Dual-mode multi-beam slot array antenna

Abstract

The present invention relates to a dual-mode multi-beam slot array antenna comprising a plurality of first slot array radiators having a plurality of slots arranged therein, a first feeder having a plurality of first feed slots arranged therein coupled in a direction orthogonal to the plurality of first slot array radiators, a plurality of second slot array radiators having a plurality of slots arranged therein disposed opposite to the plurality of first slot array radiators, and a second feeder having a plurality of second feed slots arranged therein coupled in a direction orthogonal to the lower part of the plurality of second slot array radiators, wherein each of the first slot array radiators and the second slot array radiators are arranged alternately, and the spacing between the plurality of first feed slots and the spacing between the plurality of second feed slots may be formed to be 1λ to 2λ.

Description

Technology Field

[0001] The present invention relates to a dual-mode multi-beam slot array antenna, specifically to a dual-mode multi-beam slot array antenna that provides a wide beam width on its own in the terahertz band without an additional beam steering circuit. Background Technology

[0002] The terahertz (THz) frequency band offers innovative possibilities for next-generation wireless communication and sensing technologies. Based on short wavelengths, this band enables high data transmission speeds and high-resolution imaging, and holds significant technical value, particularly in various applications such as short-range high-speed communication and high-resolution sensing. However, to ensure stable and efficient signal reception in complex environments where signals are transmitted via multiple paths, such as in-vehicle communication or indoor environments, it is essential to design antennas that provide wide beam coverage.

[0003] Phased array antennas, widely used in existing technology, can control beams with high accuracy; however, implementing them in the terahertz band requires complex phase adjustment circuits and high manufacturing costs, and miniaturization is difficult due to their structural complexity. On the other hand, leakage-based antennas can provide wide beam coverage without additional circuitry by leveraging the inherent characteristics of their structure, but they are limited by a narrowing of the beam width within the same frequency band. These issues demonstrate that existing technologies are insufficient for implementing stable and flexible communication and sensing in the terahertz band.

[0004] Therefore, a new design approach is needed that can provide stable signal reception and wide beam coverage while overcoming the complexity and limitations of existing technologies in the terahertz band. The problem to be solved

[0005] The present invention aims to propose a waveguide slot array antenna that provides a wide beam width on its own in the terahertz band without an additional beam steering circuit.

[0006] In addition, the present invention aims to artificially increase the side lobe level by increasing the array spacing of the slot antenna to 0.5λg or more, and to expand beam coverage by utilizing the side lobe for communication in addition to the main beam through additional slot arrays to compensate for the null section between the grating lobe and the main lobe.

[0007] However, the technical problem that this embodiment aims to solve is not limited to the technical problem described above, and other technical problems may exist. means of solving the problem

[0008] According to one embodiment, the dual-mode multi-beam slot array antenna of the present invention may include: a plurality of first slot array radiators having a plurality of slots arranged therein; a first feeder having a plurality of first feed slots arranged therein and coupled in a direction orthogonal to the plurality of first slot array radiators; a plurality of second slot array radiators having a plurality of slots arranged therein and disposed in a direction opposite to the first slot array radiators; and a second feeder having a plurality of second feed slots arranged therein and coupled in a direction orthogonal to the lower part of the plurality of second slot array radiators.

[0009] Here, the first slot array radiating section and the second slot array radiating section are each arranged alternately, and the spacing between the plurality of first feed slots and the spacing between the plurality of second feed slots can be formed to be 1λ to 2λ.

[0010] According to one embodiment, a groove may be formed between the first slot array radiating part and the second slot array radiating part.

[0011] According to one embodiment, a partition may be formed between the first slot array radiating part and the second slot array radiating part.

[0012] According to one embodiment, a plurality of first slot array radiating members may be configured as a phase-in-phase slot array, and a plurality of second slot array radiating members may be configured as an alternating phase slot array.

