A wide-angle scanning transmitarray antenna

Abstract

The application discloses a wide-angle scanning transmission array antenna, which comprises gradient phase surfaces I and II and a feed source, wherein the gradient phase surfaces I and II each comprise a plurality of array element units; the gradient phase surface I comprises a double-opened loop as a transmitting unit and a cut-corner patch as a receiving unit, and the double-opened loop and the cut-corner patch share a metal ground plate and are connected through a metal through hole; the gradient phase surface II comprises two cut-corner patches sharing a metal ground plate, and the two cut-corner patches are respectively used as a transmitting unit and a receiving unit; the double-opened loop comprises a radiation opened loop and a parasitic opened loop, the radiation opened loop is used for generating a circularly polarized wave, and the parasitic opened loop is used for adjusting a beam pointing direction to an inclined angle; a U-shaped groove is arranged in each cut-corner patch, and each cut-corner patch is rotated by a preset angle around the corresponding metal through hole; and the feed source is used for radiating a circularly polarized wave. The application can improve the scanning angle from two aspects of phase and amplitude.

Description

Technical Field

[0001] This invention belongs to the field of antenna technology, and specifically relates to a wide-angle scanning transmission array antenna. Background Technology

[0002] With the rapid development of wireless communication technology and radar systems, beam-scanning antennas are being used more and more widely in these fields, placing increasingly higher demands on antenna performance. Phased array antennas are a traditional solution for beam scanning, enabling rapid beam scanning; however, they require costly and complex feeding networks. Transmissive array antennas, as a new type of array antenna that has emerged in recent years, are gradually becoming a new implementation scheme for beam-scanning antennas due to their advantages such as high gain, no need for complex feeding networks, and high flexibility.

[0003] There are two main approaches to designing beam-scanning transmission array antennas: electrical scanning using active devices and mechanical scanning via a moving feed. For the electrical scanning approach, a reconfigurable transmission array antenna is achieved by loading active devices such as PIN diodes and varactor diodes onto each transmission element. [1]-[2] The active devices are used to change the phase distribution of the emitted wave to form a beam scan. However, this approach requires a large number of active devices and bias networks, which not only greatly increases cost and complexity but also introduces significant losses, especially in the millimeter-wave band. This makes it difficult to apply the electronic scanning scheme to systems operating in the millimeter-wave band. For the mechanical scanning scheme, the incident phase is changed simply by moving the feed source, thus changing the beam direction. Compared to the electronic scanning scheme, it has advantages such as low cost and simple control. However, the scanning range achievable by this mechanical scanning scheme is limited. The main reason is that phase compensation errors occur when the feed source is moved away from the focus, and these errors increase rapidly with the increase of the offset distance, making it difficult to focus the beam and limiting the scanning range to about 50°. Moreover, based on the principle of pattern product, the narrow beamwidth of the radiating element itself also causes the gain to drop rapidly when scanning at large angles. Although many designs to reduce phase compensation errors have been proposed in the literature, for example: in the literature... [3]-[6] In previous studies, several schemes were proposed, including dual-focus phase compensation, offset focus symmetry, sliding aperture technology, and multi-focus optimization, which can extend the beam scanning range to 80°, but the improvement in scanning angle remains very limited. Therefore, it is necessary to explore a new design scheme to further increase the scanning range of mechanically scanned transmission array antennas.

[0004] [1]J.Tang,S.Xu,F.Yang,and M.Li,“Design and measurement of areconfigurable transmitarray antenna with compact varactor-based phaseshifters,”IEEE Antennas Wireless Propag.Lett.,vol.20,no.10,pp.1998-2002,Oct.2021.

[0005] [2]Y.Wang,S.Xu,F.Yang,and M.Li,“A novel 1bit wide-angle beam scanningreconfigurable transmitarray antenna using an equivalent magnetic dipoleelement,”IEEE Trans.Antennas Propag.,vol.68,no.7,pp.5691-5695,Jul.2020.

[0006] [3]P.Nayeri,F.Yang,and A.Z.Elsherbeni,“Bifocal design and aperturephase optimizations of reflectarray antennas for wide-angle beam scanningperformance,”IEEE Trans.Antennas Propag.,vol.61,no.9,pp.4588-4597,Sep.2013.

