Paper folding reflective array antenna block layout method

Abstract

The invention discloses a paper folding reflective array antenna block layout method. The problem that in the prior art, periodic, symmetric and regular distribution characteristics of reflective array units are not matched with non-periodicity, asymmetry and irregularity of paper folding structures is solved. The method comprises the following steps: completing preparation work before layout, and sequentially carrying out independent layout design on each panel in a paper folding reflective array; the independent layout design of the panel comprises the following steps: generating an initial layout, determining a unit type according to the initial layout, deleting an out-board unit, and retaining an in-board unit; for the intersection units, a layout design model is established, the optimization variable is the center position offset of the intersection units, the constraint condition is that the offset intersection units do not intersect with the creases and the adjacent units, and minimization of the sum of squares of the offset of all the intersection units is taken as an optimization target; the method compensates the phase of the electromagnetic wave reaching the edge of the panel while avoiding the crease, and reduces the negative influence of the crease on the electromagnetic performance of the antenna.

Description

Technical Field

[0001] The invention relates to the technical field of deployable antennas, and in particular to a block layout method for origami reflectarray antennas. Background Art

[0002] With the development of modern technologies such as integrated circuits and micro-electromechanical systems, the field of micro-satellites has ushered in profound changes and application innovations, and the research and development projects of micro-satellites around the world have shown explosive growth. With the increase in micro-satellites in space activities, their demand for large-aperture antennas for high-performance communications and high-resolution earth observation is increasing. However, the limitations of micro-satellites in terms of volume, power consumption and weight make it a major technical challenge to design satellite-borne antennas that meet the requirements of miniaturization and high performance. The existing method is to design the satellite-borne antenna to be foldable, fold the reflector array antenna into a folded state on the ground, and then unfold it to the working state after the satellite enters orbit. At present, the high-gain foldable antenna, the reflector antenna is large in size and heavy in weight, not easy to fold and unfold, and has high requirements for surface accuracy. The phased array antenna is difficult to be widely used on micro-satellites due to power consumption, heat dissipation and weight issues. The reflector array antenna combines the advantages of both, with the advantages of low profile, no need for feeding network and large design freedom, and is an ideal choice for micro-satellites.

[0003] However, the current satellite-borne reflectarray antennas have a relatively simple folding form and still occupy a large space volume after folding. That is, the storage ratio of the current foldable reflectarray antenna is not high, which makes it difficult to increase the aperture size of the reflectarray antenna after spatial unfolding, thereby limiting the further improvement of the antenna gain.

[0004] In the prior art, some researchers have developed a variety of designs of origami reflectarrays with high storage ratios. For example, AJ Rubio designed a deployable reflectarray antenna based on an improved hexagonal curve folding pattern in the document “AJ Rubio, A.-S. Kaddour, C. Ynchausti, S. Magleby, LL Howell, and S. V. Georgakopoulos. A foldable reflectarray on a hexagonal twist origami structure. IEEE Open Journal of Antennas and Propagation, 2: 1108-1119, 2021.” A. Russo et al. proposed a single-degree-of-freedom origami antenna in the document “Aloisia Russo, Beyit Barakali, Kensei Iglesias Kitsu, Lucille Baudet, Jingyi Yang, You Zhong. Origami-inspired self-deployable reflectarray antenna, Acta Astronautica, 213: 240-251, 2023.” From the above research, we can see that the existing origami reflector array design focuses on using the advantages of origami technology to design high storage ratio configurations, while the layout method still uses the traditional periodic regular layout. When the reflector array units are evenly distributed along the two dimensions of the aperture, they will inevitably intersect with the folds in the configuration. The origami reflector array is generally composed of several rigid plates connected by metal or membrane hinges. The folds are the junctions between the plates, and there is no condition for placing reflector array units. For this reason, the method usually adopted by researchers is to remove the intersecting units. Some researchers have also realized that directly deleting intersecting units to achieve a high storage ratio layout is not advisable. For example, AJ Rubio et al. designed an origami reflector array with a diamond grid style in response to the large number of parallel oblique folds in the Miura-ori configuration in the document "AJ Rubio, A.-S. Kaddour, H. Pruett, S. Magleby, LL Howell and S. V. Georgakopoulos. A Deployable Volume-Efficient Miura-Ori Reflectarray Antenna for Small Satellite Applications. IEEE Access, 11: 119313-119329, 2023." However, this design is limited to a specific Miura-ori configuration and cannot cope with complex origami structures.

