Wide-angle scanning transmission array antenna

Abstract

The wide-angle scanning transmission array antenna comprises a gradient phase surface I, a gradient phase surface II and a feed source, and each of the gradient phase surface I and the gradient phase surface II comprises a plurality of array element units; the gradient phase surface I comprises a double-opening ring serving as a transmitting unit and a chamfered patch serving as a receiving unit, and the double-opening ring and the chamfered patch share one metal floor and are connected through a metal through hole; the gradient phase surface II comprises two corner cut patches sharing one metal floor, and the two corner cut patches serve as a transmitting unit and a receiving unit respectively; the double-split ring comprises a radiation split ring and a parasitic split ring, the radiation split ring is used for generating circularly polarized waves, and the parasitic split ring is used for adjusting beam pointing to an inclination angle; a U-shaped groove is formed in each corner cutting patch, and each corner cutting patch rotates by a preset angle around the corresponding metal through hole; the feed source is used for radiating circularly polarized waves. According to the invention, the scanning angle can be improved from two aspects of phase and amplitude.

Description

Technical Field

[0001] The present invention belongs to the technical field of antennas, and particularly relates to a wide-angle scanning transmissive array antenna. Background Art

[0002] With the rapid development of wireless communication technologies and radar systems, beam-scanning antennas are increasingly widely used in these fields, and higher requirements are also put forward for the performance of antennas. Phased array antennas are a traditional solution for beam scanning and can achieve fast beam scanning. However, they require a high-cost and complex feeding network. As a new type of array antenna emerging in recent years, transmissive array antennas have gradually become a new implementation solution for beam-scanning antennas due to their advantages such as high gain, no need for a complex feeding network, and high flexibility.

[0003] There are mainly two schemes for designing transmissive array antennas with beam-scanning capabilities, namely electrical scanning using active devices and mechanical scanning by moving the feed source. For the electrical scanning scheme, a reconfigurable transmissive array antenna is realized by loading active devices such as PIN diodes and varactor diodes on each transmissive unit [1]-[2] and using these active devices to change the phase distribution of the outgoing wave to form beam scanning. However, this scheme requires a large number of active devices and bias networks, which not only greatly increases the cost and complexity but also introduces large losses, especially more serious losses in the millimeter-wave band. This makes it difficult for the electrical scanning scheme to be applied to systems operating in the millimeter-wave band. For the mechanical scanning scheme, the mechanical scanning scheme changes the incident phase by simply moving the feed source to achieve the change of the beam direction. Compared with the electrical scanning scheme, it has advantages such as low cost and simple control. However, the scanning range that this mechanical scanning scheme can achieve is limited. The main reason is that phase compensation errors will occur after the moving feed source deviates from the focus, and as the offset distance increases, the phase compensation errors will increase rapidly, resulting in difficult beam focusing and limiting the scanning range to about 50°. Moreover, based on the pattern multiplication principle, the relatively narrow beam width of the radiation unit itself used will also cause the gain to drop rapidly when scanning to large angles. Although many designs for reducing phase compensation errors have been reported in the literature, for example: in the literature [3]-[6] dual-focus phase compensation, offset-focus symmetry, sliding aperture technology, multi-focus optimization and other schemes have been proposed, which can extend the beam scanning range to 80°, but the improvement of the scanning angle is still very limited. Therefore, it is necessary to explore a new design scheme to further increase the scanning range of the transmissive array antenna based on mechanical scanning.

