pillar 510 connects different radiating elements, adding a low-impedance path between them. The impedance of the metal pillar 510 is connected in parallel with the original input impedance, thereby reducing the fundamental mode input impedance of the radiating elements and bringing it closer to the port impedance of the feed structure 300. This improves antenna matching and expands the bandwidth.

[0059] In this embodiment, the plurality of radiating elements include a first radiating element 210 and a second radiating element 220, which are disposed on different sides of the first dielectric substrate 110. The first radiating element 210 and the second radiating element 220 form two folded dipoles symmetrical along a first direction, allowing continuous adjustment of the operating frequency in two frequency bands. The frequency-reconfigurable indoor distributed antenna 10 in this embodiment can be applied to both the L-band and S-band.

[0060] As one possible implementation, the first radiation unit 210 includes two U-shaped metal strips 211, which are symmetrically arranged along the XZ plane, and each U-shaped metal strip 211 is symmetrical with respect to the YZ plane; the second radiation unit 220 includes two straight metal strips 221, which are symmetrically arranged along the YZ plane, and the length of the straight metal strips 221 can be 8 mm and the width can be 4.5 mm.

[0061] Reference Figure 1 and Figure 2 The first direction is defined as the Y direction, the second direction as the X direction, and the vertical direction as the Z direction, which is the thickness direction of the dielectric plate 100. The X, Y, and Z directions are perpendicular to each other.

[0062] It should be noted that there are multiple metal pillars 510, which are arranged to penetrate the dielectric plate 100. The diameter and height of the multiple metal pillars 510 can be 0.8mm. Both the U-shaped metal strip 211 and the straight metal strip 221 are provided with multiple through holes. One end of the metal pillar 510 is connected to the through hole of the U-shaped metal pillar 510, and the other end is connected to the through hole of the straight metal pillar 510. The multiple metal pillars 510 form multiple metal pillar arrays 500.

[0063] It should be noted that the U-shaped metal strip 211 includes two radiating arms 2111, which extend in the same direction. The two radiating arms 2111 of the same U-shaped metal strip 211 are symmetrically arranged along the YZ plane, but their extension directions are opposite. The two radiating arms 2111 on the same side of the YZ plane of the two U-shaped metal strips 211 coincide with the vertical projection of a straight metal strip 221. The two radiating arms 2111 on the other side of the YZ plane of the two U-shaped metal strips 211 coincide with the vertical projection of another straight metal strip 221. Each radiating arm 2111 is connected to one end of a straight metal strip 221 via a metal column array 500. Thus, a total of four metal column arrays 500 connect the two U-shaped metal strips 211 and the two straight metal strips 221.

[0064] Along the YZ plane, two radiating arms 2111 and a straight metal strip 221 on the same side form a dipole. Both dipoles are connected to the metal ground plate 400, forming two independent return paths. In this embodiment, the width of a dipole is 4.5 mm and the length is 27 mm.

[0065] In this configuration, each metal pillar array 500 includes multiple columns of metal pillars along the first direction, and each column of metal pillars includes two metal pillars 510 arranged side by side along the second direction; each metal pillar array 500 includes multiple columns of metal pillars. When the number of columns of the metal pillar array 500 along the first direction is less than or equal to three, the antenna has a better impedance bandwidth.

[0066] Reference Figure 5 After introducing the metal pillar 510, the input impedance of the antenna's fundamental mode and higher-order modes is reduced accordingly, thereby improving the antenna's matching and expanding its bandwidth.

[0067] In this embodiment, the metal ground plane 400 further includes a second metal strip 420 and a third metal strip 430. The first metal strip 410 extends along the Y direction, and the second metal strip 420 and the third metal strip 430 extend along the X direction. One end of the first metal strip 410 is connected to the middle of the second metal strip 420, and the other end of the first metal strip 410 is connected to the middle of the third metal strip 430. The entire metal ground plane 400 is in the shape of an "I". By adjusting the length and width of the "I" shaped ground plane, the ground plane achieves a suitable inductive reactance, thereby making the input impedance of the antenna close to the port impedance, and thus widening the bandwidth.

