Antenna

Abstract

An antenna, according to an embodiment of the present invention, comprises: a first layer in which a plurality of radiation slots are formed; a second layer having formed on the upper portion thereof a branch structure connecting the plurality of radiation slots with a waveguide and having formed on the lower portion thereof an upper region of the waveguide; and a third layer having formed on the upper portion thereof a lower region of the waveguide corresponding to the upper region of the waveguide formed in the second layer and having formed on the lower portion thereof a signal input / output unit connected to the waveguide.

Description

antenna

[0001] The present invention relates to an antenna, and more particularly to a waveguide-fed radar antenna for a vehicle.

[0002] 4D imaging radar combines height data with the distance, angle, and velocity data required for 3D radar to create a high-resolution point cloud (a collection of 3D points), and recognizes objects by deep learning the spatial image based on this point cloud.

[0003] In a vehicle, 4D imaging radar can identify the upper and lower positions of a detected target, so it can distinguish whether the detected target is on the road surface, such as a manhole, or high above the road, such as a tunnel entrance or a sign. Therefore, it can recognize moving objects and objects in the driving environment, and can be used for autonomous driving. In addition, in-cabin 4D imaging radar installed inside a vehicle is installed on the upper part of the vehicle to identify the number of passengers, or detect the driver's posture, drowsiness, pulse, and breathing, etc., or detect moving objects in the rear seat (such as children or pets) and use the Rear Occupancy Alert (ROA) function to notify the driver of this.

[0004] These 4D imaging radars require multi-channel (e.g., 192-channel) antenna technology for high resolution, which can be achieved by using, for example, a single-chip RFIC (Radio Frequency Integrated Circuit) providing 12 transmit antennas and 16 receive antennas, or a cascaded four-chip RFIC providing 3 transmit antennas and 4 receive antennas.

[0005] When implementing an antenna for a vehicle radar as a waveguide-fed antenna, the radiated signal is transmitted to the top layer through an internal waveguide and radiated to a radiator. However, when implementing the waveguide and radiator structure in multiple layers, performance degradation due to tolerance may occur in each layer, and therefore, a design is required to improve performance degradation due to tolerance and reduce cost.

[0006] The technical problem to be solved by the present invention is to provide an antenna capable of improving performance deterioration due to tolerance.

[0007] In order to solve the above technical problem, an antenna according to an embodiment of the present invention includes a first layer having a plurality of radiating slots formed thereon; a second layer having a branch structure formed at an upper portion connecting the plurality of radiating slots and a waveguide, and an upper region of the waveguide formed at a lower portion; and a third layer having a lower region of the waveguide formed at an upper portion corresponding to the upper region of the waveguide formed at the second layer, and a signal input / output unit connected to the waveguide formed at a lower portion.

[0008] Additionally, the plurality of radiating slots may include four radiating slots, and the branch structure may include a 1-4 branch structure.

[0009] In addition, the branch structure may include a first horn structure formed at a position corresponding to the center of the four radiating slots and connected to the waveguide; and a second horn structure having a lower portion connected to the first horn structure and an upper portion connected to the four slots.

[0010] Additionally, the four radiating slots are formed spaced apart from each other, and the central axis of the first horn structure can overlap the wall between two of the four radiating slots.

[0011] Additionally, the wall between the two radiating slots overlapping the central axis of the first horn structure may be formed to extend to a portion of the second horn structure region.

[0012] Additionally, the sum of the height of the first horn structure and the height of the second horn structure may be 0.63 to 0.73 times the signal wavelength.

[0013] Additionally, the height of the second horn structure may be 0.4 to 0.5 times the signal wavelength.

[0014] Additionally, the four radiating slots can be formed in a row.

[0015] Additionally, the width of the two slots located in the center of the four radiating slots may be longer than the width of the two slots located on the outside.

[0016] Additionally, the width of the two slots located in the center may be 0.69 times the signal wavelength, and the width of the two slots located on the outside may be 0.64 times the signal wavelength.

[0017] Additionally, the first layer may be thicker than the second layer, and the second layer may be thicker than the third layer.

[0018] Additionally, the thickness of the first layer may be 1.14 times the signal wavelength, the thickness of the second layer may be 0.98 times the signal wavelength, and the thickness of the third layer may be 0.76 times the signal wavelength.

[0019] In addition, the waveguide includes a first waveguide connected to at least some of the plurality of radiating slots; and a second waveguide connected to at least some of the plurality of radiating slots connected to the first waveguide and another part thereof, wherein the first waveguide and the second waveguide may be formed in different layers when intersecting in the first direction.

[0020] Additionally, at least one of the first waveguide or the second waveguide may include a transition path that bypasses a layer and another layer in which another waveguide is formed in an area where they intersect each other.

[0021] In order to solve the above technical problem, a vehicle radar module according to one embodiment of the present invention includes an RF module for transmitting and receiving RF signals; and an antenna module connected to an input / output unit of the RF module for radiating RF signals, wherein the antenna module includes one of the antennas.

[0022] In order to solve the above technical problem, an antenna according to a second embodiment of the present invention includes a plurality of second waveguides arranged at a different height from a first waveguide to avoid overlapping with the first waveguide, and a plurality of transition sections for transitioning from the height of the second waveguides to the height of the first waveguide to connect the second waveguides to the antenna radiator.

[0023] Each of the above transition sections includes a third waveguide formed at the same height as one end of the second waveguide and the first waveguide, a fourth waveguide for vertically connecting one end of the second waveguide and the third waveguide, and a T junction for distributing an RF transmission signal of the third waveguide or synthesizing an RF reception signal received from an antenna radiator, and the lengths of all third waveguides corresponding to the plurality of transition sections are equal to a predetermined length.

[0024] In addition, the tee junction of the above transition section may have a slope formed on the upper part of the vertical input terminal and a wedge-shaped depression formed in the center of the horizontal branch terminal.

[0025] In addition, the third waveguide of the above transition section may have both ends on the lower side drawn in at a predetermined length and an inclined portion having an angle of 16 to 35° may be formed on the drawing surface.

[0026] In addition, one end of the second waveguide of the above transition section may be formed with two steps, with the lower step surface being introduced toward the cross path, and an inclined surface having an angle of 16 to 35° may be formed on the higher step surface.

[0027] In addition, the fourth waveguide of the above transition section is formed with an internal area of ​​a predetermined size to form a frequency bandwidth according to the physical size of the waveguide.

[0028] In order to solve the above technical problem, the antenna manufacturing method according to the second embodiment of the present invention includes a first step of forming the lengths of all third waveguides corresponding to a plurality of transition sections to a predetermined length, a second step of forming the branch point height and width of the T-junction of the transition section and forming the branch point angle to 5 to 35°, a third step of moving both ends of the lower surface of the third waveguide of the transition section in a plane and forming the inclination angle to 5 to 35°, a fourth step of forming one end of the second waveguide of the transition section to be stepped in two stages, moving the lower step surface in a plane toward the cross path, moving the higher step surface in a plane, and forming the inclination angle to 5 to 35°, and a fifth step of forming the internal area of ​​the fourth waveguide of the transition section to a predetermined area.