[0004] [1] J. Tang, S. Xu, F. Yang, and M. Li, “Design and measurement of a reconfigurable transmitarray antenna with compact varactor-based phase shifters,” 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 1-bit wide-angle beam scanning reconfigurable transmitarray antenna using an equivalent magnetic dipole element,” 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 aperture phase optimizations of reflectarray antennas for wide-angle beam scanning performance,” 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 of mechanically beam-steerable transmitarray antennas by using offset unifocal phase 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 multibeam transmitarray based on the sliding aperture technique,” IEEE Trans. Antennas Propag., 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. Antennas Propag., vol. 71, no. 4, pp. 3713 - 3718, Apr. 2023. Summary of the Invention

[0010] In order to solve at least one of the problems existing in the prior art, the present invention provides a wide - angle scanning transmitarray antenna. The antenna includes a circularly polarized patch antenna and two rotatable gradient - phase surfaces, which can improve the scanning angle in terms of both phase and amplitude. In terms of phase, mechanically rotating the two gradient - phase surfaces can change the beam direction, and it can ensure that the outgoing beam is a plane wave during the rotation, that is, the scanning beam always maintains a focused state. In terms of amplitude, in order to overcome the problem of the narrow beam width of the radiation element, an antenna with an inclined radiation beam is used as the radiation element, so that the change of gain during the scanning process is more stable.

[0011] In order to achieve the object of the present invention, a wide - angle scanning transmitarray antenna provided by the present invention includes a gradient - phase surface I, a gradient - phase surface II, and a feed source. Both the gradient - phase surface I and the gradient - phase surface II include a plurality of array element units;

[0012] The gradient - phase surface I includes a double - split - ring as the transmitting unit and a chamfered patch as the receiving unit, and the double - split - ring and the chamfered patch share a metal floor and are connected by a metal via - hole;

[0013] The gradient - phase surface II includes two chamfered patches sharing a metal floor, and the two chamfered patches serve as the transmitting unit and the receiving unit respectively;

[0014] Among them, the double open - loop includes a radiating open - loop located on the inner side and a parasitic open - loop located outside the radiating open - loop. The radiating open - loop is connected to a metal via - hole through a microstrip antenna. The radiating open - loop is used to generate circularly polarized waves, and the parasitic open - loop is used to adjust the beam direction to an inclined angle; a U - shaped groove is provided in each chamfered patch, and each chamfered patch rotates a preset angle around the corresponding metal via - hole;

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

[0016] Furthermore, in the gradient phase surface Ⅰ, it also includes a first dielectric plate and a second dielectric plate stacked. A first metal layer is provided on the upper surface of the first dielectric plate, and the double open - loop is arranged on the first metal layer. A second metal layer is provided on the lower surface of the second dielectric plate, and the chamfered patches are arranged on the second metal layer; the upper surface of the second dielectric plate is a metal floor.

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

[0018] Furthermore, in the gradient phase surface Ⅱ, it also includes a third dielectric plate and a fourth dielectric plate stacked. A third metal layer is provided on the upper surface of the third dielectric plate, and a fourth metal layer is provided on the lower surface of the fourth dielectric plate. Two chamfered patches are respectively arranged on the third metal layer and the fourth dielectric plate; the upper surface of the fourth dielectric plate is a metal floor.

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

[0020] Furthermore, the feed source includes a fifth dielectric plate and a sixth dielectric plate. The lower surface of the fifth dielectric plate is a metal floor, and chamfered patches are also provided on the upper surface; the sixth dielectric plate is a grounded coplanar waveguide structure.

[0021] Furthermore, after the circularly polarized wave is phase - modulated by the gradient phase surface Ⅱ, it becomes a plane wave with a specific direction. After being phase - modulated by the gradient phase surface Ⅰ again, it is still a plane wave, but only 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 with the same gradient are respectively and Then the azimuth angle of the obtained beam direction is:

[0022]

[0023] The elevation angle θ of the beam direction is:

[0024] θ = arcsin(2sinγcos(ξ / 2))

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

[0026] Furthermore, when the beam obtains the maximum deflection angle arcsin(2sinγ) in the elevation plane. When and differ by 180°, the beam points in the normal direction of the array surface.

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

[0028]

[0029] where k 0 is the free space wave constant, R ij is the distance from the focus to each array element, θ t and are the elevation angle and azimuth angle of the pointing direction of the required transmissive array antenna beam respectively, and x i and y j are the abscissa and ordinate of the element numbered (i, j) respectively.

