Protective antenna based on coupling structure

Abstract

The invention belongs to the technical field of antennas, and relates to a protective antenna based on a coupling structure, which comprises a patch layer, a first dielectric layer, a floor layer, a second dielectric layer and a feed layer which are sequentially stacked from top to bottom, and is characterized in that the patch layer comprises a plurality of radiation patches; the floor layer is provided with a coupling groove for coupling feeding; a plurality of connecting strips are arranged in the coupling groove, and the two ends of each connecting strip are connected with the two long edges of the coupling groove respectively; the connecting strip is provided with a pair of diodes in opposite directions so as to realize antenna protection; and a feed structure is arranged on the feed layer. According to the invention, protection function loading can be carried out on the coupling structure on the floor layer so as to carry out strong electromagnetic protection on the antenna.

Description

Technical Field

[0001] The present application relates to the technical field of antennas, and particularly to a protective antenna based on a coupling structure. Background Art

[0002] In recent years, with the progress of electronic technology, the RF front-end link has been continuously developing towards miniaturization and integration. The rated operating powers of various devices vary, which inevitably affects each other, and the electromagnetic compatibility problem has become increasingly severe. Coupled with the threat of strong electromagnetic pulses in the future electromagnetic space, the demand for protecting the RF front-end is becoming increasingly urgent. However, the application method of traditional energy selection protection technology still mainly adds components before and after the antenna, rather than integrating with the antenna, which brings the problem of insufficient compatibility. To further improve the compatibility between protection and the original antenna, it is necessary to study the integrated design method of the energy selection protection function and the antenna, and the protective antenna emerges as the times require.

[0003] In the prior art, there is little research on protective antennas. The main ideas include: achieving null in the main lobe by phase defocusing of the reflector surface, achieving protection by loading the feeding structure, and achieving resonance frequency offset by loading the radiation resonant structure.

[0004] However, each of the above-mentioned prior arts has its own disadvantages: for the reflector surface defocusing type protective antenna, its protection has spatial selectivity, and the protection effect is only good in the main lobe direction, and the bandwidth is narrow; for the protective antenna with loaded feeding structure, there is a problem of insufficient withstand power; for the resonant reconfigurable protective antenna, there is a problem of narrow bandwidth. Summary of the Invention

[0005] Based on this, in view of the above technical problems, it is necessary to provide a protective antenna based on a coupling structure, which can load the protection function on the coupling structure on the floor layer to provide strong electromagnetic protection for the antenna.

[0006] A protective antenna based on a coupling structure includes, from top to bottom in sequence: a patch layer, a first dielectric layer, a floor layer, a second dielectric layer, and a feeding layer: The patch layer includes a plurality of radiation patches; A coupling slot is provided on the floor layer for coupling feeding; a plurality of connection bars are provided in the coupling slot, and two ends of each connection bar are respectively connected to two long sides of the coupling slot; a pair of diodes with opposite directions are provided on the connection bar to achieve antenna protection; A feeding structure is provided on the feeding layer.

[0007] In one embodiment, the length direction of the coupling slot is perpendicular to the length direction of the connection bar.

[0008] In one embodiment, the aspect ratio range of the coupling slot is [25, 26].

[0009] In one embodiment, the number of the connecting bars satisfies:

[0010] wherein, is the number of the connecting bars, is the ceiling function, is the length of the coupling slot, is the width of the coupling slot.

[0011] In one embodiment, it further includes: an air layer; The air layer is arranged between the first dielectric layer and the second dielectric layer.