[0029] In addition, the second step can be formed by lowering the branch point height by 0.39 λ (λ is the wavelength of the operating frequency) and moving the branch point width by 0.257 λ on both sides to make an angle of 30°.

[0030] In addition, the third step can be formed by shifting the width of the lower surface of the third waveguide by 0.257 λ (λ is the wavelength of the operating frequency) on both sides so that the inclination angle becomes 30°.

[0031] In addition, the fourth step can be formed by moving the low step surface at the joint portion of the second waveguide connected to the fourth waveguide toward the cross path by 0.128 λ (λ is the wavelength of the operating frequency) and moving the high step surface on both sides by 0.257 λ to form an angle of 30°.

[0032] Additionally, the fifth step can form the inner width of the fourth waveguide to be 0.603 λ.

[0033] According to embodiments of the present invention, two layers formed with a dual-branching structure can be integrated into a single layer to achieve uniform electric field distribution. This reduces the number of layers comprising the entire antenna, thereby reducing manufacturing costs and minimizing performance degradation due to tolerances in each layer. Furthermore, the waveguide transmission optimal structure technology can be applied to a multi-array antenna.

[0034] Additionally, it can solve the waveguide overlap problem through cross-path without adding layers in size-constrained 4D image radar for vehicles, thereby reducing dependence on RFIC chips in antenna design and reducing manufacturing costs.

[0035] Figure 1 is an antenna according to one embodiment of the present invention.

[0036] FIG. 2 is a drawing for explaining an antenna according to an embodiment of the present invention.

[0037] Figure 3 is an antenna according to a comparative example of the present invention.

[0038] FIG. 4 and FIG. 5 are drawings for explaining an antenna according to an embodiment of the present invention.

[0039] Figures 6 to 10 illustrate performance measurement results of an antenna according to an embodiment of the present invention.

[0040] Figure 11 is a block diagram of a radar module according to one embodiment of the present invention.

[0041] Figure 12 is an antenna layout diagram according to a second embodiment of the present invention.

[0042] FIG. 13 and FIG. 14 are schematic drawings illustrating an antenna according to a second embodiment of the present invention.

[0043] FIG. 15 is a schematic diagram showing a side cross-section of an antenna according to a second embodiment of the present invention.

[0044] FIG. 16 and FIG. 17 are schematic diagrams showing the general path and cross path of the waveguide in the antenna according to the second embodiment of the present invention.

[0045] FIG. 18 is a plan view illustrating a general path waveguide layer in an antenna according to a second embodiment of the present invention.

[0046] FIG. 19 is a plan view illustrating a cross-path waveguide layer in an antenna according to a second embodiment of the present invention.

[0047] Figure 20 is a flowchart illustrating an antenna manufacturing method according to a second embodiment of the present invention.

[0048] FIG. 21 is a drawing for explaining a first optimization process of an antenna according to a second embodiment of the present invention.

[0049] FIG. 22 is a diagram showing the electric field distribution of a waveguide after the first optimization of an antenna according to the second embodiment of the present invention.

[0050] FIG. 23 is a graph showing the return loss measured at each port after the first optimization of the antenna according to the second embodiment of the present invention.

[0051] FIG. 24 and FIG. 25 are drawings for explaining a second optimization process of an antenna according to a second embodiment of the present invention.

[0052] FIG. 26 is a diagram showing the electric field distribution of a waveguide after the second optimization of an antenna according to the second embodiment of the present invention.

[0053] FIG. 27 is a graph showing the return loss measured at each port after the second optimization of the antenna according to the second embodiment of the present invention.

[0054]

[0055] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0056] However, the technical idea of ​​the present invention is not limited to some of the embodiments described, but can be implemented in various different forms, and within the scope of the technical idea of ​​the present invention, one or more of the components between the embodiments can be selectively combined or substituted for use.

[0057] In addition, terms (including technical and scientific terms) used in the embodiments of the present invention may be interpreted as having a meaning that can be generally understood by a person of ordinary skill in the technical field to which the present invention belongs, unless explicitly and specifically defined and described, and terms that are commonly used, such as terms defined in a dictionary, may be interpreted in consideration of the contextual meaning of the relevant technology.

[0058] Additionally, the terms used in the embodiments of the present invention are intended to describe the embodiments and are not intended to limit the present invention.

[0059] In this specification, the singular may also include the plural unless specifically stated otherwise in the phrase, and when it is described as “A and / or at least one (or more) of B, C”, it may include one or more of all combinations that can be combined with A, B, C.

[0060] Additionally, in describing components of embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only intended to distinguish the components from other components, and are not intended to limit the nature, order, or sequence of the components.

[0061] And, when a component is described as being 'connected', 'coupled', or 'connected' to another component, it may include not only cases where the component is 'connected', 'coupled', or 'connected' directly to the other component, but also cases where the component is 'connected', 'coupled', or 'connected' by another component between the component and the other component.

[0062] Additionally, when described as being formed or arranged "above" or "below" each component, "above" or "below" includes not only cases where the two components are in direct contact with each other, but also cases where one or more other components are formed or arranged between the two components. Furthermore, when expressed as "above" or "below," the meaning may include not only the upward direction but also the downward direction based on one component.

[0063] A variation according to the present embodiment may include some components of each embodiment and some components of other embodiments. That is, a variation may include one embodiment among various embodiments, but may omit some components and include some components of the corresponding other embodiment. Or, the opposite may be true. The features, structures, effects, etc. to be described in the embodiments are included in at least one embodiment, and are not necessarily limited to just one embodiment. Furthermore, the features, structures, effects, etc. exemplified in each embodiment can be combined or modified in other embodiments by a person having ordinary skill in the art to which the embodiments belong. Therefore, the contents related to such combinations and modifications should be interpreted as being included within the scope of the embodiments.

[0064] Figure 1 is an antenna according to one embodiment of the present invention.

[0065] FIGS. 2, 4 and 5 are drawings for explaining an antenna according to an embodiment of the present invention, FIG. 3 is an antenna according to a comparative example of the present invention, and FIGS. 6 to 10 illustrate performance measurement results of an antenna according to an embodiment of the present invention.

[0066] An antenna (100) according to an embodiment of the present invention is composed of a radiating slot (140), a branch structure (150), a waveguide (160), and a signal input / output unit (170), and is composed of a plurality of layers.

[0067] An antenna according to an embodiment of the present invention may be a waveguide-fed radar antenna for a vehicle, and may also be various antennas using a waveguide. First, an antenna according to an embodiment of the present invention is a vehicle radar antenna, and the vehicle radar antenna is composed of 12 transmitting antennas and 16 receiving antennas, and each transmitting / receiving antenna is a horn antenna composed of 4 array horn radiators, and a structure in which an RFIC chip and each horn radiator are connected through a waveguide will be described as an example. This structure is only one example, and may be modified into various forms depending on the type and performance of the RFIC chip, module size, target performance, application field, etc.

