A dual circularly polarized phase-independent continuously tunable filtering reflectarray antenna

Abstract

The application provides a dual-circularly-polarized phase-independent continuously adjustable filtering reflective array antenna, which comprises a dual-circularly-polarized feed source and a planar filtering reflective array. The dual-circularly-polarized feed source is placed near a focal plane of the planar filtering reflective array; and the planar filtering reflective array is composed of right-handed and left-handed circularly-polarized filtering radiators loaded with short-circuit time-delay lines in a periodic chessboard arrangement mode. The application can realize independent and continuous modulation of the right-handed and left-handed circularly-polarized reflection phases by adjusting two groups of structure parameters, i.e., time-delay line lengths and cell rotation angles, and the reflected beam has excellent filtering characteristics. The application has a simple structure, a low profile and good integration, and has an important application prospect in the fields of satellite communication and the like.

Description

Technical Field

[0001] This invention relates to the field of electronic devices for wireless communication systems, specifically to a dual-circularly polarized, phase-independently continuously adjustable filter reflective array antenna. Background Technology

[0002] Planar reflector array antennas have been widely researched and applied in the field of antenna technology due to their advantages such as high radiation gain, lightweight planar structure, simple fabrication process, and ease of integration with RF front-end systems. Current research on planar reflector array antennas mainly focuses on single-linear polarization, dual-linear polarization, and single-circular polarization structures, while research on planar reflector array antennas with dual-circular polarization characteristics remains relatively scarce. Furthermore, most existing publicly available planar reflector array antennas lack integrated filtering functions, making them difficult to adapt to increasingly complex electromagnetic operating environments. They suffer from weak electromagnetic interference immunity and poor operating frequency selectivity, significantly limiting the practical engineering applications of this type of antenna. Therefore, developing a planar filtered reflector array antenna capable of achieving independent and controllable dual-circular polarization beam pointing is of great significance.

[0003] According to existing publicly available research literature, current dual-circularly polarized reflector array antennas generally suffer from high design complexity, with most existing solutions relying on multiple functional layers or a large number of adjustable structural parameters. Typical implementations include integrating the circular polarization selection surface functional layer with the single-circularly polarized reflector array functional layer, or combining the linear-to-circular polarization converter functional layer with the dual-linearly polarized reflector array functional layer to achieve independent phase control of the dual circular polarization. While these structures can achieve independent phase control of the dual circular polarization, the stacked design of multiple functional layers significantly increases the profile height of the array, resulting in a large overall antenna profile height, which is not conducive to the miniaturization requirements of the device. To solve the problem of high profile in multi-layer structures, existing technologies further combine the design concepts of dynamic phase control and rotational phase control to achieve independent phase control of the dual circular polarization through a single-functional-layer structure. However, some publicly available single-functional-layer dual-circularly polarized reflector array antenna structures require simultaneous adjustment of seven different structural parameters to achieve precise and independent phase control of the dual circular polarization, significantly increasing the design difficulty of the antenna elements and the simulation iteration cost. On the other hand, most existing publicly available filtered reflective array antennas are single-linearly polarized or single-circularly polarized, and there are currently no reports on technologies related to dual-circularly polarized filtered reflective array antennas. For example, existing technologies have implemented linearly polarized filtered reflective array antennas using stepped waveguide structures, but their profile height exceeds 1.8 times the operating wavelength. Therefore, there is an urgent need to propose entirely new design theories and structural schemes to simplify the design process of dual-circularly polarized reflective array antennas, reduce structural complexity, and integrate high-performance filtering functions. Summary of the Invention

[0004] To address the aforementioned problems, this invention proposes a dual-circularly polarized phase-independently continuously adjustable filtered reflective array antenna, which can meet the antenna requirements of systems such as satellite communications. This filtered reflective array antenna achieves independent and continuous modulation of the dual-circularly polarized phase by adjusting only two structural parameters, while also possessing excellent filtering characteristics, thus reducing the design complexity of filtered reflective array antennas. The technical solution provided by this invention is as follows:

[0005] A dual-circularly polarized phase-independent and continuously adjustable filter reflector antenna includes a planar filter reflector array and a dual-circularly polarized feed horn positioned opposite the planar filter reflector array. The planar filter reflector array comprises several first filter reflector array elements and second filter reflector array elements arranged in a periodic checkerboard pattern. The circularly polarized radiators of the first filter reflector array elements are right-hand circularly polarized, and the circularly polarized radiators of the second filter reflector array elements are left-hand circularly polarized.