[0012] In one embodiment, the second dielectric layer is a rectangular structure with a feeding port at one end, and the central axis where the feeding port is located is used as the axis of symmetry; The patch layer is axially symmetrically distributed with respect to the axis of symmetry, and includes: a plurality of radiating patches arranged in an array to form a metasurface structure; one diagonal of the radiating patch is parallel to the straight line where the axis of symmetry is located. In one embodiment, the patch layer includes: P first queues and Q second queues; wherein, P is an odd number and Q is an even number; The first queue includes P radiating patches arranged at intervals along the axis of symmetry direction, and the second queue includes Q radiating patches arranged at intervals along the axis of symmetry direction; The first queue and the second queue are alternately arranged in the direction perpendicular to the axis of symmetry, and there is an interval between adjacent queues, so that the adjacent sides of any radiating patch and the surrounding radiating patches are parallel.

[0013] In one embodiment, a matching slot is provided on the radiating patch located at the center of the patch layer; The matching slot is a strip-shaped structure with the length direction perpendicular to the axis of symmetry, and the matching slot is arranged at the position of the diagonal of the corresponding radiating patch.

[0014] In one embodiment, the feeding structure includes: a feeding wire; One end of the feeding wire is connected to the feeding port, and the other end extends along the direction away from the feeding port towards the center of the second dielectric layer.

[0015] In one embodiment, the feeding structure further includes: a feeding patch; The feeding patch is a fan-shaped structure axially symmetrically distributed with respect to the feeding wire, and the angular end of the fan-shaped structure is connected to the other end of the feeding wire.

[0016] The above-mentioned protective antenna based on the coupling structure has good in-band impedance matching between the coupling structure and the upper radiation structure and the lower feeding structure under normal working conditions. After loading the protection function on the coupling structure on the floor layer, the cut-off frequency of the coupling structure is significantly improved, and the impedance in the original working frequency band is imaginary, resulting in impedance mismatch, causing the signal to transmit through the normal direction, converting the local high impedance into low impedance to achieve reflection (in the prior art, for the protection loading based on the defected ground, the metal ground is of low impedance, preventing the signal from transmitting through and making it transmit tangentially along its surface, which is to convert the low-impedance metal ground into local high impedance), so as to perform strong electromagnetic protection on the antenna, improve the working frequency band and the tolerance power, reduce the insertion loss, making the antenna have the characteristics of high integration, wide working frequency band, high tolerance power, low insertion loss, and wide working frequency band, and realizing the ultra-wideband performance. Description of the Drawings

[0017] Figure 1 Schematic perspective view of a protective antenna based on a coupling structure in an embodiment; Figure 2 Side view of a protective antenna based on a coupling structure in an embodiment; Figure 3 Schematic diagram of the patch layer of a protective antenna based on a coupling structure in an embodiment; Figure 4 Schematic diagram of the floor layer of a protective antenna based on a coupling structure in an embodiment; Figure 5 Schematic diagram of the feeding layer of a protective antenna based on a coupling structure in an embodiment; Figure 6 Reflection coefficient diagram of a protective antenna based on a coupling structure in an embodiment; Figure 7 Gain schematic diagram of a protective antenna based on a coupling structure in an embodiment; Figure 8 Physical diagram of the patch layer of a protective antenna based on a coupling structure in an embodiment; Figure 9 Physical diagram of the floor layer of a protective antenna based on a coupling structure in an embodiment; Figure 10 Physical diagram of the feeding layer of a protective antenna based on a coupling structure in an embodiment; Figure 11 Protective time-domain waveform diagram of a protective antenna based on a coupling structure in an embodiment; Figure 12 Comparison diagram of simulation and actual measurement of the protection effectiveness of a protective antenna based on a coupling structure in an embodiment.

[0018] Reference Signs: Patch layer 1, radiation patch 11, matching slot 12; First dielectric layer 2; Air layer 3; Ground layer 4, coupling slot 41, connection bar 42, diode 43; Second dielectric layer 5; Feeding layer 6, feeding wire 61, feeding patch 62; Fixing post 71, feeding port 72, mounting hole 73. Detailed implementation mode

[0019] In order to make the purpose, technical solutions and advantages of this application clearer, the following further details this application in combination with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not used to limit this application. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of this application.

