Sawtooth symmetrical slotting reflection unit and beam width adjustable array antenna

Abstract

The invention discloses a sawtooth symmetrical slotting reflection unit and a beam width adjustable array antenna, the reflection unit comprises a radiation patch, a first dielectric substrate, a metal floor, a second dielectric substrate and a bias line, the metal floor is located between the first dielectric substrate and the second dielectric substrate, and the bias line is located between the first dielectric substrate and the second dielectric substrate. The radiation patch is fixed on one side, far away from the metal floor, of the first dielectric substrate, the bias voltage line is fixed on the second dielectric substrate, the centers of the radiation patch, the first dielectric substrate, the metal floor and the second dielectric substrate are on the same axis, the radiation patch adopts a symmetrical stepped layout and a center hollow design and is connected with the PIN switching diode, and the PIN switching diode is connected with the bias voltage line. Resonance state switching is realized through on-off of the PIN diodes. The adjustable array antenna takes the reflecting unit as a basic unit, and the reflecting unit is arranged into a 20 * 20 intelligent reflecting surface array, so that the width of a reflected beam is dynamically regulated and controlled within the range of 6-20 degrees.

Description

Technical Field

[0001] The present invention relates to the field of antennas, and in particular to a sawtooth symmetrical slotted reflection unit and an array antenna with adjustable beam width. Background Art

[0002] For intelligent wireless communication systems in complex electromagnetic environments, the flexible control capability of the beam width and the rapid response performance of the reflector antenna have become important evaluation indicators for measuring the adaptability of the system.

[0003] Existing antenna designs face significant challenges. Traditional fixed-phase reflector arrays, due to their single beam configuration, struggle to simultaneously meet the compatibility requirements of narrow-beam high-precision tracking (e.g., satellite communications) and wide-beam multi-user coverage (e.g., 5G millimeter-wave base stations). Mechanical beam steering schemes suffer from long reconfiguration times (on the order of seconds), making them incapable of adapting to the millisecond-level switching requirements of dynamic scenarios. Existing reconfigurable elements (e.g., varactor diodes) suffer from a limited phase adjustment range (<90°) and bandwidth (<10%), resulting in a gain drop exceeding 5dB during beam switching. Current designs have yet to overcome the bottleneck of achieving the collaborative optimization of "continuously adjustable beams, high gain stability, and fast response." This is fundamentally due to the lack of a mechanism for continuous switching with a large phase difference of 180° at the element level. Furthermore, inefficient array-level optimization algorithms struggle to support dynamic beam width adaptation to meet diverse beam coverage requirements and bring new technological breakthroughs to the wireless communications field. Summary of the Invention

[0004] The purpose of the present invention is to provide a sawtooth symmetrical slotted reflector unit and an array antenna with adjustable beam width, so as to solve the problems of the traditional array beam width being fixed and unable to be continuously adjusted within the range of 6°–20°, the problem of the single beam shape caused by the insufficient phase adjustment range of the reconfigurable unit, and the problem of low efficiency and slow response speed in real-time optimization of large-scale arrays.

[0005] The technical solutions for achieving the purpose of the present invention are:

[0006] A sawtooth symmetrical slotted reflector unit includes a radiating patch, a first dielectric substrate, a metal floor, a second dielectric substrate, and a bias line. The metal floor is located between the first and second dielectric substrates. The radiating patch is fixed to a side of the first dielectric substrate away from the metal floor. The bias line is fixed to the second dielectric substrate. The centers of the radiating patch, the first dielectric substrate, the metal floor, and the second dielectric substrate are coaxial. The radiating patch adopts a symmetrical stepped layout and a central hollow design, and is connected to a PIN switching diode. The resonant state switching is achieved by turning the PIN diode on and off.

[0007] Furthermore, the radiation patch, the first dielectric substrate, the metal floor, and the second dielectric substrate are all square and fixedly connected by metal columns.

[0008] Furthermore, a rectangular protrusion is provided in the middle of each side of the radiation patch, a gap is provided inside the radiation patch, and a PIN branch node connected to the PIN switch diode is provided on one side.

[0009] Furthermore, the gaps include two rectangular gaps and one square gap, the square gap is located in the center of the radiation patch, and the two rectangular gaps are symmetrically distributed on the upper and lower sides of the square gap.

[0010] Furthermore, the PIN branch includes a rectangular patch and a circular via, the midpoint of the lower edge of the rectangle is located at the center of the circular via, the center of the circle and the center of the radiation patch are on the same axis, and the circular via is connected to the first dielectric substrate, the metal floor, and the second dielectric substrate through a metal column.