[0006] The first filter reflective array unit includes five metal layers, which, from bottom to top, are a first metal ground layer, a metal delay line layer, a second metal ground layer, a first metal patch layer, and a second metal patch layer. The second metal ground layer has etched gaps; the end of the metal delay line layer is connected to the first metal ground layer via a first metal pillar; and the first and second metal ground layers are connected via the second metal pillar.

[0007] The second filter reflective array unit includes five metal layers, which, from bottom to top, are: a first metal ground layer of the second filter reflective array unit, a metal delay line layer of the second filter reflective array unit, a second metal ground layer of the second filter reflective array unit, a first metal patch layer of the second filter reflective array unit, and a second metal patch layer of the second filter reflective array unit. The second metal ground layer of the second filter reflective array unit has etched gaps. The end of the metal delay line layer of the second filter reflective array unit is connected to the first metal ground layer of the second filter reflective array unit via a first metal pillar of the second filter reflective array unit. The first metal ground layer of the second filter reflective array unit and the second metal ground layer of the second filter reflective array unit are connected via a second metal pillar of the second filter reflective array unit.

[0008] Preferably, the dual circularly polarized feed source is placed near the focal plane of the planar filter reflector array, at a vertical distance of F from the planar filter reflector array, and the diameter of the planar filter reflector array is D, wherein 0.5≤F / D≤2.

[0009] Preferably, the first filter reflection array unit and the second filter reflection array unit are arranged on the planar filter reflection array in a two-dimensional periodic checkerboard array structure, with a period length of 0.3 to 0.8 wavelengths.

[0010] Preferably, the planar filter reflector array consists of four substrate layers and one adhesive layer. The four substrate layers, from bottom to top, are the first substrate layer, the second substrate layer, the third substrate layer, and the fourth substrate layer of the planar filter reflector array; wherein, the first adhesive layer of the planar filter reflector array is disposed between the first substrate layer and the second substrate layer.

[0011] Below the first substrate layer of the planar filter reflector array, there are first metal ground plane layers for the first filter reflector array unit and second metal ground plane layers for the second filter reflector array unit. Above the first substrate layer of the planar filter reflector array, there are first metal delay line layers for the first filter reflector array unit and second metal delay line layers for the second filter reflector array unit. Above the second substrate layer of the planar filter reflector array, there are first metal patch layers for the first filter reflector array unit and second metal patch layers for the second filter reflector array unit. Above the third substrate layer of the planar filter reflector array, there are first metal patch layers for the first filter reflector array unit and second metal patch layers for the second filter reflector array unit. Above the fourth substrate layer of the planar filter reflector array, there are first metal patch layers for the first filter reflector array unit and second metal patch layers for the second filter reflector array unit.

[0012] Preferably, both the first and second filter reflection array units adopt the form of a slot-coupled circularly polarized radiator loaded with a short-circuit delay line.

[0013] Preferably, the first metal ground plane layer of the first filter reflector unit and the first metal ground plane layer of the second filter reflector unit are both complete metal plate structures; the metal delay line layer of the first filter reflector unit and the metal delay line layer of the second filter reflector unit are both arc-shaped strip line structures with short-circuited terminals; the second metal ground plane layer of the first filter reflector unit is a metal plate structure with etched gaps in the first filter reflector unit, and the second metal ground plane layer of the second filter reflector unit is a metal plate structure with etched gaps in the second filter reflector unit; the first metal patch layer of the first filter reflector unit is a rectangular patch structure with chamfered angles in the 45° direction, and the first metal patch layer of the second filter reflector unit is a rectangular patch structure with chamfered angles in the −45° direction; the second metal patch layer of the first filter reflector unit is a rectangular patch loaded with a rectangular ring structure with chamfered angles in the 45° direction, and the second metal patch layer of the second filter reflector unit is a rectangular patch loaded with a rectangular ring structure with chamfered angles in the −45° direction.

