A broadband high-efficiency circularly polarized low-profile folded transmission array antenna

Abstract

The application provides a broadband high-efficiency circularly polarized low-profile folded transmission array antenna, and relates to the field of antennas and microwave technology.The transmission array antenna comprises a feed source, a reflection array surface and a transmission array surface; the transmission array surface is arranged by a plurality of transmission units; each transmission unit comprises a transmitting patch; the transmitting patches are arranged according to a target rotation angle; the target rotation angle is an angle corresponding to the case that the transmission phase of each transmission unit is set to be the same as the first compensation phase of each transmission unit; the reflection array surface is arranged by a plurality of reflection units; each reflection unit comprises a polarization twist patch; the polarization twist patch comprises a pair of symmetrical curved sections and a connecting part connecting the two curved sections; the radii of the two curved sections are arranged according to a target radius; the target radius is a radius corresponding to the case that the reflection phase of each reflection unit is set to be the same as the second compensation phase of each reflection unit.The transmission array antenna has the advantages of high aperture efficiency and wide bandwidth.

Description

Technical Field

[0001] This invention relates to the field of antenna and microwave technology, and in particular to a broadband, high-efficiency, circularly polarized, low-profile folded transmission array antenna. Background Technology

[0002] Transmission array antennas have attracted widespread attention due to their simple structure, flexible design, and low cost. However, a significant problem currently hinders their application: the relatively high profile of transmission array antennas. In traditional transmission array antenna designs, a feed is typically placed at the focal point to provide radiation, with a focal-to-diameter ratio usually between 0.6 and 1.2. This results in a relatively large profile for ordinary transmission array antennas, i.e., the distance between the feed and the array surface. Therefore, it is necessary to overcome the disadvantage of the high profile of transmission array antennas.

[0003] Currently, the most widely used technical solution to overcome the drawback of high antenna profile in transmission array antennas is to add a reflective array, which refracts electromagnetic waves three or four times between the transmission array and the reflective array, thereby reducing the antenna profile to one-third or one-quarter of the focal length. However, even with this reduction, the transmission array antenna still suffers from a high profile, low aperture efficiency, and narrow bandwidth. Summary of the Invention

[0004] The purpose of this invention is to provide a broadband, high-efficiency, circularly polarized, low-profile folded transmission array antenna, which solves the problems of low aperture efficiency and narrow bandwidth of transmission array antennas.

[0005] To address the aforementioned technical problems, the embodiments of the present invention provide the following technical solutions:

[0006] This invention provides a broadband, high-efficiency, circularly polarized, low-profile folded transmission array antenna, which includes a feed, a reflector array, and a transmission array.

[0007] The phase center of the feed and the reflector array are set on the same plane, and the transmission array is spaced behind the reflector array.

[0008] The transmission array is composed of multiple transmission units, each of which includes a transmitting patch. The transmitting patches are arranged according to the target rotation angle, which is the angle corresponding to setting the transmission phase of each transmission unit to be the same as the first compensation phase of each transmission unit.

[0009] The reflective array is composed of multiple reflective elements arranged together. Each reflective element includes a polarization torsion patch. The polarization torsion patch includes a pair of symmetrical curved sections and a connecting part connecting the two curved sections. The curvature of the two curved sections is arranged according to the target curvature, which is the curvature corresponding to setting the reflection phase of each reflective element to be the same as the second compensation phase of each reflective element.

[0010] In some embodiments, the transmission array consists of a receiving patch, a metal ground plane, a transmitting patch, a first dielectric substrate, and a second dielectric substrate;

[0011] The transmitter patch, the first dielectric substrate, the metal ground plane, the second dielectric substrate, and the receiver patch are stacked together. The transmitter patch is disposed on the upper surface of the first dielectric substrate, the metal ground plane is disposed on the lower surface of the first dielectric substrate and connected to the upper surface of the second dielectric substrate, and the receiver patch is disposed on the lower surface of the second dielectric substrate.

[0012] The metal floor has a circular hole in the center, through which a metal cylinder passes. One end of the metal cylinder is connected to the transmitting patch, and the other end is connected to the receiving patch.

[0013] In some embodiments, the size of the metal cylinder is adapted to the size of the circular hole.

[0014] In some embodiments, one end of the metal cylinder is connected to the center of the transmitting patch, and the other end of the metal cylinder is connected to the center of the receiving patch.

[0015] In some embodiments, the receiving patch is square in shape and has three C-shaped cutouts. The openings of adjacent C-shaped cutouts face different directions, and the three C-shaped cutouts are arranged sequentially from the inside to the outside around the center of the receiving patch.

[0016] The emitter patch is square in shape and has two C-shaped cutouts and one rectangular cutout. The openings of the two C-shaped cutouts face different directions. The two C-shaped cutouts are arranged sequentially from the inside to the outside around the center of the emitter patch, and a rectangular cutout is located outside the two C-shaped cutouts.

[0017] In some embodiments, the polarization direction of the emitting patch is a left-handed circular polarization direction.

