Resonant antenna based on frequency selective surface structure

Abstract

The present invention relates to a resonant antenna based on a frequency selective surface structure. The resonant antenna comprises: a feed antenna and a frequency selective surface FSS covering layer, wherein the feed antenna is arranged on a bottom layer, the FSS covering layer is arranged above the feed antenna, and the spacing between the feed antenna and the FSS covering layer is set to a preset value, so that the feed antenna resonates, and the feed antenna is used to adjust the corresponding working state based on different feeding positions. Through the present invention, the technical problem of narrow bandwidth caused by the use of traditional Fabry-Perot resonant antennas in related technologies is solved, and the technical effect of improving the spectrum utilization of the antenna is achieved.

Description

Technical Field

[0001] The present invention relates to the field of mobile communication technology, and in particular to a resonant antenna based on a frequency selective surface (FSS) structure. Background Art

[0002] In base stations, deep space exploration, satellite remote sensing communications and other occasions, the antenna needs to provide a high gain in a certain direction, and the antenna structure must be simple. Traditional high-gain antennas, such as reflector antennas, waveguide slot antennas and lens antennas, are large in size and are limited in antenna processing and assembly. The Fabry-Perot resonant antenna has the advantages of high gain, high efficiency, simple structure and no complex feeding network, and has been widely used.

[0003] The traditional Fabry-Perot resonant antenna has a narrow bandwidth, which limits its development. How to expand the bandwidth of the Fabry-Perot antenna and ensure circularly polarized radiation has always been a difficulty and hot spot. However, in the prior art, a substrate with a suitable dielectric constant and thickness is usually used as a covering layer to realize a broadband Fabry-Perot antenna, and the selection of a specific substrate can only be targeted at a specific frequency band; for example, the method of using a Fabry-Perot resonant antenna with a circularly polarized feed source to realize circularly polarized radiation, and the frequency band corresponding to the circularly polarized radiation realized by using a polarization converter is relatively narrow.

[0004] With respect to the technical problem that the conventional Fabry-Perot resonant antenna used in the related art results in a narrow bandwidth, no effective solution has been proposed yet. Summary of the invention

[0005] The embodiment of the present invention provides a resonant antenna based on a frequency selective surface structure, so as to at least solve the technical problem of narrow bandwidth caused by using a traditional Fabry-Perot resonant antenna in the related art.

[0006] According to one aspect of an embodiment of the present invention, a resonant antenna based on a frequency selective surface structure is provided, comprising: a feed antenna and a frequency selective surface (FSS) covering layer, wherein the feed antenna is arranged on a bottom layer, the FSS covering layer is arranged above the feed antenna, and the distance between the feed antenna and the FSS covering layer is set to a preset value so that the feed antenna resonates, and the feed antenna is used to adjust the corresponding working state based on different feeding positions.

[0007] Optionally, the feed antenna includes: a first port and a second port, wherein, when the feeding position is the first port, the working state is left-hand circularly polarized radiation; when the feeding position is the second port, the working state is right-hand circularly polarized radiation; when the feeding position is both the first port and the second port, the working state is linearly polarized radiation.

[0008] Optionally, the feed antenna also includes: a first dielectric layer, a second dielectric layer, a third dielectric layer and a fourth dielectric layer, wherein the first dielectric layer is arranged at the bottom layer, the second dielectric layer is arranged above the first dielectric layer, the third dielectric layer is arranged above the second dielectric layer, and the fourth dielectric layer is arranged above the third dielectric layer.

[0009] Optionally, the lengths and widths of the first dielectric layer, the second dielectric layer, the third dielectric layer and the fourth dielectric layer are equal, the thicknesses of the first dielectric layer and the third dielectric layer are both the first thickness, the thickness of the second dielectric layer is the second thickness, and the thickness of the fourth dielectric layer is the third thickness.

[0010] Optionally, the materials used for the first dielectric layer, the third dielectric layer and the fourth dielectric layer are all Teflon having a dielectric constant of a first dielectric constant and a loss tangent of a first loss tangent; the material used for the second dielectric layer is polytetrafluoroethylene having a dielectric constant of a second dielectric constant and a loss tangent of a second loss tangent.