[0011] Furthermore, a square protrusion is provided in the middle of the side of the rectangular protrusion of the radiation patch close to the PIN branch node, the positive electrode of the PIN switch diode is connected to the square protrusion, and the negative electrode is connected to the PIN branch node.

[0012] Furthermore, the bias line includes an L-shaped bias line, a linear bias line, and a fan-shaped branch. The L-shaped bias line is placed horizontally, and the edge of its horizontal part overlaps with the edge of the second dielectric substrate. Its vertical part is connected to the horizontally placed linear bias line, and the linear bias line is connected to the fan-shaped branch.

[0013] Furthermore, the width of the first dielectric substrate is 10 mm and the thickness is 2 mm; the width of the metal floor is 10 mm and the thickness is 0.018 mm; the width of the second dielectric substrate is 10 mm and the thickness is 0.5 mm.

[0014] Furthermore, the radiation patch is 4.5mm long and 0.018mm thick; the rectangular protrusion is 2.3mm long and 0.7mm wide; the side length of the square protrusion is 0.3mm; the distance between the upper rectangular gap and the upper edge of the radiation patch and the distance between the lower rectangular gap and the lower edge of the radiation patch are both 0.625mm, the length of the rectangular gap is 3mm, the width is 0.3mm, and the side length of the square gap is 1.4mm; the circular via is 1.025mm away from the lower edge of the first square dielectric substrate and has a diameter of 0.6mm; the length of the rectangular patch is 0.5mm and the width is 0.3mm; the width of the horizontal and vertical parts of the L-shaped bias line is 0.3mm, the horizontal length of the L-shaped bias line is 5mm, the height of the vertical part is 1mm, the length of the straight bias line is 2mm, and the radius of the fan-shaped branch is 4mm.

[0015] A beam width adjustable array antenna comprises a plurality of array-distributed sawtooth symmetrical slotted reflection units as described in any one of claims 1 to 9.

[0016] Compared with the existing technology, the present invention has the following significant effects: the PIN diode is integrated in the reflective unit of the present invention, and the resonant state switching is achieved by switching on and off, thereby achieving the phase adjustment target of 180° difference. The phase of the array arrangement is optimized based on the genetic algorithm, and the control of the reflective surface antenna beam width from 6° to 20° is achieved. Based on the proposed 1-bit reflective unit and phase optimization method, a reflective array antenna composed of 20×20 units is designed. The antenna CST simulation achieves the control of the beam width from 6° to 20°. The design of the present invention provides a theoretical basis and practical reference for the design and application of dynamically reconfigurable wireless communication systems through an intelligent reflective surface beam control solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a front view of a reflective unit structure with a zigzag symmetrical slotted structure.

[0018] Figure 2 This is the rear view of the reflective unit structure with a zigzag symmetrical slot structure.

[0019] Figure 3 A three-dimensional diagram of a reflective unit structure with a zigzag symmetrical slot structure.

[0020] Figure 4 Phase diagram of the reflection unit structure with a zigzag symmetrical slot structure.

[0021] Figure 5 Amplitude diagram of the reflection unit structure with a zigzag symmetrical slotted structure.

[0022] Figure 6 A top view of the smart reflector that allows for flexible beam width control.

[0023] Figure 7 Side view of the smart reflector that allows for flexible beamwidth control.

[0024] Figure 8 The beam width is 9° and the frequency is 13 GHz.

[0025] Figure 9 The beam width is 9° and the frequency is 14 GHz.

[0026] Figure 10 The beam width is 9° and the frequency is 15 GHz.

[0027] Figure 11 This is the gain diagram of the smart reflector with a beam width of 6° and a frequency of 14 GHz.

[0028] Figure 12 This is the gain diagram of the smart reflector with a beam width of 9° and a frequency of 14.5 GHz.

[0029] Figure 13 This is the gain diagram of the smart reflector with a beam width of 14° and a frequency of 15.5 GHz.

[0030] Figure 14 This is the gain diagram of the smart reflector with a beam width of 15° and a frequency of 15 GHz.

[0031] Figure 15 This is the gain diagram of the smart reflector with a beam width of 20° and a frequency of 12.5 GHz. DETAILED DESCRIPTION

[0032] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only 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 making creative efforts are within the scope of protection of the present invention.