[0018] In some embodiments, the reflective array consists of a polarization torsion patch, a ground plane, and a third dielectric plate;

[0019] The polarization twist patch, the third dielectric plate, and the ground plane are stacked together, with the polarization twist patch disposed on the upper surface of the third dielectric plate and the ground plane disposed on the lower surface of the third dielectric plate.

[0020] In some embodiments, the floor is square in shape, and the size of the floor is the same as the size of the third medium board.

[0021] In some embodiments, the first compensation phase of each transmission unit is:

[0022]

[0023] in, Let be the first compensation phase of each transmission unit, and k be the wavenumber in free space. Let be the distance from the phase center of the feed to the (i,j)th transmission element on the transmission array surface. Let be the position vector of the (i,j)th transmission cell on the transmission array surface. The unit vector pointing in the direction of the antenna's main beam. The initial phase is preset, i is the horizontal coordinate of the transmission unit, and j is the vertical coordinate of the transmission unit.

[0024] In some embodiments, the second compensation phase of each reflecting unit is:

[0025]

[0026] in, Let be the second compensation phase for each reflecting unit, and k be the wave number in free space. The distance from the preset feed source at the preset position to the (m,n)th element on the reflector array surface is given. Let be the distance from the phase center of the actual feed to the (m,n)th element on the reflector array. The preset initial phase is defined as follows: m is the abscissa of the reflector element, n is the ordinate of the reflector element, and the preset feed source is located directly above the center point of the reflector array, with a vertical distance from the reflector array that is twice the antenna profile height.

[0027] Compared to existing technologies, this invention provides a broadband, high-efficiency, circularly polarized, low-profile folded transmission array antenna, comprising a feed, a reflector array, and a transmission array. The phase center of the feed and the reflector array are disposed on the same plane, and the transmission array is spaced behind the reflector array. The transmission array is composed of multiple transmission elements, each including a transmitting patch. The transmitting patches are arranged according to a target rotation angle, which is the angle corresponding to setting the transmission phase of each transmission element to be the same as the first compensation phase of each transmission element. The reflector array is composed of multiple reflecting elements, each including a polarization torsion patch. The polarization torsion patch includes a pair of symmetrical curved sections and a connecting portion connecting the two curved sections. The curvature of the two curved sections is arranged according to a target curvature, which is the curvature corresponding to setting the reflection phase of each reflecting element to be the same as the second compensation phase of each reflecting element. In this way, the transmitting patches of the transmission array are arranged according to the target rotation angle. By adjusting the rotation angle of the transmitting patch of each transmission element clockwise, the transmission phase of each transmission element is adjusted so that the transmission phase of each transmission element is the same as the first compensation phase of each transmission element. By changing the arc θ of the two bending sections of the polarization torsion patch of the reflector element, the reflection phase of each reflector element is changed so that the reflection phase of each reflector element is the same as the second compensation phase of the corresponding reflector element. While changing the transmission phase of the transmission element and the reflection phase of the reflector element, the transmission amplitude of the transmission element and the reflection amplitude of the reflector element always maintain good performance. This gives the transmission array antenna high aperture efficiency. Both the transmission element and the reflector element have good reflection amplitude and transmission amplitude over a wide frequency band, giving the transmission array antenna composed of the transmission element and the reflector element the advantage of broadband. Attached Figure Description

[0028] The above and other objects, features, and advantages of exemplary embodiments of the present invention will become readily apparent upon reading the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of the invention are illustrated by way of example and not limitation, with the same or corresponding reference numerals denoteing the same or corresponding parts, wherein:

[0029] Figure 1 A schematic diagram of a broadband, high-efficiency, circularly polarized, low-profile folded transmission array antenna is shown.

[0030] Figure 2 A schematic diagram of the transmission unit is shown.

[0031] Figure 3 A schematic top view of the transmission unit is shown;

[0032] Figure 4 A bottom view of the transmission unit is shown schematically;

[0033] Figure 5 A schematic top view of the transmission array surface where the receiving patch is located is shown;

[0034] Figure 6 A schematic top view of the transmission array surface on the side where the transmitting patch is located is shown;

[0035] Figure 7 A schematic diagram of the reflective unit is shown.

[0036] Figure 8 A schematic bottom view of the reflector unit is shown;

[0037] Figure 9 A schematic top view of the reflector array is shown.

[0038] Figure 10 The transmission amplitude and transmission phase curves of the transmission unit are schematically shown.

[0039] Figure 11 The reflection amplitude and reflection phase curves of the reflecting unit are schematically shown;

[0040] Figure 12 The normalized radiation pattern of a circularly polarized low-profile folded transmission array antenna at 10 GHz is schematically shown.

[0041] Figure 13 The far-field gain plot of a circularly polarized low-profile folded transmission array antenna is schematically shown.

[0042] Figure 14 The far-field axial ratio diagram of a circularly polarized low-profile folded transmission array antenna is schematically shown.

