Holographic antenna and electronic device
By utilizing the resonant structure and waveguide feeding design of the holographic antenna and adjusting the dielectric constant of the liquid crystal layer, the problem of poor performance of the liquid crystal electronically controlled scanning antenna in the high-frequency band was solved, achieving precise beamforming and efficient radiation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- BOE TECHNOLOGY GROUP CO LTD
- Filing Date
- 2022-06-24
- Publication Date
- 2026-06-12
AI Technical Summary
Existing liquid crystal electronically controlled scanning antennas have poor performance in the high-frequency band, high loss, and difficulty in achieving accurate beamforming.
Design a holographic antenna that employs a resonant structure and a waveguide-fed structure. Utilize a liquid crystal layer to control the dielectric constant, and avoid coupling between adjacent resonant units through the specific shape and arrangement of the slit opening and patch electrodes to achieve precise beamforming.
It improves antenna performance in the high-frequency band, reduces losses, enhances beamforming accuracy and radiation efficiency, and reduces antenna size.
Smart Images
Figure CN117642933B_ABST
Abstract
Description
Technical Field
[0001] This disclosure belongs to the field of communication technology, specifically relating to a holographic antenna and electronic device. Background Technology
[0002] A liquid crystal holographic electrically controlled scanning array antenna is a low-profile, low-cost beamforming antenna achieved by applying holographic control theory to liquid crystal electrically controlled scanning antennas. Holography is a technique that uses the principles of wave interference and diffraction to record the amplitude and phase information of an object and reconstruct its three-dimensional image. A holographic antenna is an application of holographic technology in microwave engineering. This type of antenna can obtain the desired radiated electromagnetic wave by recording and recovering the interference field between a reference electromagnetic wave and the expected radiated electromagnetic wave. A holographic antenna typically has two parts: a feed structure and a holographic structure. The feed structure transmits a reference wave that can interfere with the expected radiated electromagnetic wave, while the holographic structure records the distribution of the interference field. When a holographic antenna is working, the reference electromagnetic wave and the expected radiated electromagnetic wave first form an interference field on a certain plane. Then, the holographic structure records the distribution of the interference field. Finally, the reference electromagnetic wave excites the holographic structure recording the interference field distribution, thereby recovering the radiated electromagnetic wave. Given that the antenna element has adjustable electromagnetic wave characteristics, the liquid crystal holographic electronically controlled scanning antenna can dynamically record various interference field distributions, thereby recovering the radiated electromagnetic waves and achieving beamforming characteristics.
[0003] Existing technologies utilize PIN diodes, varactor diodes, ferrites, and electromagnetic media such as liquid crystals to adjust the amplitude of antenna radiating elements, thereby achieving beamforming at a specific frequency. Compared to PIN diodes, liquid crystal materials offer continuously adjustable characteristics; compared to varactor diodes, liquid crystals can operate at higher frequencies and exhibit superior performance in the Ku band and above; compared to ferrite materials, liquid crystal materials possess lower loss characteristics and can be electrically controlled, effectively avoiding the bulkiness of magnetically controlled devices. Therefore, the superior performance of liquid crystal materials makes liquid crystal electrically controlled scanning antennas a promising candidate for applications in modern communication systems. Summary of the Invention
[0004] The present invention aims to solve at least one of the technical problems existing in the prior art, and to provide a holographic antenna and electronic device.
[0005] In a first aspect, embodiments of this disclosure provide a holographic antenna, which includes a resonant structure; wherein...
[0006] The resonant structure includes a first dielectric substrate and a second dielectric substrate disposed opposite to each other, a first electrode layer disposed on the side of the first dielectric substrate near the second dielectric substrate, a second electrode layer disposed on the side of the second dielectric substrate near the first dielectric substrate, and an adjustable dielectric layer disposed between the first electrode layer and the second electrode layer.