[0014] Preferably, the lower stopband transmission zero is achieved through the rectangular metal ring structure on the second metal patch layer of the first filter reflector unit and the second metal patch layer of the second filter reflector unit, and the upper stopband transmission zero is achieved through the cavity structure formed by the second metal pillar of the first filter reflector unit and the second metal pillar of the second filter reflector unit, thereby realizing the filtering characteristics of the reflector antenna.

[0015] Preferably, the dual circularly polarized reflection phase is modulated independently and continuously by rotating the first and second filter reflection array units and adjusting the length of the short-circuit delay line.

[0016] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0017] (1) The present invention innovatively designs a filter reflective array unit based on a short-circuit delay line structure loaded by a filter circularly polarized radiator. By adjusting only two sets of structural parameters, namely the length of the short-circuit delay line and the overall rotation angle of the unit, independent and continuous modulation of the dual circularly polarized phase can be achieved, thereby effectively reducing the design complexity of the dual circularly polarized reflective array antenna.

[0018] (2) This invention enables the reflective array element to possess the self-filtering characteristics of an antenna by setting metal pillars around the short-circuit delay line to form a cavity structure and loading a parasitic ring structure on the circularly polarized radiator. This design does not require additional external filtering devices and does not require increasing the overall size of the reflective array element;

[0019] (3) The present invention adopts a periodic checkerboard arrangement to stagger the right-hand circularly polarized filter radiator with short-circuit delay line and the left-hand circularly polarized filter radiator with short-circuit delay line, which can effectively balance the radiation characteristics of the left-hand circularly polarized radiation wave and the right-hand circularly polarized radiation wave, ensure the gain consistency of the dual circularly polarized beam, and greatly improve the radiation stability and gain balance of the antenna in the dual circularly polarized working mode.

[0020] (4) The present invention adopts a single-function layer integrated structure design, which has the advantages of broadband, filtering, low profile, simple structure and easy integration with radio frequency system. Attached Figure Description

[0021] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0022] Figure 1 This is a three-dimensional schematic diagram of a dual-circularly polarized phase-independent and continuously adjustable filter reflective array antenna proposed in this invention.

[0023] Figure 2 This is a schematic diagram of the stacked structure of a planar filter reflection array;

[0024] Figure 3 This is a top view of each metal layer of the filter reflector array unit;

[0025] In the diagram: 1. Dual-circularly polarized feed horn; 2. Planar filter reflector array; 31. First filter reflector array element; 32. Second filter reflector array element; 2a. First substrate layer of planar filter reflector array; 2b. Second substrate layer of planar filter reflector array; 2c. Third substrate layer of planar filter reflector array; 2d. Fourth substrate layer of planar filter reflector array; 2e. First adhesive layer of planar filter reflector array; 31a. First metal ground plane layer of first filter reflector array element; 31b. Metal delay line layer of first filter reflector array element; 31c. Second metal ground plane layer of first filter reflector array element; 31d. First metal patch layer of first filter reflector array element; 31e. First filter reflector array. Unit second metal patch layer, 31f first filter reflective array unit gap, 31g first filter reflective array unit first metal pillar, 31h first filter reflective array unit second metal pillar, 32a second filter reflective array unit first metal ground layer, 32b second filter reflective array unit metal delay line layer, 32c second filter reflective array unit second metal ground layer, 32d second filter reflective array unit first metal patch layer, 32e second filter reflective array unit second metal patch layer, 32f second filter reflective array unit gap, 32g second filter reflective array unit first metal pillar, 32h second filter reflective array unit second metal pillar;

[0026] Figure 4 The diagram shows the circular polarization scattering parameters of the first and second filter reflection array elements, where... Figure 4 (a) Circular polarization scattering parameters corresponding to the first filter reflection array element Figure 4 (b) Circular polarization scattering parameters corresponding to the second filter reflection array element;

