antenna

Abstract

An antenna according to an embodiment of the present invention comprises: a plurality of second waveguides disposed at a height different from that of a first waveguide so as to avoid overlapping with the first waveguide; and a plurality of transition parts for transitioning from the height of the second waveguides to the height of the first waveguide to connect the second waveguides to an antenna radiator. Each of the transition parts comprises: a third waveguide formed at the same height as one end of the second waveguides and the first waveguide; a fourth waveguide for vertically connecting the one end of the second waveguides and the third waveguide; and a T junction for distributing an RF transmission signal of the third waveguide or synthesizing RF reception signals received from the antenna radiator, wherein the third waveguides corresponding to the plurality of transition parts are all the same predetermined length.

Description

antenna

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

[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 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 a vehicle radar with multiple antennas in a limited size, the waveguides that transmit RF signals from the RFIC chip to the antenna radiator may overlap each other. To solve this overlapping problem, it is necessary to add a separate avoidance layer.

[0006] However, if layers are added to avoid overlapping, the size of the antenna increases and the radiation area is invaded, making it difficult to achieve the target performance and increasing manufacturing costs.

[0007] The technical problem to be solved by the present invention is to provide a vehicle waveguide-fed radar antenna capable of implementing a cross path to avoid overlapping of waveguides without adding layers in a vehicle radar antenna with limited size.

[0008] In addition, another technical problem to be solved by the present invention is to provide a vehicle waveguide-fed radar antenna and a manufacturing method thereof to meet the performance required by the system when implementing a cross-path.

[0009] In order to solve the above technical problem, an antenna according to one 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.

[0010] 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.

[0011] 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.

[0012] In addition, the third waveguide of the above transition section may be introduced at both ends on the lower side to a predetermined length and an inclined portion having an angle of 5 to 35° may be formed on the introduction surface.

[0013] 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 5 to 35° may be formed on the higher step surface.

[0014] 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.

[0015] In order to solve the above technical problem, an antenna manufacturing method according to an 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 branching point height and width of the T-junction of the transition section and forming the branching 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.

[0016] 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°.

[0017] 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°.

[0018] 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°.

[0019] Additionally, the fifth step can form the inner width of the fourth waveguide to be 0.603 λ.

[0020] In order to solve the above technical problem, an antenna according to an embodiment of the present invention includes a first waveguide and a second waveguide arranged at a different height from the first waveguide to avoid overlap.

[0021] Additionally, the first waveguide connects the RF transceiver and the antenna radiator, and the second waveguide connects the RF transceiver and the antenna radiator while avoiding overlap with the first waveguide.

[0022] In addition, the antenna radiator includes a plurality of antenna radiators, and the plurality of antenna radiators and each waveguide are connected by a T junction so that an RF signal can be distributed or synthesized.

[0023] In addition, in order to solve the above technical problem, an antenna according to another embodiment of the present invention may have a structure in which the first to fourth layers are laminated.

[0024] In addition, a radiating slot is formed in the first layer, and a T-junction is formed in the second layer to distribute or synthesize RF signals while connecting the radiating slot and the waveguide. In the third layer, a second waveguide is formed between the upper part and the second layer, and a first waveguide is formed between the lower part and the first layer, and a transition path is formed to connect the second waveguide and the T-junction. The fourth layer is coupled with an input / output port of an RF transceiver to connect an RF signal to the first waveguide or the second waveguide.

[0025] Additionally, the transition path may include a fourth waveguide for vertically connecting the second waveguide formed between the second layer and the third layer to the third waveguide formed between the third layer and the fourth layer.

[0026] According to embodiments of the present invention, the problem of waveguide overlap can be solved through cross-paths without adding layers in a 4D image radar for a vehicle with limited size, thereby reducing dependence on RFIC chips in antenna design and reducing manufacturing costs.

[0027] In addition, according to embodiments of the present invention, there is an effect of sufficiently satisfying the antenna target performance required in the system while solving the waveguide overlap problem through a cross path.

[0028] Figure 1 is an antenna layout diagram according to one embodiment of the present invention.

[0029] FIG. 2 and FIG. 3 are schematic drawings illustrating an antenna according to an embodiment of the present invention.

[0030] FIG. 4 is a schematic diagram showing a side cross-section of an antenna according to an embodiment of the present invention.

[0031] FIG. 5 and FIG. 6 are schematic diagrams showing the general path and cross path of a waveguide in an antenna according to an embodiment of the present invention.

[0032] FIG. 7 is a plan view illustrating a general path waveguide layer in an antenna according to an embodiment of the present invention.

[0033] FIG. 8 is a plan view illustrating a cross-path waveguide layer in an antenna according to an embodiment of the present invention.

[0034] Figure 9 is a flowchart illustrating a method for manufacturing an antenna according to an embodiment of the present invention.

[0035] FIG. 10 is a drawing for explaining a first optimization process of an antenna according to an embodiment of the present invention.

[0036] FIG. 11 is a diagram illustrating the electric field distribution of a waveguide after the first optimization of an antenna according to an embodiment of the present invention.