[0020] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of this application are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0021] In addition, the descriptions such as "first" and "second" in this application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of this application, the meaning of "multiple groups" is at least two groups, such as two groups, three groups, etc., unless otherwise specifically defined.

[0022] In this application, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection, an electrical connection, a physical connection or a wireless communication connection; it can be directly connected, or indirectly connected through an intermediate medium, and can be the connection inside two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific situations.

[0023] In addition, the technical solutions between the various embodiments of the present application can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present application.

[0024] The present application provides a protective antenna based on a coupling structure. As Figures 1 to 5 shown, in one embodiment, it includes: a patch layer, a first dielectric layer, a ground layer, a second dielectric layer, and a feeding layer. Among them, the patch layer, the first dielectric layer, the ground layer, the second dielectric layer, and the feeding layer are stacked in sequence from top to bottom. The ground layer is the same size as the second dielectric layer and larger than the first dielectric layer, so as to connect a feeding port at one end of the second dielectric layer.

[0025] The first dielectric layer and the second dielectric layer are load-bearing layers, both of which are rectangular structures. Among them, the first dielectric layer is square, and the second dielectric layer is rectangular; with the central axis where the feeding port is located on the second dielectric layer as the axis of symmetry.

[0026] The patch layer is axially symmetrically distributed with respect to the axis of symmetry, and includes a plurality of radiation patches to form a radiation structure for radiating electromagnetic waves.

[0027] A coupling slot is provided on the ground layer. The coupling slot is a strip-shaped structure with its length direction perpendicular to the axis of symmetry to couple the lower-layer current to the upper layer for coupled feeding; the coupling slot is a rectangular structure, and a plurality of connecting strips are provided in the coupling slot. The two ends of the connecting strip are respectively connected to the two long sides of the coupling slot to load a plurality of parallel structures on the same slot, thereby sharing the current, improving the power tolerance, not affecting the impedance matching, and also reducing the insertion loss; a pair of diodes with opposite directions are provided on the connecting strip (specifically: the connecting strip includes a first section and two second sections. The two ends of the first section are respectively connected to a corresponding end of the second section through a diode, and the other corresponding end of the second section is connected to the two long sides of the coupling slot). The coupling slot, the connecting strip, and the diode together form a coupling structure to achieve antenna protection.

[0028] A feeding structure is provided on the feeding layer for feeding.

[0029] Preferably, the length direction of the coupling slot is perpendicular to the length direction of the connecting strip, so that the length direction of the connecting strip is consistent with the electric field direction in the coupling structure, and when the diode is activated, the electric field isolation in this polarization direction is realized, improving the protection efficiency.

[0030] Further preferably, the aspect ratio range of the coupling slot is [25, 26], so that the LC resonance frequency of the coupling slot matches the coupling electric field, ensuring that the cut-off frequency of the passable mode can be passed and ensuring that the lower limit of the operating frequency is low enough.

[0031] More preferably, the connecting bars are distributed at unequal intervals to make the field distribution uneven, better match at the nodes, and improve the protection effect.

[0032] More preferably, the period of the connecting bars is 1 / 20 of the length of the coupling slot, and the number of the connecting bars satisfies the following formula to cover the range where the electric field is located and improve the protection effect:

[0033] In the formula, is the number of the connecting bars, is rounding up, is the length of the coupling slot, is the width of the coupling slot.

[0034] In one embodiment, it further includes: an air layer; the air layer is arranged between the first dielectric layer and the second dielectric layer. More specifically, the air layer is arranged between the first dielectric layer and the floor layer to reduce loss, have the characteristic of low loss, and reduce the processing cost.