[0027] Figure 5 The graph shows the variation of the circularly polarized scattering parameters of the first filter reflection array element with the time delay line length and rotation angle. Figure 5 (a) The change in amplitude of the circularly polarized reflection coefficient corresponding to the first filter reflection array element with time delay line length. Figure 5 (b) The phase of the circularly polarized reflection coefficient corresponding to the first filter reflection array element changes with the length of the time delay line. Figure 5 (c) The change of the amplitude of the circularly polarized reflection coefficient corresponding to the first filter reflection array element with the rotation angle. Figure 5 (d) The phase of the circularly polarized reflection coefficient corresponding to the first filter reflection array element changes with the rotation angle;

[0028] Figure 6 This is a graph showing the variation of the circularly polarized scattering parameters of the second filter reflector element with the time delay line length and rotation angle. Figure 6(a) The change in amplitude of the circularly polarized reflection coefficient corresponding to the second filter reflection array element with time delay line length. Figure 6 (b) The phase of the circularly polarized reflection coefficient corresponding to the second filter reflection array element changes with the length of the time delay line. Figure 6 (c) The change of the amplitude of the circularly polarized reflection coefficient of the second filter reflection array element with the rotation angle. Figure 6 (d) The phase of the circularly polarized reflection coefficient corresponding to the second filter reflection array unit changes with the rotation angle;

[0029] Figure 7 This is a diagram showing the chessboard-like arrangement of the first and second filter reflection array elements on the planar filter reflection array.

[0030] Figure 8 The radiation pattern of the dual-circularly polarized filtered reflective array antenna is shown below. Figure 8 (a) Radiation pattern of the corresponding planar filter reflector array at 30 GHz under right-hand circularly polarized horn feed excitation. Figure 8 (b) Radiation pattern of the corresponding planar filter reflector array at 30 GHz under left-hand circularly polarized horn feed excitation;

[0031] Figure 9 The graph shows the gain and axial ratio of the two circularly polarized beams of the dual-circularly polarized filter reflector antenna as a function of frequency. Figure 9 (a) The gain curve of the corresponding right-hand circularly polarized beam as a function of frequency. Figure 9 (b) Curve of axial ratio versus frequency for a right-hand circularly polarized beam. Figure 9 (c) The gain curve of the corresponding left-hand circularly polarized beam as a function of frequency. Figure 9 (d) Curve showing the change in axial ratio as a function of frequency for a left-hand circularly polarized beam. Detailed Implementation

[0032] 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, and 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.

[0033] To make the above-mentioned objectives, features and effects of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] like Figure 1As shown, this embodiment proposes a dual-circularly polarized phase-independent and continuously adjustable filtered reflective array antenna, including a dual-circularly polarized feed horn 1 and a planar filtered reflective array 2; the dual-circularly polarized feed horn 1 is placed near the focal plane of the planar filtered reflective array 2; the diameter of the planar filtered reflective array 2 is D, which is set to 188mm in this embodiment, and the distance between the dual-circularly polarized feed horn 1 and the planar filtered reflective array 2 is F, which is set to 208.7mm in this embodiment, and the value of F / D is between 0.5 and 2, which is 1.1 in this embodiment.

[0035] The planar filter reflector array 2 includes several first filter reflector array elements 31 and several second filter reflector array elements 32. The first filter reflector array elements 31 and the second filter reflector array elements 32 are arranged in a periodic checkerboard pattern on the planar filter reflector array 2, with a period length of 0.3 to 0.8 free space wavelengths. In this embodiment, it is set to 0.47 free space wavelengths. The first filter reflector array elements 31 and the second filter reflector array elements 32 are identical in form, both adopting a structure of slot-coupled circularly polarized radiators with short-circuited delay lines. The difference is that the circularly polarized radiator of the first filter reflector array element 31 is right-hand circularly polarized, while the circularly polarized radiator of the second filter reflector array element 32 is left-hand circularly polarized. The first filter reflector array elements 31 and the second filter reflector array elements 32 can be implemented by several metal layers arranged from bottom to top.