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

[0031]

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

[0033] (1) In the prior art, the transmissive array antenna based on mechanical scanning usually causes the beam to be unable to focus due to excessive phase error during the scanning process. And when the pointing angle of the beam is too large, the scanning loss increases rapidly due to the too much decrease in the gain of the radiation element. Therefore, there is a technical problem of narrow scanning angle. To solve this problem, on the one hand, the present invention uses two gradient phase surfaces to perform beam scanning, solving the problem of beam defocusing caused by phase error during the scanning process. On the other hand, by using an antenna with an inclined radiation beam as the radiation element of the transmissive array antenna, the problem of severe gain decrease during the scanning process is solved.

[0034] (2) The present invention can achieve a scanning range of 122° in the pitch angle plane, and can cover 0° - 360° in the azimuth angle plane at the same time, having the advantage of wide-angle scanning. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

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

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

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

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

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

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

[0044] Figure 10 is a schematic diagram of the radiation pattern and axial ratio of a double split-ring antenna in an embodiment of the present invention.

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

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

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

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

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

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

[0051] Figure 17 It is a schematic diagram of the gain of a wide-angle scanning transmissive array antenna in the embodiment of the present invention. Detailed implementation manners

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

[0053] The present invention provides a wide-angle scanning transmissive array antenna, the full view of which is as shown in Figure 1 shown. The antenna has a total of six dielectric plates, namely the first dielectric plate 11, the second dielectric plate 12, the third dielectric plate 13, the fourth dielectric plate 14, the fifth dielectric plate 15, and the sixth dielectric plate 16. The first dielectric plate 11 and the second dielectric plate 12 are stacked to form the gradient phase surface I, the third dielectric plate 13 and the fourth dielectric plate 14 are stacked to form the gradient phase surface II, and the fifth dielectric plate 15 and the sixth dielectric plate 16 are stacked to form the feed source. In some embodiments of the present invention, the PCB board material used for each dielectric plate is Rogers5880, the dielectric constant is 2.2, and the loss tangent angle is 0.0009. The thicknesses of the first dielectric plate to the sixth dielectric plate are 1.575 mm, 0.787 mm, 0.787 mm, 0.787 mm, 0.787 mm, and 0.254 mm respectively, and the sizes are 80 mm × 80 mm, 80 mm × 80 mm, 80 mm × 80 mm, 80 mm × 80 mm, 10 mm × 10 mm, and 10 mm × 10 mm respectively. The plate spacing between the gradient phase surface I and the gradient phase surface II is 2.7 mm, and the plate spacing between the gradient phase surface II and the feed source is 35 mm.

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

[0055] The top view of the first dielectric plate 11 and the first metal layer 21 located on its upper surface is as Figure 2 shown. The upper surface of the first dielectric plate 11 is provided with the first metal layer 21, and the first metal layer 21 is provided with double split rings 22 arranged periodically. The structure of each double split ring 22 is the same, and each includes a radiation split ring 23 located inside and a parasitic split ring 24 located outside the radiation split ring 23. Among them, the radiation split ring 23 is connected to a metal through hole 26 through a microstrip line 25, and the metal through hole 26 is located inside the radiation split ring 23. The double split ring 22 can radiate circularly polarized electromagnetic waves with an inclined beam direction. Among them, the radiation split ring 23 is used to generate circularly polarized waves, and the parasitic split ring 24 is used to adjust the beam direction to an inclined angle. In some embodiments of the present invention, the period size of the double split ring 22 is 5 mm.

[0056] The bottom view of the second dielectric plate 12 and the second metal layer 31 located on its lower surface is as Figure 3 shown. The lower surface of the second dielectric plate 12 is provided with the second metal layer 31, and the second metal layer 31 is provided with chamfered patches 32 arranged periodically. A U-shaped groove 33 is dug inside the chamfered patch 32, and a metal through hole 26 is provided at the center of the U-shaped groove 33. Each chamfered patch 32 rotates a certain angle around its respective metal through hole. Please refer to Figure 9 , the upper surface of the second dielectric plate 12 is provided with a metal layer to serve as the metal reflector of the double split ring 22 and the metal floor of the chamfered patch 32, and a circular patch is subtracted at the position corresponding to each metal through hole 26 on the metal layer 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] The top view of the third dielectric plate 13 and the third metal layer 41 located on its upper surface is as Figure 4 shown. The upper surface of the third dielectric plate 13 is provided with the third metal layer 41, and the third metal layer 41 is provided with chamfered patches 32 arranged periodically, 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 patch 32 on the third dielectric plate 13 is 5 mm.

