A 2bit radiation phase and quasi-2bit scattering phase reconfigurable antenna array

Abstract

The application discloses a 2bit radiation phase and quasi-2bit scattering phase reconfigurable antenna array, which is composed of M*N antenna units, each unit comprising a second dielectric plate, a third dielectric plate and a fourth dielectric plate stacked in sequence, and a first dielectric plate suspended above the second dielectric plate; the upper surface of the first dielectric plate is provided with a single polarization electromagnetic wave absorbing structure, the upper surface of the second dielectric plate is provided with an antenna radiation structure, the lower surface of the second dielectric plate is provided with a first bias feeding metal wire, the upper surface of the third dielectric plate is provided with a second bias feeding metal wire, the upper surface of the fourth dielectric plate is provided with a metal ground plate, and the lower surface of the fourth dielectric plate is provided with a feeding network. By controlling the states of PIN diodes in the antenna radiation structure and the feeding network, the antenna unit obtains 2bit radiation phase reconfiguration and quasi-2bit scattering phase reconfiguration capability, the array can realize scanning of a radiation beam in a range of 60°-60° and a scattering beam in a range of 30°-30°, and can realize scattering suppression under copolarization and cross-polarization incidence by means of a cancellation strategy and a wave absorbing structure respectively.

Description

Technical Field

[0001] This invention belongs to the field of communication technology and relates to multi-bit phase radiation and scattering antenna arrays. More specifically, it relates to an antenna array in the fields of electromagnetic field and microwave technology that simultaneously possesses 2-bit radiation phase reconfigurability and quasi-2-bit scattering phase reconfigurability. It can be used in communication and radar systems with requirements such as high-performance communication and low detectability. Background Technology

[0002] Reconfigurable antennas, capable of adjusting their electromagnetic characteristics in real time according to communication or sensing needs, have become an important research direction in modern wireless systems. In applications such as radar, satellite communication, and wireless base stations, antenna arrays are required to have flexible radiation beam scanning capabilities to cover a wider airspace, as well as low detectability or electromagnetic compatibility control capabilities to reduce the scattering cross-section when not in operation.

[0003] Currently, most research on reconfigurable antennas focuses on single-function reconfiguration. Most research teams concentrate on achieving radiation pattern reconstruction based on multi-bit radiating elements or relying solely on a 1-bit scattering phase element to control scattering characteristics. For example, domestic research teams have introduced PIN diodes into the antenna array to achieve 1-bit scattering phase reconstruction capability under cross-polarization. Researchers at Xi'an University of Electronic Science and Technology attempted to integrate a 2-bit radiating element with 1-bit scattering phase control into the same element, but this approach has the following shortcomings: the strong coupling characteristics of radiation and scattering make it difficult to achieve good independent control; scattering phase reconstruction is typically only 1 bit, resulting in high quantization loss and difficulty in achieving single-beam scanning. Furthermore, the element struggles to achieve stable absorption suppression of cross-polarized incident waves over a wide angular domain, limiting the array's low-scattering performance in complex electromagnetic environments.

[0004] Therefore, there is an urgent need for an antenna array that can simultaneously provide multi-bit radiation phase reconstruction and multi-state scattering phase modulation, and has good scattering suppression capability for both co-polarized and cross-polarized incident waves in a wide-angle domain, in order to meet the requirements of next-generation communication and sensing systems for high-performance reconfigurable antenna arrays. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an antenna array with 2-bit radiation phase and quasi-2-bit scattering phase reconfigurability, which addresses the shortcomings of existing reconfigurable antenna arrays in achieving simultaneous multi-bit radiation phase reconfiguration and multi-state scattering phase joint control.

[0006] To solve the above-mentioned technical problems, the technical solution provided by the present invention is as follows: A 2-bit radiation phase and quasi-2-bit scattering phase reconfigurable antenna array, the antenna array comprising M×N antenna elements, where M and N are both positive integers and M×N≥3, each antenna element comprising an integral laminate and a first dielectric substrate; The integrated laminate is composed of a second dielectric plate, a first adhesive layer, a third dielectric plate, a second adhesive layer, and a fourth dielectric plate stacked sequentially from top to bottom; the first dielectric plate is suspended above the integrated laminate, and its upper surface is provided with a single-polarization electromagnetic wave absorbing structure; The upper surface of the second dielectric substrate is provided with an antenna radiating structure, and the lower surface is provided with a first bias feed metal line electrically connected to the antenna radiating structure; The upper surface of the third dielectric plate is provided with a second bias feed metal line, the upper surface of the fourth dielectric plate is provided with a metal ground plane, and the lower surface is provided with the feed network. The second bias feed metal line is electrically connected to the feed network.

[0007] In one embodiment, the single-polarization electromagnetic absorbing structure includes a patch resistor and a first metal strip and a second metal strip that are connected to both sides of the patch resistor and extend horizontally along the y-axis. The first dielectric substrate and the single-polarization electromagnetic absorbing structure together constitute the top antenna cover, which is suspended above the antenna radiating structure and is fixedly connected to the integrated laminate below by plastic fasteners. A supporting spacer is also provided between the first medium plate and the laminate, and the plastic fastener passes through the first medium plate and the supporting spacer and is fixedly connected to the laminate.