[0036] like Figure 2 As shown, the planar filter reflector array 2 consists of four substrate layers and one adhesive layer, namely, the first substrate layer 2a, the second substrate layer 2b, the third substrate layer 2c, and the fourth substrate layer 2d arranged from bottom to top. Among them, the first adhesive layer 2e is arranged between the first substrate layer 2a and the second substrate layer 2b.

[0037] like Figure 2 As shown, the first filter reflective array unit 31 includes five metal layers, namely, from bottom to top: first metal ground layer 31a, first metal delay line layer 31b, second metal ground layer 31c, first metal patch layer 31d, and second metal patch layer 31e. The second metal ground layer 31c is etched with a first filter reflective array unit slot 31f. The end of the first metal delay line layer 31b is connected to the first metal ground layer 31a via a first metal pillar 31g. The first metal ground layer 31a and the second metal ground layer 31c are connected via a second metal pillar 31h.

[0038] like Figure 2 As shown, the second filter reflective array unit 32 includes five metal layers, namely, from bottom to top: the first metal ground layer 32a, the metal delay line layer 32b, the second metal ground layer 32c, the first metal patch layer 32d, and the second metal patch layer 32e. The second metal ground layer 32c has a etched gap 32f. The end of the metal delay line layer 32b is connected to the first metal ground layer 32a via a first metal pillar 32g. The first metal ground layer 32a and the second metal ground layer 32c are connected via a second metal pillar 32h.

[0039] like Figure 2 As shown, a first metal ground plane layer 31a and a second metal ground plane layer 32a of a first filter reflective array unit are disposed below the first substrate layer 2a of the planar filter reflective array. A first metal delay line layer 31b and a second metal delay line layer 32b of a first filter reflective array unit are disposed above the first substrate layer 2a of the planar filter reflective array. A second metal ground plane layer 31c and a second metal ground plane layer 32c of a first filter reflective array unit are disposed above the second substrate layer 2b of the planar filter reflective array. A first metal patch layer 31d and a second metal patch layer 32d of a first filter reflective array unit are disposed above the third substrate layer 2c of the planar filter reflective array. A second metal patch layer 31e and a second metal patch layer 32e of a first filter reflective array unit are disposed above the fourth substrate layer 2d of the planar filter reflective array.

[0040] like Figure 3As shown, the first metal ground layer 31a and the second metal ground layer 32a of the first filter reflective array unit are both complete metal plate structures; the metal delay line layer 31b and the metal delay line layer 32b of the first filter reflective array unit both adopt an arc-shaped stripline structure with short-circuited terminals; the second metal ground layer 31c of the first filter reflective array unit adopts a metal plate structure with the first filter reflective array unit slots 31f etched on it, and the second metal ground layer 32c of the second filter reflective array unit adopts a metal plate structure with the second filter reflective array unit slots 31f etched on it. The metal plate structure of the slit 32f of the reflective array unit; the first metal patch layer 31d of the first filter reflective array unit adopts a rectangular patch structure with a chamfer in the 45° direction, the first metal patch layer 32d of the second filter reflective array unit adopts a rectangular patch structure with a chamfer in the −45° direction; the second metal patch layer 31e of the first filter reflective array unit adopts a rectangular patch loaded with a rectangular ring structure with a chamfer in the 45° direction, the second metal patch layer 32e of the second filter reflective array unit adopts a rectangular patch loaded with a rectangular ring structure with a chamfer in the −45° direction.

[0041] The rectangular ring structure loaded on the second metal patch layer 31e of the first filter reflection array unit generates a transmission zero in the lower stopband of the first filter reflection array unit 31, and the second metal pillar 31h structure of the first filter reflection array unit generates a transmission zero in the upper stopband of the first filter reflection array unit 31, thereby realizing the filtering effect of the first filter reflection array unit 31; the rectangular ring structure loaded on the second metal patch layer 32e of the second filter reflection array unit generates a transmission zero in the lower stopband of the second filter reflection array unit 32, and the second metal pillar 32h structure of the second filter reflection array unit generates a transmission zero in the upper stopband of the second filter reflection array unit 32, thereby realizing the filtering effect of the second filter reflection array unit 32.