[0043] Figure 15 The aperture efficiency diagram of a circularly polarized low-profile folded transmission array antenna is schematically shown.

[0044] Figure 16 The transmission amplitude of the transmission unit and the reflection amplitude of the reflection unit are schematically shown.

[0045] Explanation of reference numerals in the attached figures:

[0046] 1. Feed source; 2. Reflector array; 21. Reflector unit; 211. Polarized torsion patch; 2111. Bending section; 2112. Connector; 212. Ground plane; 213. Third dielectric plate; 3. Transmitter array; 31. Transmitter unit; 311. Transmitter patch; 312. Metal ground plane; 313. Receiver patch; 314. First dielectric plate; 315. Second dielectric plate; 316. Metal cylinder; 317. Circular hole; 318. C-shaped cutout. Detailed Implementation

[0047] The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to illustrate the principles of the present invention by way of example, but should not be used to limit the scope of the present invention. The present invention can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0048] The following is a detailed description of a broadband, high-efficiency, circularly polarized, low-profile folded transmission array antenna according to an embodiment of the present invention.

[0049] See Figure 1 As shown, Figure 1 The schematic diagram shows the structure of a broadband high-efficiency circularly polarized low-profile folded transmission array antenna. The present invention proposes a broadband high-efficiency circularly polarized low-profile folded transmission array antenna, which includes: a feed 1, a reflector 2, and a transmission array 3.

[0050] The phase center of the feed 1 and the reflector 2 are located on the same plane, and the transmission array 3 is spaced behind the reflector 2.

[0051] The transmission array 3 is composed of multiple transmission units 31 arranged together. Each transmission unit 31 includes a transmitting patch 311. The transmitting patches 311 are arranged according to the target rotation angle. The target rotation angle is the angle corresponding to setting the transmission phase of each transmission unit 31 to be the same as the first compensation phase of each transmission unit 31.

[0052] The reflective array 2 is composed of multiple reflective units 21. Each reflective unit 21 includes a polarization torsion patch 211. The polarization torsion patch 211 includes a pair of symmetrical curved sections 2111 and a connecting part 2112 connecting the two curved sections 2111. The curvature of the two curved sections 2111 is arranged according to the target curvature, which is the curvature corresponding to setting the reflection phase of each reflective unit 21 to be the same as the second compensation phase of each reflective unit 21.

[0053] Specifically, the polarization torsion patch 211 has an I-shaped shape, which includes a pair of symmetrical curved sections 2111 and a connecting portion 2112 connecting the two curved sections 2111. The feed 1 is a rectangular horn antenna capable of exciting linearly polarized waves, with an operating frequency band covering 8.2GHz-12.4GHz. The transmission array 3 is a circular array composed of 332 transmission elements 31 arranged in a uniform distribution. The reflection array 2 is a circular array composed of 332 reflection elements 21 arranged in a uniform distribution. The number of transmission elements 31 and the number of reflection elements 21 are not limited here.

[0054] The phase center of feed 1 and reflective array 2, as a whole, are located at a distance of one-fifth of the focal length from the transmission array 3. For example, the phase center of feed 1 and reflective array 2, as a whole, are located at a distance of 40mm from the transmission array 3, which is one-fifth of the focal length, and the focal length is 200mm.

[0055] The emitter patch 311 is made of metal, and the polarization torsion patch 211 is also made of metal.

[0056] By adjusting the rotation angle of the transmitting patch 311 of each transmission unit 31 clockwise, the transmission phase of each transmission unit 31 is the same as the first compensation phase of each transmission unit 31. When the transmission phase of each transmission unit 31 is the same as the first compensation phase of each transmission unit 31, the rotation angle of the transmitting patch 311 reaches the target rotation angle, and the transmitting patch 311 can be arranged according to the target rotation angle.

[0057] By changing the curvature of the two curved sections 2111 of the I-shaped polarization torsion patch 211, the reflection phase of each reflection unit 21 is made the same as the second compensation phase of the corresponding reflection unit 21. When the reflection phase of each reflection unit 21 is the same as the second compensation phase of the corresponding reflection unit 21, the curvature of the two curved sections 2111 of the I-shaped polarization torsion patch 211 reaches the target curvature, and the curvature of the two curved sections 2111 can be arranged according to the target curvature.

[0058] In this embodiment, Figure 2 A schematic diagram of the transmission unit 31 is shown below. Figure 2 As shown, the transmission array 3 consists of a receiving patch 313, a metal ground plane 312, a transmitting patch 311, a first dielectric substrate 314, and a second dielectric substrate 315.

[0059] The transmitter patch 311, the first dielectric substrate 314, the metal ground plate 312, the second dielectric substrate 315 and the receiver patch 313 are stacked. The transmitter patch 311 is disposed on the upper surface of the first dielectric substrate 314, the metal ground plate 312 is disposed on the lower surface of the first dielectric substrate 314 and is connected to the upper surface of the second dielectric substrate 315, and the receiver patch 313 is disposed on the lower surface of the second dielectric substrate 315.

