Dual-band dual-circularly polarized bidirectional radiation transmissive and reflective antenna

Abstract

The application relates to the field of wireless communication system electronics, and discloses a dual-frequency dual-circular polarization bidirectional radiation transmissive-refractive array antenna, which comprises a planar transmissive-refractive array, a K-wave band circular polarization feed source and a Ka-wave band circular polarization feed source arranged opposite to the planar transmissive-refractive array, and the planar transmissive-refractive array comprises a plurality of K-wave band transmissive-refractive units and Ka-wave band transmissive-refractive units which are periodically staggered in the same array surface in a common aperture. The transmissive-refractive array antenna designed by the application can generate two polarized orthogonal transmissive circular polarization beams and two polarized orthogonal reflective circular polarization beams under the incidence of left-handed or right-handed circular polarization waves, four circular polarization beams generated by the transmissive-refractive array antenna can realize three degrees of freedom, and under the condition of reasonably introducing noise, the four beams can also be independently controllable.

Description

Technical Field

[0001] This invention belongs to the field of electronic devices for wireless communication systems, and specifically relates to a dual-frequency dual-circularly polarized bidirectional radiating and transflecting array antenna. Background Technology

[0002] Planar transmission and reflection array antennas are widely researched and applied due to their advantages such as low loss, high gain, and ease of fabrication. However, both planar transmission and reflection arrays can only radiate energy within half of a space, which limits their applications to some extent. For example, indoor wireless communication, radio frequency identification systems, and relay communication all require antennas capable of providing bidirectional radiation. Therefore, bidirectional transmission-reflection array antennas that integrate the advantages of transmission and reflection arrays are currently receiving widespread attention.

[0003] Based on reported literature, the functions of currently researched transmissive-reflective array antennas are relatively simple. For example, a dual-frequency transmissive-reflective array antenna can be realized by simply integrating two transmission and reflection array antennas operating in different frequency bands. However, its transmission and reflection states operate in two separate frequency bands. Some literature also reports linearly polarized transmissive-reflective array antennas implemented using linear polarization selectors and linearly polarized transmission and reflection elements. These types of transmissive-reflective array antennas typically require two states of linearly polarized incident waves, and the achieved transmission and reflection linear polarization states are also different. Linearly polarized or circularly polarized transmissive-reflective array antennas can be realized by etching slots of different sizes into a metal plate. However, this approach has some problems: firstly, the transmitted and reflected beam directions must maintain mirror symmetry and cannot be independently controlled; secondly, it can only transmit one type of circular polarization and reflect the other, resulting in half of the energy being lost, with an efficiency limit of only 50%.

[0004] In addition, some literature reports the implementation of a transmissive-reflective array antenna by arranging half of the transmission elements and half of the reflection elements on the same aperture. Although this configuration achieves the characteristics of a transmissive-reflective array, its transmission and reflection functions only occupy half of the aperture, resulting in relatively low aperture efficiency.

[0005] Multifunctional transflector array antennas, such as multi-frequency transflector array antennas and multi-polarized transflector array antennas with independently controllable beams, can realize the diversity of system functions. However, the functions of reported transflector array antennas are relatively simple, so in-depth research on multifunctional transflector array antennas is needed. Summary of the Invention

[0006] Technical Objective: This invention discloses a dual-frequency dual-circularly polarized bidirectional radiating transmittance-reflection array antenna. It achieves dual-frequency transmittance-reflection characteristics by utilizing transmittance-reflection elements arranged with the same aperture and operating at different frequency bands. Under the excitation of circularly polarized waves, each frequency band can realize two types of transmitted orthogonal circularly polarized waves and two types of reflected orthogonal circularly polarized waves. Furthermore, the four generated beams have three degrees of freedom. In addition, by reasonably introducing noise, the beam degrees of freedom can be extended to four, which can meet the antenna requirements of systems such as relay communication.

[0007] Technical solution: To achieve the above technical objectives, the present invention adopts the following technical solution:

[0008] A dual-frequency dual-circularly polarized bidirectional radiation-transmission-reflection array antenna, characterized in that: it includes a planar transmission-reflection array, a K-band circularly polarized feed source and a Ka-band circularly polarized feed source positioned opposite the planar transmission-reflection array;

[0009] The planar transmissive and reflective array includes multiple K-band and Ka-band transmissive and reflective elements arranged periodically and alternately on the same array surface with the same aperture. Both the K-band and Ka-band transmissive and reflective elements are based on a receiving antenna-phase-shifting stripline-transmitting antenna structure. Eight K-band and eight Ka-band transmissive and reflective elements are designed by setting the length of the phase-shifting stripline. The phase difference between adjacent elements of the eight K-band and eight Ka-band transmissive and reflective elements is 45 degrees. All K-band and Ka-band transmissive and reflective elements adopt the form of x-polarized reception and x-polarized transmission, and y-polarized reception and y-polarized reflection.

