HORNANTENNE

Abstract

Horn antenna, featuring: a waveguide section (21); a horn section (22) connected to one end of the waveguide section (21) and having a height as the distance between E-planes and a width as the distance between H-planes, wherein the width of the horn section (22) is greater than the width of the waveguide section (21) and the height of the horn section (22) is equal to the height of the waveguide section (21); and Column sections (23) which are electrically connected to at least one of conductors (30, 31) which each form the E-planes on the horn section (22) and are arranged at a position away from an aperture (22a) of the horn section (22) within the horn section (22), wherein two of the column sections (23) are separated by half a wavelength or less.

Description

[0001] The present disclosure relates to a horn antenna.

[0002] An antenna device described in JP 2013-229676A includes an H-plane horn antenna. For the H-plane horn antenna, the horn length L and the aperture width B are larger values ​​relative to the aperture height A. However, there is a need for further improvement of the antenna device described in JP 2013-229676A.

[0003] Furthermore, reference is made to KR 10 1 037 294 B1 and JP 2002 - 171 119 A, which were determined to be state of the art.

[0004] Furthermore, reference is made to DE 10 2016 212 655 A1, which was additionally identified as state of the art.

[0005] It is therefore an objective of the present disclosure to provide a horn antenna with a smaller dimension and a vehicle-mounted horn antenna that can transmit and receive electromagnetic waves of the E-band.

[0006] The task is solved through the subject matter of the independent claims. Advantageous further developments can be found in the dependent claims.

[0007] According to one aspect of the present disclosure, a horn antenna comprises a waveguide section, a horn section, and at least one column section. The horn section is connected to one end of the waveguide section and has a height equal to the distance between E-planes and a width equal to the distance between H-planes. The width of the horn section is greater than the width of the waveguide section, and the height of the horn section is equal to the height of the waveguide section. The column section is electrically connected to the horn section by at least one of conductors, each forming the E-planes, and is located within the horn section at a position away from an aperture of the horn section.

[0008] The horn antenna described above incorporates the column section within the horn section. The column section is electrically connected to the conductor and acts as a barrier, canceling out the electric field. Consequently, the electric field distribution differs compared to the configuration without the column section, and the operating frequency shifts to a lower frequency range. If the operating frequencies are identical for both the configuration with and without the column section, it is possible to miniaturize the dimensions of the horn antenna compared to the configuration without the column section. Therefore, it is possible to provide a smaller horn antenna.

[0009] Further tasks, features, and advantages of the present disclosure will become clearer from the following detailed description in conjunction with the drawings. These show: Fig. 1 a fixed position of a horn antenna according to the first embodiment; Fig. 2. A top view of a box containing a horn antenna; Fig. 3 a cross-sectional view of the box along a line III-III of Fig. 2; Fig. 4 a perspective view showing a horn antenna; Fig. 5 a top view of Fig. 4 viewed in one direction A; Fig. 6 a side view of Fig. 5 viewed in one direction B; Fig. 7 an example of a horn antenna on a circuit board; Fig. 8 a cross-sectional view of the horn antenna on the circuit board along a line VIII-VIII in Fig. 7; Fig. 9 a configuration of a horn antenna used in an electromagnetic field simulation; Fig. 10 the difference in reflection characteristics between a configuration having a column section as one of embodiments in the present disclosure and a configuration without a column section as a comparative example, wherein both configurations have identical dimensions; Fig. 11 changes over time in an electric field distribution; Fig. 12 changes over time in an electric field distribution in a comparative example; Fig. 13 the difference in reflection characteristics between a configuration having a column section as one of embodiments in the present disclosure and a configuration without a column section as a comparative example, wherein both configurations have identical frequencies; Fig. 14 the difference in emission characteristics between a configuration having a column section as one of embodiments in the present disclosure and a configuration without a column section as a comparative example; Fig. 15 a perspective view illustrating a horn antenna according to a modification example; Fig. 16 a perspective view illustrating a horn antenna according to a further modification example; Fig. 17 a perspective view illustrating a horn antenna according to a further modification example; and Fig. Figure 18 shows a side view illustrating a horn antenna according to another modification example.

