Low-pass, wide-stopband dual-polarized frequency selective structure, radome and antenna system

Abstract

This invention discloses a low-pass, wide-stopband, large-angle stable dual-polarized frequency selective structure, radome, and antenna system. It includes two low-pass frequency selective layers, each comprising horizontal and vertical components arranged perpendicularly to each other. Each horizontal and vertical component includes two basic components and an outer dielectric plate with a cutout between them. The basic components include an inner dielectric plate with a cutout and L-shaped conductive geometries on both sides. Each side of the inner dielectric plate has edge metal strips along its length, divided into multiple segments. A middle metal strip is located at each slot in the inner dielectric plate. The middle metal strip connects to a corresponding edge metal strip segment to form an L-shaped conductor. Multiple L-shaped conductors constitute the L-shaped conductive geometry. This invention solves the problems of existing technologies that cannot simultaneously guarantee low insertion loss in the passband, ultra-wide stopband, large-angle stability, dual polarization, and poor suppression of electromagnetic waves outside the operating frequency band. Furthermore, it is easy to manufacture.

Description

Technical Field

[0001] This invention relates to the field of antenna technology, and more specifically, to a low-pass, wide-stopband, large-angle stable dual-polarized frequency selection structure, radome, and antenna system. Background Technology

[0002] Typically, antenna systems are fitted with radomes to protect them from the effects of wind, sand, rain, snow, frost, dust, and solar radiation, ensuring stable and reliable operation. Radomes also reduce wear, corrosion, and aging, extending the antenna system's lifespan. However, as a medium, the radome can absorb and reflect electromagnetic waves, which can affect the antenna system's performance to some extent.

[0003] Existing radomes are made of pure materials or frequency-selective structures. Radomes made of pure materials have limited wave transmission capabilities and cannot effectively suppress electromagnetic waves outside the operating frequency band, making them susceptible to out-of-band interference that can affect the normal operation of the antenna system. Existing low-pass radomes made of frequency-selective structures suffer from problems such as high passband insertion loss, narrow stopband, poor angular stability, or single polarization, severely limiting their applications. Summary of the Invention

[0004] To address the problems existing in the background technology, the main objective of this invention is to provide a low-pass, wide-stopband, large-angle stable dual-polarized frequency selection structure, radome, and antenna system. This solves the problems of existing technologies being unable to simultaneously guarantee low insertion loss in the passband, ultra-wide stopband, large-angle stability, dual polarization, and poor suppression of electromagnetic waves outside the operating frequency band. Moreover, it is easy to manufacture and has great application value in modern communication, radar, and other fields.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] The present invention includes two identical low-pass frequency selection layers. Each low-pass frequency selection layer includes two types of components: a horizontal component and a vertical component. Each component consists of a dielectric substrate with slots and multiple conductive geometric structures disposed on both sides of the dielectric substrate.

[0007] The two low-pass frequency selection layers are arranged alternately, and each low-pass frequency selection layer is composed of horizontally arranged horizontal components and vertically arranged vertical components arranged perpendicularly and intersecting each other.

[0008] Both the horizontal and vertical components include two identical basic components and an outer dielectric plate with grooves. The two basic components and the outer dielectric plate are stacked, with the outer dielectric plate positioned between the two basic components. Each basic component includes an inner dielectric plate with grooves and multiple L-shaped conductive geometric structures disposed on both sides of the inner dielectric plate. Each side of the inner dielectric plate has an edge metal strip along its length direction. The inner and outer dielectric plates of the two basic components have multiple strip-shaped through-slots spaced apart along the same side along their length direction. The strip direction of each strip-shaped through-slot is perpendicular to the side direction. The edge metal strips on both sides of the inner dielectric plate are removed at the intersection with the strip direction of each strip-shaped through-slot, thus dividing the edge metal strips on each side edge into multiple segments. The inner dielectric plate has a middle metal strip at each strip-shaped through-slot. The middle metal strip and its corresponding edge metal strip segment are connected to form an L-shaped conductor. Multiple L-shaped conductors constitute an L-shaped conductive geometric structure.