[0013] According to one embodiment, the first slot array radiating part, the second slot array radiating part, the first feed part, and the second feed part may be formed as a waveguide structure. Effects of the invention

[0014] According to the present invention, a wide bandwidth within the same frequency can be provided solely by the inherent characteristics of the antenna structure without an additional beam steering circuit in the terahertz band. Brief explanation of the drawing

[0015] Figure 1(a) is a diagram showing a conventional phase array antenna. Figure 1(b) is a diagram showing a conventional leakage wave-based antenna. FIG. 2(a) is a drawing showing a conventional slotted waveguide array (SWA). FIG. 2(b) is a diagram showing the radiation pattern according to a conventional waveguide slot array antenna. Figure 3(a) is a drawing showing the case where the feed slot spacing is designed as the conventional 0.5λg. Figure 3(b) is a diagram showing the change in radiation pattern when the feed slot spacing is extended from 1λg to 2λg. FIG. 4 is a drawing showing a dual-mode multi-beam slot array antenna according to one embodiment of the present invention. FIG. 5 is a diagram showing two radiation modes of a dual-mode multi-beam slot array antenna according to one embodiment of the present invention. FIG. 6(a) is a diagram illustrating the inter-port interference problem that occurs when antennas with different input ports are placed in the same aperture and a design method to compensate for this. Figure 6(b) is a graph showing the gain according to the design of Figure 6(a). FIG. 7 is a diagram showing the actual design structure of a dual-mode multi-beam slot array antenna according to one embodiment of the present invention. Figure 8 is a graph showing the radiation pattern of a dual-mode multi-beam slot array antenna when operating at 253 GHz in the sub-terahertz frequency band. Specific details for implementing the invention

[0016] Embodiments of the present invention are described in detail below with reference to the attached drawings so that those skilled in the art can easily implement the invention. Since the present invention is susceptible to various modifications and may have various embodiments, specific embodiments are illustrated in the drawings and described in detail in the description. However, this is not intended to limit the present invention to specific embodiments, and it should be understood that it includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0017] To clearly explain the present invention, parts unrelated to the description have been omitted from the drawings, and similar parts throughout the specification have been given similar reference numerals. Furthermore, while describing with reference to the drawings, even components indicated by the same name may have different drawing numbers depending on the drawing, and drawing numbers are provided merely for the convenience of explanation; the concept, feature, function, or effect of each component is not to be interpreted restrictively by the corresponding drawing number.

[0018] Similar reference numerals are used for similar components when describing each drawing. Terms such as "first," "second," etc., may be used to describe various components, but said components should not be limited by said terms. These terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component. The term "and / or" includes a combination of a plurality of related described items or any of a plurality of related described items.

[0019] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which this invention pertains.

[0020] Terms such as those defined in commonly used dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application.

[0021] Throughout the specification, when a part is described as being "connected" to another part, this includes not only cases where they are "directly connected" but also cases where they are "electrically connected" with other elements interposed between them. Furthermore, when a part is described as "comprising" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but rather allows for the inclusion of additional components; it should be understood that this does not preclude the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0022] In this specification, the term 'part' or 'module' includes a unit realized by hardware or software, or a unit realized using both; a single unit may be realized using two or more pieces of hardware, or two or more units may be realized by a single piece of hardware.

[0023] Before describing the embodiments of the present invention, the prior art will be described.

[0024] FIG. 1(a) is a drawing showing a conventional phase array antenna, and FIG. 1(b) is a drawing showing a conventional leakage wave-based antenna.

[0025] The phased array antenna (10) illustrated in FIG. 1(a) is a representative design method widely used in existing frequency bands, which can control a beam in a specific direction by arranging multiple antenna elements and supplying an independent phase to each element. This design method provides high directional control capability across the entire frequency band and can be utilized in radar systems, communication networks, satellite communication, etc. For example, in 5G networks, signal quality can be improved by using a phased array antenna when a base station antenna focuses a high-frequency signal to a user terminal. However, the phased array antenna requires an independent phase adjustment circuit for each element, and such circuit design has limitations in that it is expensive to manufacture and has a complex structure. In particular, this method may not be suitable for the terahertz band because circuit miniaturization is difficult and efficient implementation is limited due to high-frequency characteristics.