[0005] Layout design has an important impact on antenna performance. The existing origami reflector array design layout still uses the traditional layout method, which fails to consider the impact of folds on the layout. Units that intersect with the fold area are often directly eliminated. Although this method is simple and direct, as the folded configuration becomes more complicated, the number of intersecting units to be eliminated will increase significantly, the degree of compensation phase discontinuity will increase, and the antenna performance will be difficult to achieve as expected. Summary of the invention

[0006] The present invention provides a block layout method for an origami reflectarray antenna, thereby solving the problem in the prior art that the periodic, symmetric and regular distribution characteristics of the units are not compatible with the non-periodic structure, asymmetric structure, irregular size and other structural characteristics of the origami configuration, thereby avoiding creases while maintaining the integrity of phase compensation and reducing the negative impact of creases on the electromagnetic performance of the antenna.

[0007] The present invention provides a block layout method for an origami reflectarray antenna, the method comprising:

[0008] Obtain array layout parameters, complete the initial design of the reflective array unit, and obtain the geometric structure characteristics of the reflective array unit outline and the unit phase shift curve;

[0009] The reflective array units on each panel of the origami reflective array are independently designed in turn to obtain the reflective array unit layout on each panel, and the reflective array unit layout of each panel is integrated to determine the center position and size data of the offset intersecting units and the units in the array on all panels to form a complete origami reflective array layout; wherein the independent layout design includes:

[0010] Acquire the inner area of ​​a single panel, and generate an initial layout of the reflective array units on the single panel according to the array layout parameters and the reflective array units;

[0011] Determine the panel unit type according to the internal area of ​​the single panel and the position and size information of the reflective array unit in the initial layout; wherein the panel unit type includes: intra-panel unit, extra-panel unit and intersection unit;

[0012] Modify the initial layout according to the panel unit type, delete the off-panel unit, and retain the on-panel unit;

[0013] For the intersection unit, a layout design model is established and solved; wherein, the optimization variable of the layout design model is the offset of the center position of the intersection unit, the constraint condition is that the offset intersection unit does not intersect with the fold and the adjacent unit, and the optimization goal is to minimize the mean square of the sum of the squares of all intersection unit position offsets.

[0014] In a possible implementation, obtaining the internal area of ​​a single panel includes:

[0015] Set the vertex of a single panel in the origami reflective array to be V 1 ,V 2 ,...,V A ; Where A represents the number of vertices;

[0016] The equation of the ath broken line between the vertices of the single panel is expressed as g a (x, y) = 0, a = 1, 2, ..., A, according to the broken line equation, determine the internal area Ω of the single panel; wherein the internal area Ω is expressed as: Ω = {(x, y) | g a (x,y)≤0,a=1,2,…,A}.

[0017] In a possible implementation, generating an initial layout of the reflective array units on a single panel according to the array basic layout parameters and the reflective array units includes:

[0018] According to the array layout parameters, the reflective array units are arranged on a single panel according to an initially given grid form rule to obtain an initial center position of the unit on the panel;

[0019] The phase compensation value required for each unit is calculated by ray tracing method, and the size information of each unit is obtained by interpolation according to the unit phase shift curve, and then the initial layout of the reflective array unit on a single panel is obtained according to the size information of each unit.

[0020] In a possible implementation, determining the panel unit type according to the internal area of ​​a single panel and the position and size information of the reflective array unit in the initial layout includes:

[0021] Determine an outer contour point set of each reflective array unit in the initial layout according to the center positions and unit sizes of all reflective array units in the initial layout and the geometric structure characteristics of the outer contour of the reflective array unit;

[0022] The first variable and the second variable corresponding to each reflective array unit in the initial layout are calculated according to the outer contour point set of the reflective array unit and the internal area of ​​the panel;

[0023] The corresponding unit type is determined according to the first variable and the second variable respectively corresponding to each reflective array unit.

[0024] In a possible implementation manner, the first variable and the second variable of the kth reflective array unit in the initial layout are respectively expressed as:

[0025]

[0026] Among them, p kbRepresents the outer contour point set P of the kth reflective array unit under the initial layout k ={p k1 ,p k2 ,...p kB}, B represents the number of sampling points in the outer contour point set of the kth reflective array unit; u k1 represents the first variable of the kth reflector array unit under the initial layout; u k2 Represents the second variable of the kth reflector array element in the initial layout.

[0027] In a possible implementation manner, if the first variable is 0, it is determined that the unit type of the kth reflective array unit in the initial layout is an intra-board unit;

[0028] If the second variable is 0, it is determined that the unit type of the kth reflective array unit in the initial layout is an off-board unit;

[0029] The first variable and the second variable are both not 0, and it is determined that the unit type of the kth reflective array unit in the initial layout is an intersection unit.