[0007] [4]P.Mei,G.F.Pedersen,and S.Zhang,“Performance improvement ofmechanically beam-steerable transmitarray antennas by using offset unifocalphase symmetry,”IEEE Trans.Antennas Propag.,vol.71,no.1,pp.1129-1134,Jan.2023.

[0008] [5] Y.Hou, L.Chang, Y.Li, Z.Zhang, and Z.Feng, "Linear multibeamtransmitarray based on the sliding aperture technique," IEEE Trans.AntennasPropag., vol.66, no.8, pp.3948-3958, Aug.2018.

[0009] [6] F.Vaquero et al., "Design of low-profile transmitarray antennas with wide mechanical beam steering at millimeter waves," IEEE Trans.AntennasPropag., vol.71, no.4, pp.3713-3718, Apr.2023. Summary of the Invention

[0010] To address at least one of the problems of existing technologies, this invention provides a wide-angle scanning transmission array antenna. This antenna includes a circularly polarized patch antenna and two layers of rotatable gradient phase surfaces, which can improve the scanning angle in terms of both phase and amplitude. Regarding phase, mechanically rotating the two gradient phase surfaces changes the beam direction and ensures that the emitted beam is a plane wave during rotation, meaning the scanning beam remains focused. Regarding amplitude, to overcome the problem of narrow beamwidth in the radiating element, an antenna with a tilted radiating beam is used as the radiating element, thereby making the gain change more smooth during scanning.

[0011] To achieve the objective of this invention, the present invention provides a wide-angle scanning transmission array antenna, comprising a gradient phase surface I, a gradient phase surface II, and a feed source, wherein both gradient phase surface I and gradient phase surface II comprise multiple array element units.

[0012] The gradient phase surface I includes a double-opening ring as a transmitting unit and a chamfered patch as a receiving unit, and the double-opening ring and the chamfered patch share a metal ground plane and are connected by metal through holes;

[0013] Gradient phase surface II includes two chamfered patches sharing a common metal ground plane, with the two chamfered patches serving as a transmitting unit and a receiving unit, respectively.

[0014] The dual-aperture ring includes a radiating aperture ring located on the inner side and a parasitic aperture ring located on the outer side of the radiating aperture ring. The radiating aperture ring is connected to the metal via via a microstrip antenna. The radiating aperture ring is used to generate circularly polarized waves, and the parasitic aperture ring is used to adjust the beam direction to the tilt angle. Each chamfer patch has a U-shaped groove, and each chamfer patch rotates around the corresponding metal via by a preset angle.

[0015] The feed source is used to radiate circularly polarized waves.

[0016] Furthermore, the gradient phase surface I also includes a first dielectric plate and a second dielectric plate stacked together. A first metal layer is disposed on the top of the first dielectric plate, and the double-opening ring is disposed on the first metal layer. A second metal layer is disposed on the lower surface of the second dielectric plate, and a chamfered patch is disposed on the second metal layer. The upper surface of the second dielectric plate is a metal ground plane.

[0017] Furthermore, a metal layer is provided on the upper surface of the second dielectric plate, and a gap for separating the metal through holes is provided on the metal layer at the position corresponding to the metal through holes.

[0018] Furthermore, the gradient phase surface II also includes a third dielectric plate and a fourth dielectric plate stacked together. The upper surface of the third dielectric plate is provided with a third metal layer, and the lower surface of the fourth dielectric plate is provided with a fourth metal layer. Two chamfered patches are respectively disposed on the third metal layer and the fourth dielectric plate. The upper surface of the fourth dielectric plate is a metal ground plane.

[0019] Furthermore, a metal layer is provided on the upper surface of the fourth dielectric plate, and a gap for separating the metal through holes is provided on the metal layer at the position corresponding to the metal through holes.

[0020] Furthermore, the feed source includes a fifth dielectric substrate and a sixth dielectric substrate. The lower surface of the fifth dielectric substrate is a metal ground plane, and the upper surface is also provided with a chamfered patch. The sixth dielectric substrate is a grounded coplanar waveguide structure.