[0037] FIG. 12 is a graph showing the return loss measured at each port after the first optimization of the antenna according to an embodiment of the present invention.

[0038] FIG. 13 and FIG. 14 are drawings for explaining a second optimization process of an antenna according to an embodiment of the present invention.

[0039] FIG. 15 is a diagram illustrating the electric field distribution of a waveguide after the second optimization of an antenna according to an embodiment of the present invention.

[0040] FIG. 16 is a graph showing the return loss measured at each port after the second optimization of the antenna according to an embodiment of the present invention.

[0041] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] FIG. 1 is a layout diagram of an antenna according to an embodiment of the present invention, FIGS. 2 and 3 are schematic drawings of an antenna according to an embodiment of the present invention, and FIG. 4 is a schematic diagram showing a side cross-section of an antenna according to an embodiment of the present invention.

[0051] An antenna according to one embodiment of the present invention comprises a first waveguide and a second waveguide. The antenna according to one embodiment of the present invention may include two or more waveguides that are separated to form a waveguide overlap avoidance structure, and may include 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 basis that the first waveguide is a common path waveguide, and the second waveguide is a cross-path waveguide.

[0052] 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.

[0053] A vehicle waveguide-fed radar antenna (100) according to one 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. 1, 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 embodiment of the present invention, the antenna is exemplified as having four radiating slots (112-1 to 112-4) arranged in a row, but the arrangement of the radiating slots may be arranged in various forms, such as 4 x 4, depending on the required target performance.

[0054] 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

[0055] According to the above Table 1 and FIG. 1, 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 general 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). In addition, according to the above Table 1, there are eight transmitting antennas having a general path, namely antennas 1, 2, 10, 15, 20, 23, 24, and 25, and four transmitting antennas having a cross path, namely antennas 8, 9, 16, and 19, and the receiving antennas having a general path, namely antennas 4, 7, 11, 12, 18, 21, 26, and 27, It can be seen that there are a total of 9 antennas, including 28, and a total of 7 receiving antennas with cross paths, including 3, 5, 6, 13, 14, 17, and 22.

[0056] Referring to FIGS. 1 to 3, 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).

[0057] 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).

[0058] Meanwhile, each antenna (1 to 28) according to an embodiment of the present invention, as illustrated in FIG. 4, 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. 5), and a fourth layer (L4) for coupling feed.

[0059] 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 embodiment of the present invention, for the sake of 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 (140).

[0060] 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 power supply layer (140) 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.

[0061] Referring to FIG. 4, 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).

[0062] 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.

[0063] FIG. 5 and FIG. 6 are schematic diagrams showing the general path and the cross path of the waveguide in an antenna according to an embodiment of the present invention, FIG. 7 is a plan view showing the general path waveguide layer in an antenna according to an embodiment of the present invention, and FIG. 8 is a plan view showing the cross path waveguide layer in an antenna according to an embodiment of the present invention.

[0064] The waveguide of the antenna according to the 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 shown in FIGS. 5 to 8.

[0065] Referring to FIGS. 5 to 8, 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).

[0066] In addition, in the antenna having a four-layer structure, the position of the second waveguide (134) (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), so 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).

[0067] 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.

[0068] Figure 9 is a flowchart illustrating a method for manufacturing an antenna according to an embodiment of the present invention.

[0069] The method for manufacturing an antenna according to an 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 a second waveguide (134), a step (S6) of forming an internal area of ​​a fourth waveguide (136), and a step (S6) of combining fitted antenna components.

[0070] 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.

[0071] In the antenna manufacturing method according to an 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.

[0072] <First Optimization Process>

[0073] FIG. 10 is a drawing for explaining a first optimization process of an antenna manufacturing method according to an embodiment of the present invention, FIG. 11 is a drawing showing an electric field distribution of a waveguide after the first optimization of an antenna manufacturing method according to an embodiment of the present invention, and FIG. 12 is a graph showing a return loss measured at each port after the first optimization of an antenna manufacturing method according to an embodiment of the present invention.

[0074] The first optimization process of the antenna according to the 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. 7 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. 10.

[0075] 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

[0076] Referring to Table 2 above, it can be seen that antennas 13, 3, 5, and 6 changed the length of the third waveguide (138) from 18 mm to 9.35 mm, antennas 9, 16, 19, and 8 changed the length of the third waveguide (138) from 9.35 mm to 9.35 mm, antenna 14 changed the length of the third waveguide (138) from 22.61 mm to 9.35 mm, antenna 17 changed the length of the third waveguide (138) from 22.35 mm to 9.35 mm, and antenna 22 changed the length of the third waveguide (138) from 29.51 mm to 9.35 mm. As such, the third waveguide (138) to which the first optimization is applied is as shown in FIG. 10. Likewise, the path lengths are all the same at 9.35 mm, and the phase difference is eliminated by making the electrical length phase the same, thereby improving the performance of the antenna with the cross path applied.

[0077] 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. 11, 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. 12. In Fig. 12, 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. 12, in the cross path of the structure of Fig. 7, 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.