[0060] The metal floor 312 has a circular hole 317 in the center, and a metal cylinder 316 passes through the circular hole 317. One end of the metal cylinder 316 is connected to the transmitting patch 311, and the other end of the metal cylinder 316 is connected to the receiving patch 313.

[0061] In this embodiment, the metal cylinder 316 is adapted to the size of the circular hole 317.

[0062] In this embodiment, one end of the metal cylinder 316 is connected to the center of the transmitting patch 311, and the other end of the metal cylinder 316 is connected to the center of the receiving patch 313.

[0063] Specifically, the receiving patch 313 is made of metal. Both the first dielectric substrate 314 and the second dielectric substrate 315 are cubic in shape. The first dielectric substrate 314 and the second dielectric substrate 315 are the same size. The thickness of both the first dielectric substrate 314 and the second dielectric substrate 315 is 3mm, and the material type of both the first dielectric substrate 314 and the second dielectric substrate 315 can be F4BM220.

[0064] In this embodiment, the receiving patch 313 is rectangular in shape, and three C-shaped cutouts 318 are provided on the receiving patch 313. The openings of adjacent C-shaped cutouts 318 face different directions, and the three C-shaped cutouts 318 are arranged sequentially from the inside to the outside around the center of the receiving patch 313.

[0065] The emitter patch 311 is square in shape and has two C-shaped cutouts 318 and one rectangular cutout. The openings of the two C-shaped cutouts 318 face different directions. The two C-shaped cutouts 318 are arranged sequentially from the inside to the outside around the center of the emitter patch 311, and a rectangular cutout is located outside the two C-shaped cutouts 318.

[0066] Specifically, Figure 3 A schematic top view of the transmission unit 31 is shown, see below. Figure 3As shown, the receiving patch 313 has three C-shaped cutouts 318, including an outer C-shaped cutout 318, a middle C-shaped cutout 318, and an inner C-shaped cutout 318. The openings of the outer C-shaped cutout 318 and the middle C-shaped cutout 318 face different directions, and the openings of the middle C-shaped cutout 318 and the inner C-shaped cutout 318 also face different directions. The inner, middle, and outer C-shaped cutouts 318 are arranged sequentially from the inside to the outside around the center of the receiving patch 313. The centers of the outer, middle, and inner C-shaped cutouts 318 coincide. Each of the three C-shaped cutouts 318 is a notched rectangular ring formed by cutting off one corner of a positively oriented rectangular ring. The middle C-shaped cutouts 318 are spaced apart within the outer C-shaped cutouts 318, and the inner C-shaped cutouts 318 are spaced apart within the middle C-shaped cutouts 318. Each of the three C-shaped cutouts 318 includes four sides. The lengths of two parallel sides are different. The lengths of the two sides at the cut-off corner are the same; these two sides are called the shortest sides. The lengths of the two adjacent sides opposite the cut-off corner are the same; these two adjacent sides are called the longest sides. The outer C-shaped cutout 318 is larger than the middle C-shaped cutout 318, and the middle C-shaped cutout 318 is larger than the inner C-shaped cutout 318. The specific dimensions are: P = 12.5mm, L = 7.1mm, L1 = 5.5mm, L2 = 3.5mm, L3 = 1.9mm, A1 = 4.2mm, A2 = 2.5mm, A3 = 0.5mm, W1 = 0.5mm, W2 = 0.2mm, W3 = 0.3mm. Wherein, P is the side length of the first dielectric plate 314, L is the side length of the receiving patch 313, L1 is the longest side length of the outer C-shaped cutout 318, L2 is the longest side length of the middle C-shaped cutout 318, and L3 is the longest side length of the inner C-shaped cutout 318. A1 is the shortest side length of the outer C-shaped cutout 318, A2 is the shortest side length of the middle C-shaped cutout 318, and A3 is the shortest side length of the inner C-shaped cutout. W1 is the width of the outer C-shaped cutout 318, W2 is the width of the middle C-shaped cutout 318, and W3 is the width of the inner C-shaped cutout 318.