[0009] The horizontal and vertical components are arranged in a mirror-symmetric manner.

[0010] The inner medium plate is arranged in the following manner at each strip slot:

[0011] A) On both sides of the inner medium plate along the length of the inner medium plate and on the same side of the strip groove:

[0012] A first metal strip is provided on one side surface of the inner dielectric plate, which is parallel to the strip-shaped through groove and adjacent to one side of the strip-shaped through groove. A section of side metal strip located on the same side surface of the inner dielectric plate as the first metal strip, located on the same side as the first metal strip and adjacent to the strip-shaped through groove along the length direction of the inner dielectric plate, is connected to the first metal strip to form a single L-shaped conductor.

[0013] A second metal strip is provided on the other side surface of the inner dielectric plate, parallel to the strip-shaped through groove and adjacent to the other side of the strip-shaped through groove. A section of the side metal strip located on the same side surface of the inner dielectric plate as the second metal strip, and located on the same side as the second metal strip along the length direction of the inner dielectric plate and adjacent to the strip-shaped through groove, is connected to the second metal strip to form a single L-shaped conductor.

[0014] B) On the two sides of the inner medium plate along the length of the inner medium plate and on opposite sides of the strip slot:

[0015] A third metal strip parallel to the strip groove and along the second metal strip is provided on one side surface of the inner dielectric plate. A section of the third metal strip located on the same side surface of the inner dielectric plate, on the same side as the third metal strip and adjacent to the strip groove on the opposite side along the length direction of the inner dielectric plate, is connected to the third metal strip to form a single L-shaped conductor.

[0016] A fourth metal strip parallel to the strip-shaped through groove and along the first metal strip is provided on the other side surface of the inner dielectric plate. A section of the fourth metal strip located on the same side surface of the inner dielectric plate, on the same side as the fourth metal strip and adjacent to the strip-shaped through groove along the length direction of the inner dielectric plate but on the opposite side, is connected to the fourth metal strip to form a single L-shaped conductor.

[0017] The lengths of the first, second, third, and fourth metal strips are all greater than or equal to the length of the strip-shaped through groove, and the length of the strip-shaped through groove is half the width of the inner dielectric plate.

[0018] Multiple horizontal components are arranged in parallel at intervals along the vertical direction, and multiple vertical components are arranged in parallel at intervals along the horizontal direction. The strip slots of the horizontal components are inserted into the opposite side of the strip slots of the vertical components to form a mortise and tenon joint structure, so that the horizontal and vertical components are arranged orthogonally and perpendicularly to form a low-pass frequency selection layer.

[0019] The two low-pass frequency selection layers have the same structure but different local dimensions.

[0020] According to the technical solution of the present invention, the low-pass, wide-stopband, large-angle stable dual-polarization frequency selection structure includes a first low-pass frequency selection layer and a second low-pass frequency selection layer. The conductive geometry of both low-pass frequency selection layers is L-shaped. The components of both low-pass frequency selection layers are slotted. Each low-pass frequency selection layer is composed of two types of components interlocked together. The dielectric materials of the two low-pass frequency selection layers are the same or different.

[0021] The low-pass structure described in this invention allows low-frequency electromagnetic waves to pass through while significantly suppressing high-frequency electromagnetic waves, making them almost impossible to pass through. The low-pass frequency selection layer refers to a frequency selection structure with the aforementioned low-pass performance.

[0022] The wide stopband refers to a wide suppression frequency bandwidth, and the large angle stability means that when electromagnetic waves irradiate the frequency selection structure at a large oblique incident angle, the response of the frequency selection structure can still remain almost the same as the response when the electromagnetic waves are incident at a 0° incident angle.

[0023] When the incident angle is greater than or equal to 60°, the structure's response remains stable, which is generally referred to as having large-angle stability.

