Low-profile dual-polarization ultra-wideband flexible wearable antenna

Abstract

The invention relates to the field of communication antennas, and particularly discloses a low-profile dual-polarization ultra-wideband flexible wearable antenna. The dielectric substrate layer, the micro-strip resonance feed structure layer and the radiation patch layer are arranged to form the flexible wearable antenna, the structures of the dielectric substrate layer, the micro-strip resonance feed structure layer and the radiation patch layer are specially designed, the impedance bandwidth of the formed antenna covers 300-1200 MHz, the isolation degree is 12 dB or above, quasi-omnidirectional radiation can be achieved, and the antenna has the advantages of being simple in structure, convenient to use and high in practicability. The dual-port antenna has the advantages that the dual ports respectively excite a horizontal polarization mode and a vertical polarization mode, the average gain is respectively greater than 4.74 dBi and 3.82 dBi, the mechanical robustness is better, the dual-port antenna can be effectively suitable for modern emergency communication scenes and complex and diversified emergency rescue actions in the actual wearing process, and the influence of bending, wrinkling and fracture on the antenna robustness is effectively reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of communication antennas, and in particular relates to a low-profile dual-polarization ultra-wideband flexible wearable antenna. Background Art

[0002] By summarizing the current research status of flexible wearable antennas and feeding networks at home and abroad in recent years, we can see that although the research scope is relatively broad, there is still a problem that the research frequency band is mostly ISM band, which leads to limited application scope. For example, in lower frequency band working scenarios such as emergency communication systems, there are very few related studies at home and abroad; secondly, in the current research, there are very few antennas that have broadband characteristics, multi-polarization characteristics and quasi-omnidirectional characteristics of the radiation pattern. Most antennas only have one of these characteristics or are designed as reconfigurable antennas, and the implementation method is complicated. The traditional whip antenna currently used in emergency communication systems has many usage problems, such as large size, hard texture, narrow bandwidth and single polarization. For this reason, a low-profile dual-polarization ultra-wideband flexible wearable antenna is proposed, which uses the outer slot to excite low-frequency resonance, the inner slot to excite medium and high-frequency resonance, and the resonant feeding structure to improve its impedance matching to expand the bandwidth. Summary of the invention

[0003] The object of the present invention is to provide a low-profile dual-polarization ultra-wideband flexible wearable antenna to solve the problems raised in the above background technology.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A low-profile dual-polarization ultra-wideband flexible wearable antenna, comprising:

[0006] A dielectric substrate layer, wherein the dielectric substrate layer is made of Kevlar flexible fiber;

[0007] A microstrip resonant feeding structure layer, wherein the microstrip resonant feeding structure layer is arranged on one side of the dielectric substrate layer, and the microstrip resonant feeding structure layer is provided with two ports, port 1 and port 2, and the port 1 and port 2 are arranged opposite to each other;

[0008] The radiation patch layer is arranged on the other side of the dielectric substrate layer, and a plurality of gaps are arranged on the radiation patch layer.

[0009] Preferably, the microstrip resonant feeding structure layer and the radiation patch layer both use microwave electromagnetic shielding and radiation-proof fabric as conductive material.

[0010] Preferably, the dielectric substrate layer is defined to have a width of G and a thickness of h.

[0011] Preferably, the width of the radiation patch layer is the same as the width of the dielectric basic layer, an outer square gap is etched in the middle of the radiation patch layer, and the side length of the outer square gap is defined as S1, and a corner of the outer square gap is filled with a length of L pad A metal sheet having a rectangular groove with a groove width of W and a groove depth of L is opened on the metal sheet, a square radiation patch with a side length of S2 is arranged in the middle of the outer square gap, and a square gap with a side length of S3 is etched in the middle of the square radiation patch.

[0012] Preferably, the port 1 is composed of a horizontal gradient strip, a horizontal uniform strip and three vertical uniform strips, the horizontal gradient strip has a starting width of W1 and a terminal width of W2, the horizontal uniform strip is connected to a side of the horizontal gradient strip with a width of W2, the horizontal uniform strip has a width of W3, and the distance between the end of the horizontal uniform strip and the center of the dielectric substrate layer is defined as L off One of the vertical uniform belts is L1 away from the port, has a width of w1 and a length of l1; one of the vertical uniform belts is L2 away from the port, has a width of w2 and a length of l2; and one of the vertical uniform belts is L3 away from the port, has a width of w3 and a length of l3.