[0068] An antenna according to one embodiment of the present invention may be one of a transmitting (Tx) antenna and 16 receiving (Rx) antennas of a vehicle waveguide-fed radar antenna, and may radiate signals to the outside or receive signals from the outside through a plurality of radiation slots.

[0069] An antenna according to an embodiment of the present invention may be composed of a radiating slot (140), a branch structure (150), a waveguide (160), and a signal input / output unit (170), and may be composed of a first layer (110), a second layer (120), and a third layer (130). Here, the first to third layers are sequentially stacked and formed, and the first layer (110) may be the uppermost layer or the outermost layer in the direction in which a signal is radiated outward. The third layer (130) may be the lowermost layer, and the second layer (120) may be stacked between the first layer (110) and the third layer (130).

[0070] A plurality of radiating slots (140) are formed in the first layer (110). The plurality of radiating slots (140) may include four radiating slots. First to fourth radiating slots (141 to 144) may be included. At this time, the radiating slots (140) may be formed in a horn structure. The cross-section of the radiating slots (140) may be rectangular, and may be formed in a horn structure whose area increases as it extends in the radial direction. Alternatively, the cross-section of the radiating slots (140) may be circular or may be formed in various shapes other than rectangular. The four radiating slots (141 to 144) may be formed to be spaced apart from each other by a preset distance, or a wall may be formed between adjacent radiating slots. The four radiating slots (141 to 144) may be arranged in a row. Alternatively, they may be arranged in a 2x2 arrangement in four directions from the center, or may be arranged in various other shapes.

[0071] A branch structure (150) and a waveguide (160) are formed in the second layer (120). The branch structure (150) may be formed on the upper portion of the second layer (120) that is in contact with the first layer (110) in which the radiating slot (140) is formed. The waveguide (160) may be formed on the lower portion of the second layer (120). An upper portion of the waveguide (160) is formed in the second layer (120), and a lower portion of the waveguide (160) is formed in the third layer (130), so that the second layer (120) and the third layer (130) are combined to form a cavity, which is an empty space, thereby forming one waveguide (160). The upper region (161) of the waveguide (160) can be formed in a shape in which the cross-sectional shape of the waveguide (160) is divided in half and etched on the lower surface of the second layer (120).

[0072] The branch structure (150) is a structure that connects a waveguide (160) and a plurality of radiation slots (140), and can be formed as a branching structure to connect one waveguide (160) and a plurality of radiation slots (140). When the plurality of radiation slots include the first to fourth radiation slots (141 to 144), the branch structure can be configured as a 1-4 branch structure. Depending on the number of radiation slots (140), the branch structure can be configured in various forms, such as a 1-2 or 1-3 structure.

[0073] The branch structure (150) may include a first horn structure (152) and a second horn structure (151). The first horn structure (152) may be formed at a position corresponding to the center of four radiation slots (141 to 144) and may be connected to the waveguide, and the second horn structure (151) may have a lower portion connected to the first horn structure (152) and an upper portion connected to four radiation slots (141 to 144).

[0074] The first horn structure (152) is connected to one waveguide, and the second horn structure (151) is connected to four radiating slots (141 to 144) so ​​that they are connected to each other to form a 1-4 branch structure.

[0075] The first horn structure (152) may be formed as a horn structure in which the cross-sectional area of ​​the other end connected to the second horn structure (151) is wider than the cross-sectional area of ​​the one end connected to the waveguide (160). The second horn structure (151) may also be formed as a horn structure in which the cross-sectional area of ​​the other end connected to the plurality of radiation slots (140) is wider than the cross-sectional area of ​​the one end connected to the first horn structure (152). In a form in which the cross-sectional area of ​​the second horn structure is wider than the cross-sectional area of ​​the first horn structure (152), the first horn structure (152) and the second horn structure (151) may be connected in the form of a T-junction.

[0076] The central axis of the first horn structure (152) may overlap with the wall (145) between two of the four radiation slots (142, 143). By forming the central axis of the first horn structure (152) to overlap with the wall, a signal applied through the waveguide (160) may be guided to move toward the plurality of radiation slots (140) through a passage formed on both sides through the wall. When the central axis of the first horn structure (152) overlaps with one of the radiation slots, a signal applied through the waveguide (160) may be concentrated on the corresponding radiation slot. Therefore, by forming the central axis of the first horn structure (152) to overlap with the wall, the signal may be uniformly diverged from the plurality of radiation slots (140).

[0077] The wall (145) between the two radiating slots overlapping the central axis of the first horn structure (152) may be formed to extend to a portion of the second horn structure (151) area. When four radiating slots (141 to 144) are arranged in a row, the degree of signal transmission may be lower in the radiating slots (141, 144) located at the outer edge than in the radiating slots (142, 143) located at the center. For efficient and uniform signal radiation, the wall (145) between the two radiating slots overlapping the central axis of the first horn structure (152) may be formed to extend further toward the second layer (120) than the walls between the other radiating slots. That is, the wall (145) may be formed to extend to a portion of the second horn structure (151) area. The walls between other radiating slots other than the wall (145) between the two radiating slots overlapping the central axis of the first horn structure (152) may extend only to the boundary between the first layer (110) and the second layer (120). Alternatively, they may be formed shorter inward of the first layer (110) than the boundary between the first layer (110) and the second layer (120). That is, a 1-4 branch structure may be implemented as a second branch structure in which the first branch is formed at the wall (145) between the two radiating slots overlapping the central axis of the first horn structure (152) and the second branch is formed at the wall between the other radiating slots. A signal radiated to the outside may be distributed through the 1-4 branch structure, or a signal applied from the outside may be synthesized.

[0078] An antenna according to a comparative example of the present invention is formed of a 1-2 branch structure (17) and a 2-4 branch structure (16), as shown in FIG. 3, and is composed of four layers (11 to 14) to constitute each branch structure. A signal applied from a waveguide (17) is first branched by a 1-2 branch structure (17) formed between a third layer (13) and a second layer (12), and each branched signal is secondarily branched by a 2-4 branch structure (16) formed between a second layer (12) and a first layer (11) and can be applied to four radiating slots (15). Since the 1-2 branch structure (17) and the 2-4 branch structure (16) form a double branch structure and must be formed on different layers, four layers are required, which causes performance degradation due to tolerance in each layer, and the manufacturing process becomes complicated and expensive.

[0079] An antenna according to an embodiment of the present invention can be configured with only three layers by connecting a waveguide (160) and four radiating slots (140) through a 1-4 branch structure (150), and two layers having a double branch structure can be integrated into one layer to transmit with a uniform electric field distribution. Through this, the number of layers constituting the entire antenna is reduced, thereby reducing manufacturing costs and reducing performance degradation due to tolerances occurring in each layer.