[0021] Furthermore, after phase modulation by gradient phase surface II, the circularly polarized wave becomes a plane wave with a specific direction. After phase modulation by gradient phase surface I, it remains a plane wave, but the beam direction changes. The final beam direction depends on the rotation angles of the two gradient phase surfaces. The rotation angles of the two gradient phase surfaces I and II, which have the same gradient, are respectively... and The resulting azimuth angle of the beam pointing for:

[0022]

[0023] The beam pointing elevation angle θ is:

[0024] θ=arcsin(2sinγcos(ξ / 2))

[0025] in That is, the relative rotation angle between the two phase gradient surfaces, where γ is the scanning angle obtained when either gradient phase surface I or gradient phase surface II acts alone.

[0026] Furthermore, when When the beam reaches its maximum deflection angle arcsin(2sinγ) on the elevation plane, and When the phase difference is 180°, the beam points in the direction of the normal to the array surface.

[0027] Furthermore, when the beam deflection angle is At that time, the array element (x) on the gradient phase surface II i ,y j The required compensation phase is:

[0028]

[0029] Where k0 is the free space wave constant, R ij θ is the distance from the focus to each element. t and These are the elevation and azimuth angles of the required transmission array antenna beam pointing, respectively. i and y j These are the x and y coordinates of the cell numbered (i, j).

[0030] Furthermore, each array element (x) on gradient phase surface I i ,y j The required phase shift size is:

[0031]

[0032] Compared with the prior art, the present invention can achieve at least the following beneficial effects:

[0033] (1) Existing mechanically scanned transmission array antennas often suffer from beam defocusing due to excessive phase errors during scanning. Furthermore, when the beam pointing angle is too large, the scanning loss increases rapidly due to the significant drop in gain of the radiating element, resulting in a narrow scanning angle. To address this issue, this invention utilizes two gradient phase surfaces for beam scanning, solving the beam defocusing problem caused by phase errors during scanning. Additionally, by employing an antenna with a tilted radiating beam as the radiating element of the transmission array antenna, the problem of drastic gain drop during scanning is resolved.

[0034] (2) The present invention can achieve a scanning range of 122° in the pitch plane and cover 0°-360° in the azimuth plane, which has the advantage of wide-angle scanning. Attached Figure Description

[0035] Figure 1 This is a full view of a wide-angle scanning transmission array antenna provided in an embodiment of the present invention.

[0036] Figure 2 This is a top view of the first dielectric plate and the first metal layer on its upper surface in an embodiment of the present invention.

[0037] Figure 3 This is a bottom view of the second dielectric plate and the second metal layer on its lower surface in an embodiment of the present invention.

[0038] Figure 4 This is a top view of the third dielectric plate and the third metal layer on its upper surface in an embodiment of the present invention.

[0039] Figure 5 This is a bottom view of the fourth dielectric plate and the fourth metal layer on its lower surface in an embodiment of the present invention.

[0040] Figure 6 This is a top view of the fifth medium plate in an embodiment of the present invention.

[0041] Figure 7 This is a bottom view of the sixth medium plate in an embodiment of the present invention.

[0042] Figure 8 This is a schematic diagram of the phase change of a plane wave after passing through two gradient phase surfaces in an embodiment of the present invention. In the diagram, (a) shows that gradient phase surfaces I and 2 are in their initial positions, (b) shows that gradient phase surfaces I and 2 are rotated by 30° and -30° respectively, (c) shows that gradient phase surfaces I and 2 are rotated by 45° and -45° respectively, (d) shows that gradient phase surfaces I and 2 are rotated by 60° and -60° respectively, and (e) shows that gradient phase surfaces I and 2 are rotated by 90° and -90° respectively.

[0043] Figure 9 This is a schematic diagram of the array element of gradient phase surfaces I and 2 in an embodiment of the present invention.

[0044] Figure 10 This is a schematic diagram of the radiation pattern and axial ratio of the dual-aperture loop antenna in an embodiment of the present invention.

[0045] Figure 11 This is a schematic diagram of the transmission amplitude of the chamfered patch antenna in an embodiment of the present invention.

[0046] Figure 12 This is a schematic diagram of the transmission phase of the chamfered patch antenna in an embodiment of the present invention.

[0047] Figure 13 This is a schematic diagram of the transmission amplitude of the array element of the gradient phase surface II in an embodiment of the present invention.

