Sierpinski fractal flexible antenna devices and miniaturized portable wearable devices

Abstract

The present invention provides a Sierpinski fractal flexible antenna device and a miniaturized portable wearable device, comprising a flexible dielectric substrate, a radiator portion disposed on one side of the flexible dielectric substrate, and a common ground structure. The radiator portion is slotted using an iterative fractal pattern to alter the direction of current flow within the radiator portion and increase the current path within the multi-order iterative Sierpinski fractal flexible antenna device. The Sierpinski fractal flexible antenna device utilizes a coplanar waveguide for power feeding. The present invention is well-suited for mobile communications in multiple emergency scenarios and harsh environments.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a Sierpinski fractal flexible antenna device and a miniaturized portable wearable device. Background Art

[0002] Miniaturization, multi-bandwidth, and wearability are the primary research areas for mobile terminal antennas. Conventional monopole resonant microstrip antennas have a relatively narrow bandwidth and typically require more space to achieve optimal performance. Traveling-wave microstrip antennas, for example, suffer from poor integration and compatibility, and exhibit high losses. In contrast, coplanar waveguide antennas are more compact and suitable for highly integrated modern systems. They offer wide bandwidth characteristics, uniform and stable radiation patterns, and low material costs.

[0003] Natural disasters occur frequently today. Disaster sites are often accompanied by complex terrain and bad weather, which interfere with signal transmission. Good communication guarantees in the face of natural disasters are conducive to timely communication between rescue personnel and commanders to make the right choices. However, in the face of complex application scenarios such as mine collapses and forest fires, ordinary rigid antennas are difficult to bend and deform in actual use due to the influence of dielectric substrate materials. Their use occasions are greatly limited, especially when installed on individual emergency rescue wearable equipment, making it difficult to meet the needs of most emergency rescue scenarios. Summary of the Invention

[0004] In view of this, the object of the present invention is to provide a Sierpinski fractal flexible antenna device and a miniaturized portable wearable device, which can be well applied to terminal mobile communications in multiple emergency scenarios and harsh environments.

[0005] In a first aspect, an embodiment of the present invention provides a Sierpinski fractal flexible antenna device, comprising a flexible dielectric substrate, and a radiator portion and a common ground structure provided on one side of the flexible dielectric substrate;

[0006] An iterative fractal pattern is used to groove the radiator part to change the internal current flow direction of the radiator part and increase the current path in the multi-order iterative Sierpinski fractal flexible antenna device. The Sierpinski fractal flexible antenna device is fed by a coplanar waveguide.

[0007] In one embodiment, a polygonal slot is embedded in the radiator portion, and this structure is a 0-order Sierpinski fractal flexible antenna device;

[0008] A plurality of polygonal slots are further embedded at the vertices of the polygonal slot in the radiator portion, and this structure is a first-order Sierpinski fractal flexible antenna device;

[0009] At the vertices of the polygonal slot embedded in the n+1th iteration in the radiator part, multiple polygonal slots are continuously embedded. This structure is an n-order Sierpinski fractal flexible antenna device.

[0010] In one embodiment, the polygonal slot is a rectangular slot.

[0011] In one embodiment, the side lengths of the rectangular slots embedded in the current iteration are related to the side lengths of the rectangular slots embedded in the previous iteration.

[0012] In one embodiment, the radiator portion is a regular hexagon.

[0013] In one embodiment, the common ground structure uses a copper ground plate.

[0014] In one embodiment, the flexible dielectric substrate is made of polyimide.

[0015] In one embodiment, the Sierpinski fractal flexible antenna device is bent 30° along the X-axis, and the center frequencies of the Sierpinski fractal flexible antenna device are 1.85 GHz, 3.20 GHz, and 4.90 GHz, respectively, and the frequency bands are 1.46-2.20 GHz, 2.93-3.34 GHz, and 3.99-6.42 GHz, respectively.

[0016] In one embodiment, the Sierpinski fractal flexible antenna device is bent 45° along the X-axis, and the center frequencies of the Sierpinski fractal flexible antenna device are 1.92 GHz, 3.20 GHz, and 4.90 GHz, respectively, and the frequency bands are 1.48-2.29 GHz, 2.98-3.31 GHz, and 4.00-5.75 GHz, respectively.

[0017] In a second aspect, an embodiment of the present invention further provides an emergency rescue communication system, comprising the Sierpinski fractal flexible antenna device according to any one of the first aspects, and an emergency rescue communication terminal communicatively connected to the Sierpinski fractal flexible antenna device.