[0026] The leaky wave-based antenna (20) illustrated in FIG. 1(b) is a design method that forms a beam by utilizing the characteristic that some energy is emitted to the outside as the radio wave travels through the inside of a waveguide. Since this method can control the directionality of the beam solely through the characteristics of the antenna structure itself, it can provide wide beam coverage without additional beamforming elements or complex circuits. Leaky wave-based antennas are applicable in high frequency bands and have the advantages of a simple structure and low manufacturing costs. For example, leaky wave-based antennas can be used to transmit signals over a wide area in indoor communication systems or to detect defects inside materials in non-destructive inspection devices. However, since leaky wave-based antennas use a beam scanning method in which the direction of the beam changes according to frequency changes, they have a limitation of having a narrow beam width within the same frequency band. This means that while the beam is effectively formed at a specific frequency, it can degrade the stability of signal reception in applications where frequency fixation is required. Therefore, there is a need for a new antenna design method that is structurally simple, provides wide beam coverage, and is achievable in the terahertz band.

[0027] FIG. 2(a) is a drawing showing a conventional slotted waveguide array (SWA) antenna, and FIG. 2(b) is a drawing showing a radiation pattern according to a conventional slotted waveguide array antenna.

[0028] Referring to FIGS. 2(a) and FIGS. 2(b), a conventional waveguide SWA structure (30) is configured to radiate radio waves by arranging a plurality of slots in a metal waveguide, and is designed to be divided into a feed section (210) and a radiating section (220). The feed section performs the function of supplying radio waves into the waveguide, and the radiating section is designed to radiate the radio waves transmitted from the feed section to the outside. The spacing between the feed slot and the radiating slot is generally maintained at 0.5λg (in-tube wavelength), which is used as a design standard for controlling the directionality and pattern of the beam in the existing SWA structure.

[0029] The present invention improves the existing SWA structure to achieve wide beam coverage through three major design changes. First, the spacing of the feed slots was expanded from the existing 0.5λg to 1λg or 2λg. This expansion of spacing is a design intended to intentionally generate grating lobes with the same amplitude as the main lobe. Grating lobes are secondary radiation lobes generated by the periodic slot arrangement, and in existing SWA designs, they are often designed to be suppressed. However, the present invention actively utilizes these grating lobes to provide wide beam coverage. For example, while grating lobes can cause interference problems in existing communication systems, the design of the present invention intentionally generates these lobes to contribute to the expansion of the antenna's beam pattern.

[0030] Second, to compensate for the null interval occurring between the main lobe and the grating lobe, a slot array having different radiation modes was added within the same aperture. These different radiation modes are designed with different phase distribution characteristics, preventing signal loss in the null interval and enabling stable signal radiation. This design can operate efficiently, particularly in multipath environments. For example, in in-vehicle communication systems, signal loss in the null interval can lead to a degradation of communication quality because signals are transmitted via multiple paths. To solve this problem, the design of the present invention is designed so that the two radiation modes operate complementarily.

[0031] Third, the gain difference between beams was adjusted by adding bulkheads or groove structures between adjacent slots.

[0032] Hereinafter, a dual-feed multi-beam slot antenna according to an embodiment of the present invention will be described in detail through FIGS. 3 to 8.

[0033] Figures 3(a) and 3(b) illustrate the effect of feed slot spacing on the radiation pattern of the SWA. Specifically, Figure 3(a) shows the case where the feed slot spacing is designed to be the conventional 0.5λg, and Figure 3(b) shows the change in the radiation pattern when the feed slot spacing is extended to 1λg to 2λg.

[0034] As illustrated in FIG. 3(a), in a conventional SWA design, the feed slot spacing is fixed at 0.5λg, in which case the radiation pattern forms only a main lobe in the 0-degree direction. The main lobe represents the maximum radiation direction of the beam, and while strong signal transmission is possible in a narrow area, it has the disadvantage of limited radiation coverage. This limitation can be inefficient, especially in communication environments where signals must be transmitted to multiple receivers. For example, in a communication system in an indoor environment, a narrow beam width can degrade signal transmission between receivers, and it can also be limiting in environments where multipath signals are required, such as inside a vehicle.

[0035] As illustrated in FIG. 3(b), the radiation pattern of the SWA structure is improved by extending the feed slot spacing to 1 to 2λg. In a design where the feed slot spacing is extended to 1 to 2λg, grating lobes with the same amplitude are intentionally generated in the SWA in addition to the existing main lobe. Grating lobes are secondary patterns that generate radiation energy in directions other than the main lobe due to the periodic characteristics of the slot arrangement. In conventional designs, grating lobes can cause interference and were designed to suppress this, but the present invention actively utilizes them to achieve wide beam coverage. For example, in communication systems requiring high-speed data transmission in the terahertz band, the main lobe and grating lobe can be combined to transmit signals over a wide range. Furthermore, in non-destructive inspection devices, this radiation pattern can be utilized to detect internal defects in objects from various angles.