[0010] The K-band transmissive and reflective unit (4) comprises several metal layers from bottom to top: a first circular metal patch layer of K-band with etched gaps, a first metal floor layer of K-band with etched orthogonal I-shaped gaps, two K-band first time delay lines of different lengths located on the same metal layer, a second metal floor layer of K-band with etched circular gaps, two K-band second time delay lines of different lengths located on the same metal layer, a third metal floor layer of K-band with etched orthogonal I-shaped gaps, and a second circular metal patch layer of K-band with etched gaps. The first time delay line of K-band and the second time delay line of K-band are connected by a first metal pillar of K-band, and the first metal floor layer of K-band, the second metal floor layer of K-band and the third metal floor layer of K-band are connected by a second metal pillar of K-band.

[0011] The Ka-band transmission-reflection unit comprises several metal layers from bottom to top: a first Ka-band circular metal patch layer etched with gaps, a first Ka-band metal ground layer etched with orthogonal I-shaped gaps, first Ka-band delay lines of two different lengths located on the same metal layer, a second Ka-band metal ground layer etched with a circular gap, second Ka-band delay lines of two different lengths located on the same metal layer, a third Ka-band metal ground layer etched with orthogonal I-shaped gaps, and a second Ka-band circular metal patch layer etched with gaps, wherein the first Ka-band delay lines and the second Ka-band delay lines are connected via first Ka-band metal posts, and the first Ka-band metal ground layer, the second Ka-band metal ground layer and the third Ka-band metal ground layer are connected via second Ka-band metal posts.

[0012] Preferably, the K-band transmission-reflection units and the Ka-band transmission-reflection units are arranged in a two-dimensional co-aperture periodic staggered manner on the planar transmission-reflection array, wherein the K-band transmission-reflection units are two-dimensionally periodically arranged at the vertices of a square grid with a side length equal to the periodic length of the K-band, and the Ka-band transmission-reflection units are two-dimensionally periodically arranged at the center points of the square grid with a side length equal to the periodic length of the K-band; the periodic length of the K-band transmission-reflection units is 0.3 to 0.5 times the K-band wavelength, and the periodic length of the Ka-band transmission-reflection units is 0.5 to 0.7 times the Ka-band wavelength.

[0013] Preferably, the shapes of the K-band first circular metal patch layer, the K-band second circular metal patch layer, the Ka-band first circular metal patch layer and the Ka-band second circular metal patch layer are any one of circle, ring, cross-shape or polygon, wherein the polygon comprises triangle and quadrilateral;

[0014] The gaps on the K-band first circular metal patch layer, the K-band second circular metal patch layer, the Ka-band first circular metal patch layer and the Ka-band second circular metal patch layer are located in the middle of the patches or at the edges of the patches, and the shapes of the gaps are cross-shaped,米-shaped or no gap;

[0015] The shapes of the gaps on the K-band first metal ground layer, the K-band third metal ground layer, the Ka-band first metal ground layer and the Ka-band third metal ground layer are any one of I-shape, I-shaped (vertical I-shape with horizontal sections at both ends), cross-shape, Z-shape or ellipse.

[0016] Preferably, the planar transflective array is composed of six substrate layers and three adhesive layers, namely, from bottom to top, a first substrate layer, a second substrate layer, a third substrate layer, a fourth substrate layer, a fifth substrate layer, and a sixth substrate layer; wherein, a first adhesive layer is disposed between the second and third substrate layers, a second adhesive layer is disposed between the third and fourth substrate layers, and a third adhesive layer is disposed between the fourth and fifth substrate layers.

[0017] Below the first substrate layer of the planar transflective array are disposed a first metal layer of K-band transflective unit and a first metal layer of Ka-band transflective unit. Below the second substrate layer of the planar transflective array are disposed a second metal layer of K-band transflective unit and a second metal layer of Ka-band transflective unit. Below the third substrate layer of the planar transflective array are disposed a third metal layer of K-band transflective unit and a third metal layer of Ka-band transflective unit. Below the fourth substrate layer of the planar transflective array are a fourth metal layer of K-band transflective unit and a fourth metal layer of Ka-band transflective unit. Above the fourth substrate layer of the planar transflective array are a fifth metal layer of K-band transflective unit and a fifth metal layer of Ka-band transflective unit. Above the fifth substrate layer of the planar transflective array are a sixth metal layer of K-band transflective unit and a sixth metal layer of Ka-band transflective unit. Above the sixth substrate layer of the planar transflective array are a seventh metal layer of K-band transflective unit and a seventh metal layer of Ka-band transflective unit.

[0018] Preferably, the K-band circularly polarized feed is placed near the focal plane of the planar transmission and reflection array, with a vertical distance of F1 from the planar transmission and reflection array and a diameter of D, wherein 0.6≤F1 / D≤1.5;

[0019] The Ka-band circularly polarized feed is placed near the focal plane of the planar transmission and reflection array, at a vertical distance of F2 from the array, where 0.6 ≤ F2 / D ≤ 1.5.