[0008] In one embodiment, the antenna radiating structure includes a first radiating stub, a second radiating stub, a third radiating stub, a first PIN diode, and a second PIN diode; The first radiating stub is elongated and vertically positioned between the second and third radiating stubs. The first radiating stub includes a first vertical segment and a first metallized via. The first vertical segment is a metal strip along the x-axis, with one end connected to the cathode of the first PIN diode and the other end connected to the cathode of the second PIN diode. The anode of the first PIN diode is connected to the third radiating stub, and the anode of the second PIN diode is connected to the second radiating stub. The first metallized via is electrically connected to the feed network through metal pillars embedded in the second, third, and fourth dielectric substrates.

[0009] In one embodiment, the second radiating stub includes a third vertical segment, a first horizontal segment, a second vertical segment, a fourth vertical segment, a bent metal wire, and a second metallized via. Along the y-axis, one end of the second vertical segment, the third vertical segment, the bent metal wire, and the fourth vertical segment are sequentially connected to the side of the first horizontal segment near the first radiating stub, and the other end of the third vertical segment is connected to the anode of the first PIN diode. The other end of the bent metal wire is connected to the second metallized via. The second metallized via is electrically connected to the first bias feed metal wire through a metal post embedded in the second dielectric substrate. The structure of the third radiating stub is centrally symmetrical to the structure of the second radiating stub about the center of the antenna radiating structure, and one end of its vertical segment used to connect the diode is connected to the anode of the second PIN diode.

[0010] In one embodiment, the power supply network includes a reconfigurable phase shifter structure, a first transmission line structure, a second transmission line structure, four DC power supply structures, a first capacitor, a second capacitor, a third PIN diode, and a power supply port. The reconfigurable phase shifter structure is located at the end of the feed network. One end is connected to the feed port via the second capacitor, and the other end is connected to the second transmission line structure via the first capacitor. A fourth PIN diode, a fifth PIN diode, a sixth PIN diode, and a seventh PIN diode are provided on it. By switching the conduction state of each PIN diode, the radio frequency signal transmission path is changed, thereby switching the introduced transmission phase. The first transmission line structure is a bent metal wire structure, with the starting end connected to the first metallized via; The third PIN diode is disposed between the first transmission line structure and the second transmission line structure, with its anode connected to the second transmission line structure and its cathode connected to the first transmission line structure. Of the four DC power supply structures, two are loaded on both sides of the overall structure of the fourth, fifth, sixth, and seventh PIN diodes, and the other two are loaded on both sides of the third PIN diode, for providing DC bias voltage to each PIN diode; each of the DC power supply structures includes a high-impedance bent metal wire, a fan-shaped branch, and a metallized via, and the metallized via is electrically connected to the second bias power supply metal wire through metal pillars embedded in the third and fourth dielectric plates.

[0011] In one embodiment, a circular clearance hole is provided on the metal ground plane, through which metallized vias connecting the upper and lower layers of circuits pass without short-circuiting with the metal layer; the position of the circular clearance hole corresponds to the position of the first metallized via and the metallized via in the DC power supply structure, respectively.

[0012] In one embodiment, the phase state of the antenna elements in the array is switched by a set PIN diode. The first PIN diode and the second PIN diode set in the antenna radiation structure and the third PIN diode, the fourth PIN diode, the fifth PIN diode, the sixth PIN diode, and the seventh PIN diode set in the feed network are responsible for 2-bit radiation phase reconstruction, and the first PIN diode and the second PIN diode set in the antenna radiation structure and the third PIN diode set in the feed network are responsible for quasi-2-bit scattering phase reconstruction.

[0013] In one embodiment, by controlling the on / off combinations of the first and second PIN diodes in the antenna radiation structure and the third to seventh PIN diodes in the feed network, the antenna element can obtain four radiation states with 2-bit radiation phase reconstruction, with adjacent phase states differing by 90°; and by controlling the states of the first, second, and third PIN diodes, the antenna element can obtain three scattering states with quasi-2-bit scattering phase reconstruction, with adjacent phase states differing by 120°.

[0014] Specifically, the phase state of the antenna elements in the array is switched by controlling the conduction state of the PIN diodes. The control strategy is as follows: When the first PIN diode, the third PIN diode, the fifth PIN diode, and the sixth PIN diode are turned on, and the second PIN diode, the fourth PIN diode, and the seventh PIN diode are turned off, the antenna element is in radiation state 0, which is the reference radiation phase state, when the excitation feed port is activated. When the first PIN diode, the third PIN diode, the fourth PIN diode, and the seventh PIN diode are turned on, and the second PIN diode, the fifth PIN diode, and the sixth PIN diode are turned off, the antenna element is in radiation state 1 when the excitation feed port is activated, and the radiation phase is 90° relative to the reference radiation phase state. When the second, third, fifth, and sixth PIN diodes are turned on, and the first, fourth, and seventh PIN diodes are turned off, the antenna element is in radiation state 2 at the excitation feed port, and the radiation phase is 180° relative to the reference radiation phase state. When the second, third, fourth, and seventh PIN diodes are turned on, and the first, fifth, and sixth PIN diodes are turned off, the antenna element is in radiation state 3 at the excitation feed port, and the radiation phase is 270° relative to the reference radiation phase state. When the first PIN diode, the second PIN diode, and the third PIN diode are turned off, the antenna element is in scattering state 0, which is the reference reflection phase state, at the excitation feed port. When the first PIN diode is turned on and the second and third PIN diodes are turned off, the antenna element is in scattering state 1 when the excitation feed port is activated, and the reflection phase is 120° relative to the reference reflection phase state. When the first PIN diode and the second PIN diode are turned on and the third PIN diode is turned off, the antenna element is in scattering state 2 when the excitation feed port is activated, and the reflection phase is 240° relative to the reference reflection phase state.