[0030] In a possible implementation, establishing and solving a layout design model for the intersection unit includes:

[0031] Establishing a layout design model according to the optimization goal and the constraint conditions; wherein the layout design model is related to the outer contour point set after the center position of the intersection unit is offset;

[0032] The layout design model is solved according to the GA algorithm to obtain a solution result.

[0033] In a possible implementation, the layout design model is expressed as:

[0034]

[0035] Where ΔS represents the offset of the intersection unit; N 1 represents the number of intersecting units; T represents transposition; (x i ′,y i ′) represents the coordinates of the center position of the i-th intersection unit after displacement; p i ' b Represents the outer contour point set P after the center position of the i-th intersection unit is offset i ′={p i ' 1 ,p i ' 2 ,...p i ' B} the coordinates of the bth sampling point in N 2Indicates the number of reflective array units adjacent to the intersection unit; (x ij ,y ij ) represents the jth adjacent reflective array unit of the i-th intersection unit; d c Indicates the minimum spacing between the intersection unit and the adjacent reflective array unit; Min f(ΔS) = ΔS(ΔS) T Represents the optimization objective function.

[0036] In a possible implementation, a specific method for obtaining the outer contour point set after the center position of the intersection unit is offset is:

[0037] The outer contour point set after the center position of each intersection unit is offset is obtained respectively, wherein the outer contour point set P after the center position of the i-th intersection unit is offset is i ′ is updated according to the offset of the center position of the i-th intersection unit;

[0038] The specific updating method is: the coordinates of the center position of the i-th intersection unit after displacement are (x i ',y i '), according to the offset coordinates (x i ',y i '), using ray tracing method to calculate the new compensation phase value after the center position of the i-th intersection unit is offset; and interpolating according to the phase shift curve of the reflective array unit to obtain the size of the i-th intersection unit after the center position is offset;

[0039] According to the offset coordinates (x i ',y i '), the size of the i-th intersection unit after the center position is offset, the geometric structure characteristics of the outer contour of the reflective array unit, and then determine the outer contour point set P of the i-th intersection unit after the center position is offset i ′.

[0040] In a possible implementation, the new compensated phase value after the center position of the i-th intersection unit is shifted is:

[0041]

[0042] Among them, k 0 Represented as a free beam in vacuum; d i ' represents the distance from the feed source to the center position of the i-th intersection unit after offset; Indicates the main wave number direction; (x i ',y i ') The coordinates of the center position of the i-th intersection unit after displacement; Indicates the reference phase.

[0043] One or more technical solutions provided in the present invention have at least the following technical effects or advantages:

[0044] The present invention breaks through the limitation of the previous layout for single configuration design, adopts the block layout strategy, can effectively deal with the non-periodicity and irregularity of the fold distribution, and establishes an intersection unit design model to optimize the unit position intersecting with the panel edge; compared with the layout method of deleting the intersection unit, the layout designed by the present invention reduces the negative impact of the fold on the electrical performance of the antenna. The present invention is expected to promote the application of more origami reflector arrays in micro-satellites. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 A flow chart of the steps of a method for block layout of origami reflectarray antennas provided by an embodiment of the present invention;

[0046] Figure 2 The origami reflective array unit provided for the embodiment of the present invention is a schematic diagram of a triangular ring patch unit;

[0047] Figure 3 A corresponding reflection characteristic curve when the origami reflective array unit provided in an embodiment of the present invention is a triangular ring patch unit;

[0048] Figure 4 A basic unit of the Flasher configuration provided by an embodiment of the present invention;

[0049] Figure 5 A schematic diagram of a mountain fold and a valley fold of a thick plate provided in an embodiment of the present invention;

[0050] Figure 6 A Flasher unit considering panel thickness provided in an embodiment of the present invention;

[0051] Figure 7 A schematic diagram of a traditional full array layout without fold influence provided in an embodiment of the present invention;

[0052] Figure 8 A schematic diagram of the layout of a Flasher origami reflector array with intersection units removed provided in an embodiment of the present invention;

[0053] Fig. 9 A schematic diagram of a layout obtained by using the method provided by the present invention in an embodiment of the present invention;

[0054] Fig.10 A comparison diagram of the normalized directional diagram of the xoz plane provided in an embodiment of the present invention;

[0055] Fig.11 A comparison diagram of the normalized directional diagram of the yoz′ plane provided in an embodiment of the present invention;

[0056] Fig.12 A comparison diagram of gain versus frequency provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0057] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0058] The present invention provides a block layout method for origami reflectarray antennas, such as Figure 1 The method shown includes the following steps S101 to S102.