[0042] like Figure 4As shown, both the first filter reflection array unit 31 and the second filter reflection array unit 32 can efficiently reflect circularly polarized waves. The difference lies in that the amplitude of the right-hand circularly polarized reflected wave from the first filter reflection array unit 31 is lower than that of the left-hand circularly polarized reflected wave, while the amplitude of the right-hand circularly polarized reflected wave from the second filter reflection array unit 32 is higher than that of the left-hand circularly polarized reflected wave. This is because the first filter reflection array unit 31 is a right-hand circularly polarized radiator. When a left-hand circularly polarized wave is incident, it is directly reflected. When a right-hand circularly polarized wave is incident, it is received by the first filter reflection array unit 31, phase-shifted by a time delay line, and then radiated. Therefore, compared to the left-hand circularly polarized wave, the right-hand circularly polarized wave introduces the loss of the time delay line, resulting in a lower reflection amplitude for the right-hand circularly polarized wave than for the left-hand circularly polarized wave. Similarly, since the second filter reflection array unit 32 is a left-hand circularly polarized radiator, when a right-hand circularly polarized wave is incident, it will be directly reflected. When a left-hand circularly polarized wave is incident, it will be received by the first filter reflection array unit 32, and after phase shifting through the time delay line, it will be radiated. Therefore, compared with the right-hand circularly polarized wave, the left-hand circularly polarized wave introduces the loss of the time delay line, resulting in the reflection amplitude of the left-hand circularly polarized wave being lower than that of the right-hand circularly polarized wave.

[0043] like Figure 5 As shown, the co-circular polarization reflection coefficient of the first filter reflection array unit 31 changes with the length of the time delay line and the selection angle. When the length of the time delay line increases, the amplitude of the co-circular polarization reflection coefficient remains above -1.2 dB. The phase of the right-hand circular polarization reflection coefficient decreases with the increase of the time delay line length, while the phase of the left-hand circular polarization reflection coefficient does not change with the change of the time delay line length. When the unit rotates, the amplitude of the co-circular polarization reflection coefficient remains above -0.6 dB. The phase of the right-hand circular polarization reflection coefficient increases with the increase of the rotation angle, while the phase of the left-hand circular polarization reflection coefficient decreases with the increase of the rotation angle. Therefore, by combining the changes in the time delay line length and the rotation angle, independent and continuous control of the right-hand and left-hand circular polarization waves can be achieved.

[0044] like Figure 6As shown, the co-circular polarization reflection coefficient of the second filter reflection array unit 32 changes with the length of the time delay line and the selection angle. When the length of the time delay line increases, the amplitude of the co-circular polarization reflection coefficient remains above -1.4 dB. The phase of the left-hand circular polarization reflection coefficient decreases with the increase of the time delay line length, while the phase of the right-hand circular polarization reflection coefficient does not change with the change of the time delay line length. When the unit rotates, the amplitude of the co-circular polarization reflection coefficient remains above -0.6 dB. The phase of the right-hand circular polarization reflection coefficient increases with the increase of the rotation angle, while the phase of the left-hand circular polarization reflection coefficient decreases with the increase of the rotation angle. Therefore, by combining the changes in the time delay line length and the rotation angle, independent and continuous control of both right-hand and left-hand circular polarization waves can be achieved.

[0045] like Figure 7 As shown, in this example, the first filter reflection array unit 31 and the second filter reflection array unit 32 are arranged in a checkerboard pattern on the planar filter reflection array surface 2, which can effectively eliminate the problem of inconsistent gain between the right-hand circularly polarized reflection beam and the left-hand circularly polarized reflection beam caused by the insertion loss of the time delay line when only the first filter reflection array unit 31 or the second filter reflection array unit 32 is used.

[0046] like Figure 8 As shown, under illumination from a right-hand circularly polarized horn, the reflector antenna generates a right-hand circularly polarized wave pointing at an angle of (0°, −20°), where the first term in parentheses represents the azimuth angle and the second term represents the elevation angle. At 30 GHz, the cross-polarization level of the right-hand circularly polarized reflected wave is below −26 dB, and the sidelobe levels are all below −30 dB, as shown. Figure 8 As shown in Figure a. Similarly, under illumination from a left-hand circularly polarized horn, the reflector antenna generates a left-hand circularly polarized wave pointing at an angle of (90°, 20°). At 30 GHz, the cross-polarization level of the left-hand circularly polarized reflected wave is below −27 dB, and the sidelobe levels are all below −25 dB, as shown in Figure a. Figure 8 As shown in b.