[0015] In one embodiment, the antenna elements in the array have 2-bit radiation phase reconfigurability and quasi-2-bit scattering phase reconfigurability, supporting the array to realize the radiation beam in Scanning within the 60°~60° range to achieve the scattering beam in Scanning within the 30°~30° range, combined with a cancellation strategy, the array achieves scattering suppression under common-polarized plane wave incidence; due to the single-polarized electromagnetic absorbing structure, the array has scattering suppression effect under cross-polarized plane wave incidence.

[0016] By adopting the above technical solution, the present invention has the following beneficial effects: First, the system integrates 2-bit radiation phase reconstruction and quasi-2-bit scattering phase reconstruction functions in the same array unit, which improves the pointing accuracy of the radiation beam and the degree of freedom in controlling the scattering beam, thus balancing system complexity and performance.

[0017] Second, the array can achieve a radiation beam scanning range of: The scattering beam scanning range is 60°~60°. The angle is 30°~30°, and combined with the cancellation strategy, significant scattering suppression can be achieved under co-polarized plane wave incident; at the same time, the suspended top-level single-polarized electromagnetic absorbing structure can provide broadband scattering suppression effect under cross-polarized plane wave incident, so that the array has dual-polarized low scattering characteristics. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0019] Figure 1 This is an exploded side view of the antenna element of the present invention; Figure 2(a) is a schematic diagram of the antenna unit radiation structure of the present invention; Figure 2(b) is a schematic diagram of the antenna array feed network of the present invention; Figure 3 This is a side view of the antenna array structure of the present invention; Figure 4(a) is a graph showing the variation of S-parameters with frequency under the radiation state of the antenna element in the simulation experiment of this invention; Figure 4(b) is a graph showing the change of radiation phase with frequency under the radiation state of the antenna element in the simulation experiment of this invention; Figure 4(c) is a graph showing the change of reflection phase with frequency under the scattering state of the antenna element in the simulation experiment of this invention; Figure 4(d) is a graph showing the reflection coefficient as a function of frequency under the scattering state of the antenna element in the simulation experiment of this invention; Figure 5(a) is a gain pattern curve of the antenna array structure under different scanning angles in the simulation experiment of this invention. Figure 5(b) is a graph showing the scattering pattern of the antenna array structure under different scanning angles in the simulation experiment of this invention. Figure 6(a) is a single-station RCS curve of the antenna array in the scattering suppression state under x-polarized incident wave in the simulation experiment of this invention as a function of frequency. Figure 6(b) is a curve showing the change of the single-station RCS of the antenna array under y-polarized incident wave in the simulation experiment of this invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0021] It should be noted that, in cases where parts are not shown in the accompanying drawings, those skilled in the art can clearly understand the structure and connection relationships based on the description in the text; the directional terms such as "upper," "lower," "left," "right," "horizontal," and "vertical" used in the text are based on the orientation shown in the accompanying drawings or the normal operating orientation, and are only used for the convenience of description and simplification of explanation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0022] like Figure 1 Figure 2(a), Figure 2(b) and Figure 3 As shown, this embodiment provides an antenna array with reconfigurable 2-bit radiation phase and quasi-2-bit scattering phase. The antenna array consists of M×N antenna elements; in this embodiment, M=6 and N=8. Each antenna element adopts the same structure and is arranged in a grid pattern. Antenna element period... wp =14.5mm.

[0023] Each antenna element employs a multi-layer dielectric substrate stack combined with a suspended overlay, including an integral laminate and a first dielectric substrate 1. The integral laminate is constructed by stacking a second dielectric substrate 2, a first adhesive layer 5, a third dielectric substrate 3, a second adhesive layer 6, and a fourth dielectric substrate 4 sequentially from top to bottom, and bonding them together through a lamination process. In this embodiment, the second dielectric substrate 2 and the third dielectric substrate 3 are Rogers RO4003 dielectric substrates with thicknesses of [missing information]. h 2 = 1.524 mm and h 3 = 0.254 mm; the fourth dielectric substrate 4 uses Taconic RF. 60 dielectric substrate, thickness h 4 = 0.508mm; the first adhesive layer 5 and the second adhesive layer 6 are RO4450F prepreg with a thickness of 0.1mm. The first dielectric substrate 1 uses Taconic RF. 60 dielectric substrate, thickness h 1 = 0.508mm, which is not directly attached to the laminate, but is suspended above the integrated laminate and fixedly connected to the laminate below by plastic fasteners; furthermore, a supporting spacer is provided between the first dielectric plate 1 and the second dielectric plate 2, so that an air gap is formed between the lower surface of the first dielectric plate 1 and the antenna radiation structure 7 on the upper surface of the second dielectric plate 2. g 0 = 6mm. Plastic fasteners are selected from plastic support columns, which pass through the first medium plate 1 and the support spacer and are then fixedly connected to the lower pressure plate.