[0059] S101, obtaining array layout parameters, completing the design of the reflective array unit, and obtaining the outer contour geometric structure characteristics of the reflective array unit and the unit phase shift curve;

[0060] Exemplarily, (1) determining array layout parameters, including grid arrangement, cell spacing, etc.

[0061] In a specific embodiment provided by the present invention, the grid arrangement is a rectangular grid with a cell spacing of 10 mm. Figure 2 As shown, the reflective array unit is a ring-shaped triangular patch unit, such as Figure 3 As shown, this is the reflection characteristic curve corresponding to the annular triangle patch unit.

[0062] S102, independently designing the layout of the reflective array units on each panel of the origami reflective array in turn, obtaining the reflective array unit layout on each panel, integrating the reflective array unit layout of each panel, determining the center position and size data of the offset intersecting units and the units in the array on all panels, and forming a complete origami reflective array layout. The independent layout design includes:

[0063] S1021, obtaining the inner area of ​​a single panel, and generating an initial layout of the reflective array units on the single panel according to the array layout parameters and the reflective array units;

[0064] Specifically, in step S1021, obtaining the internal area of ​​a single panel includes:

[0065] (1) Set the vertex of a single panel in the origami reflector array to V 1 ,V 2 ,...,V A ; Where A represents the number of vertices;

[0066] (2) The equation of the ath broken line between the panel vertices is expressed as g a (x, y) = 0, a = 1, 2, ..., A, according to the broken line equation, determine the internal area Ω of the single panel; where the internal area Ω is expressed as:

[0067] Ω={(x,y)|g a (x,y)≤0,a=1,2,…,A} (1)

[0068] Specifically, in step S1021, an initial layout of reflective array units on a single panel is generated according to the array basic layout parameters and the reflective array units, including:

[0069] (1) Arranging the reflective array units on a single panel in accordance with an initially given grid pattern according to the array layout parameters, and obtaining the initial center position of the units on the panel;

[0070] (2) The phase compensation value required for each unit is calculated by ray tracing method, and the size information of each unit is obtained by interpolation according to the unit phase shift curve. Then, the initial layout of the reflective array units on a single panel is obtained according to the size information of each unit.

[0071] Exemplarily, the initial position of the reflective array unit on a single panel is obtained according to the basic layout parameters of the array. Then, the phase compensation required for each reflective array unit is calculated using a ray tracing method, and the size of each unit is obtained by interpolation according to the phase shift curve of the reflective array unit, thereby generating an initial reflective array unit layout for a single panel.

[0072] S1022, determining the panel unit type according to the internal area of ​​the single panel and the position and size information of the reflective array unit in the initial layout; wherein the panel unit type includes: an intra-panel unit, an extra-panel unit, and an intersecting unit;

[0073] Specifically, in step S1022, the panel unit type is determined according to the internal area of ​​the single panel and the position and size information of the reflective array unit in the initial layout, including:

[0074] (1) determining the outer contour point set of each reflective array unit in the initial layout according to the center position, unit size and outer contour geometric structure characteristics of all reflective array units in the initial layout;

[0075] (2) calculating the first variable and the second variable corresponding to each reflective array unit under the initial layout according to the outer contour point set of the reflective array unit and the internal area of ​​the panel;

[0076] Here, the first variable and the second variable of the kth reflective array unit under the initial layout are expressed as:

[0077]

[0078] Among them, p kb Represents the outer contour point set P of the kth reflective array unit under the initial layout k ={p k1 ,p k2 ,...p kB}, B represents the number of sampling points in the outer contour point set of the kth reflective array unit; u k1 represents the first variable of the kth reflector array unit under the initial layout; u k2 Represents the second variable of the kth reflector array element in the initial layout.

[0079] Here, in the reflective array units in the initial layout, the units are divided into three categories according to the positional relationship of the reflective array units on the panel: intra-panel units (units are completely inside the panel), outside-panel units (units are completely outside the panel), and intersection units (units that intersect with the edge of the rigid board).

[0080] (3) Determine the corresponding unit type according to the first variable and the second variable corresponding to each reflective array unit.

[0081] Here, the first variable is 0, and the unit type of the kth reflective array unit under the initial layout is determined to be an intra-board unit;

[0082] The second variable is 0, which determines that the unit type of the kth reflective array unit in the initial layout is an off-board unit;

[0083] Both the first variable and the second variable are not 0, and it is determined that the unit type of the kth reflective array unit in the initial layout is an intersection unit.

[0084] S1023, modifying the initial layout according to the panel unit type, deleting the off-board units, and retaining the on-board units;

[0085] Exemplarily, for the units in the initial reflective array unit layout on a single panel that are determined to be off-board units (i.e., units completely located outside the panel), they are directly deleted from the initial reflective array unit layout, and the off-board units do not participate in subsequent optimization and adjustment. For the on-board units in the units in the initial reflective array unit layout, these units are not disturbed by the fold, so their initial positions are retained.