[0020] Beneficial effects: Compared with the prior art, the present invention provides a dual-frequency dual-circularly polarized bidirectional radiating and transflecting array antenna, which has the following advantages:

[0021] (1) The transflection array antenna designed in this invention can generate two orthogonally polarized transmissive circularly polarized beams and two orthogonally polarized reflective circularly polarized beams under the incidence of a circularly polarized wave. The four circularly polarized beams generated can realize three degrees of freedom. In addition, when noise is introduced, the degrees of freedom can be further extended to four.

[0022] (2) The novel transmission-reflection unit proposed in this invention utilizes the characteristic of reflecting one linear polarization and transmitting another orthogonal linear polarization to achieve high-efficiency circular polarization transmission and reflection. Specifically, it employs a novel transmission-reflection unit where one linear polarization receives the same linear polarization transmission, and another orthogonal linear polarization receives the same linear polarization reflection. This allows for the reflection of one right-handed circularly polarized wave and one left-handed circularly polarized wave, and the transmission of one right-handed circularly polarized wave and one left-handed circularly polarized wave, all with equal amplitudes in both reflection and transmission, under circularly polarized wave illumination. Three of the four circularly polarized beams in this transmission-reflection array are independently controllable, while the direction of the fourth beam is determined by the first three. With the reasonable introduction of noise, independent controllability of all four beams can also be achieved.

[0023] (3) The present invention achieves dual-frequency characteristics by using the K-band transmission and reflection unit and the Ka-band transmission and reflection unit with the same aperture and periodically staggered arrangement;

[0024] (4) The transflection array antenna proposed in this invention adopts only a single-functional layer structure, which has the advantages of low profile and easy integration. The profile of the transflection array is only 0.18λ0. Attached Figure Description

[0025] Figure 1 This is a three-dimensional schematic diagram of a dual-frequency dual-circularly polarized bidirectional radiation-transmission-reflection array antenna proposed in this invention.

[0026] Figure 2 This is a schematic diagram of the stacked structure of a planar transmissive and reflective array;

[0027] Figure 3 It is a top view of each metal layer of the planar transmissive array;

[0028] Among them, there is a 1-K band right-hand circularly polarized feed, a 2-Ka band right-hand circularly polarized feed, a 3-planar transmission and reflection array, a 4-K band transmission and reflection unit, and a 5-Ka band transmission and reflection unit.

[0029] 3a - First substrate layer of planar transmission and reflection array, 3b - Second substrate layer of planar transmission and reflection array, 3c - Third substrate layer of planar transmission and reflection array, 3d - Fourth substrate layer of planar transmission and reflection array, 3e - Fifth substrate layer of planar transmission and reflection array, 3f - Sixth substrate layer of planar transmission and reflection array, 3g - First adhesive layer of planar transmission and reflection array, 3h - Second adhesive layer of planar transmission and reflection array, 3i - Third adhesive layer of planar transmission and reflection array;

[0030] The 4a-K band transmission and reflection unit has a first metal layer, a 4b-K band transmission and reflection unit has a second metal layer, a 4c-K band transmission and reflection unit has a third metal layer, a 4d-K band transmission and reflection unit has a fourth metal layer, a 4e-K band transmission and reflection unit has a fifth metal layer, a 4f-K band transmission and reflection unit has a sixth metal layer, a 4g-K band transmission and reflection unit has a seventh metal layer, a 4h-K band transmission and reflection unit has a first metal pillar, and a 4i-K band transmission and reflection unit has a second metal pillar.

[0031] The 5a-Ka band transmission and reflection unit has a first metal layer, a 5b-Ka band transmission and reflection unit has a second metal layer, a 5c-Ka band transmission and reflection unit has a third metal layer, a 5d-Ka band transmission and reflection unit has a fourth metal layer, a 5e-Ka band transmission and reflection unit has a fifth metal layer, a 5f-Ka band transmission and reflection unit has a sixth metal layer, a 5g-Ka band transmission and reflection unit has a seventh metal layer, a 5h-Ka band transmission and reflection unit has a first metal pillar, and a 5i-Ka band transmission and reflection unit has a second metal pillar.

[0032] Figure 4 The circular polarization scattering parameters of eight transmission and reflection phase-shifting units in the K-band are given. Figure 4 a corresponds to the reflection coefficient amplitude and phase of right-hand circularly polarized incident light reflected by right-hand circularly polarized light. Figure 4 b corresponds to the amplitude and phase of the reflection coefficient when a right-handed circularly polarized object is incident on a left-handed circularly polarized object. Figure 4 c corresponds to the amplitude and phase of the transmission coefficient of right-handed circularly polarized incident light transmitted through right-handed circularly polarized light. Figure 4 d corresponds to the amplitude and phase of the transmission coefficient when a right-handed circularly polarized object is incident on a left-handed circularly polarized object.