[0018] An embodiment of the present invention provides a Sierpinski fractal flexible antenna device and a miniaturized portable wearable device, comprising a flexible dielectric substrate, a radiator portion disposed on one side of the flexible dielectric substrate, and a common ground structure. An iterative fractal pattern is used to create slots in the radiator portion to change the direction of current flow within the radiator portion and increase the path of the current in the multi-order iterative Sierpinski fractal flexible antenna device. The Sierpinski fractal flexible antenna device uses a coplanar waveguide for power feeding. The Sierpinski fractal flexible antenna device provided in an embodiment of the present invention is a novel coplanar waveguide fractal antenna based on a flexible structure nested with iterative fractal pattern slots. The antenna has excellent bandwidth characteristics, including multiple communication frequency bands, wide frequency bandwidth, and good frequency band isolation. In addition, the Sierpinski fractal flexible antenna device uses a flexible antenna. Due to its special material, the flexible antenna can be miniaturized and can be stretched or bent to a certain extent, making it less susceptible to damage. This ensures signal transmission and reception while also being portable, greatly meeting the requirements for mobile communications for terminals used in multiple emergency scenarios and harsh environments.

[0019] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or understood by practicing the present invention. The purposes and other advantages of the present invention are realized and obtained by the structures particularly pointed out in the description, claims and drawings.

[0020] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 A schematic diagram of a communication emergency rescue ad hoc network provided by an embodiment of the present invention;

[0023] Figure 2 A schematic diagram of a forest fire and mine collapse communication network and rescue scenario provided by an embodiment of the present invention;

[0024] Figure 3 A schematic diagram of the multi-order structural evolution of a Sierpinski fractal flexible antenna device provided in an embodiment of the present invention;

[0025] Figure 4 A schematic diagram of the physical dimensions of a second-order fractal antenna provided in an embodiment of the present invention;

[0026] Figure 5 An S11 curve diagram of an antenna iteration of order 0, order 1, and order 2 provided in an embodiment of the present invention;

[0027] Figure 6 The E / H plane radiation pattern at various frequencies of a second-order fractal antenna provided by an embodiment of the present invention;

[0028] Figure 7 A schematic diagram of an antenna structure in a bent state provided by an embodiment of the present invention;

[0029] Figure 8 This is a bending S11 curve diagram of a flexible antenna provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0031] At present, when faced with complex application scenarios such as mine collapse and forest fire fighting, ordinary rigid antennas are difficult to bend and deform in actual use due to the influence of the dielectric substrate material, and are greatly restricted in their use occasions. Therefore, in order to achieve better performance of wearable antennas in different occasions, flexible antennas have gradually replaced traditional rigid antennas. At the same time, in order to minimize the performance loss caused by antenna bending, it is necessary to select flexible antenna-related media with the best parameters. The technical problem to be solved by the present invention is to provide a wearable, broadband, miniaturized, flexible fractal coplanar waveguide antenna that can cover applications such as WLAN / ISM / Beidou / GPS / 4G / 5G for terminal mobile communication devices in multiple emergency scenarios and harsh environments.

[0032] my country has consistently been among the countries most severely affected by natural disasters, characterized by their diverse nature, high frequency, and significant losses. Disaster sites are often plagued by complex terrain and adverse weather conditions. Therefore, effective communication support is essential in the face of various natural disasters. This facilitates timely communication between rescuers and command personnel, enabling them to quickly make accurate assessments and maximize the safety of people's lives and property. Currently, my country has established an integrated emergency communication network encompassing air, land, and sea, and miniaturized, portable, and wearable emergency devices play a key role. For example, in the case of natural disasters such as forest fires and mine collapses, small, portable wearable antennas can be used on individual soldiers' backpacks to form ad hoc emergency communication networks, significantly improving communication capabilities and facilitating disaster relief efforts in disaster-stricken areas.