[0024] A single-polarization electromagnetic absorbing structure 12 is disposed on the upper surface of the first dielectric substrate 1. This single-polarization electromagnetic absorbing structure 12 includes a patch resistor 123, and a first metal strip 121 and a second metal strip 122 connected to both sides of the patch resistor 123 and extending horizontally along the y-axis, forming a highly efficient absorbing resonant structure for electromagnetic waves incident in a specific polarization direction. In this embodiment, the resistance of the patch resistor 123 is 100Ω, and the length of the metal strip is... l 1 = 6mm. The first dielectric substrate 1 and the single-polarized electromagnetic absorbing structure 12 on it together constitute the top cladding of the antenna. The top cladding is suspended above the antenna radiating structure 7 and is fixedly connected to the integrated laminate below by plastic fasteners. The above-mentioned suspended cladding structure can absorb the energy of plane waves incident in a cross-polarized manner in a wide angular range, thereby significantly reducing the cross-polarization scattering of the array.

[0025] The upper surface of the second dielectric substrate 2 is provided with an antenna radiating structure 7, and the lower surface is provided with a first bias feed metal line 10. The first bias feed metal line 10 is electrically connected to the corresponding bias node in the antenna radiating structure 7 through a metallized via in the second dielectric substrate 2, and is used to provide a DC bias path for the PIN diode in the antenna radiating structure 7.

[0026] The antenna radiating structure 7 is one of the core components for achieving phase modulation of radiation and scattering. In this embodiment, referring to Figure 2(a), the antenna radiating structure 7 includes a first radiating stub 71, a second radiating stub 72, a third radiating stub 73, a first PIN diode 74, and a second PIN diode 75. The width of the radiating stub in this embodiment is... w 1 = 0.8 mm. The first radial branch 71 is elongated and vertically positioned between the second radial branch 72 and the third radial branch 73, with a length of... l 2 = 3.5mm. The first radiating branch 71 includes a first vertical segment 711 and a first metallized via 712; the first vertical segment 711 is a metal strip, one end of which is connected to the cathode of the first PIN diode 74, and the other end is connected to the cathode of the second PIN diode 75. The first metallized via 712 is filled or plated with a metal pillar, which continuously penetrates downward through the second dielectric substrate 2, the third dielectric substrate 3, and the fourth dielectric substrate 4, and is electrically connected to the feed network 9 on the lower surface of the fourth dielectric substrate 4, thereby transmitting the feed signal from the feed network to the antenna radiating structure 7.

[0027] For ease of understanding, in this invention, the vertical segment refers to the direction along the y-axis, and the horizontal segment refers to the direction along the x-axis.

[0028] The second radiating stub 72 is located in the lower half of the antenna radiating structure 7. The second radiating stub 72 includes a third vertical segment 721, a first horizontal segment 722, a second vertical segment 723, a fourth vertical segment 724, a bent metal wire 725, and a second metallized via 726. The distal end (the end facing the third radiating stub 73) of the third vertical segment 721 is connected to the anode of the first PIN diode 74, and the proximal end (the end away from the third radiating stub 73) is connected to the first horizontal segment 722. The proximal end of the second vertical segment 723 is connected to the left side of the first horizontal segment 722, and the proximal end of the fourth vertical segment 724 is connected to the right side of the first horizontal segment 722, forming an interdigitated or symmetrical loading structure. The bent metal wire 725 is located between the third vertical segment 721 and the fourth vertical segment 724, with its proximal end connected to the first horizontal segment 722 and its right end connected to the second metallized via 726. The length of the first horizontal segment 722 is... l3 = 11.8 mm. The second metallized via 726 is electrically connected to the first bias feed metal line 10 on the lower surface of the second dielectric substrate 2 through a metal post embedded in the second dielectric substrate 2, thereby applying the DC bias voltage provided by the first bias feed metal line 10 to the anode of the second radiating branch 72 and the first PIN diode 74 connected thereto.

[0029] The third radiating stub 73 is located in the upper half of the antenna radiating structure 7. Its structure is centrally symmetrical with the second radiating stub 72 about the center of the antenna radiating structure 7. The far end of its vertical segment (the end closest to the second radiating stub 72) is connected to the anode of the second PIN diode 75, and the DC bias is connected to the corresponding bias metal line through its own metallized via. Through this symmetrical layout and the connection method of the PIN diode, the antenna radiating structure can generate radiation or scattering responses with different phases under different PIN diode conduction states.

[0030] A second bias feed metal line 11 is provided on the upper surface of the third dielectric substrate 3. The second bias feed metal line 11 is electrically connected to the corresponding node in the feed network 9 on the lower surface of the fourth dielectric substrate 4 through metallized vias provided in the third dielectric substrate 3 and the fourth dielectric substrate 4, and is used to provide a DC bias signal to the PIN diodes in the feed network 9.

[0031] A metal ground plane 8 is provided on the upper surface of the fourth dielectric substrate 4. The metal ground plane 8 serves as the common ground for the antenna element and the feed network 9. To allow through-hole metallized vias to pass through without short-circuiting the metal layer, circular clearance holes are provided on the metal ground plane 8. In this embodiment, the positions of the circular clearance holes correspond one-to-one with the positions of the first metallized via 712 and the metallized via 943 in the DC feed structure 94.