[0086] S1024, for the intersection cells, establish a layout design model and solve it; wherein the optimization variable of the layout design model is the offset of the center position of the intersection cell, the constraint condition is that the offset intersection cell does not intersect with the fold and the adjacent cell, and the optimization goal is to minimize the mean square of the sum of the squares of all intersection cell position offsets.

[0087] Specifically, in step S1024, for the intersection unit, a layout design model is established and solved, including:

[0088] (1) Determine constraints and optimization goals; wherein the constraints include: (1) the intersection unit must be completely located inside the panel after offset; (2) in order to reduce the mutual coupling effect between units in the layout and avoid the intersection unit after offset from overlapping with surrounding units, the intersection unit must maintain a minimum spacing with the surrounding units; the optimization goal is to minimize the sum of the squares of the intersection unit offsets.

[0089] (2) establishing a layout design model according to the optimization goal and the constraint conditions; wherein the layout design model is related to the outer contour point set after the center position of the intersection unit is offset;

[0090] Here, the layout design model is represented as:

[0091]

[0092] Where ΔS represents the offset of the intersection unit; N 1 represents the number of intersecting units; T represents transposition; (x i ′,y i ′) represents the coordinates of the center position of the i-th intersection unit after displacement; p i ' b Represents the outer contour point set P after the center position of the i-th intersection unit is offset i ′={p i ' 1 ,p i ' 2 ,...p i ' B} the coordinates of the bth sampling point in N 2 Indicates the number of reflective array units adjacent to the intersection unit; (x ij ,y ij ) represents the jth adjacent reflective array unit of the i-th intersection unit; d c Indicates the minimum spacing between the intersection unit and the adjacent reflective array unit; Min f(ΔS) = ΔS(ΔS) T Represents the optimization objective function.

[0093] (2.3) According to the offset coordinates (x i ',y i '), the size of the i-th intersection unit after the center position is offset, the geometric structure characteristics of the outer contour of the reflective array unit, and then determine the outer contour point set P after the center position of the i-th intersection unit is offset i ′.

[0094] Here, the specific method for obtaining the outer contour point set after the center position of the intersection unit is offset is:

[0095] (2.1) The outer contour point set P after the center position of the i-th intersection unit is offset i ′, will be updated according to the offset of the center position of the i-th intersection unit;

[0096] (2.2) The specific updating method is: the coordinates of the center position of the i-th intersection unit after offset are (x i ',y i '), according to the offset coordinates (x i ',y i ') Calculate the new compensation phase value after the center position of the i-th intersection unit is offset by using the ray tracing method; and interpolate according to the phase shift curve of the reflective array unit to obtain the size of the i-th intersection unit after the center position is offset;

[0097] Here, the new compensation phase value after the center position of the i-th intersection unit is offset is:

[0098]

[0099] Among them, k 0 Represented as a free beam in vacuum; d i ' represents the distance from the feed source to the center position of the i-th intersection unit after offset; Indicates the main wave number direction; (x i ',y i ') The coordinates of the center position of the i-th intersection unit after displacement; Indicates the reference phase.

[0100] (3) Solve the layout design model according to the GA algorithm to obtain the solution result.

[0101] In a specific embodiment provided by the present invention, the layout of the reflective array unit of the first panel is obtained. The internal area of ​​the first panel is determined according to formula (1), and the reflective array units are arranged according to the internal area of ​​the first panel and the initially given grid form rule to obtain the initial center position of all units on the first panel. Among them, the kth reflective array unit is located in the initial layout of the first panel, and the unit boundary is determined by the outer contour point set P k ={p k1 ,p k2 ,...p kB} definition, where B represents the number of sampling points of the outer contour, p b Indicates the coordinates of the bth sampling point. Introduce the first variable u k1 and the second variable u k2To determine the type of the kth reflector array unit in the initial layout of the first panel: Calculate the first variable u according to formula (2): k1 and the second variable u k2 .

[0102] According to u k1 and u k2 The value of can determine the unit type. k1 = 0, it is an internal unit; when u k2 = 0, it is an off-board unit; when u k1 ≠0 and u k2 When ≠0, it is an intersection unit. This method is used to determine the types of all reflective array units in the initial layout of the first panel, directly remove the units outside the panel, retain the units inside the panel, and adjust the positions of the intersection units.