[0033] Such as Figure 1 A schematic diagram of a communication emergency rescue ad hoc network is shown, and Figure 2 The figure shows a schematic diagram of a communication network and rescue scenario for forest fires and mine collapses. At a forest fire scene, a stable communication link is crucial for coordinating rescue operations, transmitting fire information, and ensuring personnel safety. Due to dense trees and the intensity of the fire, conventional communication methods may be severely interfered with or interrupted. However, individual backpack antennas typically have high gain and anti-interference capabilities, providing a stable communication link in complex environments and ensuring unimpeded communication between rescuers. At a mine collapse scene, individual backpack antennas can also enhance communication capabilities within the mine. Mines are typically enclosed environments with significant signal attenuation, and conventional wireless communication equipment may not function properly. Individual backpack antennas typically have stronger signal reception and transmission capabilities, can penetrate obstacles within the mine, and provide a stable communication link. This allows rescuers to communicate in real time within the mine, sharing critical information such as the location of trapped personnel and changes in the mine structure, thereby more effectively coordinating rescue operations.

[0034] During the establishment of an ad hoc emergency communication network for rescue operations, antennas used on drones can help expand communication coverage. Drones are highly maneuverable and flexible, allowing them to fly over fires and outside mines, establishing stable communication links through the ad hoc emergency communication network. The drone's onboard antennas then transmit the signals over longer distances. This helps expand the coverage of the communication network, enabling the rescue command center to obtain real-time information from the fire scene and remotely direct and control rescue operations. Drone antennas can also transmit real-time images of the rescue scene to the command center or other rescue personnel by carrying high-definition cameras and image transmission equipment. This helps rescuers gain a more intuitive understanding of the disaster situation, providing important evidence for developing rescue plans and making decisions, and providing accurate guidance for rescue operations.

[0035] With the rapid development of communication systems, antennas used for information transmission and reception have become widely used, leading to increasingly stringent requirements for antenna performance. Researching and designing miniaturized, multi-band, and broadband high-performance antennas to replace multiple independent antennas, thereby reducing device complexity, improving system reliability, and reducing costs, has gradually become a key goal for designers. Simultaneously, with the continuous advancement and development of science and technology, wearable devices are gaining widespread application in military and individual equipment. Emergency rescue equipment, as a vital weapon and support for emergency response, is gradually exploring miniaturization and portability. High-performance emergency rescue equipment enables emergency personnel to effectively handle situations while maximizing their work efficiency and safety. As a crucial component of signal transmission for mobile terminal devices, wearable antennas are facing increasing demands for miniaturization, lightweightness, and reliability, which are key indicators of their portability.

[0036] Therefore, in order to achieve miniaturization, multi-band and wearable antennas, the embodiments of the present invention mainly adopt the following two technologies.

[0037] (1) Fractal structure: Through the study of a large number of fractal antenna characteristics and performance, it is found that the fractal structure itself has two characteristics: self-similarity and space-filling property. Self-similarity means that each small structure in the fractal is similar to the whole, and space-filling property means that the limited space of the fractal structure is filled to the maximum extent from all dimensions. Therefore, the use of fractal structure for design can make the antenna have miniaturization, broadband and multi-band characteristics. Therefore, fractal structure is of great significance to the research and development of miniaturized, multi-band and broadband, high-gain antennas, and plays an important role in the field of antenna design.

[0038] (2) Flexible materials: Traditional antennas are mostly made on hard substrates, which take up a lot of space and are, to a certain extent, unable to adapt to flexible wearable devices, thus being limited. In addition, the traditional material currently used to make wearable flexible antennas is textile materials, which are non-homogeneous materials and have anisotropic characteristics. This makes the performance of wearable antennas made of textile materials difficult to predict as easily as traditional antennas. Flexible antennas have the characteristics of light weight, small size, and thin thickness, and show important application prospects in multiple communication fields, including emergency rescue communications, at present and in the future.

[0039] With the development of materials and processes, more and more new materials are gradually being applied to the research of flexible wearable antennas. Therefore, the selection of materials and the type of manufacturing technology play a decisive role in the performance of flexible antennas. The use of flexible substrates can provide many attractive new advantages for electronic products, such as wearability, bendability, lightweight and even transparency.

[0040] Based on this, the present invention provides a Sierpinski fractal flexible antenna device and a miniaturized portable wearable device, which can be well applied to terminal mobile communications in multiple emergency scenarios and harsh environments.

[0041] To facilitate understanding of this embodiment, a Sierpinski fractal flexible antenna device disclosed in an embodiment of the present invention is first introduced in detail, including a flexible dielectric substrate, and a radiator portion and a common ground structure arranged on one side of the flexible dielectric substrate. Specifically, the radiator portion and the common ground structure are located on the front side of the flexible dielectric substrate.