[0033] Figure 5 The circular polarization scattering parameters of eight phase-shifting units in the Ka-band are given. Figure 5 a corresponds to the reflection coefficient amplitude and phase of right-hand circularly polarized incident light reflected by right-hand circularly polarized light. Figure 5 b corresponds to the amplitude and phase of the reflection coefficient when a right-handed circularly polarized object is incident on a left-handed circularly polarized object. Figure 5 c corresponds to the amplitude and phase of the transmission coefficient of right-handed circularly polarized incident light transmitted through right-handed circularly polarized light. Figure 5 d corresponds to the amplitude and phase of the transmission coefficient when a right-handed circularly polarized object is incident on a left-handed circularly polarized object.

[0034] Figure 6 The circularly polarized phase constellation diagrams obtained by rotating eight phase shift units each in the K-band and Ka-band by different angles are presented. Figure 6 'a' corresponds to the constellation distribution diagram of the circularly polarized phase reflection of the eight phase-shifting units in the K-band. Figure 6 b corresponds to the transmission circularly polarized phase constellation distribution diagram of the eight phase-shifting units in the K-band. Figure 6c corresponds to the constellation distribution diagram of the eight phase-shifting units for circularly polarized reflection in the Ka-band. Figure 6 d corresponds to the transmission circularly polarized phase constellation distribution diagram of the eight phase-shifting units in the Ka band;

[0035] Figure 7 The radiation pattern of a dual-frequency, dual-circularly polarized, bidirectional radiating and transmissive array antenna is given, in which... Figure 7 'a' corresponds to the K-band radiation pattern. Figure 7 b corresponds to the Ka-band radiation pattern;

[0036] Figure 8 The gain and axial ratio of the four circularly polarized beams in the K-band of a dual-frequency, dual-circularly polarized, two-way radiating and transmitting array antenna are presented as a function of frequency. Figure 8 a corresponds to the gain and axial ratio of the reflected right-hand circularly polarized beam as a function of frequency. Figure 8 b corresponds to the curves showing the changes in gain and axial ratio of the reflected left-hand circularly polarized beam as a function of frequency. Figure 8 c corresponds to the curves showing the changes in gain and axial ratio of the transmitted right-hand circularly polarized beam as a function of frequency. Figure 8 d corresponds to the curves showing the changes in gain and axial ratio of the transmitted left-hand circularly polarized beam as a function of frequency.

[0037] Figure 9 The gain and axial ratio curves of the four circularly polarized beams in the Ka-band of a dual-frequency, dual-circularly polarized, two-way radiating and transmitting array antenna are presented as a function of frequency. Figure 9 a corresponds to the gain and axial ratio of the reflected right-hand circularly polarized beam as a function of frequency. Figure 9 b corresponds to the curves showing the changes in gain and axial ratio of the reflected left-hand circularly polarized beam as a function of frequency. Figure 9 c corresponds to the curves showing the changes in gain and axial ratio of the transmitted right-hand circularly polarized beam as a function of frequency. Figure 9 d corresponds to the curves showing the changes in gain and axial ratio of the transmitted left-hand circularly polarized beam as a function of frequency. Detailed Implementation

[0038] The invention will now be further described with reference to the accompanying drawings.

[0039] Example 1

[0040] like Figure 1As shown, this embodiment proposes a dual-band dual-circularly polarized bidirectional radiating and transmitting array antenna, including a K-band right-hand circularly polarized feed horn 1, a Ka-band right-hand circularly polarized feed horn 2, and a planar transmitting and transmitting array 3. Both the K-band right-hand circularly polarized feed horn 1 and the Ka-band right-hand circularly polarized feed horn 2 are placed near the focal plane of the planar transmitting and transmitting array 3. In this example, the diameter of the planar transmitting and transmitting array 3 is D, which is set to 232 mm here; the distance between the K-band right-hand circularly polarized feed horn 1 and the planar transmitting and transmitting array 3 is F1, which is set to 232 mm here; the value of F1 / D is between 0.3 and 1.5, and is set to 1 here; the distance between the Ka-band right-hand circularly polarized feed horn 2 and the planar transmitting and transmitting array 3 is F2, which is set to 317 mm here; the value of F2 / D is between 0.3 and 1.5, and is set to 1.4 here. In this invention, the feed horn antenna is a right-handed horn antenna, but without loss of generality, this case can also be implemented when a left-handed horn antenna is used as the feed.