[0033] Example 1

[0034] This embodiment provides a unit structure of a zigzag symmetrical slot structure, combined with Figure 3 From front to back, the unit structure consists of a radiating patch, a first square dielectric substrate, a square metal floor, a second square dielectric substrate, and a bias line. With the exception of the bias line, all other components are centered on the z-axis. The radiating patch is fixed to the first square dielectric substrate, and the bias line is fixed to the second square dielectric substrate. Symmetrical sawtooth-shaped slots are etched into the radiating patch, and a PIN diode is integrated. By controlling the diode's on / off state, resonant switching is achieved, generating a 180° phase difference.

[0035] The first square dielectric substrate has a width of p = 10 mm and a thickness of h1 = 2 mm. The square floor has a width of p = 10 mm and a thickness of h_m = 0.018 mm. The second square dielectric substrate has a width of p = 10 mm and a thickness of h2 = 0.5 mm. The unit operates at 14 GHz, with a period P of 13.5 mm, approximately 0.45 times the operating wavelength. The unit's dielectric substrate is made of AD255 material, with a height of 2 mm, a dielectric constant of 2.55, and a loss tangent of 0.002.

[0036] Combine Figure 1, the radiation patch is composed of a square patch by adding rectangular protrusions, gaps and PIN branches. The length of the square patch is m = 4.5mm, and the thickness is h_m = 0.018mm. The four rectangular protrusions are symmetrically distributed on the four sides of the square patch. Taking the protrusion located on the upper edge of the square patch as an example, the left and right edges of the protrusion are 1.1mm away from the left and right edges of the square patch respectively. The length of the rectangular protrusion is l = 2.3mm, and the width is w = 0.7mm; there is another square protrusion outside the bottom protrusion, and the axis of the square protrusion coincides with the axis of the rectangular protrusion and the square patch. The side length of the square protrusion is lay_w = 0.3mm; the two rectangular gaps are symmetrically distributed inside the square patch, and the upper edge of the upper gap is 0.625mm away from the upper edge of the square patch, and the lower edge of the lower gap is 0.625mm away from the lower edge of the square patch. The slit is 0.625mm long, with a length l3 = 3mm and a width w2 = 0.3mm. A square slit with a side length s = 1.4mm is located in the center of the square patch. This square slit serves as a key symmetric region for electromagnetic coupling, uniformly regulating the electric field concentration effect. The PIN branch consists of a rectangular patch and a circular via. The circular via's center is 1.025mm from the bottom edge of the first square dielectric substrate, with a diameter r1 = 0.6mm. The midpoint of the rectangle's lower edge is located at the center of the circle. The length l2 = 0.5mm and the width lay_w1 = 0.3mm are connected to the first dielectric substrate, the metal floor, and the second dielectric substrate via metal posts. The positive electrode of the PIN diode is connected to the entire radiating patch via a square protrusion, while its negative electrode is connected to the PIN branch. The negative electrode is connected to the metal floor through a circular via to form a loop. The PIN branches are composed of rectangular patches and circular vias, which not only ensure the integrity of the pattern structure, but also reserve symmetrical interfaces for subsequent connection with functional modules such as feeding and grounding. By coordinating the size and layout of these symmetrical structures and utilizing symmetry to optimize current distribution, the stable electromagnetic resonance and control foundation of the unit is initially established, reducing electromagnetic interference caused by asymmetry.

[0037] Combine Figure 2The bias line adopts a symmetrical "cross + fan" combination to meet diverse electromagnetic functional requirements. It consists of an L-shaped bias line, a straight bias line, and fan-shaped branches. The L-shaped bias line has a width of t1 = 0.3mm. The bias line immediately adjacent to the right edge of the second square dielectric substrate is p / 2 = 5mm long. The bias line at the bottom, where it bends downward, is t2 = 1mm long. Half the length of the straight bias line connecting the fan and the L-shaped structure is wl = 1mm. The fan-shaped branch has a radius of rd = 4mm. Its curved profile symmetrically optimizes the directional characteristics of electromagnetic radiation or reflection, similar to a "director" or "reflector." By controlling the symmetrical layout of the fan angle and radius, it uniformly controls the scattering and focusing behavior of electromagnetic waves and avoids beam distortion caused by asymmetry. This symmetrical combination combines the energy conduction advantages of a cross structure with the directional control capabilities of a fan structure. Leveraging symmetry, it ensures consistent electromagnetic performance, laying a stable foundation for the unit to achieve functions such as directional radiation and phase control.

[0038] The radiation patch, the first square dielectric substrate, the square floor, the second square dielectric substrate and the bias line are all provided with circular via-hole peripheral branches, and the radiation patch, the first square dielectric substrate, the square floor and the second square dielectric substrate are fixedly connected by metal columns passing through the via-hole peripheral branches, and the diameter of the via-hole peripheral branches d3 = 0.6 mm.