[0042] In one example, an iterative fractal pattern is used to slot the radiator portion to change the internal current flow direction of the radiator portion and increase the current path in the multi-order iterative Sierpinski fractal flexible antenna device, and the Sierpinski fractal flexible antenna device is fed by a coplanar waveguide. Optionally, the iterative fractal pattern is a rectangular pattern, that is, multiple rectangular slots are made in the radiator portion. For example, the structure when a rectangular slot is made once in the radiator portion can be called a 0-order Sierpinski fractal flexible antenna device (referred to as a 0-order fractal antenna); the structure when a rectangular slot is made again on the basis of the 0-order fractal antenna can be called a 1-order Sierpinski fractal flexible antenna device (referred to as a 1-order fractal antenna); the structure when a rectangular slot is made again on the basis of the 1-order fractal antenna can be called a 2-order Sierpinski fractal flexible antenna device (referred to as a 2-order fractal antenna), and so on.

[0043] The above-mentioned Sierpinski fractal flexible antenna device provided by the embodiment of the present invention is a new coplanar waveguide fractal antenna based on a flexible structure nested with iterative fractal pattern grooves. The antenna has excellent bandwidth characteristics and has the advantages of covering multiple communication frequency bands, wide frequency bands, and good frequency band isolation. In addition, the Sierpinski fractal flexible antenna device adopts a flexible antenna. Due to the special material of the flexible antenna, it can not only be miniaturized, but also can be stretched or bent to a certain extent, and is not easy to be damaged. It not only ensures the transmission and reception of signals but also is easy to carry, which can greatly meet the requirements for terminal mobile communications used in multiple emergency scenarios and harsh environments.

[0044] With the continuous advancement of antenna technology, microstrip antennas have emerged. They offer advantages such as low profile, light weight, low cost, conformability to various carriers, suitability for mass production using printed circuit board technology, and ease of achieving circular polarization, dual-polarization, and dual-band operation. However, their critical drawback is their narrowband nature, which limits their widespread application. Therefore, there is an urgent need to explore new theories and methods to explore modern antenna design and address the problems and contradictions inherent in traditional antenna design. Traditional rigid antennas, with their large size, heavy weight, inflexibility, and limited conformality to planar carriers, are no longer able to meet the needs of wireless communications. Flexible antennas, as a new antenna technology, are rapidly developing and gaining momentum. Flexible antennas can bend, fold, and stretch to meet diverse needs. They are lightweight, flexible, and made of materials with excellent bending properties, making them better suited to emergency communication equipment, the human body, and diverse application scenarios. As an emerging antenna technology, flexible antennas hold broad application prospects, bringing innovation and breakthroughs to wireless communications, smart devices, and individual soldier equipment.

[0045] The embodiment of the present invention applies fractal geometry to antenna engineering and proposes a new coplanar waveguide fractal antenna with a flexible structure. Specifically:

[0046] In one example, the radiator portion is a regular hexagon.

[0047] In one example, the common ground structure uses a copper ground plane.

[0048] In one example, the antenna uses polyimide as a dielectric substrate.

[0049] In one example, a polygonal slot is embedded in the radiator part, and this structure is a 0-order Sierpinski fractal flexible antenna device; multiple polygonal slots are further embedded at the vertices of the polygonal slot in the radiator part, and this structure is a 1-order Sierpinski fractal flexible antenna device; multiple polygonal slots are further embedded at the vertices of the polygonal slot embedded in the radiator part for the n+1th iteration, and this structure is an n-order Sierpinski fractal flexible antenna device.

[0050] In one example, the polygonal slot is a rectangular slot, and the side length of the rectangular slot embedded in the current iteration is related to the side length of the rectangular slot embedded in the previous iteration, for example, the side length of the rectangular slot embedded in the current iteration is half of the side length of the rectangular slot embedded in the previous iteration.

[0051] Specifically, the antenna uses a polyimide dielectric substrate and a rectangular element. An iterative fractal pattern is used to create slots within the hexagons, creating a double fractal nesting pattern. By optimizing the gaps in the antenna's radiating structure, the current flow on the metal surface is altered, enabling radiation in multiple wireless frequency bands. The antenna was bent along the X-axis at 30°, 45°, and 90°, with the 90° bend being designed to study the effects of extreme bending on antenna performance.