[0041] In this invention, the planar transflective array 3 comprises several K-band transflective elements 4 and Ka-band transflective elements 5. The K-band and Ka-band transflective elements 4 and 5 are arranged in a two-dimensional, co-aperture, periodically alternating pattern on the planar transflective array 3. Specifically, the K-band transflective elements 4 are arranged periodically at the vertices of a square grid with a side length equal to the K-band period length, and the Ka-band transflective elements 5 are arranged periodically at the center points of the square grid with a side length equal to the K-band period length. The period length of the K-band transflective elements 4 is 0.3–0.5 K-band wavelengths (here set to 0.38), and the period length of the Ka-band transflective elements 5 is 0.5–0.7 Ka-band wavelengths (here set to 0.58). The K-band and Ka-band transflective elements 4 and 5 are identical in form, both employing a receiving antenna-phase-shifting stripline-transmitting antenna configuration, with the receiving and transmitting antennas connected via the phase-shifting stripline. This can be achieved through several metal layers arranged from bottom to top.

[0042] like Figure 2 As shown, the planar transflective array 3 consists of six substrate layers and three adhesive layers, namely, from bottom to top, the planar transflective array first substrate layer 3a, planar transflective array second substrate layer 3b, planar transflective array third substrate layer 3c, planar transflective array fourth substrate layer 3d, planar transflective array fifth substrate layer 3e, and planar transflective array sixth substrate layer 3f; wherein, the planar transflective array first adhesive layer 3g is disposed between the planar transflective array second substrate layer 3b and the planar transflective array third substrate layer 3c, the planar transflective array second adhesive layer 3h is disposed between the planar transflective array third substrate layer 3c and the planar transflective array fourth substrate layer 3d, and the planar transflective array third adhesive layer 3i is disposed between the planar transflective array fourth substrate layer 3d and the planar transflective array fifth substrate layer 3e.

[0043] like Figure 2 As shown, the K-band transmission and reflection unit 4 includes seven metal layers, namely, from bottom to top, the first metal layer 4a, the second metal layer 4b, the third metal layer 4c, the fourth metal layer 4d, the fifth metal layer 4e, the sixth metal layer 4f, and the seventh metal layer 4g of the K-band transmission and reflection unit; wherein, the third metal layer 4c and the fifth metal layer 4e of the K-band transmission and reflection unit are connected by the first metal pillar 4h of the K-band transmission and reflection unit, and the second metal layer 4b, the third metal layer 4d, and the sixth metal layer 4f of the K-band transmission and reflection unit are connected by the second metal pillar 4i of the K-band transmission and reflection unit.

[0044] like Figure 2 As shown, the Ka-band transmission and reflection unit 5 includes seven metal layers, namely, from bottom to top, the first metal layer 5a, the second metal layer 5b, the third metal layer 5c, the fourth metal layer 5d, the fifth metal layer 5e, the sixth metal layer 5f, and the seventh metal layer 5g of the Ka-band transmission and reflection unit; wherein, the third metal layer 5c and the fifth metal layer 5e of the Ka-band transmission and reflection unit are connected by the first metal pillar 5h of the Ka-band transmission and reflection unit, and the second metal layer 5b, the third metal layer 5d, and the sixth metal layer 5f of the Ka-band transmission and reflection unit are connected by the second metal pillar 5i of the Ka-band transmission and reflection unit.

[0045] In this embodiment, a first metal layer 4a of the K-band transmission and reflection unit and a first metal layer 5a of the Ka-band transmission and reflection unit are disposed below the first substrate layer 3a of the planar transmission and reflection array; a second metal layer 4b of the K-band transmission and reflection unit and a second metal layer 5b of the Ka-band transmission and reflection unit are disposed below the second substrate layer 3b of the planar transmission and reflection array; a third metal layer 4c of the K-band transmission and reflection unit and a third metal layer 5c of the Ka-band transmission and reflection unit are disposed below the third substrate layer 3c of the planar transmission and reflection array; and a K-band transmission and reflection unit is disposed below the fourth substrate layer 3d of the planar transmission and reflection array. The fourth metal layer 4d of the transmissive and reflective unit and the fourth metal layer 5d of the Ka-band transmissive and reflective unit are arranged above the fourth substrate layer 3d of the planar transmissive and reflective array. The fifth metal layer 4e of the K-band transmissive and reflective unit and the fifth metal layer 5e of the Ka-band transmissive and reflective unit are arranged above the fifth substrate layer 3e of the planar transmissive and reflective array. The seventh metal layer 4g of the K-band transmissive and reflective unit and the seventh metal layer 5g of the Ka-band transmissive and reflective unit are arranged above the sixth substrate layer 3f of the planar transmissive and reflective array.

[0046] like Figure 3 As shown, in this embodiment, the first metal layer 4a of the K-band transmission and reflection unit and the first metal layer 5a of the Ka-band transmission and reflection unit both use circular patches with chamfered angles in the ±45-degree direction. The second metal layer 4b, the sixth metal layer 4f, the second metal layer 5b, and the sixth metal layer 5f of the K-band transmission and reflection unit all use metal floor layers with orthogonal "I"-shaped gaps. The third metal layer 4c, the fifth metal layer 4e, the third metal layer 5c, and the fifth metal layer 5e of the K-band transmission and reflection unit are all orthogonal strip-shaped phase shift lines. The fourth metal layer 4d of the K-band transmission and reflection unit and the fourth metal layer 5d of the Ka-band transmission and reflection unit both use metal floor layers with a circular gap.