[0024] The beneficial results of this invention are:

[0025] The structure of this invention enables electromagnetic waves within the antenna's operating frequency band to penetrate efficiently, while electromagnetic waves outside the operating frequency band can be effectively suppressed in the ultra-wideband range. Moreover, the structure can achieve 60° angular stability under both TE and TM polarization conditions, thus solving the problem that existing technologies cannot simultaneously guarantee low insertion loss in the passband, wide stopband, large angle stability, and dual polarization, and is also simple to manufacture. Attached Figure Description

[0026] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0027] Figure 1 A three-dimensional schematic diagram of the low-pass, wide-stopband, large-angle stable dual-polarization frequency selection structure provided by the present invention is shown.

[0028] Figure 2 A three-dimensional schematic diagram of the horizontal and vertical components of the first low-pass frequency selection layer is shown;

[0029] Figure 3 A three-dimensional exploded schematic diagram of the first low-pass frequency selection layer horizontal component is shown;

[0030] Figure 4 A three-dimensional exploded schematic diagram of the vertical component of the first low-pass frequency selection layer is shown;

[0031] Figure 5 A three-dimensional exploded schematic diagram of the basic components of the horizontal component and the basic components of the vertical component of the first low-pass frequency selection layer is shown.

[0032] Figure 6 A schematic diagram of key parameters of the basic components is shown;

[0033] Figure 7 It shows Figure 1 A schematic diagram of the transmission coefficient simulation curves of a preferred embodiment of a low-pass, wide-stopband, large-angle stable dual-polarization frequency selection structure in TE mode at electromagnetic wave incident angles of 0°, 30°, and 60°.

[0034] Figure 8 It shows Figure 1 A schematic diagram of the transmission coefficient simulation curves of a preferred embodiment of a low-pass, wide-stopband, large-angle stable dual-polarization frequency selection structure in TM mode at electromagnetic wave incident angles of 0°, 30°, and 60°.

[0035] Figure 9 This is a three-dimensional schematic diagram with perspective effect of the low-pass, wide-stopband, large-angle stable dual-polarization frequency selection structure provided by the present invention.

[0036] The above figures include the following reference numerals:

[0037] 1000, First low-pass frequency selection layer;

[0038] 1100, Horizontal component of the first low-pass frequency selection layer; 1110, Horizontal basic component of the first low-pass frequency selection layer; 1111, 1112, 1113, 1114, Horizontal L-shaped conductive geometry of the horizontal basic component of the first low-pass frequency selection layer; 1115, Horizontal inner dielectric plate with slots of the horizontal basic component of the first low-pass frequency selection layer; 1120, Horizontal outer dielectric plate with slots of the horizontal basic component of the first low-pass frequency selection layer;

[0039] 1200, Vertical component of the first low-pass frequency selection layer; 1210, Vertical basic component of the first low-pass frequency selection layer; 1211, 1212, 1213, 1214, Vertical L-shaped conductive geometry of the vertical basic component of the first low-pass frequency selection layer; 1215, Vertical inner dielectric plate with slots of the vertical basic component of the first low-pass frequency selection layer; 1220, Vertical outer dielectric plate with slots of the vertical basic component of the first low-pass frequency selection layer;

[0040] 2000, Second Low-Pass Frequency Selection Layer;

[0041] a The unit cycle of the basic component structure; w The width of the conductor; s The minimum distance between the middle metal strip and the strip-shaped through slot; d The thickness of the dielectric substrate; l1 The length of the metal strip in the middle; l2 Width of the medium plate. Detailed Implementation

[0042] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0043] like Figure 1 As shown, the specific implementation structure includes two low-pass frequency selection layers with the same structure but different local dimensions. Each low-pass frequency selection layer includes two types of components: a horizontal component 1100 and a vertical component 1200. Each component consists of a dielectric substrate with slots and multiple conductive geometric structures disposed on both sides of the dielectric substrate.

[0044] Two low-pass frequency selection layers are arranged alternately. Each low-pass frequency selection layer is composed of horizontally arranged horizontal components 1100 and vertically arranged vertical components 1200 arranged perpendicularly and intersecting each other.

[0045] like Figure 3 and Figure 4 As shown, both the horizontal component 1100 and the vertical component 1200 include two identical basic components 1110 / 1210 and an outer dielectric plate 1120 / 1220 with a notch. The two basic components 1110 / 1210 and the outer dielectric plate 1120 / 1220 are stacked and arranged in the same structural distribution to form a whole. The outer dielectric plate 1120 / 1220 is arranged between the two basic components 1110 / 1210. The two identical basic components are bonded together by the outer dielectric plate to form a low-pass frequency selection layer.