[0013] Preferably, the two ports are composed of two curved belts and a vertical belt, wherein the curved belt is arranged in an L shape and includes a width of w head , a horizontal segment of length x1 and width w head , a vertical segment of length x2, a curved belt including a vertical segment of width w neck , a vertical segment with a length of x3 and a slot segment, wherein the slot segment has a width of w hole , depth h hole , the vertical belt width is w tail , length l tail .

[0014] Preferably, G is 300 mm, h is 5 mm, S1 is 200 mm, S2 is 85 mm, S3 is 60 mm, L pad 85mm, W 20mm, L 84mm, W1 10mm, W2 18mm, W3 16mm, L off 32mm, L1 is 16mm, L2 is 38mm, L3 is 72mm, l1 is 24mm, l2 is 38mm, l3 is 46mm, w1 is 8mm, w2 is 5mm, w3 is 6mm, w head 6mm, x1 is 32mm, x2 is 15mm, w neck 3mm, x3 is 14mm, w hole 11mm, h hole 32mm, w tail1mm, l tail It is 18mm.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The present invention arranges a dielectric substrate layer, a microstrip resonant feeding structure layer and a radiation patch layer to form a flexible wearable antenna, and specially designs the structures of the dielectric substrate layer, the microstrip resonant feeding structure layer and the radiation patch layer. The formed antenna has an impedance bandwidth covering 300-1200MHz, an isolation degree of more than 12dB, and can achieve quasi-omnidirectional radiation. The dual ports respectively excite horizontal polarization and vertical polarization modes, and the average gains are respectively greater than 4.74dBi and 3.82dBi, and have good mechanical robustness. In the actual wearing process, it can be effectively applied to modern emergency communication scenarios and complex and diverse emergency rescue actions, and effectively reduces the influence of bending, wrinkling and fracture on the robustness of the antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the antenna structure of the present invention;

[0018] Figure 2 It is a schematic diagram of the structure of the radiation patch layer of the present invention;

[0019] Figure 3 It is a schematic diagram of the side structure of the antenna of the present invention;

[0020] Figure 4 It is a schematic diagram of the structure of the microstrip resonant feeding structure layer of the present invention;

[0021] Figure 5 Schematic diagram of the change of the dual-port reflection coefficient curve with S1 of the present invention, a is port 1, b is port 2;

[0022] Figure 6 Schematic diagram of the reflection coefficient curve of the dual port of the present invention changing with S3, a is port 1, b is port 2;

[0023] Figure 7 Schematic diagram of the reflection coefficient curve of the dual port of the present invention changing with W, a is port 1, b is port 2;

[0024] Figure 8 Schematic diagram of the reflection coefficient curve of the dual port of the present invention changing with L, a is port 1, b is port 2;

[0025] Fig. 9 The reflection coefficient curve of port 1 of the present invention changes with L off Schematic diagram of the changes;

[0026] Fig.10 It is a schematic diagram of the change of the reflection coefficient curve of port 1 with l3 of the present invention;

[0027] Fig.11 It is a schematic diagram of the reflection coefficient curve of port 1 of the present invention as L3 changes;

[0028] Fig.12 (a) Reflection coefficient curve and (b) gain curve of the two ports of the present invention as w hole Schematic diagram of the changes;

[0029] Fig.13 (a) Reflection coefficient curve and (b) gain curve of the two ports of the present invention as h increases hole Schematic diagram of the changes;

[0030] Fig.14 The reflection coefficient curve of the two ports of the present invention changes with l tail Schematic diagram of the changes;

[0031] Fig.15 Schematic diagram of (a) impedance bandwidth and (b) isolation of the antenna dual port of the present invention;

[0032] Fig.16 The E-surface radiation patterns of the 1-port excitation of the present invention at various frequencies (a) 300 MHz (b) 600 MHz (c) 1200 MHz;

[0033] Fig.17 The E-surface radiation patterns of the 2-port excitation of the present invention at various frequencies (a) 300 MHz (b) 600 MHz (c) 1200 MHz;

[0034] Fig.18 It is the antenna gain curve diagram of the present invention. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] Example:

[0037] See also Figure 1 - Fig.18 As shown, a low-profile dual-polarization ultra-wideband flexible wearable antenna comprises:

[0038] A dielectric substrate layer, wherein the dielectric substrate layer is made of Kevlar flexible fiber;

[0039] A microstrip resonant feeding structure layer, wherein the microstrip resonant feeding structure layer is arranged on one side of the dielectric substrate layer, and the microstrip resonant feeding structure layer is provided with two ports, port 1 and port 2, and the port 1 and port 2 are arranged opposite to each other;

[0040] The radiation patch layer is arranged on the other side of the dielectric substrate layer, and a plurality of gaps are arranged on the radiation patch layer.