[0047] The transmissive and reflective unit of this invention simultaneously realizes both transmission and reflection modes, enabling x-polarized incident light to be transmitted as x-polarized light, y-polarized incident light to be reflected as y-polarized light (or x-polarized incident light, x-polarized reflection, y-polarized incident light, and y-polarized transmission). Furthermore, the transmission phase, reflection phase, and unit rotation angle of the designed unit can be freely controlled. This invention introduces the x-polarized wave into the transmission antenna section through a time delay line for transmission, while short-circuiting the y-polarized time delay line for reflection. Miniaturization is achieved by slotting the patch and bending the gap in the floor.

[0048] like Figure 4 and Figure 5As shown, in this example, to achieve control over the transmission and reflection phases, eight phase-shifting units were designed in both the K-band and Ka-band. All phase-shifting units adopted the form of x-polarized reception of x-polarized transmission and y-polarized reception of y-polarized reflection. Based on the above-designed transmission and reflection phase-shifting units, when irradiated by right-hand circularly polarized waves or left-hand circularly polarized waves, they can reflect right-hand circularly polarized waves and left-hand circularly polarized waves, and transmit right-hand circularly polarized waves and left-hand circularly polarized waves. Furthermore, all reflected and transmitted waves are equal in amplitude, achieving dual-circular polarization bidirectional radiation characteristics. When the K-band and Ka-band transmission and reflection phase-shifting units are arranged with the same aperture on the same array surface, dual-frequency dual-circular polarization bidirectional radiation characteristics are achieved.

[0049] like Figure 6 As shown, in this example, eight phase-shifting units 4 are designed in the K-band, with a 45-degree phase difference between each pair of x-polarized transmission phase and y-polarized reflection phase between the units; similarly, eight phase-shifting units 5 are designed in the Ka-band, with a 45-degree phase difference between each pair of x-polarized transmission phase and y-polarized reflection phase between the units. This invention achieves simultaneous reflection and transmission modes through two orthogonal polarizations—one for transmission and the other for reflection. When the incident light is x-polarized, the phase-shifting units only transmit, producing x-polarized waves; when the incident light is y-polarized, they only reflect, producing y-polarized waves. Furthermore, the arrangement of the eight K-band and eight Ka-band phase-shifting units on the transmission and reflection array 3 can compensate for the spherical wave from the feed and superimpose the phase gradient required for beam deflection, ultimately forming a high-gain pencil beam. In the K-band, the x-polarized transmission phase and the y-polarized reflection phase of each of the eight phase-shifting units differ by 45 degrees from each other. Similarly, in the Ka-band, the x-polarized transmission phase and the y-polarized reflection phase of each of the eight phase-shifting units differ by 45 degrees from each other. Based on this, by rotating the eight phase-shifting units in both the K-band and Ka-band around their respective geometric centers, independent controllability of the transmitted and reflected circularly polarized waves can be achieved.

[0050] In this example, three of the four circularly polarized waves—transmitted right-hand circularly polarized wave, transmitted left-hand circularly polarized wave, reflected right-hand circularly polarized wave, and reflected left-hand circularly polarized wave—can have their directions independently controlled. Once the directions of the three beams are determined, the direction of the fourth beam is also determined. This is based on a complete solution of the transmission matrix. However, by reasonably introducing a certain amount of noise, it is possible to achieve the performance of independently setting the direction of all four beams. A feasible scheme for achieving independently set directions of all four beams is presented here, but without loss of generality, other schemes that can achieve four degrees of freedom for the beams are still within the scope of protection of this invention. First, the total number of K-band phase-shifting units on the array surface is counted as n, and n is randomly divided into four equal categories, with each category containing n / 4 units. The first type of unit is used to achieve the directionality of transmitting right-hand circularly polarized waves, transmitting left-hand circularly polarized waves, and reflecting right-hand circularly polarized waves; the second type of unit is used to achieve the directionality of transmitting right-hand circularly polarized waves, transmitting left-hand circularly polarized waves, and reflecting left-hand circularly polarized waves; the third type of unit is used to achieve the directionality of transmitting right-hand circularly polarized waves, reflecting right-hand circularly polarized waves, and reflecting left-hand circularly polarized waves; and the fourth type of unit is used to achieve the directionality of transmitting left-hand circularly polarized waves, reflecting right-hand circularly polarized waves, and reflecting left-hand circularly polarized waves. Based on this, four beam degrees of freedom are achieved, at the cost of a beam gain sacrifice of approximately 2.5 dB.