[0078] <Second Optimization Process>

[0079] FIG. 13 and FIG. 14 are drawings for explaining a second optimization process of an antenna manufacturing method according to an embodiment of the present invention, FIG. 15 is a drawing showing an electric field distribution of a waveguide after the second optimization of an antenna manufacturing method according to an embodiment of the present invention, and FIG. 16 is a graph showing a return loss measured at each port after the second optimization of an antenna manufacturing method according to an embodiment of the present invention.

[0080] The second optimization process of the antenna manufacturing method according to the embodiment of the present invention is to finely change the shape of each component of the transition section as illustrated in FIGS. 13 and 14. In FIGS. 13 and 14, 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.

[0081] 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 embodiment of the present invention, as illustrated in FIG. 14, 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).

[0082] 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 embodiment of the present invention, as illustrated in FIG. 14, 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°.

[0083] 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 can be formed, and a uniform electric field mode can be formed in the operating frequency section. In the embodiment of the present invention, as illustrated in FIG. 14, 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°.

[0084] 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 embodiment of the present invention, as illustrated in Fig. 14, the internal area is formed by adjusting the internal width of the fourth waveguide (136) by 0.603 λ.

[0085] 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. 15. 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. 16. In Fig. 16, 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. 16, 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 the cross path is improved, so it can be seen that the transmission characteristics are greatly improved in the operating frequency band.

[0086] The operation of the antenna manufactured according to the embodiment of the present invention is described by dividing it into transmission and reception and path as follows.

[0087] <Transmitting antenna with a common path>

[0088] 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).

[0089] Transmitting antenna with cross path

[0090] 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.

[0091] 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).

[0092] <Receiving antenna with common path>

[0093] 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.

[0094] <Receiving antenna with cross path>

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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 plurality of second waveguides arranged at different heights from the first waveguide to avoid overlapping with the first waveguide; and A plurality of transition sections are included for transitioning from the height of the second waveguide to the height of the first waveguide and connecting the second waveguide to the antenna radiator. Each of the above transition parts One end of the second waveguide; A third waveguide formed at the same height as the first waveguide; A fourth waveguide for vertically connecting one end of the second waveguide and the third waveguide; and It includes a T junction for distributing the RF transmission signal of the third waveguide or synthesizing the RF reception signal received from the antenna radiator, An antenna in which the lengths of all third waveguides corresponding to the above multiple transition sections are the same as a predetermined length.

2. In paragraph 1, The tee junction of the above transition section is An antenna in which a slope is formed on the upper part of a vertical input terminal and a wedge-shaped depression is formed in the center of a horizontal branch terminal.

3. In paragraph 1, The third waveguide of the above transition section is An antenna in which both ends of the lower side are inserted to a predetermined length and an inclined portion is formed at an angle of 5 to 35° on the insertion surface.

4. In paragraph 1, One end of the second waveguide of the above transition section An antenna in which the steps are formed in two stages, the lower step surface is introduced toward the cross path, and the higher step surface has an inclined surface with an angle of 5 to 35°.

5. In paragraph 1, The fourth waveguide of the above transition section is An antenna whose internal area is formed to a predetermined size and whose frequency bandwidth is formed according to the physical size of the waveguide.

6. In the antenna manufacturing method, The antenna is, A plurality of second waveguides arranged at different heights from the first waveguide to avoid overlapping with the first waveguide; and A plurality of transition sections are included for transitioning from the height of the second waveguide to the height of the first waveguide and connecting the second waveguide to the antenna radiator. Each of the above transition parts, One end of the second waveguide; A third waveguide formed at the same height as the first waveguide; A fourth waveguide for vertically connecting one end of the second waveguide and the third waveguide; and It includes a T junction for distributing the RF transmission signal of the third waveguide or synthesizing the RF reception signal received from the antenna radiator, A first step of forming the length of all third waveguides corresponding to the above plurality of transition sections to a predetermined length; A second step of forming the branch point height and width of the tee junction of the above 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 above transition section and forming an inclination angle of 5 to 35°; A fourth step of forming one end of the second waveguide of the above-mentioned transition section into two stages, moving the lower stage toward the cross path, and moving the higher stage at the same time to form an inclination angle of 5 to 35°; and An antenna manufacturing method including a fifth step of forming an internal area of ​​a fourth waveguide of the above transition section to a predetermined area.

7. In paragraph 6, The above second step is a method for manufacturing an antenna in which the branch point height is lowered by 0.39 λ (λ is the wavelength of the operating frequency) and the branch point width is moved by 0.257 λ on both sides to form an angle of 30°.

8. In paragraph 6, The third step is an antenna manufacturing method in which the width of the lower surface of the third waveguide is shifted by 0.257 λ (λ is the wavelength of the operating frequency) on both sides to form an inclination angle of 30°.

9. In paragraph 6, The fourth step is a method for manufacturing an antenna in which a low step surface at the joint of a second waveguide connected to the fourth waveguide is moved toward the cross path by 0.128 λ (λ is the wavelength of the operating frequency) and a high step surface is moved from both sides by 0.257 λ to form an angle of 30°.

10. In paragraph 6, The above fifth step is an antenna manufacturing method in which the inner width of the fourth waveguide is formed to be 0.603 λ.

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