[0046] The basic components 1110 / 1210 include an inner dielectric plate 1115 / 1215 with a groove and multiple L-shaped conductive geometries 1111, 1112, 1113, 1114 / 1211, 1212, 1213, 1214 disposed on both sides of the inner dielectric plate 1115 / 1215. Each side surface of the inner dielectric plate 1115 / 1215 has a fixed edge metal strip along its length direction. The inner dielectric plate 1115 / 1215 and the outer dielectric plate 1120 / 1220 of the two basic components 1110 / 1210 have equally spaced strips along their sides on the same side along their length direction. Multiple strip-shaped through slots are provided, with the strip direction of each strip-shaped through slot perpendicular to the direction of the side. The edge metal strips on both sides of the inner dielectric plate 1115 / 1215 are removed at the intersection with the strip direction of each strip-shaped through slot, so that the edge metal strips on each side edge are divided into multiple segments by the strip-shaped through slots. The inner dielectric plate 1115 / 1215 is provided with a middle metal strip near each strip-shaped through slot. The middle metal strip and the corresponding edge metal strip are connected to form an L-shaped conductor. Multiple L-shaped conductors constitute L-shaped conductive geometry 1111, 1112, 1113, 1114 / 1211, 1212, 1213, 1214.

[0047] like Figure 2 As shown, when the horizontal component 1100 and the vertical component 1200 are arranged opposite each other with their respective strip slots facing each other, the horizontal component 1100 and the vertical component 1200 are arranged in a mirror symmetrical manner.

[0048] The internal media plates 1115 / 1215 are arranged in the following manner at each strip slot:

[0049] A) On both sides of the inner media plate 1115 / 1215, which are located along the length of the inner media plate and on the same side as the strip groove:

[0050] A first metal strip is provided on one side surface of the inner dielectric plate 1115 / 1215, which is parallel to the strip-shaped through groove and adjacent to one side of the strip-shaped through groove. A section of side metal strip located on the same side surface of the inner dielectric plate 1115 / 1215, on the same side as the first metal strip and adjacent to the strip-shaped through groove along the length direction of the inner dielectric plate, is connected to the first metal strip to form a single L-shaped conductor.

[0051] A second metal strip is provided on the other side surface of the inner dielectric plate 1115 / 1215, which is parallel to the strip-shaped through groove and adjacent to the other side of the strip-shaped through groove. A section of the side metal strip located on the same side surface of the inner dielectric plate 1115 / 1215 as the second metal strip, and located on the same side as the strip-shaped through groove along the length direction of the inner dielectric plate and adjacent to the strip-shaped through groove, is connected to the second metal strip to form a single L-shaped conductor.

[0052] B) On the two sides of the inner media plate 1115 / 1215, which are located on opposite sides along the length of the inner media plate:

[0053] A third metal strip parallel to the strip groove and along the second metal strip is provided on one side surface of the inner dielectric plate 1115 / 1215. A section of the third metal strip located on the same side surface of the inner dielectric plate 1115 / 1215, on the same side as the third metal strip and adjacent to the strip groove on the opposite side along the length direction of the inner dielectric plate, is connected to the third metal strip to form a single L-shaped conductor.

[0054] On the other side surface of the inner dielectric plate 1115 / 1215, there is a fourth metal strip parallel to the strip-shaped through groove and along the first metal strip. A section of the fourth metal strip located on the same side surface of the inner dielectric plate 1115 / 1215, on the same side as the fourth metal strip and adjacent to the strip-shaped through groove along the length direction of the inner dielectric plate and on the opposite side, is connected to the fourth metal strip to form a single L-shaped conductor.