[0011] Optionally, the feed antenna further includes: a microstrip feed line, which is arranged below the first dielectric layer, and the microstrip feed line includes two rectangular strips and one annular strip.

[0012] Optionally, the feed antenna further includes: a metal floor, which is arranged between the first dielectric layer and the second dielectric layer, and a middle position of the metal floor includes a cross gap.

[0013] Optionally, the FSS covering layer includes: a dielectric substrate and a plurality of FSS units arranged on the dielectric substrate, each of the FSS units includes a square patch, a cross patch and four square parasitic patches, wherein one of the square patches is arranged above the dielectric substrate, and one of the cross patch and the four square parasitic patches are arranged below the dielectric substrate.

[0014] Optionally, the material used for the FSS covering layer is a high-frequency material having a dielectric constant of a third dielectric constant and a loss tangent of a third loss tangent.

[0015] Optionally, the preset value ranges from 10 mm to 20 mm.

[0016] In the embodiment of the present invention, the feed antenna is placed on the bottom layer, the FSS covering layer is placed above the feed antenna, and the distance between the feed antenna and the FSS covering layer is adjusted to make the antenna resonate and thus improve the gain of the antenna; in addition, the feeding position of the feed antenna can be changed to change the direction of the current on the surface of the microstrip antenna, thereby realizing dual circular polarization radiation, thereby realizing spectrum multiplexing, and further solving the technical problem of narrow bandwidth caused by the use of traditional Fabry-Perot resonant antennas in related technologies, and achieving the technical effect of improving the spectrum utilization of the antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0018] Figure 1 A schematic diagram of a resonant antenna based on a frequency selective surface structure provided by an embodiment of the present invention;

[0019] Figure 2 A schematic diagram of a feed antenna structure provided by an embodiment of the present invention;

[0020] Figure 3 A schematic diagram of a FSS covering layer structure provided by an embodiment of the present invention;

[0021] Figure 4 A schematic diagram of antenna simulation and measured return loss provided for an optional embodiment of the present invention;

[0022] Figure 5 Axial ratio diagrams of antenna simulation and actual measurement provided for an optional embodiment of the present invention;

[0023] Figure 6 A radiation pattern of an antenna provided in an optional embodiment of the present invention when the first port is fed at a frequency of 9 GHz and the second port is connected to a matching load;

[0024] Figure 7 A radiation pattern of an antenna provided in an optional embodiment of the present invention when the second port is fed at a frequency of 9 GHz and the first port is connected to a matching load;

[0025] Figure 8 This is a physical diagram of the present invention.

[0026] The above drawings include the following reference numerals:

[0027] 10. Feed antenna; 20. FSS covering layer; 101. First dielectric layer; 102. Second dielectric layer; 103. Third dielectric layer; 104. Fourth dielectric layer; 105. Microstrip feed line; 106. Metal floor with cross gap; 107. Microstrip metal patch; 22. Dielectric substrate; 24. FSS unit; 241. Square patch; 242. Cross patch; 243. Rectangular parasitic patch. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings 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 should fall within the scope of protection of the present invention.

[0029] It should be noted that the terms "first" and "second" in the specification, claims and drawings of the present invention are Figure 1 The marked location.

[0030] An embodiment of the present invention provides a resonant antenna based on a frequency selective surface structure. Figure 1 A schematic diagram of a resonant antenna based on a frequency selective surface structure provided by an embodiment of the present invention.

[0031] Optionally, application scenarios of the embodiments of the present invention include but are not limited to: X-band base stations, deep space exploration, and satellite remote sensing communications.

[0032] like Figure 1 As shown, the resonant antenna based on the frequency selective surface structure provided in an embodiment of the present invention includes: a feed antenna 10 and a frequency selective surface FSS covering layer 20, wherein the feed antenna 10 is arranged on the bottom layer, the FSS covering layer 20 is arranged above the feed antenna 10, and the distance between the feed antenna 10 and the FSS covering layer 20 is set to a preset value, so that the feed antenna 10 resonates, and the feed antenna 10 is used to adjust the corresponding working state based on different feeding positions.