[0035] In one embodiment, the patch layer includes: a plurality of square radiating patches arranged in an array to form a metasurface structure; one diagonal of the radiating patch is parallel to the straight line where the symmetry axis is located to generate more surface current modes, so that the surface current of the radiating structure is decomposed into orthogonal mode currents perpendicular to the sides of the square, which is beneficial to broadband matching. Preferably, the patch layer includes: P first queues and Q second queues; where P is an odd number and Q is an even number; the first queue includes P radiating patches arranged at intervals along the symmetry axis direction, and the second queue includes Q radiating patches arranged at intervals along the symmetry axis direction; the first queue and the second queue are alternately arranged in the direction perpendicular to the symmetry axis, and there is an interval between adjacent queues, so that the adjacent sides of any radiating patch and the surrounding radiating patches are parallel to ensure the symmetry of the entire radiating structure and achieve an excellent main lobe perpendicular to the side radiation pattern of the antenna.

[0036] More preferably, a matching slot is provided on the radiating patch located at the center of the patch layer; the matching slot is a strip structure with a length direction perpendicular to the symmetry axis, and the matching slot is arranged at the position of the diagonal of the corresponding radiating patch to divide the radiating patch where the matching slot is located into two symmetrically spaced parts. The setting of the matching slot makes the low-impedance slot structure match the high-impedance radiating patch, which is beneficial to improving the impedance matching effect of the antenna and enhancing the radiation performance.

[0037] In one embodiment, the feeding structure includes: a feeding wire; one end of the feeding wire is connected to the feeding port, and the other end extends along the direction away from the feeding port towards the center of the second dielectric layer to maintain symmetry and ensure that the performances of the two transceiver ports are basically the same.

[0038] Preferably, the feeding structure further includes: a feeding sheet; the feeding sheet is a fan-shaped structure symmetrically distributed about the feeding line, and the angular ends of the fan-shaped structure are connected to the other end of the feeding line for matching between the feeding line and the coupling slot structure.

[0039] In the present application, the antenna further includes: a non-metallic fixing post (such as a nylon stud) that penetrates through the first dielectric layer, the floor layer, and the second dielectric layer to make the antenna a stable whole.

[0040] The working process of the antenna is as follows: a solderless SMA to microstrip line connector is installed through the SMA connector hole at the feeding port for feeding, and then it is coupled to the radiation patch of the patch layer through the coupling slot on the metal floor layer and radiated into the free space; when a normal working signal is transmitted to the antenna, the diode is in the cut-off state and can be normally transmitted to the feeding structure; when a strong electromagnetic wave signal irradiates the antenna, the diode is in the conducting state, and at this time the electromagnetic energy is reflected and cannot be transmitted to the feeding structure, thus achieving protection.

[0041] For the above-mentioned protection antenna based on the coupling structure, in the normal working state, the coupling structure has good impedance matching in the passband with the upper radiation structure and the lower feeding structure. After loading the protection function on the coupling structure on the floor layer, the cut-off frequency of the coupling structure is significantly improved, and the impedance in the original working frequency band is imaginary, resulting in impedance mismatch, causing the signal to be transmitted through the normal direction, converting the local high impedance into low impedance to achieve reflection (in the prior art, for the protection loading based on the defected ground, the metal ground is of low impedance and does not allow the signal to pass through but transmits along its surface tangentially, which is to convert the low-impedance metal ground into local high impedance), so as to perform strong electromagnetic protection on the antenna, improve the working frequency band and the tolerance power, reduce the insertion loss, and enable the antenna to have the characteristics of high integration, wide working frequency band, high tolerance power, low insertion loss, and wide working frequency band, achieving ultra-wideband performance.

[0042] In a specific embodiment, the size parameters of the antenna are shown in Table 1.

[0043] Table 1: Size parameters of the antenna

[0044] The above antenna is simulated, such as Figure 6 the reflection coefficient diagram of the antenna shown, and such as Figure 7 the gain schematic diagram of the antenna shown. It can be seen that the antenna standing wave is significantly improved, the working frequency band is broadened to 7.1 GHz to 10.2 GHz, the antenna gain reaches more than 10 dBi at most, and the protection efficiency reaches more than 15 dB.