[0055] Specifically, such as Figure 3 As shown, the horizontal assembly 1100 mainly consists of two identical horizontal basic assemblies 1110 and a horizontal outer dielectric plate 1120 with grooves. The horizontal outer dielectric plate 1120 with grooves is disposed between the two identical horizontal basic assemblies 1110. The horizontal basic assembly 1110 mainly consists of a horizontal inner dielectric plate 1115 with grooves and multiple horizontal L-shaped conductive geometries 1111, 1112, 1113, and 1114 disposed on the two surfaces of the horizontal inner dielectric plate 1115 with grooves.

[0056] like Figure 5As shown, multiple horizontal L-shaped conductive geometries 1111, 1112, 1113, and 1114 of the horizontal basic component 1110 are periodically arranged on the two surfaces of the horizontal inner dielectric substrate 1115 with grooves. The L-shaped conductive geometries 1111 and 1112 of the first low-pass frequency selection layer 1000 are centrally symmetric, as are the L-shaped conductive geometries 1113 and 1114.

[0057] like Figure 4 As shown, the vertical assembly 1200 mainly consists of two identical vertical basic assemblies 1210 and a vertical outer dielectric plate 1220 with slots. The vertical outer dielectric plate 1220 with slots is disposed between the two identical vertical basic assemblies 1210. The vertical basic assembly 1210 mainly consists of a vertical inner dielectric plate 1215 with slots and multiple vertical L-shaped conductive geometric structures 1211, 1212, 1213, and 1214 disposed on the two surfaces of the vertical inner dielectric plate 1215 with slots.

[0058] like Figure 5 As shown, multiple vertical L-shaped conductive geometric structures 1211, 1212, 1213, and 1214 of the vertical basic component 1210 are periodically arranged on the two surfaces of the vertical inner dielectric plate 1215 with grooves. The L-shaped conductive geometric structures 1211 and 1212 are centrally symmetric, the L-shaped conductive geometric structures 1213 and 1214 are centrally symmetric, and the L-shaped conductive geometric structures 1212 and 1214 are centrally symmetric.

[0059] The lengths of the first, second, third, and fourth metal strips are all greater than or equal to the length of the strip-shaped through-slot of the inner dielectric plate 1115 / 1215, and the length of the strip-shaped through-slot is half the width of the inner dielectric plate (1115 / 1215).

[0060] In the horizontal component 1100 and the vertical component 1200 themselves, the strip slots of the inner medium plates 1115 / 1215 of the two basic components 1110 / 1210 are located on the same side and are aligned. The edge metal strips and the middle metal strips on the upper surface of the inner medium plates 1115 / 1215 of the two basic components 1110 / 1210 are distributed in the same way and are aligned.

[0061] Multiple horizontal components 1100 are arranged in parallel at intervals along the vertical direction, and multiple vertical components 1200 are arranged in parallel at intervals along the horizontal direction. The strip slots of the horizontal components 1100 are inserted into the opposite side of the strip slots of the vertical components 1200 to form a mortise and tenon joint structure, so that the horizontal components 1100 and the vertical components 1200 are arranged orthogonally and perpendicularly to form a low-pass frequency selection layer, that is, they are interlocked to form a low-pass frequency selection layer.

[0062] The dual-polarization frequency selection structure includes two low-pass frequency selection layers: a first low-pass frequency selection layer 1000 and a second low-pass frequency selection layer 2000.

[0063] The two low-pass frequency selection layers have the same structure but different local dimensions. Specifically, the two low-pass frequency selection layers differ only in the width and length of the strip slot itself and the length of the metal strip in the middle.

[0064] The two low-pass frequency selection layers have the same period size, that is, the period spacing between adjacent strip slots along the length direction is the same for both the horizontal component 1100 and the vertical component 1200.

[0065] The inner dielectric plate 1115 and the outer dielectric plate 1120 of the two basic components 1110 / 1210 may use the same or different dielectric materials.

[0066] The linewidth, spacing, and size of the conductive geometry of the same low-pass frequency selection layer in two low-pass frequency selection layers may be the same or different. The linewidth, spacing, and size of the conductive geometry of different low-pass frequency selection layers in two low-pass frequency selection layers may be the same or different.

[0067] The conductive geometry in the two low-pass frequency selection layers is a metallic conductive geometry and / or a non-metallic conductive geometry.