[0007] The first electrode layer has a plurality of slit openings, and the second electrode layer includes a plurality of patch electrodes, wherein the orthographic projection of one of the patch electrodes and one of the slit openings on the first dielectric substrate at least partially overlaps; and the orthographic projection of the slit opening on the first dielectric substrate includes at least an arc segment.
[0008] The slit opening comprises a first part and a second part that are connected to each other. The first part and the second part are centrally symmetrical, and the midpoint of their connection point is the center of symmetry.
[0009] The outline of the orthographic projection of the slit opening on the first dielectric substrate includes a first side and a second side disposed opposite to each other, and both the first side and the second side intersect with the orthographic projection of the patch electrode on the first dielectric substrate; the first side and the second side are S-shaped.
[0010] In this case, the orthographic projections of the slit opening and the patch electrode overlap, and the orthographic projections of their centers on the first dielectric substrate coincide.
[0011] The resonant structure includes multiple resonant units, each of which includes an overlapping slit opening projected onto the first dielectric substrate and a patch electrode. The multiple resonant units are arranged in nested groups, with the resonant units in each group arranged sequentially. The center lines connecting the patch electrodes in each group form a first pattern, and the centers of the formed first patterns are the same.
[0012] In this case, the distance between adjacent first graphics is equal.
[0013] Wherein, the center of the first pattern serves as the feed point of the holographic antenna, and in the first group of resonant units in the direction from the feed point to the edge of the first dielectric substrate, the distance between the centers of the adjacent patch electrodes is equal to the distance between the adjacent first patterns.
[0014] Among the second to last group of resonant units in the direction from the feed point to the edge of the first dielectric substrate, the distance between the centers of adjacent patch electrodes in the group of resonant units that are closer to the feed point is greater.
[0015] It also includes a waveguide-fed structure configured to transmit electromagnetic waves to the resonant structure.
[0016] The waveguide feeding structure includes a reflective component, and a first reference electrode layer, a first support layer, a second reference electrode layer, and a second support layer arranged sequentially close to the resonant structure. The reflective component has a receiving space, and at least the first support layer, the second reference electrode layer, and the second support layer are disposed within the receiving space. Electromagnetic waves transmitted via the first support layer can be reflected to the second support layer when they are irradiated onto the sidewall of the reflective component, so as to be transmitted to the resonant structure.
[0017] The sidewalls of the reflective component are arc-shaped.
[0018] The reflective component and the first reference electrode layer are an integral structure.
[0019] The waveguide feeding structure further includes an absorbing load disposed in the second support layer.
[0020] The waveguide feeding structure includes a coaxial connector configured to feed electromagnetic waves into the first support layer.
[0021] Secondly, embodiments of this disclosure provide an electronic device that includes any of the holographic antennas described above. Attached Figure Description
[0022] Figure 1 This is a top view of the resonant structure in the holographic antenna according to an embodiment of this disclosure.
[0023] Figure 2 This is a schematic diagram of a resonant element in a holographic antenna according to an embodiment of this disclosure.
[0024] Figure 3 for Figure 2 A cross-sectional view of AA'.
[0025] Figure 4 This is a schematic diagram of a resonant element in a holographic antenna according to an embodiment of the present disclosure, comprising a first part and a second part.
[0026] Figure 5 This is a schematic diagram of a holographic antenna according to an embodiment of this disclosure.
[0027] Figure 6 The radiation pattern of the holographic antenna in the embodiment of this disclosure is shown at theta=0deg and ±45deg. Detailed Implementation
[0028] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0029] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an,” “a,” or “the,” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “including,” “comprising,” or “containing,” and similar terms mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. The terms “connected,” “linked,” or similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” and “right,” etc., are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described objects changes.