[0067] Figure 4 A bottom view of the transmission unit 31 is schematically shown; see below. Figure 4As shown, the emitter patch 311 has two C-shaped cutouts 318 and one rectangular cutout. The two C-shaped cutouts 318 on the emitter patch 311 include an outer C-shaped cutout 318 and an inner C-shaped cutout 318. The openings of the outer C-shaped cutouts 318 and the inner C-shaped cutouts 318 face different directions. The inner and outer C-shaped cutouts 318 are arranged sequentially from the inside to the outside around the center of the emitter patch 311, and their centers coincide. The outer C-shaped cutout 318 is a notched rectangular ring formed by cutting off two adjacent corners of a positively oriented rectangular ring. The inner C-shaped cutout 318 is a notched rectangular ring formed by cutting off one corner of a positively oriented rectangular ring. A portion of the inner C-shaped cutout 318 is spaced within the outer C-shaped cutout 318, and the opening of the inner C-shaped cutout 318 is located within the outer C-shaped cutout 318. A rectangular cutout is located on the outer side of the inner C-shaped cutout 318, away from the opening. The outer C-shaped cutout 318 includes three sides: two parallel sides and the longest side perpendicular to the two parallel sides. One of the two parallel sides is called the shortest side, and the other is called the middle side. The lengths of these three sides are all different. The inner C-shaped cutout 318 includes four sides: the lengths of the two parallel sides are different; the lengths of the two sides at the cut-off corner are the same (called the shortest side); and the lengths of the two adjacent sides at the opposite corner are the same (called the longest side). The size of the outer C-shaped cutout 318 is larger than the size of the inner C-shaped cutout 318. The specific dimensions are: L4 = 6.3mm, L5 = 4.4mm, L6 = 2.3mm, A4 = 3.8mm, A41 = 4.8mm, A5 = 1.9mm, W4 = 0.5mm, W5 = 0.7mm. Where L4 is the longest side of the outer C-shaped cutout 318, L5 is the longest side of the inner C-shaped cutout 318, L6 is the side length of a rectangular cutout, A4 is the shortest side of the outer C-shaped cutout 318, A41 is the middle side of the outer C-shaped cutout 318, A5 is the shortest side of the inner C-shaped cutout 318, W4 is the width of the outer C-shaped cutout 318, and W5 is the width of the inner C-shaped cutout 318.

[0068] Figure 5 A schematic top view of the transmission array 3 on the side where the receiving patch 313 is located is shown. The receiving patches 313 of each transmission unit 31 are arranged in the same direction, enabling them to receive a single linearly polarized wave. Figure 6 A schematic top view of the transmission array 3 on the surface where the transmitting patch 311 is located is shown. In order for each transmission unit 31 to compensate for the first compensation phase of its own position, the transmitting patch 311 of each transmission unit 31 is rotated clockwise by the corresponding target rotation angle. That is, the transmitting patches 311 are arranged according to the target rotation angle.

[0069] In this embodiment, the polarization direction of the emitter patch 311 is a left-handed circular polarization direction.

[0070] Specifically, the circularly polarized low-profile folded transmission array antenna can convert a single linearly polarized electromagnetic wave into a left-hand circularly polarized electromagnetic wave. This is achieved by adjusting the polarization direction of each receiving patch 313 to a single linear polarization; since the transmitting patch 311 of the transmission unit 31 has the function of transmitting left-hand circularly polarized waves, the electromagnetic wave transmitted by the antenna has a left-hand circularly polarized polarization direction. This allows the energy of the linearly polarized electromagnetic wave from the feed 1 to be received by the receiving patch 313 and transmitted to the transmitting patch 311 via the metal cylinder 316. The transmitting patch 311 then transmits the left-hand circularly polarized electromagnetic wave into free space, successfully realizing the function of converting linear polarization to left-hand circular polarization.

[0071] In this embodiment, Figure 7 A schematic diagram of the reflective unit 21 is shown below. Figure 7 As shown, the reflector array 2 consists of a polarization torsion patch 211, a ground plane 212, and a third dielectric plate 213. The polarization torsion patch 211, the third dielectric plate 213, and the ground plane 212 are stacked, with the polarization torsion patch 211 disposed on the upper surface of the third dielectric plate 213 and the ground plane 212 disposed on the lower surface of the third dielectric plate 213. The polarization torsion patch 211 has an I-shaped shape, which includes a pair of symmetrical curved sections 2111 and a connecting portion 2112 connecting the two curved sections 2111. The curvature of the two curved sections 2111 is arranged according to the target curvature.

[0072] In this embodiment, the floor 212 is square in shape, and the size of the floor 212 is the same as that of the third medium plate 213.

[0073] Specifically, both the polarization torsion patch 211 and the floor 212 are made of metal. The third dielectric plate 213 is cubic in shape. The thickness of the third dielectric plate 213 is 5.2mm, and the material type of the third dielectric plate 213 can be F4BM220.

[0074] Figure 8 A bottom view of the reflecting unit 21 is schematically shown; see [link / reference]. Figure 8As shown, the polarization torsion patch 211 has an I-shape. The I-shaped polarization torsion patch 211 includes a pair of symmetrical curved sections 2111 and a connecting portion 2112 connecting the two curved sections 2111. The curvatures of the two curved sections 2111 are arranged according to the target curvature θ. The two curved sections 2111 have the same dimensions: PP = 10mm, LL = 7.3mm, WW = 0.9mm, 15° << θ << 130°. Here, PP is the side length of the floor 212, the side length of the third dielectric plate 213 is the same as the side length of the floor 212 (10mm), LL is the length of the connecting portion 2112, WW is the width of the curved section 2111, and θ is the target curvature.

[0075] Figure 9 A schematic top view of the reflector array 2 is shown. In order for each reflector element 21 to compensate for the second compensation phase at its respective position, the polarization torsion patch 211 of each reflector element 21 has a different pattern.