[0032] A power supply network 9 is provided on the lower surface of the fourth dielectric substrate 4, as shown in Figure 2(b). The power supply network 9 includes a reconfigurable phase shifter structure 91, a first transmission line structure 92, a second transmission line structure 93, four DC power supply structures 94, a first capacitor 95, a second capacitor 96, a third PIN diode 97, and a power supply port 98. The transmission lines in the power supply network are microstrip lines. In this embodiment, the microstrip line width is... w 3 = 0.73 mm.

[0033] The reconfigurable phase shifter structure 91 is located at the end of the feed network 9. One end of it is connected to the feed port 98 via the second capacitor 96, and the other end is connected to the second transmission line structure 93 via the first capacitor 95. The reconfigurable phase shifter structure 91 is equipped with a fourth PIN diode 911, a fifth PIN diode 912, a sixth PIN diode 913, and a seventh PIN diode 914. By switching the on / off combination of these four PIN diodes, the RF signal transmission path can be selectively switched, allowing the phase shifter to introduce four relative phase values ​​in a 2-bit phase state, such as achieving quantized phase states of 0°, 90°, 180°, and 270°. In this embodiment, the dimensions of the reconfigurable phase shifter structure 91... l 4 = 2.32 mm.

[0034] The first transmission line structure 92 is a bent metal wire structure, the starting end of which is connected to the first metallized via 712 extending upward to the antenna radiating structure, thereby realizing the radio frequency signal connection between the feed network 9 and the antenna radiating structure 7.

[0035] The third PIN diode 97 is connected in series between the first transmission line structure 92 and the second transmission line structure 93. Its anode is connected to the second transmission line structure 93, and its cathode is connected to the first transmission line structure 92. The third PIN diode 97 is used to switch the radiation state and scattering state of the antenna element and participates in scattering phase modulation. Its conduction and cutoff directly affect the switching between the radiation state and scattering state of the antenna element, and it is also one of the key components for realizing scattering state phase modulation. The first transmission line structure 92 is L-shaped, and in this embodiment, the first segment length of the first transmission line structure is selected. l 5 = 1.35mm, length of the second segment l 6 = 2.34 mm.

[0036] The four DC feed structures 94 are similar in structure and are respectively loaded on both sides of the fourth PIN diode 911, the fifth PIN diode 912, the sixth PIN diode 913, and the seventh PIN diode 914 to provide DC bias voltage to the four PIN diodes. Each DC feed structure 94 includes a high-impedance bent metal line 941, a fan-shaped stub 943, and a metallized via 942. The high-impedance bent metal line 941 and the fan-shaped stub 942 together form a low-pass bias feed network, which can effectively isolate the radio frequency signal while introducing DC bias into the PIN diodes. The metallized via 943 passes upward through the third dielectric substrate 3 and the fourth dielectric substrate 4, and is electrically connected to the second bias feed metal line 11 on the upper surface of the third dielectric substrate 3, thereby establishing a complete bias link from the external DC control circuit to each PIN diode. It can be understood that the DC bias of the first PIN diode 74 and the second PIN diode 75 in the antenna radiating structure 7 is introduced through the first bias feed metal line 10 and the metallized via in the second dielectric substrate 2.

[0037] In this embodiment, all PIN diodes are MADP diodes from MACOM. 000907 Diode model 14020.

[0038] By controlling the on / off states of each PIN diode through the above structure, this invention can achieve 2-bit radiation phase reconstruction and quasi-2-bit scattering phase reconstruction functions. Specifically, the first PIN diode 74 and the second PIN diode 75 in the antenna radiation structure 7, and the third PIN diode 97, the fourth PIN diode 911, the fifth PIN diode 912, the sixth PIN diode 913, and the seventh PIN diode 914 in the feed network 9 are jointly responsible for 2-bit radiation phase reconstruction; the first PIN diode 74 and the second PIN diode 75 in the antenna radiation structure 7, and the third PIN diode 97 in the feed network 9 are responsible for quasi-2-bit scattering phase reconstruction.

[0039] In terms of specific control strategy, in this embodiment, the phase state of each antenna element is switched by controlling the on / off state of each PIN diode. When the excitation feed port 98 is activated: Radiation state 0: First PIN diode 74, third PIN diode 97, fifth PIN diode 912, and sixth PIN diode 913 are turned on, while second PIN diode 75, fourth PIN diode 911, and seventh PIN diode 914 are turned off. This is the reference radiation phase state. Radiation state 1: First PIN diode 74, third PIN diode 97, fourth PIN diode 911, and seventh PIN diode 914 are turned on, second PIN diode 75, fifth PIN diode 912, and sixth PIN diode 913 are turned off, and the radiation phase is 90° relative to the reference radiation phase state. Radiation state 2: Second PIN diode 75, third PIN diode 97, fifth PIN diode 912, and sixth PIN diode 913 are turned on, while first PIN diode 74, fourth PIN diode 911, and seventh PIN diode 914 are turned off. The radiation phase is 180° relative to the reference radiation phase state. Radiation state 3: Second PIN diode 75, third PIN diode 97, fourth PIN diode 911, and seventh PIN diode 914 are turned on, first PIN diode 74, fifth PIN diode 912, and sixth PIN diode 913 are turned off, and the radiation phase is 270° relative to the reference radiation phase state. Scattering state 0: The first PIN diode 74, the second PIN diode 75, and the third PIN diode 97 are all cut off. This is the reference reflection phase state. Scattering state 1: The first PIN diode 74 is turned on, the second PIN diode 75 and the third PIN diode 97 are turned off, and the reflection phase is 120° relative to the reference reflection phase state; Scattering state 2: The first PIN diode 74 and the second PIN diode 75 are turned on, the third PIN diode 97 is turned off, and the reflection phase is 240° relative to the reference reflection phase state.