[0030] Firstly, Figure 1 This is a top view of the resonant structure 100 in the holographic antenna according to an embodiment of this disclosure; Figure 2 This is a schematic diagram of a resonant element 10 in a holographic antenna according to an embodiment of the present disclosure; Figure 3 for Figure 2 A cross-sectional view of AA'; as shown Figures 1-3 As shown, this disclosure provides a holographic antenna with a resonant structure 100. The resonant structure 100 includes a first dielectric substrate 1 and a second dielectric substrate 2 disposed opposite to each other, a first electrode layer 11 disposed on the first dielectric substrate 1 near the second dielectric substrate 2, a second electrode layer 20 disposed on the second dielectric substrate 2 near the first dielectric substrate 1, and a tunable dielectric layer disposed between the first electrode layer 11 and the second electrode layer 20. The tunable dielectric layer includes, but is not limited to, a liquid crystal layer; in this disclosure, a liquid crystal layer is used as an example. The first electrode layer 11 has a plurality of slit openings 12, and the second electrode layer has a plurality of patch electrodes 21. The orthographic projections of a slit opening 12 and a patch electrode 21 on the first dielectric substrate 1 at least partially overlap. For example, the slit opening 12 and the patch electrode 21 are arranged in a one-to-one correspondence. Specifically, in this disclosure, the orthographic projection of the slit opening 12 on the first electrode layer 11 on the first dielectric substrate 1 includes at least an arc segment.
[0031] It should be noted that, in this embodiment of the disclosure, a slit opening 12 and a patch electrode 21 are respectively configured as an example. The corresponding slit opening 12 and patch electrode 21 constitute a resonant unit 10 (or patch slit pair).
[0032] In this embodiment, since the first electrode layer 11 has a slit opening 12 and the second electrode layer 20 includes a patch electrode 21 corresponding to the slit opening 12, when a voltage is applied to the patch electrode 21 of the first electrode layer 11 and the second electrode layer 20, the electric field formed between the patch electrode 21 and the first electrode layer 11 can control the deflection of the liquid crystal molecules in the liquid crystal layer 30, thereby changing the dielectric constant of the liquid crystal layer 30, adjusting the resonant frequency of each resonant unit 10, and thus controlling the exit angle of the electromagnetic wave fed into the first electrode layer 11 after passing through the slit opening 12, thereby achieving beamforming. Simultaneously, since the orthographic projection of the slit opening 12 in the first electrode layer 11 of this embodiment includes at least an arc segment, coupling between adjacent resonant units 10 can be effectively avoided, thereby making the direction of the target wave more precise.
[0033] In some examples, Figure 4 A schematic diagram of a resonant element 10 in a holographic antenna according to an embodiment of this disclosure, including a first part and a second part; as shown... Figure 4 As shown, the slit opening 12 includes a first part 111 and a second part 112 that are interconnected, and the first part 111 and the second part 112 are a single integrated structure. The first part and the second part are centrally symmetrical, and the midpoint of their connection point is the center of symmetry. Furthermore, for a resonant unit 10, the center of the orthographic projection of the patch electrode 21 onto the first dielectric substrate 1 serves as the center of symmetry for the orthographic projections of the first part and the second part of the slit opening 12 onto the first dielectric substrate 1. In this way, coupling between adjacent resonant units 10 can be effectively avoided.
[0034] In some examples, continue to refer to Figure 4The outline of the orthographic projection of the slit opening 12 on the first dielectric substrate 1 includes a first side S1 and a second side S2 arranged opposite to each other, and both the first side S1 and the second side S2 intersect the orthographic projection of the patch electrode 21 on the first dielectric substrate 1. Both the first side S1 and the second side S2 are S-shaped, for example, both are sine curves or cosine curves. Of course, the first side S1 and the second side S2 are not limited to S-shapes; they can also be semicircular, pointed, etc. Since both the first side S1 and the second side S2 are non-linear, it can be understood that the shape of the slit opening 12 is irregular, not a regular shape such as a rectangle. By designing an irregularly shaped opening on the first electrode layer 11, coupling between adjacent resonant units 10 can also be effectively avoided.