[0080] A waveguide (160) and a signal input / output section (170) are formed on the third layer (130). A lower region (162) of the waveguide (160) corresponding to the upper region (161) of the waveguide (160) formed on the second layer (120) may be formed on the upper part of the third layer (130). The lower region (162) of the waveguide (160) may be formed in a shape in which a cross-sectional shape of the waveguide (160) is divided in half and etched on the upper surface of the third layer (130). When the second layer (120) and the third layer (130) are combined, the upper region (161) and the lower region (162) of the waveguide (160) form the upper surface and the lower surface of the waveguide (160), thereby forming one waveguide (160).

[0081] A signal input / output unit (170) connected to a waveguide (160) may be formed at the bottom of the third layer (130). The signal input / output unit (170) may input a signal radiated to the outside through the waveguide (160), the branch structure (150), and the radiating slot (140), or may output an external signal applied to the radiating slot (140), the branch structure (150), and the waveguide (160). A communication module for transmitting and receiving a signal may be connected to the signal input / output unit (170), and the signal input / output unit (170) may be referred to as a feed unit. An RF module may be connected to the bottom of the third layer (130). The RF module may include a PCB on which an RFIC chip is mounted or an RF input / output port of the RFIC chip. The RF input / output port may be connected to the signal input / output unit (170). Here, the RF module may be a module used in a 4D image radar for vehicles, and the RFIC chip may be a MIMO FMCW transceiver of 76 to 81 GHz with a bandwidth of 5 GHz. Here, the MIMO (Muiti Input Muiti Output) FMCW (Frequency-Modulated Continuous-Wave) RFIC chip uses a linear frequency modulation method in which the frequency increases over time, and can estimate the distance and relative velocity between the radar and the target by using the time delay and Doppler frequency shift between the transmitted signal and the received signal, and the angle of the target can be estimated through the phase difference caused by the antenna spacing in the MIMO antenna.

[0082] The first layer (110) to the third layer (130) can be coupled through coupling grooves and coupling portions, as shown in FIG. 4. A signal input / output unit (170) is formed at the bottom of the third layer (130), and the lower region (162) of the waveguide formed at the top of the third layer (130) and connected to the signal input / output unit (170) and the upper region (161) of the waveguide formed at the bottom of the second layer (120) can form a waveguide when the second layer (120) and the third layer (130) are coupled. At this time, the waveguide (160) can form a path to the radiating slot (140) in order to secure a length according to the wavelength of the signal. The waveguide (160) can include a general path, a cross path that intersects with another waveguide (160), a transition path that connects the general path and the cross path, etc. A branch structure (150) is formed on the upper part of the second layer (120) to connect the waveguide (160) and the radiation slot (140), and a horn-shaped radiation slot (140) is connected to the waveguide (160) through the branch structure (150), so that a signal can be radiated to the outside or a signal can be received from the outside.

[0083] Each component of the antenna according to an embodiment of the present invention may be set in terms of length, area, shape, etc., depending on the wavelength of the signal. For example, as shown in FIG. 5, the numerical values ​​of each component may be set.

[0084] The first layer (110) may be thicker than the second layer (120), and the second layer (120) may be thicker than the first layer (110). For example, the thickness of the first layer (110) may be 1 to 2 times the signal wavelength (λ), the thickness of the second layer (120) may be 0.8 to 1.1 times the signal wavelength, and the thickness of the third layer (130) may be 0.5 to 0.9 times the signal wavelength. Alternatively, the thickness of the first layer (110) may be 1.14 times the signal wavelength (λ), the thickness of the second layer (120) may be 0.98 times the signal wavelength, and the thickness of the third layer (130) may be 0.76 times the signal wavelength.

[0085] The height of the first horn structure (152) may be lower than the height of the second horn structure. For example, the sum of the heights of the first horn structure (152) and the second horn structure (151) may be 0.5 to 1 times the signal wavelength, and the height of the second horn structure (151) may be 0.3 to 0.6 times the signal wavelength. Alternatively, the sum of the heights of the first horn structure (152) and the second horn structure (151) may be 0.68 ± 0.05 times the signal wavelength, and the height of the second horn structure (151) may be 0.45 ± 0.05 times the signal wavelength.

[0086] The four radiating slots (141 to 144) are arranged in a row, and the total length of the four radiating slots (140) can be 2.5 to 4 times the signal wavelength. Additionally, it can be 3.17 times.

[0087] Among the four radiating slots (141 to 144), the width of the two centrally located slots (142, 143) may be longer than the width of the two peripherally located slots (141, 144). For example, the width of the two centrally located slots (142, 143) may be 1.01 to 1.2 times the width of the two peripherally located slots (141, 144). The width of the two centrally located slots (142, 143) may be 0.5 to 0.8 times the signal wavelength, and the width of the two peripherally located slots (141, 144) may be 0.45 to 0.75 times the signal wavelength. Alternatively, the width of the two centrally located slots (142, 143) may be 0.69 times the signal wavelength, and the width of the two peripherally located slots (141, 144) may be 0.64 times the signal wavelength.

[0088] The height of the waveguide (160) may be 0.4 to 0.8 times the signal wavelength, and the area in contact with the signal input / output unit (170) may be 0.6 to 0.9 times the height and 0.2 to 0.4 times the width. Alternatively, the area in contact with the signal input / output unit (170) may be 0.74 times the height and 0.3 times the width.

[0089] As described above, a signal radiated through an antenna connecting a waveguide and a radiation slot through a branch structure may be applied through a waveguide (160), as shown in FIG. 6, branched in a 1-4 branch structure (150), distributed to each radiation slot (141 to 144), and radiated, or an external signal may be applied to a radiation slot (140), synthesized in a 1-4 branch structure (150), and applied to a waveguide (160).

[0090] The length of each configuration is set according to the wavelength of the signal, and the wall (145) between the two radiating slots overlapping with the central axis of the first horn structure (152) can be formed to extend to a part of the area of ​​the second horn structure (151), thereby allowing a uniform electric field distribution throughout the branching structure and the entire radiating slots, as shown in FIG. 7. At this time, the walls between other radiating slots, other than the wall (145) between the two radiating slots overlapping with the central axis of the first horn structure (152), can be formed shorter inward of the first layer (110) than the boundary between the first layer (110) and the second layer (120). That is, a 1-4 branching structure can be implemented as a secondary branching structure in which the first branch is formed at the wall (145) between the two radiating slots overlapping with the central axis of the first horn structure (152) and the second branch is formed at the wall between the other radiating slots, as a single 1-4 branching structure. The signal radiated to the outside can be evenly distributed through the 1-4 branch structure.

[0091] As shown in Fig. 3, it can be confirmed that even though the number of layers is reduced from 4 to 3, equivalent performance can be secured, as shown in Figs. 8 to 10, compared to an antenna including a double-branched structure.