[0045] Such as Figures 8 to 10The shown physical diagram is irradiated with a high-power microwave source with a frequency of 5.8 GHz and a pulse width of 30 ns. The field strength at the position of the antenna aperture is about 19440 V / m. The field strength receiving antennas are respectively a protective antenna and a control antenna, which are connected to a transmission oscilloscope through an attenuator and a detector, and the signal intensities received by the protective antenna and the control antenna are compared to conduct physical tests.

[0046] As Figure 11 Shown in the time-domain waveform diagram of the protection of the antenna, it can be seen that there is an obvious attenuation of the received signal when the protective antenna is used, and the attenuation value is about 16 dB.

[0047] As Figure 12 Shown in the comparison diagram of the simulation and actual measurement of the protection effectiveness of the antenna, it can be seen that the actual measurement is basically consistent with the simulation prediction.

[0048] The content not described in detail in this specification belongs to the prior art well-known to those skilled in the art.

[0049] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0050] The above-described embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several deformations and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A protective antenna based on a coupling structure, characterized in that: It includes the following stacked layers from top to bottom: patch layer, first dielectric layer, floor layer, second dielectric layer and feed layer: The patch layer includes a plurality of radiation patches; A coupling slot is provided on the floor layer for coupling and feeding; a plurality of connecting strips are provided in the coupling slot, and the two ends of the connecting strips are respectively connected to the two long sides of the coupling slot; a pair of diodes in opposite directions are provided on the connecting strips to realize antenna protection; A feeding structure is provided on the feeding layer.

2. The protective antenna based on a coupling structure according to claim 1, characterized in that: The length direction of the coupling slot is perpendicular to the length direction of the connecting bar.

3. The protective antenna based on a coupling structure according to claim 2, characterized in that: The aspect ratio range of the coupling slot is [25,26].

4. The protective antenna based on a coupling structure according to claim 3, characterized in that: The number of the connecting strips meets the following requirements: In the formula, is the number of connecting strips, To round up, is the length of the coupling slot, is the width of the coupling slot.

5. The protective antenna based on a coupling structure according to any one of claims 1 to 4, characterized in that: Also includes: Air layer; The air layer is provided between the first dielectric layer and the second dielectric layer.

6. The protective antenna based on a coupling structure according to any one of claims 1 to 4, characterized in that: The second dielectric layer is a rectangular structure with a feeding port at one end, and the central axis where the feeding port is located is the symmetry axis; The patch layer is axially symmetrically distributed about the symmetry axis, and includes: a plurality of radiation patches arranged in an array to form a metasurface structure; A diagonal line of the radiation patch is parallel to the straight line where the symmetry axis is located.

7. The protective antenna based on a coupling structure according to claim 6, characterized in that: The patch layer includes: P first queues and Q second queues; wherein P is an odd number and Q is an even number; The first queue includes P radiation patches spaced apart along the symmetry axis, and the second queue includes Q radiation patches spaced apart along the symmetry axis; The first queue and the second queue are alternately arranged in a direction perpendicular to the symmetry axis, and intervals are provided between adjacent queues, so that any radiation patch is parallel to adjacent sides of surrounding radiation patches.

8. The protective antenna based on a coupling structure according to claim 7, characterized in that: A matching groove is provided on the radiation patch located at the center of the patch layer; The matching slot is a strip structure whose length direction is perpendicular to the symmetry axis, and the matching slot is arranged at a position corresponding to the diagonal line of the radiation patch.

9. The protective antenna based on a coupling structure according to any one of claims 1 to 4, characterized in that: The feeding structure comprises: a feeding line; One end of the feed line is connected to the feed port, and the other end extends toward the center of the second dielectric layer along a direction away from the feed port.

10. The protective antenna based on a coupling structure according to claim 9, characterized in that: The feeding structure further includes: a feeding sheet; The feed sheet is a fan-shaped structure that is axially symmetrically distributed about the feed line, and a corner end of the fan-shaped structure is connected to the other end of the feed line.

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