[0039] The circular via has three peripheral branches and three metal columns. Figure 3 As shown, three metal pillars connect the two dielectric substrates.

[0040] This embodiment uses an RLC series circuit to represent the switching diode. When the diode is in the on state, it is equivalent to a series circuit consisting of a 7.8Ω resistor and a 30pH inductor. When the diode is in the off state, it is equivalent to a series circuit consisting of a 25fF capacitor and a 30pH inductor, producing a stable 180° reflection phase difference at a center frequency of 14GHz.

[0041] The structural unit induces the excitation of coupled resonant modes in adjacent frequency bands through rectangular slots (slots), and switches between two resonant states by controlling the on-off of the diode, achieving a 1-bit phase change, that is, the phase difference between the on-off of the diode reaches 180°. The phase diagram is shown in Figure 4 As shown, the operating frequency band is 12.5~15.5GHz, indicating that it is a broadband reflection unit structure. The amplitude diagram is shown in Figure 5 As shown in the figure, the diode has stable working performance in both on and off states at all frequencies, indicating that it has good performance and is suitable for controlling phase changes.

[0042] Example 2

[0043] This embodiment provides an array antenna structure with adjustable beam width based on the unit structure of embodiment 1, such as Figure 6 and Figure 7 As shown, the array antenna structure is directly composed of 20×20 unit radiation patches of the same size. Relying on a double-layer dielectric substrate design: the upper substrate uses AD255 material (thickness 2mm, dielectric constant 2.55) to carry the zigzag symmetrical slotted structural unit to ensure the consistency of electromagnetic characteristics; the lower substrate is FR4 material to facilitate the design of the bias circuit. The dielectric constant, loss tangent angle, and dielectric height of AD255 are 2.55, 0.02, and 0.4mm respectively. The two layers of dielectric are connected by a metal plate adhesive layer. The integrated bias circuit controls the on and off state of the unit PIN diode to achieve 1-bit phase control (180° reflection phase difference). The model of the PIN switch diode used is MACOM MADP-000907-14020W. The on and off state of the unit PIN diode is controlled by the lower substrate bias circuit, and the phase control matrix is generated by combining the genetic algorithm to achieve beam width control of 6° to 20° within 12.5~15.5GHz. Here, taking the beam width of 9° as an example, the directional patterns at different frequencies are as follows Figures 8 to 10 As shown. In narrow beam (such as 6°, 14GHz) scenarios, the center unit phase consistency and edge unit gradient compensation strategy are used to focus the main lobe gain, with the target side lobe level ≤-18dB; in wide beam (such as 20°, 12.5GHz) scenarios, the symmetrical unit phase complementary strategy is used to expand the coverage range, and the multipath interference suppression algorithm is used to compensate for the gain loss. Figures 11 to 15 The gain characteristics show that the mainlobe gain of high-frequency narrow beam combinations (such as 14 GHz and 6° beams) conforms to the "gain is inversely proportional to the square of the beamwidth" theory, making them suitable for long-distance directional communications such as satellite links. Low-frequency wide beam combinations (such as 12.5 GHz and 20° beams) prioritize coverage and are suitable for wide-area coverage scenarios such as indoor IoT. Mid-frequency transition scenarios (such as 14.5 GHz and 9° beams) balance gain and coverage, optimizing the "frequency-beamwidth" coupling effect by dynamically adjusting the feed phase distribution. This demonstrates the effectiveness of the genetic algorithm-based phase optimization method. The results also show that when the antenna center frequency is 14 GHz, the relative bandwidth is above 12%, and the antenna gain is above 11 dBi. Through dynamic phase control and algorithm-driven beam adaptation, control from narrow beam high gain to wide beam wide coverage is achieved, providing a new idea for the collaborative optimization of hardware and algorithms for future intelligent communication and perception systems; the antenna CST simulation achieves control of beam width from 6° to 20°, proving the effectiveness of the phase optimization method based on genetic algorithm. At the same time, the results show that the antenna center frequency is 14GHz, the relative bandwidth is above 12%, and the antenna gain is above 11dBi.