[0076] In this embodiment, the first compensation phase of each transmission unit 31 is:

[0077]

[0078] in, Here, k represents the first compensation phase of each transmission unit 31, and k is the wavenumber in free space. Let be the distance from the phase center of feed 1 to the (i,j)th transmission unit 31 on the transmission array 3. Let be the position vector of the (i,j)th transmission unit 31 on transmission array 3. The unit vector pointing in the direction of the antenna's main beam. The initial phase is preset, i is the horizontal coordinate of the transmission unit 31, and j is the vertical coordinate of the transmission unit 31.

[0079] Specifically, It is a constant, and the first compensation phase of each transmission unit 31 is the phase that the transmission unit 31 at each position on the transmission array 3 needs to compensate for. By adjusting the rotation angle of the transmitting patch 311 of each transmission unit 31 clockwise, the transmission phase of each transmission unit 31 is the same as the first compensation phase of each transmission unit 31. When the transmission phase of each transmission unit 31 is the same as the first compensation phase of each transmission unit 31, the rotation angle of the transmitting patch 311 reaches the target rotation angle, and the transmitting patches 311 can be arranged according to the target rotation angle.

[0080] By precisely adjusting the rotation angle of the transmitting patch 311, the spatial phase delay of each element on the transmission array 3 is compensated, thereby forming a plane wave with high gain radiation.

[0081] In this embodiment, the second compensation phase of each reflection unit 21 is:

[0082]

[0083] in, Here, k represents the second compensation phase for each reflection unit 21, and k is the wavenumber in free space. The distance from the preset feed 1 at the preset position to the (m,n)th element on the reflector array 2 is given. Let be the distance from the phase center of the actual feed 1 to the (m,n)th element on the reflector array 2. The initial phase is preset, m is the abscissa of the reflector 21, n is the ordinate of the reflector 21, and the feed 1 is preset to be located directly above the center point of the reflector 2, and the vertical distance between the feed 1 and the reflector 2 is twice the height of the antenna profile.

[0084] Specifically, It is a constant, and the second compensation phase of each reflective unit 21 is the phase that needs to be compensated for for each reflective unit 21 at each position on the reflective array 2. By changing the curvature θ of the two curved sections 2111 of the I-shaped polarization torsion patch 211, the reflection phase of each reflective unit 21 is made the same as the second compensation phase of the corresponding reflective unit 21. When the reflection phase of each reflective unit 21 is the same as the second compensation phase of the corresponding reflective unit 21, the curvature of the two curved sections 2111 of the I-shaped polarization torsion patch 211 reaches the target curvature, and the curvature of the two curved sections 2111 can be arranged according to the target curvature.

[0085] By adjusting the curvature of the two curved sections 2111 of the polarization torsion patch 211, the spatial phase delay of each reflecting element 21 on the reflective array 2 is compensated, thereby performing phase compensation and polarization torsion on the linearly polarized electromagnetic wave and reflecting it into the transmission array 3, thereby further reducing the antenna profile.

[0086] Using the first compensation phase formula for each transmission unit 31, the phase compensation required for each transmission unit 31 to form a high-gain plane wave can be calculated. Using the second compensation phase formula for each reflection unit 21, the phase compensation required for each reflection unit 21 to reduce the profile to 1 / 5 of the focal length can be calculated. By changing the rotation angle of the transmitting patch 311 of the transmission unit 31 and the arc θ of the two curved sections 2111 of the reflection unit 21, the transmission phase of the transmission unit 31 itself can be made equal to the phase compensation required, i.e., the first compensation phase, and the reflection phase of the reflection unit 21 itself can be made equal to the phase compensation required, i.e., the second compensation phase, thereby achieving the goal of forming a high-gain plane wave and reducing the profile to 1 / 5 of the focal length.

[0087] Figure 10 The diagram schematically illustrates the transmission amplitude and transmission phase curves of the transmission unit 31. There are two curves in the diagram. The upper curve with squares is the transmission amplitude curve, and the lower curve with circles is the transmission phase curve. It can be seen from these two curves that by adjusting the rotation angle of the transmitting patch 311 from 0° to 360°, the transmission unit 31 designed in this invention can achieve a 360° phase change.

[0088] Figure 11 The diagram schematically illustrates the reflection amplitude and phase curves of the reflecting unit 21. The diagram shows four curves: the curve with squares represents the reflection amplitude when the torsion unit rotates 0 degrees; the curve with circles represents the reflection amplitude when the torsion unit rotates 90 degrees; the curve with triangles represents the reflection phase when the torsion unit rotates 0 degrees; and the curve with diamonds represents the reflection phase when the torsion unit rotates 90 degrees. By adjusting the arc θ of the two curved sections 2111 of the polarization torsion patch 211 from 15° to 130°, the reflecting unit 21 in this invention can achieve a phase change greater than 180°. By rotating the polarization torsion patch 211 by 90°, the reflecting unit 21 in this invention can achieve another 180° phase change, i.e., a phase change from 180° to 360°. Combining the phases of the transmission unit 31 and the reflecting unit 21 can further reduce the profile and achieve high-gain planar transmitted waves, and both possess excellent transmission and reflection characteristics.