[0051] The transmittance-reflection phase shifter of this invention employs a stripline slot-coupled patch antenna structure. The stacked structure of the transmittance-reflection phase shifter is simple, significantly reducing the number of metal layers and metal vias. The transmittance-reflection phase shifter of this invention is not limited to the above structural form. Regardless of the stacked structure or form, any unit based on the principle of one polarized transmission and another orthogonally polarized reflection should be within the protection scope of this invention.

[0052] like Figure 7 As shown, under the illumination of the K-band right-hand circularly polarized horn 1, the transmission-reflection array 3 generates four K-band circularly polarized beams: a reflected right-hand circularly polarized wave pointing at (90°, 5.2°), a reflected left-hand circularly polarized wave pointing at (90°, 340°), a transmitted right-hand circularly polarized wave pointing at (90°, 195°), and a transmitted left-hand circularly polarized wave pointing at (90°, 170°). Under the illumination of the Ka-band right-hand circularly polarized horn 2, the transmission-reflection array 3 generates four Ka-band circularly polarized beams: a reflected right-hand circularly polarized wave pointing at (0°, 13°), a reflected left-hand circularly polarized wave pointing at (0°, 355°), a transmitted right-hand circularly polarized wave pointing at (0°, 190°), and a transmitted left-hand circularly polarized wave pointing at (0°, 172°). The first term in parentheses indicates... Angle, the second term represents the angle θ.

[0053] Figure 8The curves of gain and axial ratio of the four circularly polarized beams in the K-band as a function of frequency are given. It can be seen that the 2-dB gain and axial ratio bandwidth of the four beams are greater than 11%.

[0054] Figure 9 The curves of gain and axial ratio of the four circularly polarized beams in the Ka band as a function of frequency are given. It can be seen that the 2-dB gain and axial ratio bandwidth of the four beams are greater than 8.5%.

[0055] In summary, the present invention provides a dual-frequency dual-circular polarization bidirectional radiation-transmissive-reflective array antenna, which has advantages such as low profile and easy integration. It can provide dual-frequency dual-circular polarization, bidirectional radiation, high gain, low axial ratio, and independently controllable circular polarization beam, and has important application prospects in future relay communication and other fields.

[0056] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A dual-frequency, dual-circularly polarized, bidirectional radiating and transmitting array antenna, characterized in that: It includes a planar transmission and reflection array (3), a K-band circularly polarized feed (1) positioned opposite the planar transmission and reflection array (3), and a Ka-band circularly polarized feed (2); The planar transflective array (3) includes multiple K-band transflective elements (4) and Ka-band transflective elements (5) arranged periodically and alternately on the same array surface with the same aperture. Both the K-band and Ka-band transflective elements are based on a receiving antenna-phase-shifting stripline-transmitting antenna structure. Eight K-band and eight Ka-band transflective elements are designed by setting the length of the phase-shifting stripline, and the phase difference between adjacent elements of the eight K-band and eight Ka-band transflective elements is 45 degrees. All K-band and Ka-band transmission-reflection units adopt the form of x-polarized reception and x-polarized transmission, and y-polarized reception and y-polarized reflection. The K-band transmission-reflection unit (4) and Ka-band transmission-reflection unit (5) introduce x-polarized waves into the transmission antenna part through the time delay line for transmission, while short-circuiting the y-polarized time delay line for reflection. At the same time, the K-band transmission-reflection unit (4) and Ka-band transmission-reflection unit (5) are miniaturized by slotting on the patch and bending the gap in the floor. The K-band transmissive and reflective unit (4) comprises several metal layers from bottom to top: a first circular metal patch layer (4a) of K-band with etched gaps, a first metal floor layer (4b) of K-band with etched orthogonal I-shaped gaps, two first time delay lines (4c) of K-band with different lengths located on the same metal layer, a second metal floor layer (4d) of K-band with etched circular gaps, two second time delay lines (4e) of K-band with different lengths located on the same metal layer, a third metal floor layer (4f) of K-band with etched orthogonal I-shaped gaps, and a second circular metal patch layer (4g) of K-band with etched gaps. The first time delay line (4c) and the second time delay line (4e) of K-band are connected by a first metal pillar (4h) of K-band, and the first metal floor layer (4b), the second metal floor layer (4d) and the third metal floor layer (4f) of K-band are connected by a second metal pillar (4i) of K-band. The Ka-band transmissive and reflective unit (5) comprises, from bottom to top, several metal layers: a first circular metal patch layer (5a) with etched slots in the Ka-band, a first metal floor layer (5b) with etched orthogonal I-shaped slots in the Ka-band, two Ka-band first time delay lines (5c) of different lengths located on the same metal layer, a second metal floor layer (5d) with etched circular slots in the Ka-band, two second Ka-band time delay lines (5e) of different lengths located on the same metal layer, a third metal floor layer (5f) with etched orthogonal I-shaped slots in the Ka-band, and a second circular metal patch layer (5g) with etched slots in the Ka-band. The first Ka-band time delay line (5c) and the second Ka-band time delay line (5e) are connected by a first metal pillar (5h) in the Ka-band, and the first metal floor layer (5b), the second metal floor layer (5d), and the third metal floor layer (5f) in the Ka-band are connected by a second metal pillar (5i) in the Ka-band.