[0048] Figure 14 This is a schematic diagram of the transmission phase of the array element of gradient phase surface II in an embodiment of the present invention.

[0049] Figure 15 This is a schematic diagram of the S-parameter performance of a wide-angle scanning transmission array antenna in an embodiment of the present invention.

[0050] Figure 16 This is a schematic diagram of beam scanning at a center frequency of 32 GHz for a wide-angle scanning transmission array antenna in an embodiment of the present invention.

[0051] Figure 17 This is a schematic diagram of the gain of a wide-angle scanning transmission array antenna according to an embodiment of the present invention. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] This invention provides a wide-angle scanning transmission array antenna, the full view of which is shown below. Figure 1 As shown, the antenna has six dielectric substrates: a first dielectric substrate 11, a second dielectric substrate 12, a third dielectric substrate 13, a fourth dielectric substrate 14, a fifth dielectric substrate 15, and a sixth dielectric substrate 16. The first dielectric substrate 11 and the second dielectric substrate 12 are stacked to form gradient phase surface I; the third dielectric substrate 13 and the fourth dielectric substrate 14 are stacked to form gradient phase surface II; and the fifth dielectric substrate 15 and the sixth dielectric substrate 16 are stacked to form a feed. In some embodiments of the present invention, the PCB material used for each dielectric substrate is Rogers 5880, with a dielectric constant of 2.2 and a loss tangent of 0.0009. The thicknesses of the first to sixth dielectric substrates are 1.575 mm, 0.787 mm, 0.787 mm, 0.787 mm, 0.787 mm, and 0.254 mm, respectively, and their dimensions are 80 mm × 80 mm, 80 mm × 80 mm, 80 mm × 80 mm, 10 mm × 10 mm, and 10 mm × 10 mm, respectively. The spacing between gradient phase surface I and gradient phase surface II is 2.7 mm, and the spacing between gradient phase surface II and the feed is 35 mm.

[0054] The coordinate system is established as follows: the x-axis and y-axis of the rectangular coordinate system are parallel to the two rectangular sides of the PCB board, and the maximum radiation direction of the array points to the z-axis.

[0055] A top view of the first dielectric plate 11 and the first metal layer 21 located on its upper surface is shown below. Figure 2 As shown, a first metal layer 21 is disposed on the upper surface of the first dielectric substrate 11, and periodically arranged double-opening rings 22 are disposed on the first metal layer 21. Each double-opening ring 22 has the same structure, including an inner radiating opening ring 23 and an outer parasitic opening ring 24. The radiating opening ring 23 is connected to a metal via 26 via a microstrip line 25, and the metal via 26 is located inside the radiating opening ring 23. The double-opening rings 22 can radiate circularly polarized electromagnetic waves with a tilted beam direction, wherein the radiating opening ring 23 is used to generate the circularly polarized wave, and the parasitic opening ring 24 is used to adjust the beam direction to the tilt angle. In some embodiments of the present invention, the period of the double-opening rings 22 is 5 mm.

[0056] A bottom view of the second dielectric plate 12 and the second metal layer 31 located on its lower surface is shown below. Figure 3 As shown, a second metal layer 31 is disposed on the lower surface of the second dielectric substrate 12, and chamfered patches 32 are disposed on the second metal layer 31 in a periodic arrangement. A U-shaped groove 33 is cut out of the interior of each chamfered patch 32, and a metal through-hole 26 is disposed at the center of the U-shaped groove 33. Each chamfered patch 32 rotates around its respective metal through-hole by a certain angle. Please refer to... Figure 9 The upper surface of the second dielectric plate 12 is provided with a metal layer to serve as a metal reflector for the double-opening ring 22 and a metal ground for the chamfered patch 32. A circular patch is subtracted from the metal layer at the position corresponding to each metal through-hole 26 to space the metal through-hole 26 from the metal reflector. In some embodiments of the present invention, the period size of the chamfered patch 32 is 5 mm.