[0052] The specific center frequency and frequency band of the antenna are as follows: (1) When the Sierpinski fractal flexible antenna device is bent 30° along the X-axis, the center frequencies of the Sierpinski fractal flexible antenna device are 1.85GHz, 3.20GHz, and 4.90GHz, and the frequency bands are 1.46-2.20GHz, 2.93-3.34GHz, and 3.99-6.42GHz, respectively. (2) When the Sierpinski fractal flexible antenna device is bent 45° along the X-axis, the center frequencies of the Sierpinski fractal flexible antenna device are 1.92GHz, 3.20GHz, and 4.90GHz, and the frequency bands are 1.48-2.29GHz, 2.98-3.31GHz, and 4.00-5.75GHz, respectively. (3) When the Sierpinski fractal flexible antenna device is bent 90° along the X-axis in the extreme case, the antenna performance deteriorates sharply and becomes unusable.

[0053] The flexible antenna's low-frequency bands cover BeiDou, GSM1800, DCS1800 (1.71-1.82GHz), WCDMA (1.755-1.880GHz), TD-SCDMA (1.88-2.025GHz), and LTE33-37 (1.9-2.025GHz). In less extreme situations, the high-frequency bands can cover multiple mobile operating frequency bands, including WLAN (4.02-5.45GHz). During emergency rescue operations, many areas lack public network coverage or are damaged. Team members can use a set of communication equipment and leverage the emergency communication command network for emergency rescue operations. This can include utilizing 5G+ drone AI for high-altitude inspections, 5G+AR remote command, and 5G+ robots to assist in emergency rescue operations. This antenna offers excellent 5G frequency band coverage, maximizing wireless communication and rescue efforts with emergency equipment such as the RA-300C 5G emergency communication base station and the RZ-501 5G private network terminal (4.8-5.0GHz).

[0054] For ease of understanding, the embodiment of the present invention provides a specific structure of a Sierpinski fractal flexible antenna device, see Figure 3 The schematic diagram of the multi-order structural evolution of a Sierpinski fractal flexible antenna device is shown. Figure 3The fractal process of each order of the antenna is illustrated.

[0055] like Figure 3 As shown in FIG, the broadband fractal flexible antenna includes a radiator part and a copper ground plane, both of which are located on the front of the dielectric material. By making rectangular slots on the regular hexagonal patch, this structure is a 0-order fractal antenna, as shown in FIG. Figure 3 As shown in (a) in the figure, at the four vertices of the rectangular slot in this structure, new rectangular slots with a side length of half the original rectangular side length are embedded, which is a first-order fractal antenna, as shown in Figure 3 As shown in (b) of the figure, based on the first-order structure, nesting the same method again yields a second-order fractal. Similarly, an n-order fractal antenna can be obtained. By using rectangular slots, the current path in the antenna is increased, while the current flow direction within the radiator is altered. Using a coplanar waveguide for feeding enables multi-band and miniaturized antennas.

[0056] The antenna of the embodiment of the present invention has undergone two iterations to achieve coverage of commonly used mobile frequency bands. If higher frequency coverage is desired, more iterations can be performed on the basis of the antenna to match the required frequency band; if low frequency bands are considered, you can choose to change the parameters of the hexagonal radiator or perform additional fractal operations on the radiator.

[0057] Take the 2nd order fractal antenna as an example, see Figure 4 Figure 1 shows a schematic diagram of the physical dimensions of a second-order fractal antenna. In this antenna model, the side length of each nested rectangle is proportional to the side length of the previous nested rectangle, that is, the side length of the next nested rectangle is 1 / 2 of the previous one, so that the side length of the rectangle in the nth iteration can be determined by the first slot.

[0058] The fractal antenna was simulated using HFSS software. After testing, the radiator's bandwidth gradually narrowed after 3 iterations, so a 2nd-order iteration was used and its evolution process was displayed. Figure 5 The S11 curve diagram of an antenna iteration 0th order, 1st order, and 2nd order is shown. Figure 5The S11 curves of the antenna when the dielectric plate is made of polyimide at various iteration numbers are given. It can be clearly seen in the figure that with increasing iteration numbers, the -10dB bandwidth of the antenna becomes significantly wider. In addition, with increasing iteration numbers, the center resonant frequency of the antenna in the required frequency band shifts downward, the return loss performance becomes increasingly better, and the bandwidth of the higher frequency band is expanded. When the number of antenna iterations is 2, the antenna has good radiation characteristics in the three frequency bands of 1.38-2.83GHz, 3.13-4.23GHz, and 4.72-5.73GHz, and the three frequency points of 2.2GHz, 3.72GHz, and 5.05GHz. It can cover common mobile frequency bands such as GSM1800, DCS1800, WCDMA (1.755GHz-1.880GHz), YD-LTE (B-TrunC) (1.447-1.467GHz), TD-SCDMA (1.88-2.025GHz), LTE33-37 (1.9-2.025GHz), Beidou, and 5G, as well as emergency mobile frequency bands such as 5G base stations and terminal emergency equipment, meeting the requirements of mobile terminal antennas.