[0041] This new type of material has low density, high strength, good toughness, high temperature resistance, and is easy to process and form. Its strength is five times that of steel of the same quality, but its density is only one-fifth of that of steel (Kevlar density is 1.44g / cm3, and steel density is 7.859g / cm3), and it has attracted people's attention.

[0042] The microstrip resonant feeding structure layer and the radiation patch layer both use microwave electromagnetic shielding anti-radiation fabric as the conductive material. The fabric is made of polyester taffeta after pre-treatment, combined with chemical plating and electroplating process to cover the metal shielding layer to make it conductive, and then coated with acrylic conductive pressure-sensitive adhesive through a special process to form an electromagnetic shielding conductive fabric. The thickness is 0.08±0.01mm, and the surface resistance is ≤0.05Ω

[0043] / square, the shielding effectiveness can reach 44.1-82.7dB in the range of 30MHz-40GHz.

[0044] The dielectric substrate layer is defined to have a width of G and a thickness of h.

[0045] The width of the radiation patch layer is the same as that of the dielectric basic layer. An outer square gap is etched in the middle of the radiation patch layer. The side length of the outer square gap is defined as S1, which can effectively excite the vertical polarization low-frequency resonance mode of port 1. In order to excite the horizontal polarization low-frequency resonance mode of port 2, one corner of the outer square gap is filled with a length of L. pad A metal sheet is provided with a rectangular groove with a groove width of W and a groove depth of L. A square radiation patch with a side length of S2 is arranged in the middle of the outer square gap, which can effectively expand the antenna bandwidth, and a square gap with a side length of S3 is etched in the middle of the square radiation patch, which can effectively excite the intermediate frequency resonance mode.

[0046] The port 1 is composed of a horizontal gradient strip, a horizontal uniform strip and three vertical uniform strips. The width of the horizontal gradient strip at the beginning is W1 and the width of the end is W2. The gradient strip is mainly fed by the upper layer S1 slot, effectively excites the low-frequency resonance mode, and plays a role in impedance matching. The horizontal uniform strip is connected to the side of the horizontal gradient strip with a width of W2. The width of the horizontal uniform strip is W3. The distance between the end of the horizontal uniform strip and the center of the dielectric substrate layer is defined as L. offThe uniform strip is mainly used to feed the upper S2 slot to excite the mid-frequency resonance mode. The vertical strip is used to match the impedance and excite the high-frequency resonance mode, but it will excite a certain horizontal cross-polarization. One of the vertical uniform belts is L1 away from the port, has a width of w1 and a length of l1. One of the vertical uniform belts is L2 away from the port, has a width of w2 and a length of l2. One of the vertical uniform belts is L3 away from the port, has a width of w3 and a length of l3.

[0047] The 2-port is composed of two curved belts and a vertical belt, wherein the curved belt is arranged in an L shape and includes a width of w head , a horizontal segment of length x1 and width w head , a vertical segment of length x2, a curved belt including a vertical segment of width w neck , a vertical segment with a length of x3 and a slot segment, wherein the slot segment has a width of w hole , depth h hole , the vertical belt width is w tail , length l tail .

[0048] G is 300mm, h is 5mm, S1 is 200mm, S2 is 85mm, S3 is 60mm, L pad 85mm, W 20mm, L 84mm, W1 10mm, W2 18mm, W3 16mm, L off 32mm, L1 is 16mm, L2 is 38mm, L3 is 72mm, l1 is 24mm, l2 is 38mm, l3 is 46mm, w1 is 8mm, w2 is 5mm, w3 is 6mm, w head 6mm, x1 is 32mm, x2 is 15mm, w neck 3mm, x3 is 14mm, w hole 11mm, h hole 32mm, w tail 1mm, l tail It is 18mm.

[0049] When S1 changes in the range of 190mm-210mm with a step size of 5mm, it can be seen that as S1 increases, the low-frequency and medium-frequency resonant frequencies of port 1 move down, and the high-frequency resonant frequency moves up; the overall resonant frequency of port 2 moves slightly down, but the impact is not large. It can be seen that S1 mainly affects the impedance of port 1 when it is excited.