[0057] A top view of the third dielectric plate 13 and the third metal layer 41 located on its upper surface is shown below. Figure 4 As shown, a third metal layer 41 is disposed on the upper surface of the third dielectric substrate 13, and chamfered patches 32 are disposed on the third metal layer 41 in a periodic arrangement, and the structure of the chamfered patches is the same as that of the chamfered patches on the second metal layer 31. In some embodiments of the present invention, the period size of the chamfered patches 32 on the third dielectric substrate 13 is 5 mm.

[0058] A bottom view of the fourth dielectric plate 14 and the fourth metal layer 51 on its lower surface is shown below. Figure 5As shown, a fourth metal layer 51 is disposed on the lower surface of the fourth dielectric substrate 14. Chamfered patches 32 are periodically arranged on the fourth metal layer 51, and the structure of the chamfered patches is the same as that of the chamfered patches on the second metal layer 31. Please refer to... Figure 9 The upper surface of the fourth dielectric plate 14 is provided with a metal layer to serve as the metal ground for the chamfered patches 32 on the third metal layer 41 and the fourth metal layer 51. A circular slit is provided on the metal layer at the position corresponding to each metal through hole 26 to space the metal through hole 26 from the metal reflector. In some embodiments of the present invention, the period size of the chamfered patches 32 on the fourth dielectric plate 14 is 5 mm.

[0059] A top view of the upper surface of the fifth medium plate 15 is shown below. Figure 6 As shown. The upper surface of the fifth medium plate 15 is provided with a chamfered patch 32, and the lower surface is the metal floor of the chamfered patch.

[0060] The sixth dielectric substrate 16 is a grounded coplanar waveguide structure (GCPW), and the bottom view of its lower surface is shown below. Figure 7 As shown, the electromagnetic wave input from the excitation port is transmitted through the metal through-holes 26 on the sixth dielectric substrate 16 and the fifth dielectric substrate 15 to the chamfered patch 32 on the fifth dielectric substrate 15, thereby exciting the chamfered patch antenna on the fifth dielectric substrate 15.

[0061] In terms of working principle, the feed emits a circularly polarized wave after being excited. This circularly polarized wave is then received by the receiving unit on gradient phase surface II and transmitted to the transmitting unit for radiation. The radiated wave is still a circularly polarized wave. This circularly polarized wave is then received by the receiving unit on gradient phase surface I and transmitted to the transmitting unit, finally radiating into the atmosphere from the transmitting unit on gradient phase surface I. In the above process, the circularly polarized wave becomes a plane wave with a specific direction after phase modulation by gradient phase surface II. After phase modulation by gradient phase surface I, it is still a plane wave, but the beam direction changes. The final beam direction depends on the rotation angle of the two gradient phase surfaces. The phase change of a plane wave after passing through two gradient phase surfaces is as follows: Figure 8 As shown, the compensated phases of both gradient phase surface I and gradient phase surface II in the initial state increase linearly along the x-axis (i.e., change according to a certain gradient) and remain unchanged along the y-axis. The two phase gradient surfaces are then rotated counterclockwise. and when From 0° to 90° and During the transition from 0° to -90°, the outgoing phase obtained after passing through two gradient phase surfaces remains unchanged along the y-axis but exhibits a gradient change along the x-axis, gradually decreasing to 0. This means that during the rotation of the two gradient phase surfaces, the scanning beam remains a plane wave, and the beam scanning angle gradually decreases to 0°. Specifically, the rotation angles of the two gradient phase surfaces I and II, which have the same gradient, are respectively... and The resulting azimuth angle of the beam pointing for:

[0062]

[0063] The beam pointing elevation angle θ is:

[0064] θ=arcsin(2sinγcos(ξ / 2))

[0065] in That is, the relative rotation angle between the two phase gradient surfaces, where γ is the scanning angle obtained when either gradient phase surface I or gradient phase surface II acts alone. When the beam reaches its maximum deflection angle arcsin(2sinγ) on the elevation plane, and When the phase difference is 180°, the beam points in the direction of the normal to the array surface.

[0066] For this invention, the gradient phase surface II also needs to be supplemented with a compensating phase to convert the spherical wave radiated by the feed source into a plane wave. When the beam deflection angle is... At that time, the array element (x) on the gradient phase surface II i ,y j The required compensation phase is:

[0067]

[0068] Where k0 is the free space wave constant, R ij θ is the distance from the focus to each element. t and These are the elevation and azimuth angles of the required transmission array antenna beam pointing, respectively. i and y j The x and y coordinates of the cells numbered (i, j) are respectively. In some embodiments of the present invention, i, j = 1, 2, 3, ..., 14.