[0059] Furthermore, continuing with the example of the 2nd order fractal antenna, Figure 6 The E / H plane pattern of a 2nd order fractal antenna at different frequencies is shown. Figure 6 Simulation results for the 0-degree and 90-degree E / H-plane patterns of a second-order fractal antenna are presented at center resonant frequencies of 2.2 GHz, 3.72 GHz, and 5.05 GHz. It can be seen that at low frequencies, the antenna radiation pattern is essentially the same as that of a monopole antenna, with high omnidirectionality and minimal cross-polarization. However, as the frequency increases, the antenna loses its omnidirectionality and becomes concentrated in its two main lobes. However, cross-polarization is still minimal, indicating good performance.

[0060] For further information, see Figure 7 A schematic diagram of the antenna structure in a bent state is shown. Figure 7 (a), (b), and (c) are schematic diagrams of the antenna structure when the flexible antenna is bent 30 degrees, 45 degrees, and 90 degrees, respectively.

[0061] On this basis, see Figure 8 The S11 curve diagram of a flexible antenna bending is shown, specifically, Figure 8The following are S11 graphs of the flexible antenna when bent at 30, 45, and 90 degrees. As can be seen from the graph, as the antenna's bending angle increases, it maintains a wide bandwidth while covering three frequency bands at 30 and 45 degrees. In the low-frequency band, although the frequency shifts slightly to the right, the bandwidth still covers the main application bands within 2.4 GHz. In the high-frequency region, the center frequency remains essentially unchanged at these two bending angles, with a slight left shift in the frequency band. In the extreme case of a 90-degree bend, the antenna's performance deteriorates dramatically, rendering it unusable. However, in actual use, the antenna is unlikely to undergo a 90-degree bend, so this does not significantly impact its actual use.

[0062] In summary, the key points of the Sierpinski fractal flexible antenna device provided by the embodiment of the present invention are: (1) The embodiment of the present invention proposes a new coplanar waveguide fractal antenna based on a rectangular slot nested flexible structure, using polyimide as a dielectric substrate and rectangle as a basic element. A rectangular slot is made on a regular hexagonal patch, and an iterative fractal pattern is used to embed a new rectangular slot with a side length of half the original rectangle at the four vertices of the rectangular slot to obtain a first-order fractal antenna. The same method is then used to nest the first-order fractal antenna, which has the best frequency radiation characteristics and can meet the requirements of mobile terminal antennas; (2) Natural disasters occur frequently today, and disaster sites are often accompanied by complex terrain and bad weather, which interfere with signal transmission. In the face of natural disasters, good communication guarantees are conducive to timely communication between rescue personnel and commanders to make the right choices. Miniaturized portable wearable devices also play an important role in emergency rescue. This antenna achieves most mobile frequency band coverage in a miniaturized size and can be used for terminal mobile communications in multiple emergency scenarios and harsh environments. Among them, it can cover common frequency bands such as GSM1800, DCS1800, WCDMA (1.755GHz-1.880GHz), YD-LTE (B-TrunC) (1.447-1.467GHz), TD-SCDMA (1.88-2.025GHz), LTE33-37 (1.9-2.025GHz), Beidou, 5G, as well as emergency equipment communication bands such as RA-300C5G emergency communication base station and RZ-5015G private network terminal (4.8-5.0GHz).