2. The dual-frequency dual-circularly polarized bidirectional radiation-transmission-reflection array antenna according to claim 1, characterized in that: The K-band transmission and reflection units (4) and Ka-band transmission and reflection units (5) are arranged in a two-dimensional, co-aperture, periodically alternating pattern on the planar transmission and reflection array (3). The K-band transmission and reflection units (4) are arranged in a two-dimensional, periodic pattern at the vertices of a square grid with a side length equal to the period length of the K-band, and the Ka-band transmission and reflection units (5) are arranged in a two-dimensional, periodic pattern at the center point of a square grid with a side length equal to the period length of the K-band. The period length of the K-band transmission and reflection unit is 0.3 to 0.5 K-band wavelengths, and the period length of the Ka-band transmission and reflection unit is 0.5 to 0.7 Ka-band wavelengths.

3. The dual-frequency dual-circularly polarized bidirectional radiation-transmission-reflection array antenna according to claim 1, characterized in that: The first circular metal patch layer (4a) of the K-band, the second circular metal patch layer (4g) of the K-band, the first circular metal patch layer (5a) of the Ka-band, and the second circular metal patch layer (5g) of the Ka-band are any one of the following: circular, annular, cross-shaped, or polygonal. Polygons include triangles and quadrilaterals. The gaps on the K-band first circular metal patch layer (4a), K-band second circular metal patch layer (4g), Ka-band first circular metal patch layer (5a) and Ka-band second circular metal patch layer (5g) are in the middle of the patch or at the edge of the patch, and are in the shape of a cross, a rice-shaped patch or without gaps. The gaps on the K-band first metal floor layer (4b), K-band third metal floor layer (4f), Ka-band first metal floor layer (5b) and Ka-band third metal floor layer (5f) are any one of the following shapes: "I", "I", "+", "Z" or ellipse.

4. The dual-frequency dual-circularly polarized bidirectional radiation-transmission-reflection array antenna according to claim 1, characterized in that: The planar transflective array (3) consists of six substrate layers and three adhesive layers, namely, from bottom to top, the first substrate layer (3a), the second substrate layer (3b), the third substrate layer (3c), the fourth substrate layer (3d), the fifth substrate layer (3e), and the sixth substrate layer (3f); wherein, the first adhesive layer (3g) is disposed between the second substrate layer (3b) and the third substrate layer (3c), the second adhesive layer (3h) is disposed between the third substrate layer (3c) and the fourth substrate layer (3d), and the third adhesive layer (3i) is disposed between the fourth substrate layer (3d) and the fifth substrate layer (3e); Below the first substrate layer (3a) of the planar transflective array, a first metal layer (4a) of K-band transflective unit and a first metal layer (5a) of Ka-band transflective unit are disposed; below the second substrate layer (3b) of the planar transflective array, a second metal layer (4b) of K-band transflective unit and a second metal layer (5b) of Ka-band transflective unit are disposed; below the third substrate layer (3c) of the planar transflective array, a third metal layer (4c) of K-band transflective unit and a third metal layer (5c) of Ka-band transflective unit are disposed; and below the fourth substrate layer (3d) of the planar transflective array, a K-band transflective unit is disposed. The fourth metal layer (4d) and the fourth metal layer (5d) of the Ka-band transmission and reflection unit are arranged above the fourth substrate layer (3d) of the planar transmission and reflection array. The fifth metal layer (4e) of the K-band transmission and reflection unit and the fifth metal layer (5e) of the Ka-band transmission and reflection unit are arranged above the fifth substrate layer (3e) of the planar transmission and reflection array. The sixth metal layer (4f) of the K-band transmission and reflection unit and the sixth metal layer (5f) of the Ka-band transmission and reflection unit are arranged above the sixth substrate layer (3f) of the planar transmission and reflection array. The seventh metal layer (4g) of the K-band transmission and reflection unit and the seventh metal layer (5g) of the Ka-band transmission and reflection unit are arranged above the sixth substrate layer (3f) of the planar transmission and reflection array.

5. The dual-frequency dual-circularly polarized bidirectional radiation-transmission-reflection array antenna according to claim 1, characterized in that: The K-band circularly polarized feed (1) is placed near the focal plane of the planar transflector array (3), with a vertical distance of F1 from the planar transflector array (3) and a diameter of D, where 0.6≤F1 / D≤1.5; The Ka-band circularly polarized feed (2) is placed near the focal plane of the planar transflector array (3), and the vertical distance from the planar transflector array is F2, where 0.6≤F2 / D≤1.5.

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