[0103] Integrate the intersecting unit position information, assuming that there are N units under the initial layout of the first panel 1 intersection units. Let the initial center position of the i-th intersection unit be (x i ,y i ), let the offset be (Δx i ,Δy i ), the new center position can be expressed as (x′ i ,y i ′)=(x i +Δx i ,y i +Δy i ). Assume the main beam direction is The compensation phase after the center position of the i-th intersection unit is changed is expressed as formula (4).

[0104] According to the unit phase shift characteristics, the unit size changes with the compensation phase. Let the new boundary point set of the i-th intersection unit be P i ′={p i ' 1 ,p i ' 2 ,...,p i ' B}.

[0105] The moved intersecting cells must always satisfy the following two constraints:

[0106] (1) The unit must be completely inside the panel after offset;

[0107] (2) To reduce the mutual coupling between units and avoid the overlap of the moved units with the surrounding units, a minimum spacing must be maintained between the units.

[0108] At the same time, considering the uniformity of the near-field electromagnetic field distribution and the mutual coupling between units, a smaller offset helps to keep the electromagnetic field interaction between units close to the periodic arrangement. Based on the above conditions, the first panel layout design model is established as expressed in formula (4).

[0109] The first constraint ensures that the offset cell is inside the panel, and the second and third constraints ensure that the minimum spacing between the offset cell and the surrounding cells is greater than d. c , to avoid overlap and reduce the coupling effect between units. Assume that each intersecting unit has N 2 The jth neighboring unit of the i-th intersection unit is represented as (x ij ,y ij ).

[0110] The model is solved by using the GA algorithm to obtain the offset of the intersection unit of the first panel, and if the units at certain positions cannot meet the constraint conditions, they are deleted. The effect of the present invention can be further illustrated by the following simulation experiment.

[0111] 1. Simulation conditions

[0112] The present invention is simulated on an Intel(R) Core(TM) i5-10400 2.90GG CPU, an NVIDIATitan X GPU, and an Ubuntu 16.04 operating system using MATLAB 2021a developed by Mathworks of the United States and Ansys HFSS developed by Ansoft of the United States.

[0113] The methods compared in the experiment are as follows:

[0114] In order to verify the proposed method, the performance of three different layouts was compared and analyzed: a full array layout without folds was used, which was recorded as Scheme 1 in the experiment. A layout with origami reflective arrays directly removing intersecting units was recorded as Scheme 2 in the experiment. A layout using the layout design method of the present invention was recorded as Scheme 3 in the experiment.

[0115] 2. Simulation content

[0116] Taking the triangular ring reflectarray unit and Flasher origami configuration as examples, the reflectarray layout is designed and numerical experiments are carried out.

[0117] like Figure 2 As shown in the figure, the unit structure of the reflect array antenna is given. The unit consists of a four-layer structure. The first layer is a unit composed of equilateral triangle rings. The second layer is a polyimide film layer with a thickness of H 2=0.1mm, and its dielectric constant is 2.5. The third layer is made of Rogers RT / duroid 5880, with a dielectric constant of about 2.2 and a thickness of H 1 =1.316mm. The fourth layer is the metal floor. Figure 2 The side lengths of the triangles in the figure have a certain linear relationship, namely, L 2 =cL,L 3 =0.5L 1 , L 4 =0.5L 2 , where c = 0.75, the reflection phase is changed by changing the length of the outermost triangle L, and the center frequency is 15GHz. The unit is simulated in an infinite period environment, and the curves of reflection phase and reflection amplitude changing with L are as follows: Figure 3 As shown, it can be seen that the unit meets the 360° phase shift requirement at 15 GHz frequency and has low return loss.

[0118] The Flasher origami configuration is a single-degree-of-freedom configuration with a high storage ratio and high flexibility. In this case, the Flasher configuration with a hexagonal central hub is applied to the origami reflector array. Figure 4 The basic unit of the configuration is shown in Figure 1. The complete configuration can be formed by splicing the units in a circular array. Figure 4 As shown, the solid line represents the peak mark and the dotted line represents the valley mark, which satisfies α i =β i (i=1,2,3...,n). By increasing the crease order, the height of the folded configuration can be reduced. The above analysis is based on the assumption that the Flasher configuration is zero thickness, but in actual applications, the reflector substrate is not zero thickness. The folding of the reflector rigid plate can be achieved by increasing the crease gap width. Figure 5 As shown in the figure, assuming that the plate thickness is t, successful folding can be achieved when the crease gap is greater than or equal to 2t. Figure 6 The flasher unit takes the panel thickness into consideration, and the area inside the dotted line is the actual array area. This configuration has 121 rigid panels, and the side length of the central hub of the configuration is set to L = 40 mm. When the thickness of the rigid panel of the reflective array is t = 1.416 mm, the fold gap width is set to s = 3 (s>2t).