[0033] In the embodiment of the present invention, the feed antenna 10 is placed on the bottom layer, the FSS cover layer 20 is placed above the feed antenna 10, and the distance between the feed antenna 10 and the FSS cover layer 20 is adjusted to make the antenna resonate and thus improve the gain of the antenna; in addition, the feeding position of the feed antenna 10 can be changed to change the direction of the current on the surface of the microstrip antenna to achieve dual circular polarization radiation, thereby achieving spectrum multiplexing, thereby solving the technical problem of narrow bandwidth caused by the use of traditional Fabry-Perot resonant antennas in related technologies, and achieving the technical effect of improving the spectrum utilization of the antenna.

[0034] It should be noted that the impedance bandwidth of the above-mentioned resonant antenna can reach 23.1%, the left-hand axis ratio is 14.5%, and the right-hand axis ratio is 16.3%; in addition, the gain of the antenna within the frequency band is greater than 10dBi, and it has a simple structure and is easy to manufacture. The planar structure can be mass-produced by rapid printing and can be used in X-band satellite remote sensing communications and other occasions.

[0035] In an optional embodiment, the above-mentioned feed antenna 10 includes: a first port and a second port, wherein, when the feeding position is the first port, the working state is left-hand circularly polarized radiation; when the feeding position is the second port, the working state is right-hand circularly polarized radiation; when the feeding position is both the first port and the second port, the working state is linearly polarized radiation.

[0036] The above embodiments of the present invention can realize dual circular polarization radiation, thereby realizing spectrum multiplexing. For example, when the first port is fed with power, left-hand circular polarization radiation is realized, and when the second port is fed with power, right-hand circular polarization radiation is realized.

[0037] In addition, compared with the traditional Fabry-Perot antenna, the present invention adopts a FSS structure with a positive slope as the antenna cover layer, and designs a dual circularly polarized microstrip antenna as a feed source, which broadens the bandwidth of the Fabry-Perot antenna. The designed antenna is processed and tested to obtain an impedance bandwidth of 8.69-10.96GHz (23.1%), a left-hand axis ratio bandwidth of 8.68-10.04GHz (14.5%), and a right-hand axis ratio bandwidth of 8.55-10.07GHz (16.33%).

[0038] Figure 2 A schematic diagram of a feed antenna structure provided by an embodiment of the present invention, such as Figure 2As shown, the feed antenna 10 further includes: a first dielectric layer 101, a second dielectric layer 102, a third dielectric layer 103 and a fourth dielectric layer 104, a microstrip feed line 105, a metal floor 106 and a microstrip metal patch 107. The first dielectric layer 101 is arranged at the bottom layer, the second dielectric layer 102 is arranged above the first dielectric layer 101, the third dielectric layer 103 is arranged above the second dielectric layer 102, and the fourth dielectric layer 104 is arranged above the third dielectric layer 103. The microstrip feed line 105 is arranged below the first dielectric layer 101, and includes two rectangular strips and one annular strip; the metal floor 106 is arranged between the first dielectric layer 101 and the second dielectric layer 102, and the middle position of the metal floor 106 includes a cross gap; the microstrip metal patch 107 is arranged above the fourth dielectric layer.

[0039] It should be noted that the above feed antenna is composed of four layers of dielectric plates, which are respectively a first dielectric layer 101 , a second dielectric layer 102 , a third dielectric layer 103 and a fourth dielectric layer 104 from bottom to top.

[0040] In an optional embodiment, the lengths and widths of the first dielectric layer 101, the second dielectric layer 102, the third dielectric layer 103 and the fourth dielectric layer 104 are equal, the thicknesses of the first dielectric layer 101 and the third dielectric layer 103 are both the first thickness, the thickness of the second dielectric layer 102 is the second thickness, and the thickness of the fourth dielectric layer 104 is the third thickness.

[0041] Optionally, the length and width values ​​corresponding to the first dielectric layer 101, the second dielectric layer 102, the third dielectric layer 103 and the fourth dielectric layer 104 include but are not limited to 137 mm; the value of the first thickness includes but is not limited to 0.684 mm; the value of the second thickness includes but is not limited to 0.508 mm; the value of the third thickness includes but is not limited to 1.03 mm.

[0042] In an optional embodiment, the materials used for the first dielectric layer 101, the third dielectric layer 103 and the fourth dielectric layer 104 are all Teflon having a dielectric constant of the first dielectric constant and a loss tangent of the first loss tangent; the material used for the second dielectric layer 102 is polytetrafluoroethylene having a dielectric constant of the second dielectric constant and a loss tangent of the second loss tangent.