[0058] The bottom view of the fourth dielectric plate 14 and the fourth metal layer 51 on its lower surface is as Figure 5As shown, a fourth metal layer 51 is provided on the lower surface of the fourth dielectric plate 14, and chamfered patches 32 arranged periodically are provided 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 , a metal layer is provided on the upper surface of the fourth dielectric plate 14 to serve as a metal floor for the chamfered patches 32 on the third metal layer 41 and the fourth metal layer 51, and a circular slit is provided at a position corresponding to each metal via 26 on the metal layer to space the metal via 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] The top view of the upper surface of the fifth dielectric plate 15 is as shown in Figure 6 . A chamfered patch 32 is provided on the upper surface of the fifth dielectric plate 15, and the lower surface is the metal floor of the chamfered patch.

[0060] The sixth dielectric plate 16 is a grounded coplanar waveguide structure (GCPW), and the bottom view of the lower surface is as shown in Figure 7 . The electromagnetic wave input from the excitation port is transmitted to the chamfered patch 32 on the fifth dielectric plate 15 through the metal vias 26 on the sixth dielectric plate 16 and the fifth dielectric plate 15, thereby realizing the excitation of the chamfered patch antenna on the fifth dielectric plate 15.

[0061] In terms of the working principle, the wave emitted after the feed is excited is a circularly polarized wave. Subsequently, this circularly polarized wave is received by the receiving unit on the gradient phase surface II and transmitted to the transmitting unit for radiation. The radiated wave is still a circularly polarized wave. Then, this circularly polarized wave is received by the receiving unit on the gradient phase surface I and transmitted to the transmitting unit. Finally, it is radiated from the transmitting unit on the gradient phase surface I into the atmosphere. In the above process, the circularly polarized wave becomes a plane wave with a specific direction after the phase modulation by the gradient phase surface II. After the phase modulation by the gradient phase surface I, it is still a plane wave, but only the beam direction changes. The final beam direction depends on the rotation angles of the two gradient phase surfaces. The phase change of a beam of plane waves after passing through the two gradient phase surfaces is as shown in Figure 8 . In the initial state, the compensation phases of the gradient phase surface I and the gradient phase surface II both increase linearly along the x-axis direction (i.e., change according to a certain gradient) and remain unchanged along the y-axis direction. The two phase gradient surfaces are respectively rotated counterclockwise by and When changes from 0° to 90° and During the process of changing from 0° to -90°, the emerging phase obtained after passing through two gradient phase surfaces remains unchanged along the y-axis direction and varies in a gradient manner along the x-axis direction, but the gradient gradually decreases to 0. This means that during the rotation of the two gradient phase surfaces, the scanning beam is always a plane wave, and the beam scanning angle gradually decreases to 0°. Specifically, the rotation angles of two gradient phase surfaces Ⅰ and Ⅱ with the same gradient are respectively and Then the azimuth angle of the beam pointing is:

[0062]

[0063] The elevation angle θ of the beam pointing is:

[0064] θ = arcsin(2sinγcos(ξ / 2))

[0065] where i.e., the relative rotation angle of the two-layer phase gradient surface, and γ is the scanning angle obtained when the gradient phase surface Ⅰ or the gradient phase surface Ⅱ acts alone. When , the beam obtains the maximum deflection angle arcsin(2sinγ) in the elevation plane. When and differ by 180°, the beam points to the normal direction of the array surface.