[0119] To avoid the problem of feed source shielding, a 15dB standard gain horn is used to feed the array at an angle of -30° from the X axis, and the focal ratio is calculated based on the -10dB half-lobe width. The initial arrangement uniformly adopts a rectangular grid arrangement with a center frequency of 15GHz. The pencil beam is designed using the ray tracing method, and the main beam direction is set to

[0120]

[0121] Combining the aforementioned reflectarray unit and Flasher configuration, we developed three reflectarray layouts through the following schemes.

[0122] Solution 1 uses the traditional full array layout without the influence of folds, and the resulting reflective array layout is as follows Figure 7 As shown. On this basis, the unit position and boundary conditions are determined, and then the fold information is introduced. Formula (2) is used to determine the reflective array unit type, and the out-of-array units and intersecting units are directly deleted to obtain the final unit layout of Scheme 2 as shown below: Figure 8 shown.

[0123] The final layout obtained by using the specific implementation method of the present invention is as follows: Fig. 9 shown.

[0124] Calculation shows that Scheme 1, Scheme 2 and Scheme 3 can arrange 2356, 1584 and 2218 units respectively.

[0125] HFSS software is used to perform full-wave simulation of the reflector arrays in three layout situations. The z′ coordinate axis direction is set as the main beam direction, and xoz and yoz′ are the two main planes of the two directional diagrams. Fig.10 and Fig.11 The gain patterns of the reflectarray antenna at 15 GHz are given for three layouts. Fig.12 The gain changes with frequency under three layout conditions. The analysis results show that with the reduction of the number of units in Scheme 2, the reflector array antenna gain decreases significantly, and the maximum sidelobe levels of the two main planes increase, which verifies the infeasibility of Scheme 2 in the complex configuration of fold distribution. In contrast, after the layout optimization of Scheme 3, the number of units contributing to the electrical performance increases, the electrical performance is significantly improved, and its performance tends to the full array design of Scheme 1, which verifies the advancement of the present invention.

[0126] In addition, the 3dB beamwidths of Scheme 1 and Scheme 3 on both main planes are maintained at about 6°, and their gain changes with frequency in the same trend. Although the gain of Scheme 3 is 0.1 to 0.66dBi lower than that of Scheme 1 at different frequencies, and the sidelobe levels of the two main planes increase by 8.9 to 10.23dB, this phenomenon is inevitable and is attributed to the existence of the fold, which is an inherent feature for achieving a high storage ratio.

[0127] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. All or part of the present invention can be used in many general or special computer system environments or configurations. For example: personal computers, server computers, handheld devices or portable devices, tablet devices, mobile communication terminals, multi-processor systems, microprocessor-based systems, programmable electronic devices, network PCs, minicomputers, mainframe computers, distributed computing environments including any of the above systems or devices, etc.

[0128] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the present invention.

Claims

1. A block layout method for origami reflectarray antennas, characterized in that: include: Obtain array layout parameters, complete the initial design of the reflective array unit, and obtain the geometric structure characteristics of the reflective array unit outline and the unit phase shift curve; The reflective array units on each panel of the origami reflective array are independently designed in turn to obtain the reflective array unit layout on each panel, and the reflective array unit layout of each panel is integrated to determine the center position and size data of the offset intersecting units and the units in the array on all panels to form a complete origami reflective array layout; wherein the independent layout design includes: Acquire the inner area of ​​a single panel, and generate an initial layout of the reflective array units on the single panel according to the array layout parameters and the reflective array units; Determine the panel unit type according to the internal area of ​​the single panel and the position and size information of the reflective array unit in the initial layout; wherein the panel unit type includes: intra-panel unit, extra-panel unit and intersection unit; Modify the initial layout according to the panel unit type, delete the off-panel unit, and retain the on-panel unit; For the intersection unit, a layout design model is established and solved; wherein, the optimization variable of the layout design model is the offset of the center position of the intersection unit, the constraint condition is that the offset intersection unit does not intersect with the fold and the adjacent unit, and the optimization goal is to minimize the mean square of the sum of the squares of all intersection unit position offsets.

2. The origami reflectarray antenna block layout method according to claim 1, characterized in that: The step of obtaining the inner area of ​​a single panel comprises: Set the vertices of a single panel in the origami reflector array to V1, V2, ..., V A ; Where A represents the number of vertices; The equation of the ath broken line between the vertices of the single panel is expressed as g a (x, y) = 0, a = 1, 2, ..., A, according to the broken line equation, determine the internal area Ω of the single panel; wherein the internal area Ω is expressed as: Ω = {(x, y) | g a (x,y)≤0,a=1,2,…,A}.