[0068] Reference Figure 6 , combined Figure 1 and Figure 4 The third metal strip 430 has metal extensions 431 at both ends, which extend towards the second metal strip 420 and are parallel to the first metal strip 410. The two metal extensions 431 effectively lengthen the ground plane path, providing a return path with lower inductance, thus significantly reducing the antenna's input impedance and bringing the fundamental mode input impedance closer to the port impedance. Furthermore, the metal strip also acts as a new resonator; by optimizing its length, its resonant frequency is made close to the fundamental mode resonant frequency, further extending the fundamental mode impedance bandwidth.

[0069] In this embodiment, the second radiating unit 220 and the metal floor 400 are located on the same side of the dielectric plate 100; along the X direction, a straight metal strip 221 is disposed between the first metal strip 410 and the metal extension 431, and the two straight metal strips 221 are symmetrically arranged with respect to the first metal strip 410. The first metal strip 410 separates the two straight metal strips 221, which can reduce the mutual coupling between the two dipoles, prevent the two dipoles from interfering with each other, and improve the radiation efficiency.

[0070] As one possible implementation, the power supply structure 300 is a microstrip line, which is located on the same side of the dielectric substrate 100 along with two U-shaped metal strips 211. The width of the microstrip line can be 1 mm. The microstrip line is connected to one of the two U-shaped metal strips 211, and the other of the two U-shaped metal strips 211 is connected to the metal ground plane 400 through a metal post 510.

[0071] In some embodiments, a microstrip line is connected to the middle of a U-shaped metal strip 211, so that the current flows evenly to the two radiating arms 2111 of the U-shaped metal strip 211. The middle of another U-shaped metal strip 211 is disconnected to form a gap through which the microstrip line passes. A metal post 510 is provided on each side of the gap, and the two metal posts 510 connect the U-shaped metal strip 211 and the first metal strip 410.

[0072] When the microstrip line is fed, the current flows uniformly to the two radiating arms 2111 of the U-shaped metal strip 211 connected to the microstrip line, then flows through two corresponding metal pillar arrays 500 to two straight metal strips 221 on the other side of the dielectric substrate 100, and then through the two metal pillar arrays 500 on the other side of the two straight metal strips 221 to another U-shaped metal strip 211. Finally, the current flows through the two metal pillars 510 on both sides of the gap in the middle of the U-shaped metal strip 211 to the metal ground plane 400, forming a short-circuit structure. The short-circuit structure introduces a parallel inductor, which lowers the fundamental mode resonant frequency of the antenna, allowing the antenna to be made smaller at the same operating frequency. At the same time, the short-circuit structure introduces an additional resonant mode, which can expand the overall impedance bandwidth of the antenna.

[0073] It should be noted that the dielectric substrate 100 also includes a second dielectric substrate 120 and a third dielectric substrate 130, which are disposed on both sides of the first dielectric substrate 110 in the thickness direction; the thickness of the second dielectric substrate 120 and the thickness of the third dielectric substrate 130 are less than the thickness of the first dielectric substrate 110. The first radiating unit 210 and the feeding structure 300 are disposed on the upper surface of the first dielectric substrate 110, and the second radiating unit 220 and the metal ground plane 400 are disposed on the lower surface of the first dielectric substrate 110.

[0074] For example, the thickness of the second dielectric substrate 120 and the third dielectric substrate 130 can be 0.1 mm, and the thickness of the first dielectric substrate 110 can be 0.8 mm. Conductive structures such as the radiating structure 200, the feeding structure 300, and the metal ground plate 400 are all disposed on the upper and lower sides of the thicker first dielectric substrate 110, which can increase the impedance bandwidth. The dimensions of the second dielectric substrate 120, the first dielectric substrate 110, and the third dielectric substrate 130 can be 50 × 27 mm. 2 .

[0075] In this embodiment, the dielectric substrate 100 uses SEBS (styrene-ethylene / butene-styrene copolymer) as an elastic material. SEBS has strong self-healing ability, which makes the antenna have fully flexible and cyclic stretchable characteristics. Its relative permittivity is 2.4. The composite conductive ink is made by mixing gallium indium alloy (EGaIn) as a conductive material and SEBS as an elastomer matrix to form a stretchable conductive structure.

[0076] The preparation process of composite metal ink is described below.

[0077] 1) Preparation of liquid metal particles: Gallium-indium alloy (mass ratio, gallium:indium = 75.5:24.5) was used as the conductive material. It was mixed with 0.1 mM ethyl 3-mercaptopropionate surfactant and treated under ultrasonic conditions for 30 minutes (ultrasonic power 30%, pulse mode: 3 seconds on, 2 seconds off) to obtain uniformly dispersed liquid metal particles.