[0069] Each element (x) on gradient phase surface I i ,y j The required phase shift size is:

[0070]

[0071] In some embodiments of the present invention, a 14×14 array distribution is adopted, the aperture size is 70mm×70mm, the focal diameter ratio is selected as 0.5, and the maximum scanning angle to be obtained is 60°.

[0072] Both gradient phase surface I and gradient phase surface II consist of multiple array elements, and the array element structure is as follows: Figure 9 As shown, all array elements are transceiver structures. For the array elements on gradient phase surface I, the double-opening ring 22 and the chamfered patch 32 serve as the transmitting and receiving elements, respectively, connected by a metal through-hole and sharing the same metal ground plane. Electromagnetic waves are received by the chamfered patch 32 and transmitted through the metal through-hole to the double-opening ring 22, and then radiated into the atmosphere from the double-opening ring 22. Due to the asymmetrical current distribution, the radiation pattern of the double-opening ring antenna will be tilted. The parasitic ring structure can further increase the tilt angle, and its radiation pattern and axis are as follows. Figure 10 As shown, the tilt angle of the radiation pattern is approximately 30°. Within the range of 0 to 60°, the gain variation is less than 3dB, and the axial ratio is good. Therefore, according to the pattern product theorem, using this antenna as the transmitting element of gradient phase surface I will effectively alleviate the problem of rapid gain drop when scanning large angles. The chamfered patch antenna is used to receive circularly polarized waves. The U-shaped slot loaded in the middle of the chamfered patch can improve the matching with the double-opening loop antenna, thereby increasing the transmission amplitude. The transmission amplitude of this array element is as follows: Figure 11 As shown, the transmission loss remains below -1dB within the 31-33.5GHz range, indicating good transmission performance. The transmission phase is as follows... Figure 12 As shown, rotating the chamfered patch around the metal through-hole can change the transmission phase. Since the receiving unit is rotated, the rotation angle is opposite to the change in transmission phase, thus obtaining a unit with arbitrary compensated phase. For the array element of gradient phase surface II, the transmitting and receiving units use the same U-shaped slot chamfered patch, which is connected by a metal through-hole and shares the same metal ground plane. The transmission amplitude and phase of this array element are as follows: Figure 13 and Figure 14 As shown, the transmission loss is less than 1 dB in the 31-33.5 GHz range, enabling efficient reception and transmission of right-hand circularly polarized electromagnetic waves, and allowing for phase compensation at arbitrary angles. Considering low profile and low complexity, a circularly polarized patch antenna was selected as the feed for the transmission array antenna. Its patch structure is similar to the chamfered patch structure in the phase gradient surface and is capable of radiating right-hand circularly polarized electromagnetic waves.

[0073] Regarding antenna performance, the S-parameters are as follows: Figure 15 As shown, within the 30.5GHz-33.5GHz frequency band, |S 11| Less than -10dB, good impedance matching. Figure 16 This describes the beam scanning of the antenna at a center frequency of 32 GHz, where the rotation angle of gradient phase surface I is... The rotation angle of gradient phase surface II is When the rotation angle is 90°, the beam points in the direction of the array normal, combined with Figure 17 At this point, the gain is 22.18 dBic; when the rotation angle is 0°, the antenna achieves a maximum scanning angle of 61°, corresponding to a gain of 18.9 dBic. During scanning, the maximum scanning loss is 3.3 dB, and the azimuth plane can cover 360°.

[0074] The transmission array antenna proposed in the foregoing embodiments of the present invention can ultimately achieve a scanning range of up to 122° in the elevation plane, and at the same time cover 0° to 360° in the azimuth plane, with a very wide beam scanning range, which is superior to the current technical level.

[0075] In summary, the transmission array antenna proposed in this invention has high gain and a wide beam scanning range, and its beam scanning capability is at a leading level among similar transmission array antennas.