[0068] The specific implementation of this invention is as follows:

[0069] The horizontal inner dielectric substrate 1115 with slots in the horizontal basic component 1110 of the first low-pass frequency selection layer 1000 and the vertical inner dielectric substrate 1215 with slots in the vertical basic component 1210 of the first low-pass frequency selection layer 1000 are both made of Rogers RO4350B material with a dielectric constant of 3.66 and a dielectric loss tangent of 0.0037. The width of the dielectric substrate is... l2 The thickness of the dielectric substrate is 13.2 mm. d The diameter is 0.168mm, the length of the strip groove is 6.6mm, and the width of the strip groove is greater than or equal to 0.536mm and less than or equal to 0.936mm.

[0070] The horizontal inner dielectric substrate 1115 with slots in the horizontal basic component 1110 of the second low-pass frequency selection layer 2000 and the vertical inner dielectric substrate 1215 with slots in the vertical basic component 1210 of the second low-pass frequency selection layer 2000 are both made of Rogers RO4350B material with a dielectric constant of 3.66 and a dielectric loss tangent of 0.0037. The width of the dielectric substrate is... l2 The thickness of the medium plate is 0.254 mm, and the width of the strip groove is greater than or equal to 0.254 mm and less than or equal to 0.654 mm.

[0071] The horizontal outer dielectric substrate 1120 with a slot in the horizontal component 1100 of the first low-pass frequency selection layer 1000 and the vertical outer dielectric substrate 1220 with a slot in the vertical component 1200 of the first low-pass frequency selection layer 1000 are both made of Rogers RO4450F material with a dielectric constant of 3.52, a dielectric loss tangent of 0.004, a width of 13.2 mm, and a thickness of 0.2 mm.

[0072] Set the linewidth for all L-shaped conductive geometries. w The maximum vertical length of the L-shaped conductive geometry of the first low-pass frequency selection layer 1000 is 5.864 mm, with a thickness of 0.2 mm. The length of the middle metal strip is... l1 The minimum distance between the middle metal strip and the strip groove is 6.6mm. s The length is 0.2mm; the maximum vertical length of the L-shaped conductive geometry of the second low-pass frequency selection layer 2000 is 6.146mm, and the length of the middle metal strip is... l1 The minimum distance between the middle metal strip and the strip groove is 3.8mm. s It is 0.2mm.

[0073] The distance between the first low-pass frequency selection layer 1000 and the second low-pass frequency selection layer 2000 is between 24mm and 28mm.

[0074] like Figure 7 and Figure 8 As shown, the horizontal axis represents the antenna's operating frequency, and the vertical axis represents the transmission coefficient. The unit for operating frequency is GHz, and the unit for transmission coefficient is dB.

[0075] like Figure 7 As shown in the figure, the simulation results of the transmission coefficient when the incident electromagnetic wave polarization mode TE mode (TEmode, which represents a propagation mode in which the electric field component in the propagation direction is zero) is radiated onto the low-pass, wide-stopband, large-angle stable dual-polarization frequency selection structure in the embodiment are shown.

[0076] like Figure 8As shown in the figure, the simulation results of the transmission coefficient when the incident electromagnetic wave polarization mode TM mode (English name TMmode, which represents the propagation mode in which the magnetic field component in the propagation direction is zero) is radiated onto the low-pass, wide-stopband, large-angle stable dual-polarization frequency selection structure in the embodiment are shown.

[0077] like Figure 7 As shown, simulation results for electromagnetic wave incident angles in the TE polarization range of 0° to 60° show that: in the operating frequency band of 0.2GHz to 2GHz, the average transmission coefficient is -0.337dB when the incident angle is 0°, -0.458dB when the incident angle is 30°, and -1.587dB when the incident angle is 60°; in the non-operating frequency band of 4GHz to 12GHz, the average transmission coefficient is -27.215dB when the incident angle is 0°, -28.943dB when the incident angle is 30°, and -39.575dB when the incident angle is 60°. The results show that electromagnetic waves in the frequency range of 0.2 GHz to 2 GHz can pass through the low-pass, wide-stopband, large-angle stable dual-polarization frequency selection structure with low loss; electromagnetic waves in the frequency range of 4 GHz to 12 GHz are greatly suppressed when passing through the low-pass, wide-stopband, large-angle stable dual-polarization frequency selection structure; and it works stably in a wide range of electromagnetic wave incident angles from 0° to 60°.