[0040] With the aforementioned multi-state control, the antenna elements, when used as radiating elements, can switch between four equally spaced or nearly equally spaced phase states. The array applies different quantization phases to each element through a wave control circuit to achieve radiated beam scanning. Under the conditions of external incident plane wave illumination and appropriate termination of the matching load at the feed port 98, each antenna element can operate as a reconfigurable reflective element. By setting it to three different scattering states, the array can achieve scattered beam scanning. At the same time, combined with an appropriate cancellation strategy, significant scattering suppression is achieved under common-polarized plane wave incident conditions.

[0041] Specifically, in the radiation state, the feed signal is fed in through the feed port 98, passes through the reconfigurable phase shifter structure 91, the second transmission line structure 93, the third PIN diode 97, the first transmission line structure 92, and the first metallized via 712 before entering the antenna radiation structure 7. By switching the fourth to seventh PIN diodes to change the transmission path of the phase shifter, and in conjunction with the switching of the antenna radiation stubs by the first PIN diode 74 and the second PIN diode 75, the antenna element can switch between four radiation phase states, with adjacent phase states differing by 90°, thereby achieving 2-bit radiation phase reconstruction. In the array, applying different radiation phase codes to each antenna element enables radiation beam scanning.

[0042] In the scattering state, when the feed port 98 is appropriately terminated with a matched load and an external plane wave illuminates the antenna element, the reflection phase of the antenna element can be changed by controlling the on / off states of the first PIN diode 74, the second PIN diode 75, and the third PIN diode 97. This allows switching between three scattering phase states, with adjacent phase states differing by 120°, thus achieving quasi-2-bit scattering phase reconstruction. Applying different scattering codes to each antenna element enables scattering beam scanning. Combined with a cancellation strategy, by optimizing the array's scattering state coding, the array can achieve scattering suppression under common-polarized plane wave incidence.

[0043] Furthermore, since a single-polarization electromagnetic absorbing structure 12 is provided on the first dielectric plate 1 and a suspended air layer is maintained between it and the antenna radiating structure 7, the absorbing structure has an efficient resonant absorption effect on plane waves incident in a cross-polarization manner in a wide angular range, so that the array still has a good scattering suppression effect under the incident cross-polarization plane waves, which significantly reduces the cross-section of the bistatic radar.

[0044] The technical effects of this embodiment will be further explained below with reference to simulation experiments.

[0045] The antenna array in the above embodiment was simulated using the commercial simulation software HFSS 2022 R1. The antenna element was switched between different radiation states by controlling the on / off state of the PIN diode. Its port matching characteristics and radiation phase are shown in Figures 4(a) and 4(b). In this embodiment, the antenna element operates in the frequency band of 9.60~11.35GHz under the four radiation states. Within this frequency band, the radiation phase difference between adjacent phase elements is approximately 90°, thus the antenna element possesses a 2-bit radiation characteristic. Then, the antenna element was switched between different scattering states by controlling the on / off state of the PIN diode, as shown in Figures 4(c) and 4(d). Under plane wave incidence, the adjacent elements in the three scattering states have a phase difference of 120° at the center frequency, and the reflection coefficient at the center frequency is greater than -1.35dB.

[0046] In the radiation state, all antenna element ports are excited with equal amplitude and in phase, and the radiation phase of each element is determined by a 2-bit radiation state code controlled by a PIN diode. Discrete scanning of the radiation beam can be achieved by configuring the array with a coding sequence having a linear phase gradient. Figure 5a Simulated radiation patterns at a center frequency of 10.5 GHz with beam pointing at 0°, -15°, -30°, -45° and -60° are presented, verifying the beam scanning capability based on 2-bit radiation state.

[0047] In the scattering state, all antenna elements are terminated with matched loads, and the reflection phase of each element is determined by quasi-2-bit scattering state coding controlled by PIN diodes. By configuring the scattering coding sequence for the array, discrete scanning of the scattering beam is achieved. Figure 5(b) shows the simulated radiation pattern at a center frequency of 10.5 GHz with beam pointing at 0° and -30°, respectively, verifying the beam scanning capability based on quasi-2-bit scattering state.

[0048] Finally, the scattering suppression effect of the array was verified. Using the three discrete phases provided by the quasi-2-bit scattering state, the scattering state encoding of the antenna array was optimized using a genetic algorithm, with the goal of minimizing the single-station RCS in the image direction.

[0049] like Figure 6a As shown, the single-station RCS of the optimized scattering-suppressed antenna array and the same-size PEC are presented as a function of frequency. Compared with a metal plate of the same size, under x-polarized plane wave incidence, the optimized coded array achieves a single-station RCS reduction of more than 10 dB in the range of 10.18–11.39 GHz, with a maximum reduction of 24.76 dB; and due to the introduction of a single-polarized absorber on the antenna surface, effective suppression of cross-polarization scattering of the antenna array can be achieved. Figure 6a The optimized antenna array and the PEC of the same size are presented as monocentric frequency curves under y-polarized plane wave incidence. Compared with the metal plate of the same size, the antenna array shows a monocentric RCS reduction of more than 10 dB in the 9.5~11.46 GHz range under y-polarized plane wave incidence, with a maximum reduction of 30 dB.