[0044] In summary, this embodiment is based on the array antenna structure with adjustable beam width designed based on the unit structure of Example 1, and combines the phase control algorithm with the frequency-beam width collaborative optimization to achieve gain characteristic adaptation within the beam width range of 6° to 20°, and realize flexible switching between narrow beam high gain and wide beam wide coverage, providing a solution for hardware and algorithm collaborative optimization for intelligent communication and perception systems, taking into account the high-frequency narrow beam high gain requirements of satellite communication and the low-frequency wide beam wide coverage requirements of the Internet of Things, with the advantages of low cost, easy manufacturing and dynamic control, and has application potential in complex electromagnetic environments such as drone communications and indoor positioning. The coupling effect can be further optimized through the meta-high frequency matching algorithm and the like to improve the gain stability in extreme scenarios.

[0045] The above description is only the preferred implementation steps of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A sawtooth symmetrical slotted reflector unit, characterized in that: The invention comprises a radiating patch, a first dielectric substrate, a metal floor, a second dielectric substrate and a bias line. The metal floor is located between the first dielectric substrate and the second dielectric substrate. The radiating patch is fixed to a side of the first dielectric substrate away from the metal floor. The bias line is fixed to the second dielectric substrate. The centers of the radiating patch, the first dielectric substrate, the metal floor and the second dielectric substrate are on the same axis. The radiating patch adopts a symmetrical stepped layout and a central hollow design, and is connected to a PIN switch diode. The resonant state switching is achieved by turning the PIN diode on and off.

2. The sawtooth symmetrical slotted reflective unit according to claim 1, characterized in that: The radiation patch, the first dielectric substrate, the metal floor, and the second dielectric substrate are all square and are fixedly connected by metal columns.

3. The sawtooth symmetrical slotted reflective unit according to claim 2, characterized in that: A rectangular protrusion is provided in the middle of each side of the radiation patch, a gap is provided inside the radiation patch, and a PIN branch node connected to the PIN switch diode is provided on one side.

4. The sawtooth symmetrical slotted reflective unit according to claim 3, characterized in that: The gaps include two rectangular gaps and one square gap. The square gap is located in the center of the radiation patch, and the two rectangular gaps are symmetrically distributed on the upper and lower sides of the square gap.

5. The sawtooth symmetrical slotted reflective unit according to claim 4, characterized in that: The PIN branch includes a rectangular patch and a circular via. The midpoint of the lower edge of the rectangle is located at the center of the circular via. The center and the center of the radiation patch are on the same axis. The circular via is connected to the first dielectric substrate, the metal floor, and the second dielectric substrate through a metal column.

6. The sawtooth symmetrical slotted reflective unit according to claim 5, characterized in that: A square protrusion is provided at the middle of the side of the rectangular protrusion of the radiation patch close to the PIN branch node. The positive electrode of the PIN switch diode is connected to the square protrusion, and the negative electrode is connected to the PIN branch node.

7. The sawtooth symmetrical slotted reflective unit according to claim 6, characterized in that: The bias line includes an L-shaped bias line, a linear bias line, and a fan-shaped branch. The L-shaped bias line is placed horizontally, and the edge of its horizontal part overlaps with the edge of the second dielectric substrate. Its vertical part is connected to the horizontally placed linear bias line, and the linear bias line is connected to the fan-shaped branch.

8. The sawtooth symmetrical slotted reflective unit according to claim 7, characterized in that: The width of the first dielectric substrate is 10 mm and the thickness is 2 mm; the width of the metal floor is 10 mm and the thickness is 0.018 mm; The second dielectric substrate has a width of 10 mm and a thickness of 0.5 mm.

9. The sawtooth symmetrical slotted reflective unit according to claim 8, characterized in that: The radiation patch is 4.5mm long and 0.018mm thick; the rectangular protrusion is 2.3mm long and 0.7mm wide; the side length of the square protrusion is 0.3mm; the distance between the upper rectangular gap and the upper edge of the radiation patch and the distance between the lower rectangular gap and the lower edge of the radiation patch are both 0.625mm, the length of the rectangular gap is 3mm, the width is 0.3mm, and the side length of the square gap is 1.4mm; the circular via is 1.025mm away from the lower edge of the first square dielectric substrate and has a diameter of 0.6mm; the length of the rectangular patch is 0.5mm and the width is 0.3mm; the width of the horizontal and vertical parts of the L-shaped bias line is 0.3mm, the horizontal length of the L-shaped bias line is 5mm, the height of the vertical part is 1mm, the length of the straight bias line is 2mm, and the radius of the fan-shaped branch is 4mm.

10. A beamwidth adjustable array antenna, characterized in that: The invention comprises a plurality of sawtooth symmetrical slotted reflective units as described in any one of claims 1 to 9 distributed in an array.

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