[0066] For the present invention, the gradient phase surface Ⅱ also needs to add a compensation phase for converting the spherical wave radiated by the feed into a plane wave. When the beam deflection angle is , the compensation phase required for the array element unit (x i , y j ) on the gradient phase surface Ⅱ is:

[0067]

[0068] where k 0 is the free space wave constant, R ij is the distance from the focus to each array element unit, θ t and are respectively the elevation angle and azimuth angle of the required transmitting array antenna beam pointing, x i and y j are respectively the abscissa and ordinate of the unit numbered (i, j). In some embodiments of the present invention, i, j = 1, 2, 3, ···, 14.

[0069] The phase shift magnitude required for each array element unit (x i , y j ) on the gradient phase surface Ⅰ is:

[0070]

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

[0072] Both the gradient phase surface I and the gradient phase surface II include a plurality of array element units, and the structure of the array element units is as Figure 9 shown. The array element units are all of the transceiver structure type. For the array element units of the gradient phase surface I, the double split ring 22 and the chamfered patch 32 serve as the transmitting unit and the receiving unit respectively. The two are connected by a metal through hole and share the same metal floor. After the electromagnetic wave is received by the chamfered patch 32, it is transmitted to the double split ring 22 through the metal through hole, and then radiated from the double split ring 22 into the atmosphere. Due to the asymmetric current distribution, the radiation pattern of the double split ring antenna will be tilted. The parasitic ring structure can further increase the tilt angle. Its radiation pattern and axial ratio are as Figure 10 shown. It can be seen that the tilt angle of the radiation pattern is about 30°. In the range of 0 to 60°, the gain change is less than 3dB, and the axial ratio is good. Therefore, according to the radiation pattern multiplication theorem, using this antenna as the transmitting unit of the gradient phase surface I will effectively alleviate the problem of rapid gain decline when scanning to 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 split ring antenna, thereby increasing the transmission amplitude. The transmission amplitude of this array element unit is as Figure 11 shown. It can be seen that the transmission loss is maintained at less than -1dB in the range of 31 - 33.5GHz, and the transmission performance is good. The transmission phase is as Figure 12 shown. Rotating the chamfered patch around the metal through hole can realize the change of the transmission phase. Since it is the receiving unit that is rotated, the rotation angle and the change value of the transmission phase are opposite, and thus a unit with arbitrary compensation phase can be obtained. For the array element units of the gradient phase surface II, the transmitting unit and the receiving unit adopt the same U-shaped slot chamfered patch. The two are connected by a metal through hole and share the same metal floor. The transmission amplitude and phase of this array element unit are as Figure 13 and Figure 14 shown respectively. The transmission loss is less than 1dB in the range of 31 - 33.5GHz, and it can efficiently receive and transmit right-handed circularly polarized electromagnetic waves and perform phase compensation at any angle. Considering the low profile and low complexity, a circularly polarized patch antenna is selected as the feed source of the transmissive array antenna. Its patch structure is similar to the chamfered patch structure in the phase gradient surface and can radiate right-handed circularly polarized electromagnetic waves.

[0073] In terms of antenna performance, the S-parameters are as Figure 15 shown. In the frequency band of 30.5GHz - 33.5GHz, |S11 |Less than -10 dB, with good impedance matching. Figure 16 This is the beam scanning situation of the antenna at the center frequency of 32 GHz, where the rotation angle of the gradient phase surface Ⅰ is The rotation angle of the gradient phase surface Ⅱ is When the rotation angle is 90°, the beam points to the normal direction of the array plane. Combining Figure 17 , the gain at this time is 22.18 dBic; when the rotation angle is 0°, the antenna achieves the maximum scanning angle of 61°, and the corresponding gain is 18.9 dBic. During the scanning process, the maximum scanning loss is 3.3 dB, and the azimuth plane can cover 360°.

[0074] The transmissive 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 can cover 0° to 360° in the azimuth plane, having a very wide beam scanning range, which is superior to the current technical level.

[0075] In summary, the transmissive array antenna proposed by the present invention has a high gain, a very wide beam scanning range, and the beam scanning ability is at the leading level among the current same type of transmissive array antennas.