[0092] As described above, by connecting the waveguide and the radiating slot through a single branch structure, two layers forming a double-branched structure can be integrated into a single layer, thereby ensuring transmission with a uniform electric field distribution. This reduces the number of layers comprising the entire antenna, thereby reducing manufacturing costs and minimizing performance degradation due to tolerances within each layer. Furthermore, by applying waveguide transmission optimal structure technology, it can be applied to multiple array antennas.

[0093] Figure 11 is a block diagram of a radar module according to one embodiment of the present invention.

[0094] A radar module (300) according to an embodiment of the present invention includes an RF module (200) and an antenna module (100). A detailed description of each component of the radar module according to an embodiment of the present invention corresponds to the detailed description of the antenna of FIGS. 1 to 10, and any overlapping description will be briefly described below.

[0095] The RF module (200) generates and transmits and receives RF signals, and the antenna module (100) is connected to the input / output section of the RF module and radiates RF signals.

[0096] An antenna module (100) may include a second layer having a branch structure formed on an upper portion of a first layer on which a plurality of radiation slots are formed and a waveguide connected thereto, and an upper region of the waveguide formed on a lower portion thereof; and a third layer having a lower region of the waveguide formed on an upper portion thereof corresponding to the upper region of the waveguide formed on the second layer, and a signal input / output unit connected to the waveguide formed on a lower portion thereof.

[0097] The above-described plurality of radiating slots may include four radiating slots, and the branching structure may include a 1-4 branching structure, and the branching structure may include a first horn structure formed at a position corresponding to the center of the four radiating slots and connected to the waveguide; and a second horn structure having a lower portion connected to the first horn structure and an upper portion connected to the four slots.

[0098] The four radiating slots are formed spaced apart from each other, the central axis of the first horn structure can overlap with the walls between two of the four radiating slots, and the walls between the two radiating slots overlapping with the central axis of the first horn structure can be formed to extend to a part of the second horn structure region.

[0099] The four radiating slots may be formed in a row, and the width of two slots located in the center of the four radiating slots may be longer than the width of two slots located at the outer edge, and the first layer may be thicker than the second layer, and the second layer may be thicker than the third layer.

[0100] The sum of the height of the first horn structure and the height of the second horn structure may be 0.63 to 0.73 times the signal wavelength, and the height of the second horn structure may be 0.4 to 0.5 times the signal wavelength. The width of the two slots located in the center may be 0.69 times the signal wavelength, the width of the two slots located at the outside may be 0.64 times the signal wavelength, the thickness of the first layer may be 1.14 times the signal wavelength, the thickness of the second layer may be 0.98 times the signal wavelength, and the thickness of the third layer may be 0.76 times the signal wavelength.

[0101] The waveguide (160) may include a plurality of waveguides, and may include a first waveguide (132) and a second waveguide (134). The first waveguide (132) may be connected to at least some of the plurality of radiating slots, and the second waveguide (134) may be connected to at least some of the plurality of radiating slots that are connected to the first waveguide and other parts of the plurality of radiating slots. The first waveguide (132) and the second waveguide (134) may be spaced apart from each other. The first waveguide (132) and the second waveguide (134) may be formed in different layers when intersecting in a first direction in a path connected to each radiating slot. Here, the first direction may be a stacking direction of the plurality of layers of the antenna or a radiating direction of the radiating slot.

[0102] At least one of the first waveguide (132) or the second waveguide (134) may include a transition path that bypasses a layer and another layer in which the other waveguide is formed in an area where they intersect each other.

[0103] FIG. 12 is a layout diagram of an antenna according to a second embodiment of the present invention, FIGS. 13 and 14 are schematic drawings of an antenna according to a second embodiment of the present invention, and FIG. 15 is a schematic diagram showing a side cross-section of an antenna according to a second embodiment of the present invention.

[0104] An antenna having a waveguide overlap avoidance structure according to a second embodiment of the present invention comprises a first waveguide and a second waveguide. Here, the first waveguide may be a common-path waveguide, and the second waveguide may be a cross-path waveguide that intersects the first waveguide, which is a common-path waveguide. Hereinafter, the description will be made on the assumption that the first waveguide is a common-path waveguide, and the second waveguide is a cross-path waveguide.

[0105] The antenna having a waveguide overlap avoidance structure according to the second embodiment of the present invention may be a vehicle waveguide-fed radar antenna, and may also be various antennas using waveguides. First, the antenna according to the second embodiment of the present invention is a vehicle radar antenna, and the vehicle radar antenna is composed of 12 transmitting antennas and 16 receiving antennas, and each transmitting / receiving antenna is a horn antenna composed of 4 array horn radiators, and a structure in which an RFIC chip and each horn radiator are connected through a waveguide will be described as an example. This structure is only one example, and may be modified into various forms depending on the type and performance of the RFIC chip, module size, target performance, application field, etc.

[0106] A vehicle waveguide-fed radar antenna (100) according to a second embodiment of the present invention is composed of 12 transmitting (Tx) antennas and 16 receiving (Rx) antennas, as shown in Table 1 below, and a total of 28 antennas are divided into 17 antennas in which the waveguide is formed as a normal path and 11 antennas in which the waveguide is formed as a cross path. In addition, referring to FIG. 12, it can be seen that the transmitting antenna and the receiving antenna are array horn antennas having four radiating slots (112-1 to 112-4) arranged in a row with the same shape. In the second embodiment of the present invention, an antenna having four radiating slots (112-1 to 112-4) arranged in a row is exemplified, but the arrangement of the radiating slots may be arranged in various forms, such as 4 x 4, depending on the required target performance.

[0107] Antenna number (n) Transmission classification Path classification Antenna number (n) Transmission classification Path classification 1 Transmission general 15 Transmission general 2 Transmission general 16 Transmission cross 3 Reception cross 17 Reception cross 4 Reception general 18 Reception general 5 Reception cross 19 Transmission cross 6 Reception cross 20 Transmission general 7 Reception general 21 Reception general 8 Transmission cross 22 Reception cross 9 Transmission cross 23 Transmission general 10 Transmission general 24 Transmission general 11 Reception general 25 Transmission general 12 Reception general 26 Reception general 13 Reception cross 27 Reception general 14 Reception cross 28 Reception general

[0108] According to the above Table 1 and FIG. 12, the first antenna (antenna with antenna number 1, hereinafter referred to as the n-th antenna) is a transmitting antenna in which a waveguide is formed as a common path and is arranged parallel to the second antenna (2) on the upper side of the plane of the radiation layer (110), and the 17th antenna (17) is a receiving antenna in which a waveguide is formed as a cross path and is arranged on the lower left side of the plane of the radiation layer (110).

[0109] In addition, according to Table 1 above, it can be seen that there are a total of 8 transmitting antennas with a normal path, namely antennas 1, 2, 10, 15, 20, 23, 24, and 25, a total of 4 transmitting antennas with a cross path, namely antennas 8, 9, 16, and 19, a total of 9 receiving antennas with a normal path, namely antennas 4, 7, 11, 12, 18, 21, 26, 27, and 28, and a total of 7 receiving antennas with a cross path, namely antennas 3, 5, 6, 13, 14, 17, and 22.