[0050] In summary, the 2-bit radiation phase and quasi-2-bit scattering phase reconfigurable antenna array provided in this embodiment integrates 2-bit radiation phase reconstruction and quasi-2-bit scattering phase reconstruction functions in the same array element, enabling the radiation beam to be reconfigured in both directions. Scanning within the range of 60° to 60°, the scattered beam is in It can scan within the range of 30° to 30° and has good scattering suppression capability under both common polarization and cross polarization incident waves. It has the advantages of compact structure and excellent performance and can be applied to the fields of next-generation multifunctional wireless communication, radar detection and smart skin antenna system.

[0051] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Obviously, those skilled in the art, after understanding the content and principle of the present invention, may make various modifications and changes in form and detail without departing from the principle and structure of the present invention. However, these modifications and changes based on the concept of the present invention are still within the protection scope of the claims of the present invention.

Claims

1. An antenna array with reconfigurable 2-bit radiation phase and quasi-2-bit scattering phase, characterized in that, The antenna array includes M×N antenna elements, where M and N are both positive integers and M×N≥3. Each antenna element includes an integral laminate and a first dielectric substrate (1). The integrated laminate is composed of a second dielectric plate (2), a first adhesive layer (5), a third dielectric plate (3), a second adhesive layer (6), and a fourth dielectric plate (4) stacked from top to bottom; the first dielectric plate (1) is suspended above the integrated laminate, and its upper surface is provided with a single-polarization electromagnetic wave absorbing structure (12). The upper surface of the second dielectric substrate (2) is provided with an antenna radiation structure (7), and the lower surface is provided with a first bias feed metal line (10) electrically connected to the antenna radiation structure (7); The upper surface of the third dielectric plate (3) is provided with a second bias feed metal line (11), the upper surface of the fourth dielectric plate (4) is provided with a metal ground plate (8), and the lower surface is provided with the feed network (9). The second bias feed metal line (11) is electrically connected to the feed network (9).

2. The antenna array with reconfigurable 2-bit radiation phase and quasi-2-bit scattering phase according to claim 1, characterized in that, The single-polarization electromagnetic absorbing structure (12) includes a patch resistor (123), and a first metal strip (121) and a second metal strip (122) that are connected to both sides of the patch resistor (123) and extend horizontally along the y-axis. The first dielectric substrate (1) and the single-polarization electromagnetic absorbing structure (12) together constitute the top layer of the antenna cover. The top layer of the antenna cover is suspended above the antenna radiating structure (7) and is fixedly connected to the integrated laminate below by plastic fasteners. A support spacer is provided between the first medium plate (1) and the laminate, and the plastic fastener passes through the first medium plate (1) and the support spacer and is fixedly connected to the laminate.

3. An antenna array with reconfigurable 2-bit radiation phase and quasi-2-bit scattering phase according to claim 1 or 2, characterized in that, The antenna radiation structure (7) includes a first radiation stub (71), a second radiation stub (72), a third radiation stub (73), a first PIN diode (74), and a second PIN diode (75); The first radiating branch (71) is elongated and vertically disposed between the second radiating branch (72) and the third radiating branch (73). The first radiating branch (71) includes a first vertical segment (711) and a first metallized via (712). The first vertical segment (711) is a metal strip along the x-axis, one end of which is connected to the cathode of the first PIN diode (74), and the other end is connected to the cathode of the second PIN diode (75). The anode of the first PIN diode (74) is connected to the third radiating branch (73), and the anode of the second PIN diode (75) is connected to the second radiating branch (72). The first metallized via (712) is electrically connected to the feed network (9) through metal pillars embedded in the second dielectric plate (2), the third dielectric plate (3), and the fourth dielectric plate (4).

4. The antenna array with reconfigurable 2-bit radiation phase and quasi-2-bit scattering phase according to claim 3, characterized in that, The second radiating stub (72) includes a third vertical segment (721), a first horizontal segment (722), a second vertical segment (723), a fourth vertical segment (724), a bent metal wire (725), and a second metallized via (726). Along the y-axis, one end of the second vertical segment (723), the third vertical segment (721), the bent metal wire (725), and the fourth vertical segment (724) are sequentially connected to the side of the first horizontal segment (722) near the first radiating stub (71), and the other end of the third vertical segment (721) is connected to the anode of the first PIN diode (74). The other end of the bent metal wire (725) is connected to the second metallized via (726). The second metallized via (726) is electrically connected to the first bias feed metal wire (10) through a metal post embedded in the second dielectric substrate (2). The structure of the third radiating stub (73) is centrally symmetrical with respect to the center of the antenna radiating structure (7) to the structure of the second radiating stub (72), and one end of its vertical segment for connecting the diode is connected to the anode of the second PIN diode (75).

5. The antenna array with reconfigurable 2-bit radiation phase and quasi-2-bit scattering phase according to claim 4, characterized in that, The power supply network (9) includes a reconfigurable phase shifter structure (91), a first transmission line structure (92), a second transmission line structure (93), four DC power supply structures (94), a first capacitor (95), a second capacitor (96), a third PIN diode (97), and a power supply port (98). The reconfigurable phase shifter structure (91) is located at the end of the power supply network (9). One end is connected to the power supply port (98) via the second capacitor (96), and the other end is connected to the second transmission line structure (93) via the first capacitor (95). A fourth PIN diode (911), a fifth PIN diode (912), a sixth PIN diode (913), and a seventh PIN diode (914) are provided on it. By switching the conduction state of each PIN diode, the radio frequency signal transmission path is changed, thereby switching the introduced transmission phase.