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

Claims

1. A wide-angle scanning transmission array antenna, characterized in that: It includes a gradient phase surface I, a gradient phase surface II and a feed source, and the gradient phase surface I and the gradient phase surface II both include a plurality of array element units; The gradient phase surface I includes a double open ring as a transmitting unit and a cut-corner patch as a receiving unit, and the double open ring and the cut-corner patch share a metal floor and are connected through metal through holes; The gradient phase surface II includes two cut-angle patches that share a metal floor, and the two cut-angle patches serve as a transmitting unit and a receiving unit respectively; The double opening ring includes a radiation opening ring located inside and a parasitic opening ring located outside the radiation opening ring. The radiation opening ring is connected to the metal through hole through a microstrip antenna. The radiation opening ring is used to generate circularly polarized waves, and the parasitic opening ring is used to adjust the beam pointing to a tilt angle. A U-shaped groove is provided in each cut-angle patch, and each cut-angle patch rotates around a correspondingly arranged metal through hole at a preset angle. The feed is used to radiate circularly polarized waves.

2. The wide-angle scanning transmission array antenna according to claim 1, characterized in that: The gradient phase surface I also includes a first dielectric plate and a second dielectric plate which are stacked, a first metal layer is arranged on the first dielectric plate, the double open ring is arranged on the first metal layer, a second metal layer is arranged on the lower surface of the second dielectric plate, and a cut-angle patch is arranged on the second metal layer; The upper surface of the second dielectric plate is a metal floor.

3. The wide-angle scanning transmission array antenna according to claim 2, characterized in that: A metal layer is disposed on the upper surface of the second dielectric plate, and gaps for separating the metal through holes are disposed on the metal layer at positions corresponding to the metal through holes.

4. The wide-angle scanning transmission array antenna according to claim 1, characterized in that: The gradient phase surface II also includes 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 two cut-angle patches are respectively provided on the third metal layer and the fourth dielectric plate; the upper surface of the fourth dielectric plate is a metal floor.

5. The wide-angle scanning transmission array antenna according to claim 4, characterized in that: A metal layer is disposed on the upper surface of the fourth dielectric plate, and gaps for separating the metal through holes are disposed on the metal layer at positions corresponding to the metal through holes.

6. The wide-angle scanning transmission array antenna according to claim 1, characterized in that: The feed source comprises a fifth dielectric plate and a sixth dielectric plate. The lower surface of the fifth dielectric plate is a metal floor, and the upper surface is also provided with a cut-angle patch; the sixth dielectric plate is a grounded coplanar waveguide structure.

7. A wide angle scanning transmission array antenna according to any one of claims 1 to 6, characterized in that: The circularly polarized wave becomes a plane wave with a specific direction after phase modulation by the gradient phase surface II. After phase modulation by the 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 rotation angles of the two gradient phase surfaces I and II with the same gradient are and The azimuth angle of the beam is for: The beam pointing elevation angle θ is: θ=arcsin(2sinγcos(ξ / 2)) in That is, the relative rotation angle of the two layers of phase gradient surfaces, and γ is the scanning angle obtained when gradient phase surface I or gradient phase surface II acts alone.

8. The wide-angle scanning transmission array antenna according to claim 7, characterized in that: when When , the beam gets the maximum deflection angle arcsin(2sinγ) in the pitch plane. and When the phase difference is 180°, the beam points in the normal direction of the array.

9. The wide-angle scanning transmission array antenna according to claim 7, characterized in that: When the beam deflection angle is When the array element unit (x i ,y j )The required compensation phase is: where k0 is the free space wave constant, R ij is the distance from the focus to each array element, θ t and are the required elevation and azimuth angles of the transmission array antenna beam, respectively. i and j They are the horizontal and vertical coordinates of the unit numbered (i, j) respectively.

10. The wide-angle scanning transmission array antenna according to claim 9, characterized in that: Each array element unit (x i ,y j )The required phase shift is:

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