[0063] The Sierpinski fractal flexible antenna device provided by the embodiment of the present invention has at least the following characteristics: (1) The embodiment of the present invention uses a hexagonal geometric appearance outline and applies fractal theory to the improvement of the traditional coplanar waveguide monopole antenna, and invents a coplanar waveguide monopole antenna with a new structure of outer hexagonal and inner cubic fractal. (2) The improved Sierpinski fractal antenna of the embodiment of the present invention has excellent bandwidth characteristics. It covers many communication frequency bands, has a wide frequency band, and has good frequency band isolation. (3) The appearance design of the fractal structure antenna is an axisymmetric figure, which makes the antenna tend to be symmetrical in directionality and can meet the needs of mobile users. (4) The frequency band isolation of the fractal antenna is related to the number of fractals, and the number of frequency bands can be increased or decreased by changing the number of fractals. (5) Due to the special material, the flexible antenna can not only be miniaturized, but also can be stretched or bent to a certain extent, and is not easy to be damaged, which ensures the transmission and reception of signals and is also convenient to carry. (6) The production of flexible antennas can greatly meet the development needs of wearable and implantable emergency rescue equipment for individual soldiers. (7) The antenna achieves coverage of multiple mobile frequency bands within a limited size and can meet the requirements of mobile terminal antennas in terms of radiation directivity, gain, and efficiency.

[0064] Based on the above embodiments, an embodiment of the present invention provides an emergency rescue communication system, including the Sierpinski fractal flexible antenna device provided by the above embodiments, and an emergency rescue communication terminal communicatively connected to the Sierpinski fractal flexible antenna device.

[0065] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working process of the emergency rescue communication system described above can refer to the corresponding process in the aforementioned embodiment and will not be repeated here.

[0066] In the description of the embodiments of the present invention, unless otherwise specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0067] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0068] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the above-described embodiments, those skilled in the art should understand that any person skilled in the art can modify or easily conceive of changes to the technical solutions described in the above-described embodiments within the technical scope disclosed by the present invention, or replace some of the technical features therein with equivalents. Such modifications, changes, or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A Sierpinski fractal flexible antenna device, characterized in that: It includes a flexible dielectric substrate, and a radiator portion and a common ground structure arranged on one side of the flexible dielectric substrate; An iterative fractal pattern is used to groove the radiator portion to change the internal current flow direction of the radiator portion and increase the current path in the multi-order iterative Sierpinski fractal flexible antenna device, which is fed by a coplanar waveguide; A polygonal slot is embedded in the radiator portion, and this structure is a 0-order Sierpinski fractal flexible antenna device; At the vertices of the polygonal slot in the radiator portion, a plurality of polygonal slots are continuously embedded, that is, one polygonal slot is embedded at each vertex, and this structure is a first-order Sierpinski fractal flexible antenna device; At the vertices of the polygonal slot embedded in the n+1th iteration in the radiator part, multiple polygonal slots are continuously embedded, that is, a polygonal slot is embedded at each vertex. This structure is an n-order Sierpinski fractal flexible antenna device.

2. The Sierpinski fractal flexible antenna device according to claim 1, characterized in that: The polygonal slot is a rectangular slot.

3. The Sierpinski fractal flexible antenna device according to claim 2, characterized in that: The side lengths of the rectangular slots embedded in the current iteration are related to the side lengths of the rectangular slots embedded in the previous iteration.

4. The Sierpinski fractal flexible antenna device according to any one of claims 1 to 3, characterized in that: The radiator portion is a regular hexagon.

5. The Sierpinski fractal flexible antenna device according to any one of claims 1 to 3, characterized in that: The common ground structure adopts a copper grounding plate.

6. The Sierpinski fractal flexible antenna device according to any one of claims 1 to 3, characterized in that: The flexible dielectric substrate is made of polyimide.

7. The Sierpinski fractal flexible antenna device according to any one of claims 1 to 3, characterized in that: The Sierpinski fractal flexible antenna device is bent 30 degrees along the X-axis. The center frequencies of the Sierpinski fractal flexible antenna device are 1.85 GHz, 3.20 GHz and 4.90 GHz, and the frequency bands are 1.46-2.20 GHz, 2.92-3.34 GHz and 3.99-6.42 GHz, respectively.

8. The Sierpinski fractal flexible antenna device according to any one of claims 1 to 3, characterized in that: The Sierpinski fractal flexible antenna device is bent 45 degrees along the X-axis. The center frequencies of the Sierpinski fractal flexible antenna device are 1.92 GHz, 3.20 GHz and 4.90 GHz, and the frequency bands are 1.48-2.29 GHz, 2.98-3.31 GHz and 4.00-5.75 GHz, respectively.

9. A miniaturized portable wearable device, characterized in that: The invention comprises the Sierpinski fractal flexible antenna device according to any one of claims 1 to 8.

Images