[0050] When S3 changes in the range of 50mm-70mm with a step size of 5mm, it can be seen that as S3 increases, the low-frequency resonant frequency of port 1 remains basically unchanged, while the mid-frequency and high-frequency resonant frequencies move downward; the resonant frequency of port 2 moves slightly downward as a whole, but the impact is not significant. It can be seen that S3 also mainly affects the impedance of port 1 when it is excited.

[0051] When W changes in the range of 10mm-30mm with a step length of 5mm, it can be seen that as W increases, the resonant frequency of port 1 remains basically unchanged; the resonant frequency of port 2 moves up as a whole, which shows that W mainly affects the impedance when port 2 is excited.

[0052] When L changes in the range of 68mm-84mm with a step length of 4mm, it can be seen that as L increases, the resonant frequency of port 1 remains basically unchanged; the resonant frequency of port 2 is excited from high frequency to medium frequency and then to low frequency, which shows that L mainly affects the impedance when port 2 is excited.

[0053] When L off When the range of 24mm-40mm is changed in 4mm steps, it can be seen that as L off As the L increases, the low-frequency resonance frequency and the intermediate-frequency resonance frequency of port 1 are getting closer and closer, and the high-frequency resonance frequency remains basically unchanged. off It has a great impact on low-frequency and medium-frequency impedance.

[0054] When l3 changes in the range of 42mm-50mm with a step size of 2mm, it can be seen that as l3 increases, the low-frequency resonant frequency and the intermediate-frequency resonant frequency of port 1 remain basically unchanged, but it will play a role in improving the impedance; the high-frequency resonant frequency is obviously shifted downward, which shows that l3 has a great influence on the high-frequency impedance, which also implies that the strip will also excite a certain cross-polarization.

[0055] When L3 changes in the range of 64mm-80mm with a step length of 4mm, it can be seen that as L3 increases, the low-frequency resonant frequency and intermediate-frequency resonant frequency of port 1 remain basically unchanged, but it will play a role in improving the impedance; the high-frequency resonant frequency is significantly shifted downward, and the impedance is significantly improved. It can be seen that L3 has a great influence on the high-frequency impedance.

[0056] When hole When the step length changes from 8mm to 16mm with a step length of 2mm, it can be seen that as w hole As w increases, the overall resonant frequency of the 2 ports moves downward, which has a great impact on impedance matching. hole As the diameter increases, the mid-frequency gain increases first and then decreases, reaching the maximum at 11mm, and the low-frequency and high-frequency gains increase.

[0057] When h hole When the range of 24mm-40mm is changed in steps of 4mm, it can be seen that as h holeAs h increases, the overall resonant frequency of the 2 ports moves downward, which has a great impact on impedance matching. hole As the diameter increases, the mid-frequency gain increases first and then decreases, reaching the maximum at 36mm, and the low-frequency and high-frequency gains increase.

[0058] When l tail When the step length changes from 12mm to 24mm with 3mm as the step length, it can be seen that as l tail As the impedance increases, the overall resonant frequency of the 2-port moves downward, which has a great impact on the low-frequency and medium-frequency impedance matching.

[0059] The High Frequency Structure Simulator (HFSS) full-wave simulation software is used to simulate and analyze the antenna, and the antenna performance is checked. When the two ports are excited separately, the impedance bandwidth covers 300-1200MHz, and the antenna reflection coefficient is less than -10dB. When the two ports are excited separately, the antenna isolation is above 12dB, which meets the conventional standards and has good isolation.

[0060] For 1-port excitation, the horizontal polarization mode is mainly excited, and its main radiation plane is the E-plane (the main radiation plane is the xOz plane). For 2-port excitation, the vertical polarization mode is mainly excited, and its main radiation plane is the E-plane (the main radiation plane is the yOz plane). When 1-port excitation is used, the antenna radiation pattern is quasi-omnidirectional. Below 900MHz, the main polarization is significantly greater than the cross-polarization. When the frequency reaches 900MHz, the cross-polarization increases. This is caused by the vertical strip resonance. It can be seen from the radiation pattern that when 2-port excitation is used, the main polarization is significantly greater than the cross-polarization antenna direction in the full frequency band. Figure 1 The radiation at one end (180°-360°) is greater than that at the other end (0°-180°), but the gain at the end with smaller radiation is still greater than 0dBi. When the frequency reaches about 1200MHz, it changes to quasi-omnidirectional radiation, but the gain decreases slightly, but is still greater than 0dBi. The maximum gain of port 1 is greater than 5.82dBi, and the average gain is greater than 4.74dBi; the maximum gain of port 2 is greater than 5.18dBi, and the average gain is greater than 3.82dBi.