6. The antenna array with reconfigurable 2-bit radiation phase and quasi-2-bit scattering phase according to claim 5, characterized in that, The first transmission line structure (92) is a bent metal wire structure, and its starting end is connected to the first metallized via (712); The third PIN diode (97) is disposed between the first transmission line structure (92) and the second transmission line structure (93), with its anode connected to the second transmission line structure (93) and its cathode connected to the first transmission line structure (92); Two of the four DC power supply structures (94) are loaded on both sides of the overall structure of the fourth PIN diode (911), the fifth PIN diode (912), the sixth PIN diode (913), and the seventh PIN diode (914), and the other two are loaded on both sides of the third PIN diode (97) to provide DC bias voltage for each PIN diode. Each of the DC power supply structures (94) includes a high-impedance bent metal wire (941), a fan-shaped stub (943), and a metallized via (942). The metallized via (943) is electrically connected to the second bias power supply metal wire (11) through a metal post embedded in the third dielectric plate (3) and the fourth dielectric plate (4).

7. The antenna array with reconfigurable 2-bit radiation phase and quasi-2-bit scattering phase according to claim 6, characterized in that, The metal ground plane (8) is provided with a circular clearance hole, through which the metallized via connecting the upper and lower circuits can pass without being short-circuited to the metal layer; the position of the circular clearance hole corresponds to the position of the first metallized via (712) and the metallized via (943) in the DC power supply structure (94).

8. The antenna array with reconfigurable 2-bit radiation phase and quasi-2-bit scattering phase according to claim 6, characterized in that, The phase state of the antenna elements in the array is switched by the PIN diodes. The first PIN diode (74), the second PIN diode (75) in the antenna radiation structure (7) and the third PIN diode (97), the fourth PIN diode (911), the fifth PIN diode (912), the sixth PIN diode (913), and the seventh PIN diode (914) in the feed network (9) are responsible for 2-bit radiation phase reconstruction. The first PIN diode (74), the second PIN diode (75) in the antenna radiation structure (7) and the third PIN diode (97) in the feed network (9) are responsible for quasi-2-bit scattering phase reconstruction.

9. The antenna array with reconfigurable 2-bit radiation phase and quasi-2-bit scattering phase according to claim 8, characterized in that, The phase state of the antenna elements in the array is switched by controlling the conduction state of the PIN diodes. The control strategy is as follows: When the first PIN diode (74), the third PIN diode (97), the fifth PIN diode (912), and the sixth PIN diode (913) are turned on, and the second PIN diode (75), the fourth PIN diode (911), and the seventh PIN diode (914) are turned off, the antenna element is in radiation state 0, which is the reference radiation phase state, at the excitation feed port (98). When the first PIN diode (74), the third PIN diode (97), the fourth PIN diode (911), and the seventh PIN diode (914) are turned on, and the second PIN diode (75), the fifth PIN diode (912), and the sixth PIN diode (913) are turned off, the antenna element is in radiation state 1 at the excitation feed port (98), and the radiation phase is 90° relative to the reference radiation phase state. When the second PIN diode (75), the third PIN diode (97), the fifth PIN diode (912), and the sixth PIN diode (913) are turned on, and the first PIN diode (74), the fourth PIN diode (911), and the seventh PIN diode (914) are turned off, the antenna element is in radiation state 2 at the excitation feed port (98), and the radiation phase is 180° relative to the reference radiation phase state. When the second PIN diode (75), the third PIN diode (97), the fourth PIN diode (911), and the seventh PIN diode (914) are turned on, and the first PIN diode (74), the fifth PIN diode (912), and the sixth PIN diode (913) are turned off, the antenna element is in radiation state 3 at the excitation feed port (98), and the radiation phase is 270° relative to the reference radiation phase state. When the first PIN diode (74), the second PIN diode (75), and the third PIN diode (97) are turned off, the antenna element is in scattering state 0, which is the reference reflection phase state, at the excitation feed port (98). When the first PIN diode (74) is turned on and the second PIN diode (75) and the third PIN diode (97) are turned off, the antenna element is in scattering state 1 at the excitation feed port (98), and the reflection phase is 120° relative to the reference reflection phase state. When the first PIN diode (74) and the second PIN diode (75) are turned on and the third PIN diode (97) is turned off, the antenna element is in scattering state 2 at the excitation feed port (98), and the reflection phase is 240° relative to the reference reflection phase state.

10. The antenna array with reconfigurable 2-bit radiation phase and quasi-2-bit scattering phase according to claim 1, characterized in that, The antenna elements in the array have 2-bit reconfigurable radiation phase and quasi-2-bit reconfigurable scattering phase, enabling the array to achieve radiated beam reconfiguration. Scanning within the 60°~60° range to achieve the scattering beam in Scanning within the range of 30°~30°, combined with the cancellation strategy, the array achieves scattering suppression under the incident of co-polarized plane waves; due to the single-polarized electromagnetic absorbing structure (12), the array has a scattering suppression effect under the incident of cross-polarized plane waves.

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