[0035] Furthermore, refer to Figure 4 When the first side S1 and the second side S2 of the orthographic projection of the slit opening 12 on the first dielectric substrate 1 are both S-shaped, the slit opening 12 also includes a third side S3 and a fourth side S4 connected to and opposite to the first side S1 and the second side S2. The first side S1 and the second side S2 are parallel, and the third side S3 and the fourth side S4 are parallel. In this case, the center of the slit opening 12 on the first dielectric substrate 1 is the midpoint of the line connecting the midpoint of the first side S1 and the midpoint of the second side S2. For any resonant unit 10, the center of the orthographic projection of the slit electrode on the first dielectric substrate 1 coincides with the center of the orthographic projection of the patch electrode 21 on the first dielectric substrate 1.
[0036] Furthermore, refer to Figure 4 When the first side S1 and the second side S2 of the orthographic projection of the slit opening 12 onto the first dielectric substrate 1 are both S-shaped, the slit opening 12 is divided into a first part 111 and a second part 112 by a straight line passing through its center and parallel to the third side S3 and the fourth side S4. The first part 111 and the second part 112 are centrally symmetrical about the center O of the slit opening 12. This arrangement reduces the length of the slit opening 12, effectively shrinking the antenna size. With a limited antenna size, the number of resonant elements 10 can be increased, improving the antenna's sampling accuracy and pointing accuracy, among other performance indicators.
[0037] In some examples, multiple resonant units 10 in the resonant structure 100 are arranged in nested groups, with the resonant units 10 in each group arranged sequentially. The center lines connecting the patch electrodes 21 in each group of resonant units 10 form a first pattern, where the centers of all the formed first patterns are the same. For example, the formed first pattern is a circle, and the various first patterns form concentric circles. Of course, the formed first pattern can also be a rectangle, a regular hexagon, etc. In this embodiment, only a circle is used as an example of the formed first pattern.
[0038] Furthermore, the center of the first pattern serves as the feed point for the holographic antenna. The spacing between the centers of the patch electrodes 21 of adjacent resonant units 10 forming the first pattern is equal and is 1 / 5 to 1 / 10 of the spatial wave wavelength (subwavelength). In the first group of resonant units 10 (hereinafter referred to as the first group of resonant units 10) pointing from the feed point to the edge of the first dielectric substrate 1, the distance between the centers of adjacent patch electrodes 21 is equal to the distance between adjacent first patterns, i.e., 1 / 5 to 1 / 10 of the spatial wave wavelength. Simultaneously, in the second to last group of resonant units 10 pointing from the feed point to the edge of the first dielectric substrate 1, the closer a group of resonant units 10 is to the feed point, the greater the distance between the centers of adjacent patch electrodes 21. In this embodiment, ensuring that the resonant unit 10 is perpendicular to the radial vector effectively increases the antenna's radiation efficiency, thereby improving the antenna's main lobe gain and radiation efficiency.
[0039] In some examples, the holographic antenna in this disclosure includes not only the structure described above, but also a waveguide-fed structure configured with a resonant structure 100 to transmit electromagnetic waves.
[0040] In one example Figure 5 This is a schematic diagram of a holographic antenna according to an embodiment of this disclosure; as shown Figure 5 As shown, the waveguide feeding structure includes a reflector component 201, and a first reference electrode layer 202, a first support layer 203, a second reference electrode layer 204, and a second support layer 205 sequentially disposed close to the resonant structure 100. The reflector component 201 has a receiving space, within which at least the first support layer 203, the second reference electrode layer 204, and the second support layer 205 are disposed. Electromagnetic waves transmitted via the first support layer 203, when irradiated onto the sidewall of the reflector component 201, are reflected to the second support layer 205 and transmitted to the resonant structure 100. The first reference electrode layer 202 and the second reference electrode layer 204 include, but are not limited to, ground electrode layers. In this embodiment, the first reference electrode layer 202 and the second reference electrode layer 204 are taken as ground electrodes.