[0089] See Figure 10 and Figure 11 It can be seen that while changing the phase of the transmission unit 31 and the reflection unit 21, the transmission amplitude and the reflection amplitude always maintain good performance. In particular, the transmission amplitude and the reflection amplitude remain above -0.5dB while the phase of the unit is changed, which gives the final antenna the advantage of high aperture efficiency.

[0090] Figure 12 The normalized radiation pattern of a circularly polarized low-profile folded transmission array antenna at 10 GHz is schematically shown. A rectangular horn antenna is used as the antenna feed 1. The incident wave emitted by the feed 1 is first reflected by the receiving patch 313 of the transmission array 3, then polarized and partially compensated for by the reflecting array 2 before being reflected again. Finally, it is transmitted through the transmission array 3, forming a high-gain radiation with left-hand circular polarization. Its normalized radiation pattern is shown below. Figure 12 As shown, it can be seen that after passing through transmission array 3, the antenna's energy is concentrated in axial radiation.

[0091] Figure 13 The far-field gain plot of the circularly polarized low-profile folded transmission array antenna is schematically shown. The antenna achieves a peak gain of 24.62 dB and a 3 dBi gain bandwidth of 24.7%. Figure 14The far-field axial ratio diagram of a circularly polarized low-profile folded transmission array antenna is schematically shown. The 3dB axial ratio bandwidth can be determined to be 30.4% by using the frequency corresponding to the 3dB axial ratio in the diagram. Figure 15 The aperture efficiency diagram of a circularly polarized low-profile folded transmission array antenna is schematically shown, with a peak aperture efficiency of 40%. This demonstrates that the transmission antenna designed in this invention achieves a lower profile while possessing the advantages of high gain, high aperture efficiency, and wide bandwidth.

[0092] Figure 16 The diagram schematically illustrates the transmission amplitude of the transmission unit 31 and the reflection amplitude of the reflection unit 21, with two curves: the dashed curve represents the reflection amplitude, and the solid curve represents the transmission amplitude. The reflection amplitude of the reflection unit 21 remains above -0.2 dB consistently between 8.5 GHz and 11.5 GHz; the transmission amplitude of the transmission unit 31 remains almost above -1 dB between 8.5 and 11.5 GHz, and also above -0.5 dB between 9 GHz and 10.4 GHz. Both the transmission unit 31 and the reflection unit 21 exhibit good reflection and transmission amplitudes over a wide frequency band, giving this antenna, composed of these two units, the advantage of broadband performance.

[0093] The broadband, high-efficiency circularly polarized low-profile folded transmission array antenna of the present invention further reduces the antenna profile by simultaneously adjusting the reflection array elements and the transmission array elements, reducing the profile to one-fifth of the focal length, and making the ratio of profile height to array diameter 0.16. In addition, the antenna also has the advantages of high gain, broadband, and high efficiency. The gain at 10 GHz reaches 24.62 dB, corresponding to an aperture efficiency of 40%, a 3 dBi gain bandwidth of 24.7%, and a 3 dB axial ratio bandwidth of 30.4%, overcoming the shortcomings of low aperture efficiency and narrow bandwidth of known solutions, thus expanding the application scope of the present invention.

[0094] The broadband, high-efficiency, circularly polarized, low-profile folded transmission array antenna of this application includes a feed 1, a reflector array 2, and a transmission array 3. The phase center of the feed 1 and the reflector array 2 are disposed on the same plane, and the transmission array 3 is disposed at intervals behind the reflector array 2. The transmission array 3 is composed of a plurality of transmission elements 31, each transmission element 31 including a transmitting patch 311. The transmitting patches 311 are arranged according to a target rotation angle, which is the angle corresponding to setting the transmission phase of each transmission element 31 to be the same as the first compensation phase of each transmission element 31. The reflector array 2 is composed of a plurality of reflecting elements 21, each reflecting element 21 including a polarization torsion patch 211. The polarization torsion patch 211 includes a pair of symmetrical curved sections 2111 and a connecting portion 2112 connecting the two curved sections 2111. The curvature of the two curved sections 2111 is arranged according to a target curvature, which is the curvature corresponding to setting the reflection phase of each reflecting element 21 to be the same as the second compensation phase of each reflecting element 21. In this way, the transmitting patches 311 of the transmission array 3 are arranged according to the target rotation angle. By adjusting the rotation angle of the transmitting patches 311 of each transmission unit 31 clockwise, the transmission phase of each transmission unit 31 is adjusted so that the transmission phase of each transmission unit 31 is the same as the first compensation phase of each transmission unit 31. By changing the arc θ of the two curved sections 2111 of the polarization torsion patch 211 of the reflection unit 21, the reflection phase of each reflection unit 21 is changed so that the reflection phase of each reflection unit 21 is the same as the second compensation phase of the corresponding reflection unit 21. While changing the transmission phase of the transmission unit 31 and the reflection phase of the reflection unit 21, the transmission amplitude of the transmission unit 31 and the reflection amplitude of the reflection unit 21 always maintain good performance. This makes the transmission array antenna have high aperture efficiency. Both the transmission unit 31 and the reflection unit 21 have good reflection amplitude and transmission amplitude over a wide frequency band, so that the transmission array antenna composed of the transmission unit 31 and the reflection unit 21 has the advantage of broadband.