[0036] As can be seen in the radiation pattern on the right in Fig. 3(b), in a design where the feed slot spacing is extended to 1 to 2λg, the main lobe and grating lobe each radiate over a wider area. The fact that the gain difference between the main lobe and the grating lobe is very small, thereby minimizing the performance difference between each beam, can serve as a significant advantage in communication and sensing systems. However, there is a limitation in that a null section is formed between the main lobe and the grating lobe. A null section refers to an area where no signal is radiated in a specific region of the radiation angle, which can degrade the continuity of communication. For example, in a mobile communication system, a null section can cause quality degradation by preventing a user terminal at a specific location from receiving a signal.

[0037] In order to solve the problem of null intervals, the present invention employs a method of supplementing null intervals through additional beam generation. This method is implemented by adding a slot array having different radiation modes within the same aperture. Each slot array supplements the null interval through an independent radiation mode, and this method can operate effectively in environments requiring multipath transmission. For example, in an in-vehicle communication system, signals are transmitted in various directions, so signal loss in null intervals needs to be minimized.

[0038] FIG. 4 is a drawing showing a dual-mode multi-beam slot array antenna according to one embodiment of the present invention.

[0039] Referring to FIG. 4, the null section problem is solved by arranging two slot arrays having different radiation modes in the same aperture. As illustrated in FIG. 4, the antenna of the present invention may include a first port (410) and a second port (420). Here, the first port (410) can perform the role of generating the existing main lobe and grating lobe, and the second port (420) is designed to compensate for signal loss occurring in the null section.

[0040] FIG. 5 is a diagram showing two radiation modes of a dual-mode multi-beam slot array antenna according to one embodiment of the present invention.

[0041] Figure 5 illustrates the principles of a co-phased slot array and an alternating-phased slot array, and shows in detail how each radiation mode is designed and operates.

[0042] Since waves propagate within a waveguide with phases that intersect every half wavelength, the phase of each slot may vary depending on the placement position of the slots. In the present invention, different radiation modes are implemented in the first port (410) and the second port (420) by utilizing these wave characteristics within the waveguide.

[0043] Specifically, referring to FIGS. 4 and 5, the first port (410) is designed to have a phase-in-slot array radiator (411, 412, 413). The phase-in-slot array radiator is a radiation method designed such that the phases of the radiating slots are arranged identically, so that signals radiated from all slots are combined in the 0-degree direction. Through this, the main lobe has high gain in the 0-degree direction.

[0044] The second port (420) is designed to have alternating phase slot array radiation sections (421, 422, 423, 424). Alternating phase slot array radiation is a method in which slots are arranged so that adjacent waveguides have opposite phases to each other, so that the radiated signals generated from adjacent slots are canceled out in the 0-degree direction, and a main beam is not formed. Instead, beams are formed that are symmetrically divided with respect to the main beam direction, which can be used to compensate for null sections that the in-phase slot array radiation of the first port (410) cannot form. For example, in a communication system, signal loss occurring in null sections can reduce the reliability of data transmission, but through alternating phase slot array radiation, stable signal radiation is possible even in such null sections. Since in-vehicle communication systems must provide signals in various directions in a multipath environment, this alternating phase slot array can be particularly usefully applied.

[0045] FIG. 6(a) is a diagram illustrating the inter-port interference problem that occurs when antennas with different input ports are placed in the same aperture and a design method to compensate for this, and FIG. 6(b) is a graph showing the gain according to the design of FIG. 6(a).

[0046] If two ports are placed on the same aperture, the signals radiated from the two ports may interfere with each other, causing a problem in which the gain of the main lobe is reduced. In order to solve this interference problem, the present invention proposes adding a groove structure (610) or a partition structure (620) to the radiating section. The groove structure (610) adjusts the electromagnetic wave path around the radiating slot to minimize signal interference between ports and enables independent radiation from each port. For example, in the simulation results of FIG. 6(b), a phenomenon in which the gain of the main lobe is reduced was observed when there is no groove structure or partition structure, but when a groove structure or partition structure is added, the reduction in the gain of the main lobe is compensated, and a uniform radiation pattern is realized over the entire coverage.