3. The origami reflectarray antenna block layout method according to claim 1, characterized in that: The step of generating an initial layout of the reflective array units on a single panel according to the array basic layout parameters and the reflective array units comprises: According to the array layout parameters, the reflective array units are arranged on a single panel according to an initially given grid form rule to obtain an initial center position of the unit on the panel; The phase compensation value required for each unit is calculated by ray tracing method, and the size information of each unit is obtained by interpolation according to the unit phase shift curve, and then the initial layout of the reflective array unit on a single panel is obtained according to the size information of each unit.

4. The origami reflectarray antenna block layout method according to claim 1, characterized in that: The method of determining the panel unit type according to the internal area of ​​a single panel and the position and size information of the reflective array unit in the initial layout includes: Determine an outer contour point set of each reflective array unit in the initial layout according to the center positions and unit sizes of all reflective array units in the initial layout and the geometric structure characteristics of the outer contour of the reflective array unit; The first variable and the second variable corresponding to each reflective array unit in the initial layout are calculated according to the outer contour point set of the reflective array unit and the internal area of ​​the panel; The corresponding unit type is determined according to the first variable and the second variable respectively corresponding to each reflective array unit.

5. The origami reflectarray antenna block layout method according to claim 4, characterized in that: The first variable and the second variable of the kth reflective array unit under the initial layout are respectively expressed as: Among them, p kb Represents the outer contour point set P of the kth reflective array unit under the initial layout k ={p k1 ,p k2 ,...p kB }, B represents the number of sampling points in the outer contour point set of the kth reflective array unit; u k1 represents the first variable of the kth reflector array unit under the initial layout; u k2 Represents the second variable of the kth reflector array element in the initial layout.

6. The block layout method of origami reflectarray antenna according to claim 5, characterized in that: If the first variable is 0, it is determined that the unit type of the kth reflective array unit in the initial layout is an intra-board unit; If the second variable is 0, it is determined that the unit type of the kth reflective array unit in the initial layout is an off-board unit; The first variable and the second variable are both not 0, and it is determined that the unit type of the kth reflective array unit in the initial layout is an intersection unit.

7. The origami reflectarray antenna block layout method according to claim 1, characterized in that: The step of establishing and solving a layout design model for the intersection unit includes: Establishing a layout design model according to the optimization goal and the constraint conditions; wherein the layout design model is related to the outer contour point set after the center position of the intersection unit is offset; The layout design model is solved according to the GA algorithm to obtain a solution result.

8. The block layout method of origami reflectarray antenna according to claim 7, characterized in that: The layout design model is expressed as: Where ΔS represents the offset of the intersection unit; N1 represents the number of intersection units; T represents transposition; (x i ′,y i ′) represents the coordinates of the center position of the i-th intersection unit after displacement; p i ' b Represents the outer contour point set P after the center position of the i-th intersection unit is offset i ′={p i ′1,p i ′2,...p i ' B }; N2 represents the number of reflective array units adjacent to the intersection unit; (x ij ,y ij ) represents the jth adjacent reflective array unit of the i-th intersection unit; d c Indicates the minimum spacing between the intersection unit and the adjacent reflective array unit; Min f(ΔS) = ΔS(ΔS) T Represents the optimization objective function.

9. The origami reflectarray antenna block layout method according to claim 7, characterized in that: The specific method for obtaining the outer contour point set after the center position of the intersection unit is offset is: The outer contour point set after the center position of each intersection unit is offset is obtained respectively, wherein the outer contour point set P after the center position of the i-th intersection unit is offset is i ′ is updated according to the offset of the center position of the i-th intersection unit; The specific updating method is: the coordinates of the center position of the i-th intersection unit after displacement are (x i ',y i '), according to the offset coordinates (x i ',y i '), using ray tracing method to calculate the new compensation phase value after the center position of the i-th intersection unit is offset; and interpolating according to the phase shift curve of the reflective array unit to obtain the size of the i-th intersection unit after the center position is offset; According to the offset coordinates (x i ',y i '), the size of the i-th intersection unit after the center position is offset, the geometric structure characteristics of the outer contour of the reflective array unit, and then determine the outer contour point set P of the i-th intersection unit after the center position is offset i ′.

10. The block layout method of origami reflectarray antenna according to claim 9, characterized in that: The new compensation phase value after the center position of the i-th intersection unit is offset: Where k0 represents a free wave beam in vacuum; d i ' represents the distance from the feed source to the center position of the i-th intersection unit after offset; Indicates the main wave number direction; (x i ',y i ') The coordinates of the center position of the i-th intersection unit after displacement; Indicates the reference phase.

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