[0095] While specific embodiments of the present invention have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the invention. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of the invention. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any manner.

[0096] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A broadband, high-efficiency, circularly polarized, low-profile folded transmission array antenna, characterized in that, The broadband, high-efficiency, circularly polarized, low-profile folded transmission array antenna includes: a feed, a reflector array, and a transmission array. The phase center of the feed and the reflector array are located on the same plane, and the transmission array is spaced behind the reflector array. The transmission array is composed of multiple transmission units, each transmission unit including a transmitting patch. The transmitting patches are arranged according to a target rotation angle, which is the angle corresponding to setting the transmission phase of each transmission unit to be the same as the first compensation phase of each transmission unit. The reflective array is composed of multiple reflective units arranged together. Each reflective unit includes a polarized torsion patch. The polarized torsion patch includes a pair of symmetrical curved sections and a connecting part connecting the two curved sections. The curvature of the two curved sections is arranged according to a target curvature. The target curvature is the curvature corresponding to setting the reflection phase of each reflective unit to be the same as the second compensation phase of each reflective unit. The polarized torsion patches have different styles. The transmission array consists of a receiving patch, a metal ground plane, the transmitting patch, a first dielectric substrate, and a second dielectric substrate; The transmitting patch, the first dielectric substrate, the metal ground plate, the second dielectric substrate, and the receiving patch are stacked together. The transmitting patch is disposed on the upper surface of the first dielectric substrate, the metal ground plate is disposed on the lower surface of the first dielectric substrate and connected to the upper surface of the second dielectric substrate, and the receiving patch is disposed on the lower surface of the second dielectric substrate. The metal floor has a circular hole in the center, through which a metal cylinder passes, with one end of the metal cylinder connected to the transmitting patch and the other end connected to the receiving patch. The receiving patch is square in shape and has three C-shaped cutouts. The openings of adjacent C-shaped cutouts face different directions. The three C-shaped cutouts are arranged sequentially from the inside to the outside around the center of the receiving patch. The emitter patch is square in shape and has two C-shaped cutouts and one rectangular cutout. The openings of the two C-shaped cutouts face different directions. The two C-shaped cutouts are arranged sequentially from the inside to the outside around the center of the emitter patch. The rectangular cutout is located outside the two C-shaped cutouts. The second compensation phase of each reflective element is: ； in, This is the second compensation phase for each of the reflecting units. For the wavenumber in free space, A preset feed source at a preset position is fed onto the first reflector surface. The distance of each unit, The phase center of the actual feed source is the distance from the first point on the reflector surface. The distance of each unit, To preset the initial phase, Let x be the x-coordinate of the reflecting unit. Let be the ordinate of the reflecting element. The preset feed source is located directly above the center point of the reflecting array, and its vertical distance from the reflecting array is twice the antenna profile height.

2. The broadband, high-efficiency, circularly polarized, low-profile folded transmission array antenna according to claim 1, characterized in that, The size of the metal cylinder is adapted to the size of the circular hole.

3. The broadband, high-efficiency, circularly polarized, low-profile folded transmission array antenna according to claim 1, characterized in that, One end of the metal cylinder is connected to the center of the transmitting patch, and the other end of the metal cylinder is connected to the center of the receiving patch.

4. The broadband, high-efficiency, circularly polarized, low-profile folded transmission array antenna according to claim 1, characterized in that, The polarization direction of the emitter patch is a left-handed circular polarization direction.

5. The broadband, high-efficiency, circularly polarized, low-profile folded transmission array antenna according to claim 1, characterized in that, The reflective array is composed of the polarized torsion patch, the ground plane, and the third dielectric plate; The polarization twist patch, the third dielectric plate, and the floor are stacked together, with the polarization twist patch disposed on the upper surface of the third dielectric plate and the floor disposed on the lower surface of the third dielectric plate.

6. The broadband, high-efficiency, circularly polarized, low-profile folded transmission array antenna according to claim 5, characterized in that, The floor is square in shape, and the size of the floor is the same as that of the third medium board.

7. The broadband, high-efficiency, circularly polarized, low-profile folded transmission array antenna according to claim 1, characterized in that, The first compensation phase of each transmission unit is: ； in, This is the first compensation phase for each transmission unit. For the wavenumber in free space, The phase center of the feed source to the first phase on the transmission array surface. The distance between transmission units, For the first on the transmission array surface The position vector of each transmission unit The unit vector pointing in the direction of the antenna's main beam. To preset the initial phase, The x-coordinate of the transmission unit is... The vertical coordinate of the transmission unit is denoted as .

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