[0078] 2) Preparation of SEBS solution: SEBS (styrene-ethylene / butene-styrene copolymer, model H1221) is used as the elastomer matrix. SEBS particles are mixed with the organic solvents n-hexane and toluene at a mass ratio of 1:1:4 and dissolved evenly to form an SEBS solution.

[0079] 3) Mixing into ink: Mix the above liquid metal particles with the SEBS solution, controlling the mass ratio of liquid metal particles to SEBS solids between 6:1 and 8:1. Then stir on a magnetic stirrer at 300-600 rpm for 30-60 minutes until uniformly mixed to obtain liquid metal ink.

[0080] After the composite conductive ink is made, it needs to be patterned into an antenna pattern. The patterning process of composite metallic ink is described below.

[0081] 1) Film formation by blade coating: On a polytetrafluoroethylene substrate, use an adjustable blade coater (blade height 50μm) to evenly coat 3-5mL of liquid metallic ink. Then place it in a fume hood and let it stand for more than 12 hours to allow the organic solvent to evaporate completely.

[0082] 2) Transfer to glass slide: After the ink dries and forms a film, transfer it together with the polytetrafluoroethylene base onto a glass slide with dimensions of 20cm×10cm×5mm for subsequent processing.

[0083] 3) Laser pattern cutting: Use an ultraviolet laser cutter to cut the pattern according to the pre-designed folded dipole antenna pattern. Recommended laser parameters are: scanning rate 100-500mm / s, power 50-80%, frequency 30-50kHz, and 20-100 cuts. After cutting, remove the excess parts to obtain the desired antenna pattern.

[0084] After the composite conductive ink forms a pattern, it is then activated: An ultraviolet laser can be used to scan and activate the entire antenna pattern area in one pass. Laser parameters are set as follows: scan rate 500 mm / s, power 40-60%, frequency 40-50 kHz, and one scan. The laser-activated area must completely cover the entire conductor pattern, causing the antenna pattern to transition from an insulating state to a conductive state.

[0085] Then, the laser-activated antenna pattern is pressed face down onto the prepared SEBS elastic substrate film. After standing for more than 12 hours to allow the residual solvent to evaporate, the polytetrafluoroethylene film is removed, and the antenna pattern is transferred to the SEBS substrate, completing the pattern transfer.

[0086] Finally, a layer of SEBS solution is spin-coated onto the surface of the transferred antenna as an encapsulation and protective layer. The SEBS solution ratio is SEBS:n-hexane:toluene of 1:1:2 or 1:1:3 (mass ratio), and the spin-coating speed is 300-500 rpm for 10 seconds. After coating, the antenna is allowed to stand for at least 12 hours to allow the solvent to evaporate completely, resulting in a flexible frequency reconfigurable antenna.

[0087] Reference Figures 7 to 9 The frequency-reconfigurable indoor antenna 10 achieves passive dual-band continuous reconfigurability in the broadband ranges of 1.4–2.26 GHz (47%) and 2.39–4.56 GHz (62.4%), with overall gains of 3.32–8.17 dBi and 2.36–3.67 dBi, respectively. Simultaneously, due to the symmetry of the folded dipole, omnidirectional radiation pattern is achieved, allowing the frequency-reconfigurable indoor antenna 10 to receive signals omnidirectionally in the H-plane within the tunable frequency band.