[0041] Specifically, such as Figure 5The electromagnetic wave propagation direction is shown. The center of the first reference electrode layer 202 can be the feed point. The electromagnetic wave signal enters the first support layer 203 from the center of the first reference electrode layer 202 and then irradiates the reflector 201. It is then reflected by the reflector 201 to the second support layer 205, and from the second support layer 205 into the resonant structure 100. To avoid introducing higher-order modes, the thickness of the first support layer 203 is required to be less than half the wavelength of the operating frequency. The reflector layer introduces the electromagnetic wave signal from below the second reference electrode layer 204 to above it. The second support layer 205 slows down the waveguide by approximately 30% compared to free space. To eliminate higher-order modes, the thickness of the second support layer 205 is required to be less than half the wavelength of the operating frequency. The first support layer 203 and the second support layer 205 serve as support structures, and their materials include, but are not limited to, foam, plastic, and resin. Preferably, the dielectric constant of the first support layer 203 and the second support layer 205 is the same as or similar to that of air to reduce microwave transmission loss.
[0042] Continue to refer to Figure 5 The sidewall of the reflective component 201 is arc-shaped. In this case, when the electromagnetic wave transmitted in the first support layer 203 irradiates the reflective component 201, the transmission direction of the electromagnetic wave changes twice. First, it changes from a horizontal direction to a vertical direction when it irradiates the sidewall of the reflective component 201. Then, it changes to a horizontal direction when it irradiates the sidewall of the reflective component 201 again. After that, it enters the second support layer 205.
[0043] It should be noted that, in this embodiment, the sidewall of the reflective component 201 is arc-shaped only. In some examples, the sidewall of the reflective component 201 forms a dihedral angle, and this dihedral angle can also illuminate the electromagnetic wave and change the direction of electromagnetic wave transmission, so as to transmit the electromagnetic wave to the second support layer 205.
[0044] In some examples, the reflective component 201 and the first reference electrode layer 202 are integrally formed. In this case, the reflective component 201 and the first reference electrode layer 202 can be formed in a single process. This structure is simple and easy to fabricate. Of course, the reflective component 201 and the first reference electrode layer 202 can also be separate structures, and the reflective component 201 and the first reference electrode layer 202 are assembled together during antenna fabrication.
[0045] In some examples, an absorbing load 206 is also provided in the second support layer 205. The center of the absorbing load 206 is positioned opposite the feed point to absorb residual guided waves and prevent electromagnetic waves from reflecting back into the waveguide feed structure and interfering with the normal radiation of the antenna. Furthermore, the distance between the orthographic projection of the absorbing load 206 onto the first dielectric substrate 1 and the orthographic projection of the patch electrode 21 in the first resonant unit 10 onto the first dielectric substrate 1 is at least half the wavelength of the operating frequency.
[0046] In some examples, the waveguide feeding structure in this disclosure includes not only the structure described above, but also a coaxial connector 207. This coaxial connector 207 can penetrate through the center of the first reference electrode layer 202 and be inserted into the first support layer 203 to feed electromagnetic waves into the first support layer 203. The connection point of the coaxial connector 207 is also the feed point of the antenna. The coaxial connector 207 can be a probe.
[0047] In some examples, the holographic antenna in this embodiment is cylindrical, meaning that the first reference electrode, the first support layer 203, the first reference electrode layer 202, the second support layer 205, the first dielectric substrate 1, and the second dielectric substrate 2 are all cylindrical. The first reference electrode, the first support layer 203, the first reference electrode layer 202, the second support layer 205, the first dielectric substrate 1, and the second dielectric substrate 2 can all be arranged in parallel, thereby reducing the size of the antenna.
[0048] To better understand the effect of the holographic antenna in the embodiments of this disclosure, Figure 5 The holographic antenna shown is simulated. Figure 5 The resonant structure 100 in the holographic antenna shown can be Figure 1 The resonant structure 100 shown can specifically have the following resonant unit 10: Figure 4 The resonant unit 10 shown. Figure 6 The radiation pattern of the holographic antenna in this embodiment of the present disclosure is shown at theta = 0° and ±45°. Figure 6 As shown, beam scanning can be achieved by controlling the voltage applied to the patch electrodes 21 of each resonant unit 10 on the resonant structure 100.