[0047] Figure 9 (a) and (b) show the curves of gain and axial ratio of the right-hand circularly polarized reflected wave as a function of frequency. It can be seen that the maximum gain of the right-hand circularly polarized beam is 30.2 dBic, and the 3-dB gain and axial ratio bandwidth are 12.2%. At the same time, it can be seen from the curve of gain as a function of frequency that it generates a lower stopband transmission zero near 24 GHz and an upper stopband transmission zero near 34.2 GHz, thus achieving excellent filtering characteristics.

[0048] Figure 9(c) and (d) show the curves of gain and axial ratio of the left-hand circularly polarized reflected wave as a function of frequency. It can be seen that the maximum gain of the left-hand circularly polarized beam is 29.9 dBic, and the 3-dB gain and axial ratio bandwidth are 9.5%. At the same time, it can be seen from the curve of gain as a function of frequency that a lower stopband transmission zero is generated near 24.2 GHz and an upper stopband transmission zero is generated near 34.8 GHz, achieving excellent filtering characteristics.

[0049] like Figure 9 As shown, by arranging the first filter reflection array unit 31 and the second filter reflection array unit 32 in a checkerboard pattern on the planar filter reflection array 2, the consistency of the gain of the right-hand circularly polarized beam and the left-hand circularly polarized beam can be achieved. Moreover, thanks to the filtering performance of the unit, the final radiated right-hand circularly polarized beam and left-hand circularly polarized beam also have excellent filtering characteristics.

[0050] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A dual-circularly polarized, phase-independently continuously adjustable filtered reflective array antenna, characterized in that, It includes a planar filter reflector array (2) and a dual circularly polarized feed horn (1) facing the planar filter reflector array (2); the planar filter reflector array (2) includes a number of first filter reflector array units (31) and second filter reflector array units (32) arranged in a periodic checkerboard pattern; the circularly polarized radiator of the first filter reflector array unit (31) is right-hand circularly polarized, and the circularly polarized radiator of the second filter reflector array unit (32) is left-hand circularly polarized; The first filter reflective array unit (31) includes five metal layers, which are, from bottom to top, the first metal ground layer (31a), the first metal delay line layer (31b), the second metal ground layer (31c), the first metal patch layer (31d), and the second metal patch layer (31e). The second metal ground layer (31c) of the first filter reflective array unit has a first filter reflective array unit gap (31f) etched on it. The end of the first metal delay line layer (31b) of the first filter reflective array unit is connected to the first metal ground layer (31a) of the first filter reflective array unit through the first metal pillar (31g). The first metal ground layer (31a) of the first filter reflective array unit and the second metal ground layer (31c) of the first filter reflective array unit are connected through the second metal pillar (31h). The second filter reflective array unit (32) includes five metal layers, which, from bottom to top, are the first metal ground layer (32a) of the second filter reflective array unit, the metal delay line layer (32b) of the second filter reflective array unit, the second metal ground layer (32c) of the second filter reflective array unit, the first metal patch layer (32d) of the second filter reflective array unit, and the second metal patch layer (32e) of the second filter reflective array unit. The second metal ground layer (32c) of the second filter reflective array unit has a second filter reflective array unit gap (32f) etched on it. The end of the metal delay line layer (32b) of the second filter reflective array unit is connected to the first metal ground layer (32a) of the second filter reflective array unit through the first metal pillar (32g) of the second filter reflective array unit. The first metal ground layer (32a) of the second filter reflective array unit and the second metal ground layer (32c) of the second filter reflective array unit are connected through the second metal pillar (32h) of the second filter reflective array unit.

2. The dual-circularly polarized phase-independently continuously adjustable filtered reflective array antenna according to claim 1, characterized in that, The dual circularly polarized feed (1) is placed near the focal plane of the planar filter reflection array (2), with a vertical distance of F from the planar filter reflection array (2) and a diameter of D, where 0.5≤F / D≤2.