[0047] In addition, the groove structure can further improve the uniformity of the radiation pattern by adjusting the spacing between slots and the arrangement direction. The groove structure can be used to reduce distortion in the signal radiation direction and optimize radiation efficiency by controlling the phase and amplitude of the signal emitted from the radiation slots.

[0048] FIG. 7 is a diagram showing the actual design structure of a dual-mode multi-beam slot array antenna according to one embodiment of the present invention, and FIG. 8 is a graph showing the radiation pattern when the dual-mode multi-beam slot array antenna operates at 253 GHz, which is a sub-terahertz frequency band.

[0049] FIG. 8 independently shows the radiation patterns of the first port (Port 1) and the second port (Port 2), respectively, and is designed to allow verification of the total beam coverage when the two ports are combined. The red line represents the radiation pattern of the first port (Port 1), forming a strong main lobe in the 0-degree direction. The in-phase slot array radiation of the first port (Port 1) radiates signals having the same phase in all slots, providing high radiation gain concentrated in a specific direction.

[0050] The blue line represents the radiation pattern of Port 2, which suppresses radiation in the 0-degree direction and symmetrically disperses the beam through alternating phase slot array radiation. This array method is configured so that the signals cancel out in the 0-degree direction by designing the phases between adjacent slots to be reversed. The radiation pattern of Port 2 effectively compensates for the null intervals occurring in the radiation pattern of Port 1, making it suitable for supporting multiple users and providing a wide sensing area in communication systems. For example, in indoor communication systems, stable signals must be provided to user terminals located at various positions, and the radiation of Port 2 is highly suitable for achieving this.

[0051] As can be seen in the graph, combining the radiation patterns of the first port (Port 1) and the second port (Port 2) can form a wide beam coverage of over approximately 100 degrees, providing stable signal radiation across the entire area without any null intervals. In particular, the radiation from the first port (Port 1) and the second port (Port 2) acts complementarily to prevent the phenomenon where signal strength weakens in specific directions. This design ensures signal stability in high-frequency environments and provides uniform radiation gain even in sub-terahertz bands such as 253 GHz.

[0052] Although the embodiments have been described above with reference to limited examples and drawings, those skilled in the art can make various modifications and variations from the description above. For example, suitable results can be achieved even if the described techniques are performed in a different order than described, and / or the components of the described system, structure, device, circuit, etc. are combined or assembled in a form different from described, or replaced or substituted by other components or equivalents.

[0053] Therefore, other implementations, other embodiments, and equivalents to the claims also fall within the scope of the claims set forth below. Explanation of the symbols

[0054] 10: Phased array antenna 20: Leakage-based antenna 30: Waveguide slot array antenna 210: Emergency Department 220: Radiation section 410: Port 1 411, 412, 413: In-phase slot array radiators 420: Port 2 421, 422, 423, 424: Alternating phase slot array radiator

Claims

Claim 1 A dual-mode multi-beam slot array antenna comprising: a plurality of first slot array radiators having a plurality of slots arranged therein; a first feeder having a plurality of first feed slots arranged therein, coupled to the lower portion of the plurality of first slot array radiators in a direction orthogonal to the plurality of first slot array radiators; a plurality of second slot array radiators having a plurality of slots arranged therein, alternately disposed on the same opening surface as the plurality of first slot array radiators; and a second feeder having a plurality of second feed slots arranged therein, coupled to the lower portion of the plurality of second slot array radiators in a direction orthogonal to the plurality of second slot array radiators; wherein the spacing between the plurality of first feed slots is 1λg to 2λg and the spacing between the plurality of second feed slots is 1λg to 2λg, and the plurality of first slot array radiators are configured as in-phase slot arrays and the plurality of second slot array radiators are configured as alternating phase slot arrays. Claim 2 A dual-mode multi-beam slot array antenna according to claim 1, characterized in that a groove is formed between the first slot array radiating part and the second slot array radiating part. Claim 3 A dual-mode multi-beam slot array antenna according to claim 1, characterized in that a partition is formed between the first slot array radiating part and the second slot array radiating part. Claim 4 delete Claim 5 A dual-mode multi-beam slot array antenna according to claim 1, characterized in that the first slot array radiating part, the second slot array radiating part, the first feed part, and the second feed part are formed as waveguide structures.

Images