[0049] In some examples, the patch electrode 21 in the second electrode layer 20 can be rectangular; in the accompanying drawings of the embodiments of this disclosure, only a rectangular patch electrode 21 is used as an example. In actual products, the patch electrode 21 can also be other shapes such as circular, annular, or triangular.
[0050] In some examples, the materials of the first dielectric substrate 1 and the second dielectric substrate 2 can be rigid materials with low microwave loss, such as quartz and glass.
[0051] In some examples, the tunable dielectric layer can be the liquid crystal layer described above, or other dielectric materials with tunable dielectric constants, such as graphene. The thickness of the liquid crystal layer affects the beam scanning time. Considering that the beam switching time needs to be on the order of milliseconds, the thickness of the liquid crystal layer should not be too large. In the embodiments of this disclosure, the thickness of the liquid crystal layer is approximately 35 μm. Different types of liquid crystals have different tunable dielectric constants, and a suitable liquid crystal needs to be selected according to the required antenna beam scanning angle.
[0052] In some examples, the materials for the first electrode layer 11 and the second electrode layer 20 can be low-resistance, low-loss metals such as copper, gold, and silver, and can be prepared by magnetron sputtering, thermal evaporation, electroplating, etc.
[0053] Secondly, embodiments of this disclosure provide an electronic device including the aforementioned holographic antenna. The antenna further includes a transceiver unit, a radio frequency transceiver, a signal amplifier, a power amplifier, and a filtering unit. The antenna can function as either a transmitting antenna or a receiving antenna. The transceiver unit may include a baseband and a receiving end. The baseband provides signals in at least one frequency band, such as 2G, 3G, 4G, and 5G signals, and transmits these signals to the radio frequency transceiver. After receiving the signal, the transparent antenna in the communication system processes it through the filtering unit, power amplifier, signal amplifier, and radio frequency transceiver (not shown) before transmitting it to the receiving end in the transceiver unit. The receiving end may be, for example, a smart gateway.
[0054] Furthermore, the RF transceiver is connected to the transceiver unit and is used to modulate the signals transmitted by the transceiver unit, or to demodulate the signals received by the transparent antenna before transmitting them to the transceiver unit. Specifically, the RF transceiver may include a transmitting circuit, a receiving circuit, a modulation circuit, and a demodulation circuit. After the transmitting circuit receives various types of signals provided by the baseband, the modulation circuit can modulate the various types of signals provided by the baseband before transmitting them to the antenna. The transparent antenna receives the signals and transmits them to the receiving circuit of the RF transceiver. The receiving circuit then transmits the signals to the demodulation circuit, which demodulates the signals before transmitting them to the receiving end.
[0055] Furthermore, the RF transceiver is connected to a signal amplifier and a power amplifier, which are then connected to a filtering unit. The filtering unit is connected to at least one antenna. During signal transmission in the communication system, the signal amplifier improves the signal-to-noise ratio (SNR) of the RF transceiver's output signal before transmitting it to the filtering unit; the power amplifier amplifies the power of the RF transceiver's output signal before transmitting it to the filtering unit. The filtering unit may specifically include a duplexer and a filtering circuit. The filtering unit combines the signals output from the signal amplifier and power amplifier, filters out clutter, and transmits them to the transparent antenna, which radiates the signal. During signal reception in the communication system, the antenna receives the signal and transmits it to the filtering unit. The filtering unit filters out clutter from the received signal and transmits it to the signal amplifier and power amplifier. The signal amplifier increases the gain of the received signal, improving the SNR; the power amplifier amplifies the power of the received signal. The signal received by the antenna, after processing by the power amplifier and signal amplifier, is transmitted to the RF transceiver, which then transmits it to the transceiver unit.