[0110] Referring to FIGS. 1 to 14, the transmitting antennas (1, 2, 10, 15, 20, 23, 24, 25) and receiving antennas (4, 7, 11, 12, 18, 21, 26, 27, 28) having a general path are composed of a first waveguide (132) positioned at a lower height than a second waveguide (134), a first stage tee junction (122), a second stage tee junction (124-1, 124-2), and four radiating slots (112-1 to 112-4).

[0111] In addition, the transmitting antennas (8, 9, 16, 1) and receiving antennas (3, 5, 6, 13, 14, 17, 22) having cross paths are arranged at a higher position than the first waveguide (132) to avoid overlapping with the first waveguide (132), the second waveguide (134) is arranged at a higher position than the first waveguide (132) to lower the height of the second waveguide (134) to connect the second waveguide (134) to a two-stage tee (T) junction (122, 124-1, 124-2), the third waveguide (138) is arranged at the same height as the first waveguide (132), the first stage tee junction (122), the second stage tee junction (124-1, 124-2), and four radiating slots (112-1 to 112-4).

[0112] Meanwhile, each antenna (1 to 28) according to the second embodiment of the present invention, as illustrated in FIG. 15, is composed of a first layer (L1) having four radiating slots (112-1 to 112-4), a second layer (L2) for distributing one RF signal to four two-stage T-junctions, a third layer (L3) for propagating the RF signal through a first waveguide (132) or a second waveguide (134 in FIG. 16), and a fourth layer (L4) for coupling feed.

[0113] In reality, due to reasons of the manufacturing process (mold, etc.), antenna components such as waveguides, tee junctions, and radiating slots are formed between adjacent layers, so it is difficult to uniformly define the function of each layer. However, in the second embodiment of the present invention, for the convenience of understanding, the first layer (L1) is referred to as a radiating layer (110), the second layer (L2) is referred to as a distribution / synthesis layer (120), the third layer (L3) is referred to as a propagation layer (130), and the fourth layer (L4) is referred to as a feed layer (131).

[0114] The radiating layer (110) includes four radiating slots (112-1 to 112-4), and the distribution / synthesis layer (120) includes one first stage tee junction (122) and two second stage tee junctions (124-1, 124-2), which serve to evenly distribute one RF transmission signal into four RF transmission signals during transmission and to synthesize four RF reception signals into one RF reception signal during reception. The propagation layer (130) includes a first waveguide (132) of a general path (NP), a second waveguide (134) of a cross path (CP), a fourth waveguide (136) for height transition, and a third waveguide (138), which serve to propagate an RF signal. A coupling feed pipe (142) is formed in the feed layer (131) to transmit the transmission port signal of the RFIC chip to the waveguide (132, 134) or transmit the reception signal of the waveguide (132, 134) to the reception port of the RFIC chip.

[0115] Referring to FIG. 15, each of the four layers (L1 to L4) is divided into an upper region (UP) and a lower region (DN), and the first waveguide (132) of the general path is formed in a portion of the upper region (UP) of the fourth layer (L4) and a portion of the lower region (DN) of the third layer (L3). The first stage tee junction (122) is formed in a portion of the upper region (UP) of the third layer (L3) and a portion of the lower region (DN) of the second layer (L2), the second stage tee junctions (124-1, 124-2) are formed in a portion of the upper region (UP) of the second layer (L2) and a portion of the lower region (DN) of the first layer (L1), and the radiating slots (112-1 to 112-4) are formed in a portion of the upper region (UP) of the first layer (L1).

[0116] Also, the outer surface of the fourth layer (L4) may be connected to a PCB mounted with an RFIC chip or to an RF input / output port of the RFIC chip. Typically, the RFIC chip used in a vehicle 4D image radar is a MIMO FMCW transceiver of 76 to 81 GHz with a bandwidth of 5 GHz. Here, the MIMO (Muiti Input Muiti Output) FMCW (Frequency-Modulated Continuous-Wave) RFIC chip uses a linear frequency modulation method in which the frequency increases over time, and can estimate the distance and relative velocity between the radar and the target by using the time delay and Doppler frequency shift between the transmitted and received signals, and the angle of the target can be estimated through the phase difference caused by the antenna spacing in the MIMO antenna.

[0117] FIG. 16 and FIG. 17 are schematic diagrams showing the general path and the cross path of the waveguide in the antenna according to the second embodiment of the present invention, FIG. 18 is a plan view showing the general path waveguide layer in the antenna according to the second embodiment of the present invention, and FIG. 19 is a plan view showing the cross path waveguide layer in the antenna according to the second embodiment of the present invention.

[0118] The waveguide of the antenna according to the second embodiment of the present invention may be composed of a first waveguide (132) of the general path (NP), a second waveguide (134) of the cross path (CP), a fourth waveguide (136) for transitioning the cross path (CP) to the general path (NP), and a third waveguide (138) of the general path (NP), as illustrated in FIGS. 16 to 19.

[0119] Referring to FIGS. 16 to 19, the first waveguide (132) of the general path (NP) is manufactured by forming a cavity in the upper part of the fourth layer (L4) and the lower part of the third layer (L3), and the second waveguide (134) of the cross path is manufactured by forming a cavity in the upper part of the third layer (L3) and the lower part of the second layer (L2).

[0120] In addition, since the position of the second waveguide (134) in the four-layer antenna (between the second and third layers) is the same as the position where the first stage tee junction (122) is installed (between the second and third layers), the second waveguide (134) cannot be directly connected to the first stage tee junction (122). Therefore, in order to connect the second waveguide (134) of the cross path (CP) to the first stage tee junction (122), the height must be changed through the fourth waveguide (136) and then connected through the third waveguide (138).

[0121] Therefore, an antenna having a cross path requires an additional transition section to transition from the cross path back to the normal path. This transition section is composed of the end of the second waveguide (134), the fourth waveguide (136), the third waveguide (138), and the first stage tee junction (122), and the characteristics of the antenna having a cross path are greatly affected by this transition section.

[0122] FIG. 20 is a flowchart illustrating a method for manufacturing an antenna having a waveguide overlap avoidance structure according to a second embodiment of the present invention.

[0123] The method for manufacturing an antenna according to the second embodiment of the present invention includes a step (S1) of preparing antenna components (first to fourth waveguides, a T-junction, a radiator, etc.), a step (S2) of forming a length of a third waveguide (138), a step (S3) of forming a branch point of a T-junction (122), a step (S4) of moving a surface of the third waveguide (138) and forming an inclination angle, a step (S5) of forming an end of the second waveguide (134), a step (S6) of forming an internal area of ​​the fourth waveguide (136), and a step (S6) of combining fitted antenna components.