[0076] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined in this invention may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A wide-angle scanning transmitarray antenna, characterized by, The gradient phase surface I and the gradient phase surface II each comprise a plurality of array element units, and the gradient phase surface I and the gradient phase surface II each comprise a double-opened ring as a transmitting unit and a cut-corner patch as a receiving unit. The gradient phase surface I comprises a double-opened ring as a transmitting unit and a cut-corner patch as a receiving unit, and the double-opened ring and the cut-corner patch share a metal ground plate and are connected through a metal via hole. The gradient phase surface II comprises two cut-corner patches sharing a metal ground plate, and the two cut-corner patches are respectively used as a transmitting unit and a receiving unit. The double-opened ring comprises a radiation opened ring located at an inner side and a parasitic opened ring located at an outer side of the radiation opened ring, the radiation opened ring is connected with the metal via hole through a microstrip antenna, the radiation opened ring is used for generating a circularly polarized wave, and the parasitic opened ring is used for adjusting a beam pointing direction to an inclined angle; each cut-corner patch is provided with a U-shaped slot, and each cut-corner patch is rotated by a preset angle around the corresponding metal via hole. The feed source is used for radiating a circularly polarized wave. After the phase modulation of the circularly polarized wave by the gradient phase surface II, the circularly polarized wave becomes a plane wave with a specific direction. After the phase modulation of the plane wave by the gradient phase surface I, the plane wave is still a plane wave, but the beam direction is changed. The final beam direction depends on the rotation angles of the two gradient phase surfaces. The rotation angles of the two gradient phase surfaces I and II with the same gradient are respectively .

2. The wide-angle scanning transmitarray antenna of claim 1, wherein, The gradient phase surface I further comprises a first dielectric plate and a second dielectric plate which are stacked, the first dielectric plate is provided with a first metal layer on an upper surface, the double-opened ring is arranged on the first metal layer, the second dielectric plate is provided with a second metal layer on a lower surface, and the cut-corner patch is arranged on the second metal layer. The upper surface of the second dielectric plate is a metal ground plate.

3. The wide-angle scanning transmitarray antenna of claim 2, wherein, The upper surface of the second dielectric plate is provided with a metal layer, and a gap is arranged on the metal layer corresponding to the position of the metal via hole to separate the metal via hole.

4. The wide-angle scanning transmitarray antenna of claim 1, wherein, The gradient phase surface II further comprises a third dielectric plate and a fourth dielectric plate which are stacked, the upper surface of the third dielectric plate is provided with a third metal layer, the lower surface of the fourth dielectric plate is provided with a fourth metal layer, and the two cut-corner patches are arranged on the third metal layer and the fourth dielectric plate respectively; and the upper surface of the fourth dielectric plate is a metal ground plate.

5. The wide-angle scanning transmitarray antenna of claim 4, wherein, The upper surface of the fourth dielectric plate is provided with a metal layer, and a gap is arranged on the metal layer corresponding to the position of the metal via hole to separate the metal via hole.

6. The wide-angle scanning transmitarray antenna of claim 1, wherein, The feed source comprises a fifth dielectric plate and a sixth dielectric plate, the lower surface of the fifth dielectric plate is a metal ground plate, and the upper surface is also provided with a cut-corner patch; and the sixth dielectric plate is a ground coplanar waveguide structure.

7. A wide-angle scanning transmitarray antenna according to any one of claims 1 to 6, wherein, Azimuth of beam pointing Is: Beam pointing elevation angle Is: wherein = 2π / λ is the relative rotation angle of the two gradient phase surfaces, is the scanning angle obtained when the gradient phase surface I or the gradient phase surface II acts alone.

8. The wide-angle scanning transmitarray antenna of claim 7, wherein, When the beam gets the maximum deflection angle in the elevation plane ), the beam points in the direction of the normal to the array plane when the beams are 180° out of phase.

9. The wide-angle scanning transmitarray antenna of claim 7, wherein, When the beam deflection angle is ), the element unit on the gradient phase surface II The required compensation phase is: wherein is the free space wave constant, is the distance from the focal point to each element, and are the required elevation and azimuth angles of the transmitted array antenna beam pointing, and are the x and y coordinates of the element numbered (i,j).

10. The wide-angle scanning transmitarray antenna of claim 9, wherein, Each element unit on the gradient phase surface I The phase shift size required is: 。

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