[0056] In some examples, the signal amplifier may include various types of signal amplifiers, such as low-noise amplifiers, without limitation.
[0057] In some examples, the antenna provided in this disclosure also includes a power management unit connected to a power amplifier to provide voltage to the power amplifier for amplifying signals.
[0058] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.
Claims
1. A holographic antenna comprising a resonant structure; wherein, The resonant structure includes a first dielectric substrate and a second dielectric substrate disposed opposite to each other, a first electrode layer disposed on the side of the first dielectric substrate near the second dielectric substrate, a second electrode layer disposed on the side of the second dielectric substrate near the first dielectric substrate, and an adjustable dielectric layer disposed between the first electrode layer and the second electrode layer. The first electrode layer has a plurality of slit openings, and the second electrode layer includes a plurality of patch electrodes, wherein the orthographic projection of one of the patch electrodes and one of the slit openings on the first dielectric substrate at least partially overlaps. Furthermore, the orthographic projection of the slit opening onto the first dielectric substrate includes at least an arc segment; The outline of the orthographic projection of the slit opening on the first dielectric substrate includes a first side and a second side disposed opposite to each other, and both the first side and the second side intersect the orthographic projection of the patch electrode on the first dielectric substrate; the first side and the second side are S-shaped.
2. The holographic antenna according to claim 1, wherein, The slit opening includes a first part and a second part that are connected to each other. The first part and the second part are centrally symmetrical, and the midpoint of their connection point is the center of symmetry.
3. The holographic antenna according to claim 1, wherein, For the orthographic projection, the slit opening and the patch electrode overlap, and their centers coincide on the orthographic projection of the first dielectric substrate.
4. The holographic antenna according to claim 1, wherein, The resonant structure includes multiple resonant units, each of which includes an overlapping slit opening projected onto the first dielectric substrate and a patch electrode; the multiple resonant units are arranged to form multiple nested groups, the resonant units in each group are arranged sequentially, and the center line connecting the patch electrodes in each group of resonant units forms a first pattern, and the centers of the formed first patterns are the same.
5. The holographic antenna according to claim 4, wherein, The distance between adjacent first graphics is equal.
6. The holographic antenna according to claim 4, wherein, The center of the first pattern serves as the feed point of the holographic antenna. In the first group of resonant units, the distance between the centers of adjacent patch electrodes in the direction from the feed point to the edge of the first dielectric substrate is equal to the distance between adjacent first patterns.
7. The holographic antenna according to claim 4, wherein, In the second to last group of resonant units in the direction from the feed point to the edge of the first dielectric substrate, the distance between the centers of adjacent patch electrodes in the group of resonant units that are closer to the feed point is greater.
8. The holographic antenna according to any one of claims 1-7, wherein, It also includes a waveguide-fed structure configured to transmit electromagnetic waves to the resonant structure.
9. The holographic antenna according to claim 8, wherein, The waveguide feeding structure includes a reflective component, and a first reference electrode layer, a first support layer, a second reference electrode layer, and a second support layer arranged sequentially close to the resonant structure; the reflective component has a receiving space, and at least the first support layer, the second reference electrode layer, and the second support layer are disposed within the receiving space, and electromagnetic waves transmitted via the first support layer can be reflected to the second support layer when they irradiate the sidewall of the reflective component, so as to be transmitted to the resonant structure.
10. The holographic antenna according to claim 9, wherein, The sidewalls of the reflective component are arc-shaped.
11. The holographic antenna according to claim 9, wherein, The reflective component and the first reference electrode layer are an integral structure.
12. The holographic antenna according to claim 9, wherein, The waveguide feeding structure also includes an absorption load disposed in the second support layer.
13. The holographic antenna according to claim 9, wherein, The waveguide feeding structure includes a coaxial connector configured to feed electromagnetic waves into the first support layer.
14. An electronic device comprising the holographic antenna according to any one of claims 1-13.