[0078] like Figure 8 As shown, the simulation results of electromagnetic wave incident angles in the TM polarization range of 0° to 60° show that: in the operating frequency band of 0.2GHz to 2GHz, the average transmission coefficient is -0.337dB when the incident angle is 0°, -0.218dB when the incident angle is 30°, and -0.0137dB when the incident angle is 60°; in the non-operating frequency band of 4GHz to 12GHz, the average transmission coefficient is -27.197dB when the incident angle is 0°, -26.003dB when the incident angle is 30°, and -21.554dB when the incident angle is 60°. The results show that electromagnetic waves in the frequency range of 0.2 GHz to 2 GHz can pass through the low-pass, wide-stopband, large-angle stable dual-polarization frequency selection structure with very low loss; electromagnetic waves in the frequency range of 4 GHz to 12 GHz are greatly suppressed when passing through the low-pass, wide-stopband, large-angle stable dual-polarization frequency selection structure; and it works stably in a wide range of electromagnetic wave incident angles from 0° to 60°.

[0079] According to one aspect of the present invention, a radome is provided, comprising the low-pass, wide-stopband, large-angle stable dual-polarization frequency selective structure described in the above embodiments. This radome effectively suppresses electromagnetic waves outside the operating frequency band, thereby reducing interference outside the operating frequency band.

[0080] According to another aspect of the present invention, a specific embodiment provides an antenna system including an antenna and an radome covering the antenna, wherein the radome is the radome described in the above embodiments. By providing the radome in the antenna system, electromagnetic waves in non-operating frequency bands can be effectively suppressed, enhancing the anti-interference capability of the antenna system.