[0124] As explained above, an antenna with a cross path to avoid waveguide overlap needs to additionally have a transition section, and the shape of the components that make up this transition section greatly affects the target performance of the antenna.

[0125] In the antenna manufacturing method according to the second embodiment of the present invention, the process (S2) of forming (fitting) the length of the third waveguide (138) in the transition section is referred to as the first optimization process, and the process (S3 to S6) of forming (fitting) the shape of each element of the transition section is referred to as the second optimization process. Then, the contents of each optimization process and the change in antenna characteristics after the optimization process will be specifically examined.

[0126] <First Optimization Process>

[0127] FIG. 21 is a drawing for explaining a first optimization process of an antenna manufacturing method according to a second embodiment of the present invention, FIG. 22 is a drawing showing an electric field distribution of a waveguide after the first optimization of an antenna manufacturing method according to a second embodiment of the present invention, and FIG. 23 is a graph showing a return loss measured at each port after the first optimization of an antenna manufacturing method according to a second embodiment of the present invention.

[0128] The first optimization process of the antenna according to the second embodiment of the present invention is to improve the performance of the antenna by changing the length of the third waveguide (138) as shown in FIG. 18 as shown in Table 2 below. An example of the third waveguide (138) to which the first optimization is applied is as shown in FIG. 21.

[0129] Antenna number (n) 3rd waveguide path length (unit: mm) Example 1 of Fig. 7 Optimization application 13189.353189.355189.356189.3599.359.35169.359.35199.359.3589.359.351422.619.351722.359.352229.519.35

[0130] Referring to Table 2 above, it can be seen that antennas 13, 3, 5, and 6 have the length of the third waveguide (138) changed from 18 mm to 9.35 mm, antennas 9, 16, 19, and 8 have the length of the third waveguide (138) changed from 9.35 mm to 9.35 mm, antenna 14 has the length of the third waveguide (138) changed from 22.61 mm to 9.35 mm, antenna 17 has the length of the third waveguide (138) changed from 22.35 mm to 9.35 mm, and antenna 22 has the length of the third waveguide (138) changed from 29.51 mm to 9.35 mm.

[0131] As shown in Fig. 21, the third waveguide (138) to which the first optimization is applied has the same path length of 9.35 mm, and the phase difference is eliminated by making the phase of the electrical length the same, thereby improving the performance of the antenna to which the cross path is applied.

[0132] Looking at the electric field (E-field) distribution of the transition section after applying the first optimization, the characteristics are improved to some extent as shown in Fig. 22, and looking at the return loss at all ports after applying the first optimization, it can be seen that they are clustered at the resonance point as shown in Fig. 23. In Fig. 23, the horizontal axis represents the frequency (unit: GHz), and the vertical axis represents the level of the return loss (unit: dB). According to the return loss graph of Fig. 23, in the cross path of the structure of Fig. 18, the return loss was spread around the resonance point, but by applying the first optimization to eliminate the phase difference, it can be seen that some frequency sections satisfy the target performance.

[0133] <Second Optimization Process>

[0134] FIG. 24 and FIG. 25 are drawings for explaining a second optimization process of an antenna manufacturing method according to a second embodiment of the present invention, FIG. 26 is a drawing showing an electric field distribution of a waveguide after a second optimization of an antenna manufacturing method according to a second embodiment of the present invention, and FIG. 27 is a graph showing a return loss measured at each port after a second optimization of an antenna manufacturing method according to a second embodiment of the present invention.

[0135] The second optimization process of the antenna manufacturing method according to the second embodiment of the present invention is to finely change the shapes of each component of the transition section as shown in FIGS. 24 and 25. In FIGS. 24 and 25, ① represents the application of the second optimization in the first stage T-junction region, ② represents the application of the second optimization in the third waveguide (138) region, ③ represents the application of the second optimization in the boundary region between the second waveguide (134) and the fourth waveguide (136), and ④ represents the application of the second optimization in the fourth waveguide (136) region.

[0136] Looking more specifically, in region ①, the branch point height of the first stage tee junction (122) is adjusted (①-1), and the branch point width and angle are adjusted to 5 to 35° (①-2), so that a slope is formed on the upper part of the vertical input terminal, and a wedge-shaped depression is formed in the center of the horizontal branch terminal. Accordingly, uniform electric field (E-field) distribution is enabled during radiation, thereby improving gain and beam performance. In the second embodiment of the present invention, as illustrated in FIG. 25, the branch point height of the depression is lowered by 0.39λ, and the branch point width at the upper part of the input terminal is moved by 0.257λ on both sides to form a slope having an angle of 30°. Here, λ represents the wavelength of the RF transmission / reception signal (operating frequency).

[0137] In addition, in region ②, the ends of the lower surface of the third waveguide (138) are moved in a plane to form an inlet surface of a predetermined length, and an inclined portion is formed so that the angle is 5 to 35°. Accordingly, a uniform electric field mode can be formed in the transition-propagation section, and a uniform electric field mode can be formed in the operating frequency section. In the second embodiment of the present invention, as illustrated in FIG. 25, the width of the lower surface of the third waveguide (138) is moved in a plane by 0.257λ on both sides to form an inclined portion having an angle of 30°.

[0138] In addition, in region ③, the joint portion of the second waveguide (134) connected to the fourth waveguide (136) is formed in two steps, and then the low step surface is moved toward the cross path side, and the high step surface is moved toward the cross path side, and an inclined surface having an angle of 5 to 35° is formed. Accordingly, an electric field branch in the propagation-transition section is formed, and a uniform electric field mode can be formed in the operating frequency section. In the second embodiment of the present invention, as illustrated in FIG. 25, the low step surface at the joint portion of the second waveguide (134) connected to the fourth waveguide (136) is moved toward the cross path side by 0.128λ, and the high step surfaces are moved toward both sides by 0.257λ to form an inclined surface having an angle of 30°.

[0139] In addition, in the ④ region, the internal area of ​​the fourth waveguide (136) is adjusted to form (determine) a frequency bandwidth according to the physical size of the waveguide. In the second embodiment of the present invention, as illustrated in Fig. 25, the internal area is formed by adjusting the internal width of the fourth waveguide (136) by 0.603 λ.

[0140] In this way, in the second optimization process, each component of the transition part was fine-tuned, and when looking at the electric field (E-field) distribution of the transition part after applying the second optimization, it can be seen that the transmission characteristics were improved by forming a TE10 mode with uniform electric field characteristics throughout the entire section, as shown in Fig. 26. When looking at the return loss at all ports after applying the second optimization, it can be seen that the target performance is satisfied in the operating frequency range (76 to 81 GHz), as shown in Fig. 27. In Fig. 27, the horizontal axis represents the frequency (unit: GHz), and the vertical axis represents the return loss level (unit: dB). According to the return loss graph of Fig. 27, after applying the second optimization, the return loss is -5 dB or less in the 76 GHz to 81 GHz band, satisfying the target performance, and the bandwidth of the antenna with a cross path is improved, so it can be seen that the transmission characteristics are greatly improved in the operating frequency band.