[0043] Optionally, the value of the first dielectric constant includes but is not limited to 2.65, and the value of the first loss tangent includes but is not limited to 0.0035; the value of the second dielectric constant includes but is not limited to 3, and the value of the second loss tangent includes but is not limited to 0.0035.

[0044] Optionally, the cross gap in the middle of the metal floor 106 of the above-mentioned feed antenna 10 is 7.29 mm long and 1.2 mm wide; the microstrip feed line 105 is composed of two rectangular strips with a length of 26.96 mm and a width of 1.08 mm and a 3 / 4 annular strip with a radius of 2 mm and a width of 1.08 mm; the microstrip metal patch is composed of a square with a side length of 7.7 mm.

[0045] Figure 3 A schematic diagram of the FSS cover layer structure provided by an embodiment of the present invention is shown in FIG. Figure 4 As shown, the FSS cover layer 20 comprises: a dielectric substrate 22 and a plurality of FSS units 24 arranged on the dielectric substrate 22, each FSS unit 24 comprising a square patch 241, a cross patch 242, and a square parasitic patch 243. Among them, a square patch 241 is arranged above the dielectric substrate 22; a cross patch 242 and a square parasitic patch 243 are arranged below the dielectric substrate 22.

[0046] Optionally, the square patch of the upper layer of the FSS unit 24 has a side length of 5 mm, the cross-gap patch of the lower layer has a length of 7 mm and a width of 1.2 mm, and the side of the rectangular parasitic patch 243 of the lower layer has a side length of 1.5 mm.

[0047] In an optional implementation, the material used for the FSS covering layer 20 is a high-frequency material having a dielectric constant of the third dielectric constant and a loss tangent of the third loss tangent.

[0048] Optionally, the value of the third dielectric constant includes but is not limited to 3.55, and the value of the third loss tangent includes but is not limited to 0.0027. The high-frequency material may be Rogers 4003 material. It should be noted that the thickness of the FSS cover layer 20 may be 0.508 mm.

[0049] In an optional implementation, the preset value ranges from 10 mm to 20 mm.

[0050] In a specific implementation, the spacing between the feed antenna and the FSS cover layer includes but is not limited to 10 mm, 15 mm, 20 mm, etc. Optionally, the above preset value is 15 mm.

[0051] An optional implementation manner of the present invention is described in detail below.

[0052] An optional embodiment of the present invention provides a dual circular polarization Fabry-Perot broadband antenna based on an FSS structure, the antenna comprising a feed antenna 10 and an FSS covering layer 20. The feed antenna 10 is composed of four layers of dielectrics, namely, the first dielectric layer 101, the second dielectric layer 102, the third dielectric layer 103, and the fourth dielectric layer 104 from bottom to top, and a microstrip feed line 105 located at the bottom of the first dielectric layer 101, a metal floor 106 with a cross gap between the first dielectric layer 101 and the second dielectric layer 102, and a microstrip metal patch 107 located above the fourth dielectric layer. The FSS covering layer 20 is a radiation patch composed of 8*8 FSS units 24, each of which is composed of a square patch 241, a cross patch 242, and a square parasitic patch 243. The antenna uses an FSS structure with a positive slope as the covering layer of the antenna to broaden the bandwidth of the antenna, and designs a dual circular polarization feed to improve the spectrum utilization of the antenna.

[0053] It should be noted that, compared with the selection of a specific substrate that can only target a specific frequency band, the use of a cover layer with a positive slope phase characteristic is more flexible. In addition, the use of a circularly polarized feed source to achieve a circularly polarized radiation design is relatively simple and easy to make into a broadband.

[0054] Figure 4 A schematic diagram of antenna simulation and measured return loss provided by an optional embodiment of the present invention, such as Figure 4 As shown, the impedance bandwidth (S11<-10dB) of the antenna is 8.69-10.96GHz (23.1%).

[0055] Figure 5 The axial ratio diagram of the antenna simulation and actual measurement provided by the optional embodiment of the present invention is as follows: Figure 5 As shown, (a) is the left-hand axis bandwidth of the antenna is 8.68-10.04 GHz (14.5%), and (b) is the right-hand axis bandwidth is 8.55-10.07 GHz (16.33%).