[0088] This application provides a frequency-reconfigurable indoor distributed antenna 10, including a dielectric substrate 100, a radiating structure 200, a feeding structure 300, a metal ground plane 400, and metal pillars 510. The dielectric substrate 100 is made of a flexible material; the radiating structure 200 includes multiple radiating elements disposed on different sides of the dielectric substrate 100 to form a multi-resonance mode; the feeding structure 300 is used to feed power to the radiating structure 200; the metal ground plane 400 is disposed on the dielectric substrate 100; the metal pillars 510 connect different radiating elements; the radiating elements, the feeding structure 300, and the metal ground plane 400 are made of composite conductive ink. The frequency-reconfigurable indoor distributed antenna 10 provided by this application has a wide bandwidth and can achieve dual-frequency continuous reconfiguration.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A frequency reconfigurable room division antenna, characterized in that, include: A dielectric substrate (100) is made of a flexible material; The radiation structure (200) includes multiple radiation units, which are separated by the dielectric plate (100) and form two folded dipoles symmetrical along a first direction. A power feeding structure (300) for feeding power to the radiation structure (200); A metal floor (400) is disposed on the dielectric plate (100), the metal floor (400) includes a first metal strip (410), and the radiation structure (200) is symmetrically disposed with respect to the first metal strip (410); Metal pillar (510) connecting different radiating units; The plurality of the radiating units, the feeding structure (300) and the metal floor (400) are composite conductive inks; The dielectric plate (100) includes a first dielectric plate (110), and the plurality of radiation units include a first radiation unit (210) and a second radiation unit (220). The first radiation unit (210) and the feeding structure (300) are disposed on the upper surface of the first dielectric plate (110), and the second radiation unit (220) and the metal floor (400) are disposed on the lower surface of the first dielectric plate (110). The first radiating unit (210) includes two U-shaped metal strips (211), which are symmetrically arranged along a second direction; the feeding structure (300) is a microstrip line, which is connected to one of the two U-shaped metal strips (211), and the other of the two U-shaped metal strips (211) is disconnected and connected to the metal floor (400) through the metal pillar (510); The second radiating unit (220) includes two straight metal strips (221), and the U-shaped metal strip (211) includes two radiating arms (2111). Along the second direction, the two radiating arms (2111) of the two U-shaped metal strips (211) located on the same side are connected to the same straight metal strip (221) through the metal post (510). The width direction of the dielectric substrate (100) is defined as the X direction, the length direction of the dielectric substrate (100) is defined as the Y direction, and the thickness direction of the dielectric substrate (100) is defined as the Z direction; wherein, the first direction is the Y direction and the second direction is the X direction.

2. The frequency-reconfigurable indoor distributed antenna according to claim 1, characterized in that, The two straight metal strips (221) are symmetrically arranged along the first direction.

3. The frequency-reconfigurable indoor distributed antenna according to claim 2, characterized in that, The two radial arms (2111) of the same U-shaped metal strip (211) are symmetrically arranged along the first direction.

4. The frequency-reconfigurable indoor distributed antenna according to claim 3, characterized in that, There are multiple metal pillars (510), which are disposed through the dielectric plate (100) and form multiple sets of metal pillar arrays (500); along the first direction, each set of metal pillar arrays (500) includes multiple columns of metal pillars (510). One end of the straight metal strip (221) is connected to a radial arm (2111) of a U-shaped metal strip (211) via a set of the metal column array (500), and the other end of the straight metal strip (221) is connected to a radial arm (2111) of another U-shaped metal strip (211) via a set of the metal column array (500).

5. The frequency-reconfigurable indoor distributed antenna according to claim 2, characterized in that, The metal floor (400) further includes a second metal strip (420) and a third metal strip (430), wherein the first metal strip (410) extends along a first direction, and the second metal strip (420) and the third metal strip (430) extend along a second direction; one end of the first metal strip (410) is connected to the middle of the second metal strip (420), and the other end of the first metal strip (410) is connected to the middle of the third metal strip (430); The third metal strip (430) has metal extension sections (431) at both ends, and the metal extension sections (431) extend in the direction of the second metal strip (420).

6. The frequency-reconfigurable indoor distributed antenna according to claim 5, characterized in that, Along the second direction, the straight metal strip (221) is disposed between the first metal strip (410) and the metal extension (431), and the two straight metal strips (221) are symmetrically disposed relative to the first metal strip (410).

7. The frequency-reconfigurable indoor distributed antenna according to claim 1, characterized in that, The dielectric substrate (100) is made of styrene-ethylene / butene-styrene; the composite conductive ink includes gallium-indium alloy and styrene-ethylene / butene-styrene.

8. The frequency-reconfigurable indoor distributed antenna according to claim 1, characterized in that, The dielectric plate (100) further includes a second dielectric plate (120) and a third dielectric plate (130), the second dielectric plate (120) and the third dielectric plate (130) being disposed on both sides of the first dielectric plate (110) in the thickness direction; the thickness of the second dielectric plate (120) and the thickness of the third dielectric plate (130) are less than the thickness of the first dielectric plate (110).

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