3. The dual-circularly polarized phase-independently continuously adjustable filtered reflective array antenna according to claim 1, characterized in that, The first filter reflection array unit (31) and the second filter reflection array unit (32) are arranged on the planar filter reflection array (2) in a two-dimensional periodic checkerboard array structure with a period length of 0.3 to 0.8 wavelengths.

4. The dual-circularly polarized phase-independently continuously adjustable filtered reflective array antenna according to claim 1, characterized in that, The planar filter reflector array (2) consists of four substrate layers and one adhesive layer. The four substrate layers, from bottom to top, are the first substrate layer (2a), the second substrate layer (2b), the third substrate layer (2c), and the fourth substrate layer (2d) of the planar filter reflector array. Among them, the first adhesive layer (2e) of the planar filter reflector array is provided between the first substrate layer (2a) and the second substrate layer (2b). Below the first substrate layer (2a) of the planar filter reflector array, there are a first metal ground layer (31a) of the first filter reflector array unit and a first metal ground layer (32a) of the second filter reflector array unit. Above the first substrate layer (2a) of the planar filter reflector array, there are a first metal delay line layer (31b) of the first filter reflector array unit and a second metal delay line layer (32b) of the second filter reflector array unit. Above the second substrate layer (2b) of the planar filter reflector array, there are a first metal patch layer (31d) of the first filter reflector array unit and a first metal patch layer (32d) of the second filter reflector array unit. Above the third substrate layer (2c) of the planar filter reflector array, there are a first metal patch layer (31e) of the first filter reflector array unit and a second metal patch layer (32e) of the second filter reflector array unit.

5. A dual-circularly polarized, phase-independently continuously adjustable filtered reflective array antenna according to claim 1, characterized in that, Both the first filter reflection array unit (31) and the second filter reflection array unit (32) adopt the form of a slot-coupled circularly polarized radiator loaded with a short-circuit delay line.

6. A dual-circularly polarized phase-independently continuously adjustable filtered reflective array antenna according to claim 5, characterized in that, Both the first metal floor layer (31a) of the first filter reflection array unit and the first metal floor layer (32a) of the second filter reflection array unit are complete metal plate structures; Both the first filter reflector unit metal delay line layer (31b) and the second filter reflector unit metal delay line layer (32b) are arc-shaped strip line structures with short-circuited terminals; the first filter reflector unit second metal ground layer (31c) is a metal plate structure with the first filter reflector unit slots (31f) etched on it, and the second filter reflector unit second metal ground layer (32c) is a metal plate structure with the second filter reflector unit slots (32f) etched on it; The first metal patch layer (31d) of the first filter reflective array unit is a rectangular patch structure with a chamfered angle in the 45° direction; the first metal patch layer (32d) of the second filter reflective array unit is a rectangular patch structure with a chamfered angle in the −45° direction; the second metal patch layer (31e) of the first filter reflective array unit is a rectangular patch loaded with a rectangular ring structure with a chamfered angle in the 45° direction; the second metal patch layer (32e) of the second filter reflective array unit is a rectangular patch loaded with a rectangular ring structure with a chamfered angle in the −45° direction.

7. A dual-circularly polarized phase-independently continuously adjustable filtered reflective array antenna according to claim 6, characterized in that, The lower stopband transmission zero is achieved through the rectangular metal ring structure on the second metal patch layer (31e) of the first filter reflective array unit and the second metal patch layer (32e) of the second filter reflective array unit, and the upper stopband transmission zero is achieved through the cavity structure formed by the second metal pillar (31h) of the first filter reflective array unit and the second metal pillar (32h) of the second filter reflective array unit, thereby realizing the filtering characteristics of the reflective array antenna.

8. A dual-circularly polarized phase-independently continuously adjustable filtered reflective array antenna according to claim 6, characterized in that, By rotating the first filter reflection array unit (31) and the second filter reflection array unit (32) and adjusting the length of the short-circuit delay line, the dual circular polarization reflection phase is modulated independently and continuously.

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