[0056] Figure 6 The radiation pattern of the antenna provided in the optional embodiment of the present invention when the first port is fed at a frequency of 9 GHz and the second port is connected to a matching load, such as Figure 6 As shown in the figure, (a) is the radiation pattern of the antenna in the xoy plane, and (b) is the radiation pattern of the antenna in the xoz plane. It can be seen from the two radiation patterns that the antenna radiates left-handed circularly polarized waves, and the radiation pattern is basically symmetrical, with high gain.

[0057] Figure 7 The radiation pattern of the antenna provided in the optional embodiment of the present invention when the second port is fed at a frequency of 9 GHz and the first port is connected to a matching load, such as Figure 7As shown in the figure, (a) is the radiation pattern of the antenna in the xoy plane, and (b) is the radiation pattern of the antenna in the xoz plane. It can be seen from the two radiation patterns that the antenna radiates right-hand circularly polarized waves, and the radiation pattern is basically symmetrical, with high gain.

[0058] It should be noted that the gain of the antenna of the present invention is greater than 10dBi within the frequency band, and the peak gain is 11.2dBi, which is 4dBi higher than the feed antenna gain, and can be used in X-band satellite remote sensing communications and other occasions. In addition, the antenna of the present invention has a simple structure and is easy to manufacture, and the planar structure can be manufactured by rapid printing.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention.

Claims

1. A resonant antenna based on a frequency selective surface structure, characterized in that: include: A feed antenna and a frequency selective surface FSS covering layer, wherein the feed antenna is arranged on a bottom layer, the FSS covering layer is arranged above the feed antenna, and the spacing between the feed antenna and the FSS covering layer is set to a preset value so that the feed antenna resonates, and the feed antenna is used to adjust the corresponding working state based on different feeding positions; The feed antenna also includes: a first dielectric layer, a second dielectric layer, a third dielectric layer and a fourth dielectric layer, wherein the first dielectric layer is arranged at the bottom layer, the second dielectric layer is arranged above the first dielectric layer, the third dielectric layer is arranged above the second dielectric layer, and the fourth dielectric layer is arranged above the third dielectric layer; a microstrip feed line, arranged below the first dielectric layer, the microstrip feed line includes two rectangular strips and one annular strip; a metal floor, arranged between the first dielectric layer and the second dielectric layer, and the middle position of the metal floor includes a cross gap.

2. The resonant antenna according to claim 1, characterized in that: The feed antenna includes: a first port and a second port, wherein when the feeding position is the first port, the working state is left-hand circularly polarized radiation; when the feeding position is the second port, the working state is right-hand circularly polarized radiation; when the feeding position is both the first port and the second port, the working state is linearly polarized radiation.

3. The resonant antenna according to claim 1, characterized in that: The first dielectric layer, the second dielectric layer, the third dielectric layer and the fourth dielectric layer have the same length and width, the first dielectric layer and the third dielectric layer have the first thickness, the second dielectric layer has the second thickness, and the fourth dielectric layer has the third thickness.

4. The resonant antenna according to claim 1, characterized in that: The materials used for the first dielectric layer, the third dielectric layer and the fourth dielectric layer are all Teflon with a dielectric constant of the first dielectric constant and a loss tangent of the first loss tangent; the material used for the second dielectric layer is polytetrafluoroethylene with a dielectric constant of the second dielectric constant and a loss tangent of the second loss tangent.

5. The resonant antenna according to claim 1, characterized in that: The FSS covering layer includes: a dielectric substrate and a plurality of FSS units arranged on the dielectric substrate, each of the FSS units includes a square patch, a cross patch and four square parasitic patches, wherein one of the square patches is arranged above the dielectric substrate, and one of the cross patch and the four square parasitic patches are arranged below the dielectric substrate.

6. The resonant antenna according to claim 5, characterized in that: The material used for the FSS covering layer is a high-frequency material with a dielectric constant of the third dielectric constant and a loss tangent of the third loss tangent.

7. The resonant antenna according to any one of claims 1 to 6, characterized in that: The preset value ranges from 10mm to 20mm.

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