[0141] The operation of the antenna manufactured according to the second embodiment of the present invention is described by dividing it into transmission and reception and path as follows.

[0142] <Transmitting antenna with a common path>

[0143] Each transmitting antenna (1, 2, 10, 15, 20, 23, 24, 25) having a common path receives an RF transmission signal from the transmission port of the RFIC chip through the coupling feed pipe (142) of the fourth layer (L4) and transmits the RF transmission signal to the first stage tee junction (122) of the distribution / synthesis layer (120) through the first waveguide (132) formed between the fourth layer and the third layer. The first stage tee junction (122) equally divides one RF transmission signal into two RF transmission signals. The RF signal divided at the first stage tee junction (122) is divided again into two RF transmission signals by the second stage tee junctions (124-1, 124-2), and then a total of four divided RF transmission signals are radiated into the air through four radiation slots (112-1 to 112-4).

[0144] Transmitting antenna with cross path

[0145] Each transmitting antenna (8, 9, 16, 19) having a cross path receives an RF transmission signal from the transmitting port of the RFIC chip through the coupling feed tube (142) of the fourth layer (L4) and propagates the signal to the second waveguide (134) formed between the third layer and the second layer. After avoiding overlap with the first waveguide (132) by the second waveguide (134), the output signal of the second waveguide (134) is transmitted to the first stage tee junction (122) of the distribution / synthesis layer (120) through the fourth waveguide (136) and the third waveguide (138). That is, in the case of the second waveguide (134), since it cannot be directly connected to the first stage tee junction (122) at the same location as described above, the RF transmission signal is transmitted to the first stage tee junction (122) in the same manner as the other first waveguide (132) through the third waveguide (138) formed between the fourth layer and the third layer.

[0146] The first stage tee junction (122) equally distributes one RF transmission signal into two RF transmission signals, and the RF transmission signal distributed from the first stage tee junction (122) is again distributed into two RF transmission signals by the second stage tee junctions (124-1, 124-2), and then a total of four distributed RF transmission signals are radiated into the air through four radiation slots (112-1 to 112-4).

[0147] <Receiving antenna with common path>

[0148] Each receiving antenna (4, 7, 11, 12, 18, 21, 26, 27, 28) having a common path receives an RF reception signal (a signal in which an RF transmission signal emitted from a transmitting antenna is reflected from a target) reflected from the air through four radiating slots (112-1 to 112-4) formed in the first layer (L1), and the RF reception signals received through the four radiating slots (112-1 to 112-4) are each synthesized into one RF reception signal by two second stage tee junctions (124-1, 124-2). The two RF reception signals each synthesized by the second stage tee junctions (124-1, 124-2) are synthesized into one RF reception signal by the first stage tee junction (122). The RF reception signal synthesized by the first stage tee junction (122) is transmitted to the reception port of the RFIC chip through the first waveguide (132) formed between the fourth layer and the third layer. Accordingly, the RFIC chip can process the RF reception signal received through the reception port.

[0149] <Receiving antenna with cross path>

[0150] Each receiving antenna (3, 5, 6, 13, 14, 17, 22) having a cross path receives an RF reception signal reflected from a target in the air through four radiating slots (112-1 to 112-4) formed in the first layer (L1), and the signals received through the four radiating slots (112-1 to 112-4) are each synthesized into one RF reception signal by two second stage tee junctions (124-1, 124-2). The two RF reception signals each synthesized by the second stage tee junctions (124-1, 124-2) are synthesized into one RF reception signal by the first stage tee junction (122). The RF reception signal synthesized by the first stage tee junction (122) is transmitted to the second waveguide (134) formed between the third layer and the second layer through the third waveguide (138) and the fourth waveguide (136) formed between the fourth layer and the third layer.

[0151] And after avoiding the overlap with the first waveguide (132) by the second waveguide (134), the RF reception signal of the second waveguide (134) is transmitted to the reception port of the RFIC chip. Accordingly, the RFIC chip can process the RF signal received through the reception port.

[0152] The features, structures, effects, etc. described in the embodiments above are included in at least one embodiment, and are not necessarily limited to just one embodiment. Furthermore, the features, structures, effects, etc. exemplified in each embodiment can be combined or modified in other embodiments by those skilled in the art to which the embodiments pertain. Therefore, the contents related to such combinations and modifications should be construed as being included within the scope of the embodiments.

[0153] Those skilled in the art will appreciate that the present invention can be implemented in modified forms without departing from the essential characteristics of the above-described description. Therefore, the disclosed methods should be considered illustrative rather than restrictive. The scope of the present invention is set forth in the claims, not the foregoing description, and all differences within the scope equivalent thereto should be construed as being encompassed by the present invention.

Claims

1. A first layer having multiple radiation slots formed; A second layer in which a branch structure connecting the plurality of radiation slots and the waveguide is formed at the upper portion and an upper region of the waveguide is formed at the lower portion; and An antenna including a third layer in which a lower region of the waveguide corresponding to the upper region of the waveguide formed in the second layer is formed on the upper side, and a signal input / output section connected to the waveguide is formed on the lower side.

2. In paragraph 1, The above plurality of radiating slots include four radiating slots, The above branch structure is an antenna including 1-4 branch structures.

3. In paragraph 2, The above branch structure is, A first horn structure formed at a position corresponding to the center of the four radiating slots and connected to the waveguide; and An antenna comprising a second horn structure, the lower portion of which is connected to the first horn structure and the upper portion of which is connected to the four slots.

4. In paragraph 3, The above four radiating slots are formed spaced apart from each other, An antenna in which the central axis of the first horn structure overlaps the walls between two of the four radiating slots.

5. In paragraph 4, An antenna in which a wall between the two radiating slots overlapping the central axis of the first horn structure is formed to extend to a part of the second horn structure area.

6. In paragraph 3, The sum of the height of the first horn structure and the height of the second horn structure is 0.63 to 0.73 times the signal wavelength, An antenna wherein the height of the second horn structure is 0.4 to 0.5 times the signal wavelength.

7. In paragraph 2, The above four radiating slots are formed in a row, An antenna in which the width of the two centrally located slots among the four radiating slots is longer than the width of the two slots located on the outside.

8. In paragraph 7, The width of the two slots located in the center above is 0.69 times the signal wavelength, An antenna having two slots located on the outer periphery with a width of 0.64 times the signal wavelength.

9. In paragraph 1, The above waveguide, a first waveguide connected to at least some of the plurality of radiating slots; and Including a second waveguide connected to at least some of the first waveguide and other parts of the plurality of radiating slots, The above first waveguide and the above second waveguide, Antennas formed on different layers when crossing in the first direction.

10. In paragraph 9, At least one of the first waveguide or the second waveguide, An antenna comprising layers in which different waveguides are formed in intersecting regions and transition paths that bypass other layers.

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