[0081] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A low-pass, wide-stopband, large-angle stable dual-polarization frequency selection structure, characterized in that: It includes two low-pass frequency selection layers with the same structure. Each low-pass frequency selection layer includes two types of components: a horizontal component (1100) and a vertical component (1200). Each component consists of a dielectric substrate with through slots and multiple conductive geometric structures disposed on both sides of the dielectric substrate. The horizontal component (1100) and the vertical component (1200) each include two identical basic components (1110 / 1210) and an outer medium plate (1120 / 1220) with a through slot. The two basic components (1110 / 1210) and the outer medium plate (1120 / 1220) are stacked and arranged in a stacked manner, with the outer medium plate (1120 / 1220) arranged between the two basic components (1110 / 1210). The basic components (1110 / 1210) include an inner dielectric plate (1115 / 1215) with a through slot and multiple L-shaped conductive geometries (1111, 1112, 1113, 1114 / 1211, 1212, 1213, 1214) disposed on both sides of the inner dielectric plate (1115 / 1215). Each side of the inner dielectric plate (1115 / 1215) has edge metal strips along its length. The inner dielectric plate (1115 / 1215) and outer dielectric plate (1120 / 1220) of the two basic components (1110 / 1210) are arranged on the same side along their length. Multiple strip-shaped through slots are arranged at intervals along the side, with the strip direction of each through slot perpendicular to the side direction. The edge metal strips on both sides of the inner dielectric plate (1115 / 1215) are removed at the intersection with the strip direction of each through slot, so that the edge metal strips on each side edge are divided into multiple segments. The inner dielectric plate (1115 / 1215) is provided with a middle metal strip at each through slot. The middle metal strip and the corresponding edge metal strip are connected to form an L-shaped conductor. Multiple L-shaped conductors constitute an L-shaped conductive geometry (1111, 1112, 1113, 1114 / 1211, 1212, 1213, 1214). The internal media plates (1115 / 1215) are arranged in the following manner at each strip slot: A) On both sides of the inner media plate (1115 / 1215) along the length of the inner media plate and on the same side of the strip groove: A first medium metal strip is provided on one side surface of the inner dielectric plate (1115 / 1215), which is parallel to the strip-shaped through groove and adjacent to the first side edge of the strip-shaped through groove along the strip direction. A section of side metal strip located on the same side surface of the inner dielectric plate (1115 / 1215) as the first medium metal strip, located on the same side of the strip-shaped through groove along the strip direction, and adjacent to the strip-shaped through groove along the length direction of the inner dielectric plate and on the same side edge, is connected to the first medium metal strip to form a single L-shaped conductor. A second metal strip is provided on the other side surface of the inner dielectric plate (1115 / 1215), which is parallel to the strip-shaped through groove and adjacent to the second side of the strip-shaped through groove along the strip direction. A section of the metal strip located on the same side surface of the inner dielectric plate (1115 / 1215) as the second metal strip, located on the same side of the strip-shaped through groove along the strip direction, and adjacent to the strip-shaped through groove along the length direction of the inner dielectric plate and on the same side, is connected to the second metal strip to form a single L-shaped conductor. B) On the two sides of the inner media plate (1115 / 1215) along the length of the inner media plate and where the strip slot is located on opposite sides: A third metal strip is provided on one side surface of the inner dielectric plate (1115 / 1215), which is parallel to the strip-shaped through groove and arranged along the length direction of the second metal strip. A section of side metal strip located on the same side surface of the inner dielectric plate (1115 / 1215) as the third metal strip, and located on the same side of the strip-shaped through groove along the strip-shaped direction, and located adjacent to the strip-shaped through groove along the length direction of the inner dielectric plate and on different sides, is connected to the third metal strip to form a single L-shaped conductor. A fourth metal strip is provided on the other side surface of the inner dielectric plate (1115 / 1215), which is parallel to the strip-shaped through groove and arranged along the length direction of the first metal strip. A side metal strip located on the same side surface of the inner dielectric plate (1115 / 1215) as the fourth metal strip, and located on the same side of the strip-shaped through groove along the strip-shaped direction, and located adjacent to the strip-shaped through groove along the length direction of the inner dielectric plate and on different sides, is connected to the fourth metal strip to form a single L-shaped conductor.

2. A low-pass, wide-stopband, large-angle stable dual-polarized frequency selective surface according to claim 1, characterized in that: The two low-pass frequency selection layers are arranged alternately, and each low-pass frequency selection layer is composed of horizontally arranged horizontal components (1100) and vertically arranged vertical components (1200) arranged perpendicularly and intersecting each other.

3. A low-pass, wide-stopband, large-angle stable dual-polarized frequency selective surface according to claim 1, characterized in that: The horizontal component (1100) and the vertical component (1200) are arranged in a mirror-symmetric manner.

4. The low-pass, wide-stopband, large-angle stable dual-polarization frequency selection structure according to claim 1, characterized in that: The lengths of the first, second, third, and fourth metal strips are all greater than or equal to the length of the strip-shaped through groove, and the length of the strip-shaped through groove is half the width of the inner medium plate (1115 / 1215).

5. A low-pass, wide-stopband, large-angle stable dual-polarization frequency selection structure according to any one of claims 3-4, characterized in that: Multiple horizontal components (1100) are arranged in parallel at intervals along the vertical direction, and multiple vertical components (1200) are arranged in parallel at intervals along the horizontal direction. The strip slots of the horizontal components (1100) are inserted into the opposite side of the strip slots of the vertical components (1200) to form a mortise and tenon joint structure, so that the horizontal components (1100) and the vertical components (1200) are arranged orthogonally and vertically to form a low-pass frequency selection layer.

6. A low-pass, wide-stopband, large-angle stable dual-polarization frequency selection structure according to any one of claims 3-4, characterized in that: The two low-pass frequency selection layers have the same structure but different local dimensions.

7. An antenna radome, characterized in that, Includes the low-pass, wide-stopband, large-angle stable dual-polarization frequency selection structure as described in any one of claims 1 to 6.

8. An antenna system, comprising: An antenna and an antenna cover disposed on the antenna, characterized in that the antenna cover is the antenna cover as described in claim 7.

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