[0061] The standard parts used in the present invention can all be purchased from the market, and the special-shaped parts can be customized according to the description and the drawings. The specific connection methods of each part adopt conventional means such as mature bolts, rivets, welding, etc. in the prior art. The machinery, parts and equipment all adopt conventional models in the prior art, and the circuit connection adopts the conventional connection method in the prior art, which will not be described in detail here. The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

[0062] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0063] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0064] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0065] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0066] In the drawings of the embodiments disclosed in the present invention, only the structures related to the embodiments disclosed in the present invention are involved, and other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of the present invention can be combined with each other.

Claims

1. A low-profile dual-polarized ultra-wideband flexible wearable antenna, It is characterized in that include: A dielectric substrate layer, wherein the dielectric substrate layer is made of Kevlar flexible fiber; A microstrip resonant feeding structure layer, wherein the microstrip resonant feeding structure layer is arranged on one side of the dielectric substrate layer, and the microstrip resonant feeding structure layer is provided with two ports, port 1 and port 2, and the port 1 and port 2 are arranged opposite to each other; The radiation patch layer is arranged on the other side of the dielectric substrate layer, and a plurality of gaps are arranged on the radiation patch layer.

2. A low-profile dual-polarization ultra-wideband flexible wearable antenna according to claim 1, Features: The microstrip resonant feeding structure layer and the radiation patch layer both use microwave electromagnetic shielding and radiation-proof fabric as conductive material.

3. The low-profile dual-polarization ultra-wideband flexible wearable antenna according to claim 2, Features: The dielectric substrate layer is defined to have a width of G and a thickness of h.

4. The low-profile dual-polarization ultra-wideband flexible wearable antenna according to claim 3, Features: The width of the radiation patch layer is the same as the width of the dielectric basic layer. An outer square gap is etched in the middle of the radiation patch layer, and the side length of the outer square gap is defined as S. 1 The outer square gap is filled with a length of L at one corner. pad A metal sheet having a rectangular groove with a groove width of W and a groove depth of L is provided on the metal sheet, and a side length of S is provided in the middle of the outer square gap 2 A square radiation patch with a side length of S is etched in the middle of the square radiation patch. 3 square gap.

5. A low-profile dual-polarization ultra-wideband flexible wearable antenna according to claim 4, Features: The port 1 is composed of a horizontal gradient strip, a horizontal uniform strip and three vertical uniform strips. The width of the horizontal gradient strip at the beginning is W. 1 , terminal width is W 2 The horizontal uniform strip is connected to the horizontal gradient strip with a width of W. 2 On one side, the horizontal uniform strip width is W 3 , define the distance between the end of the horizontal uniform strip and the center of the dielectric substrate layer as L off , one of the vertical uniform belt distance ports is L 1 , width is w 1 , length l 1 , one of the vertical uniform belt distance ports is L 2 , width is w 2 , length l 2 , one of the vertical uniform belt distance ports is L 3 , width is w 3 , length l 3 .

6. The low-profile dual-polarization ultra-wideband flexible wearable antenna according to claim 5, Features: The 2-port is composed of two curved belts and a vertical belt, wherein the curved belt is arranged in an L shape and includes a width of w head , length x 1 The horizontal segment and width is w head , length x 2 A curved belt includes a vertical segment with a width of w neck , length x 3 The vertical section and the slot section, the width of the slot section is w hole , depth h hole , the vertical belt width is w tail , length l tail .

7. The low-profile dual-polarization ultra-wideband flexible wearable antenna according to claim 6, Features: The G is 300 mm, h is 5 mm, S 1 200mm, S 2 85mm, S 3 60mm, L pad 85mm, W 20mm, L 84mm, W 1 10mm, W 2 18mm, W 3 16mm, L off 32mm, L 1 16mm, L 2 38mm, L 3 72mm, l 1 24mm, l 2 38mm, l 3 46mm, w 1 8mm, w 2 5mm, w 3 6mm, w head 6mm, x 1 32mm, x 2 15mm, w neck 3mm, x 3 14mm, w hole 11mm, h hole 32mm, w tail 1mm, l tail It is 18mm.

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