[0010] Several embodiments are described below with reference to the drawings. In these embodiments, functionally or structurally corresponding parts are provided with identical reference numerals. (First embodiment)

[0011] A horn antenna according to the present embodiment can be used for wireless communication employing high-frequency signals in a microwave band (3 GHz to 30 GHz) and a millimeter-wave band (30 GHz to 300 GHz). An application example in an in-vehicle system, and in particular road-to-vehicle communication, is described below.

[0012] The fixed position of the horn antenna is described below according to Fig. 1, Fig. 2 to Fig. 3 described.

[0013] As in Fig. As shown in Figure 1, a horn antenna 20 is attached to a vehicle 10. The horn antenna 20 includes a communication device that performs road-to-vehicle communication with the roadside device 5. The frequency band used for road-to-vehicle communication is the E-band (60 GHz to 90 GHz). The roadside device 5 can be, for example, an ITS spot, a roadside device used for a remote toll transmission system, or a roadside device arranged around an intersection. The communication device performs various applications by communicating with the roadside device 5 around the vehicle 10.

[0014] A box 12 is attached to a roof 11, in other words, a roof section of the vehicle 10. The box 12 can also be described as a shark fin. The horn antenna 20 is housed in the box 12. The box 12 is formed, for example, by inserting a resin material.

[0015] As in Fig. As illustrated in Figure 2, the box 12 has a streamlined shape in a top view. The length of the box 12 in a lateral direction is slightly narrower at the front of the vehicle (left side of the drawing) than at the rear of the vehicle (right side of the drawing). The length of the box 12 in the front-to-rear direction of the vehicle is longer than its length in the lateral direction of the vehicle. As shown in Fig. As illustrated in Figure 3, the length of box 12 is in the width direction (a left-right direction or horizontal direction). Fig. 3) Narrower on the top than on the bottom. The horn antenna 20 is located on the underside of the box 12. The horn antenna 20 is fixed to the roof 11 and / or the box 12 by a mounting element (not shown).

[0016] Box 12 is streamlined and arranged such that its longitudinal direction is the vehicle front-to-rear direction. Therefore, the length of the interior of box 12 in the vehicle front-to-rear direction is longer than its length in the vehicle width direction. For the sake of simplicity, Fig. 3 remove the illustration of elements other than the horn antenna 20, which is included in box 12.

[0017] The following is the configuration of the horn antenna 20 according to Fig. 4 and Fig. 6 described. Below, three directions that are perpendicular to each other are designated as an X-direction, a Y-direction, and a Z-direction.

[0018] As in Fig. 4 to Fig. As illustrated in Figure 6, the horn antenna 20 includes a waveguide section 21, a horn section 22 and at least one column section 23. Fig. 4 a perspective view of the horn antenna 20. Fig. 5 is a top view of Fig. 4 viewed in one direction A. Fig. 6 is a side view of Fig. 5 viewed in one direction B.

[0019] Waveguide section 21 transmits electromagnetic waves. Waveguide section 21 extends in the X-direction, and both ends in the X-direction form openings. These openings can also be referred to as apertures. Waveguide section 21 has a rectangular cross-section (YZ plane) perpendicular to the X-direction. Waveguide section 21 has a rectangular shape with the Y-direction as one long side or direction and the Z-direction as the short side or transverse direction. Such a waveguide section 21 can also be described as a rectangular waveguide. The X-direction corresponds to a first direction, and the Z-direction corresponds to a second direction.

[0020] When transmitting electromagnetic waves in the basic mode (e.g., TE10 mode), the electric field is parallel to the short side of the rectangular cross-section of waveguide section 21, and the magnetic field is parallel to the long side of the rectangular cross-section. Therefore, the surfaces on the long side, that is, the surfaces facing each other in the Z-direction, are the E-planes. The surfaces on the short side, that is, the surfaces facing each other in the Y-direction, are the H-planes. In waveguide section 21, the height, which is the distance between the E-planes, is constant over the entire area. The width of the H-plane spacing is also constant over the entire area.However, the description "constant over the entire range" does not only include a situation in which the height is exactly constant over the entire range, but can also include a situation in which the height is essentially constant over the entire range.

[0021] Horn section 22 radiates the transmitted electromagnetic waves into space. Horn section 22 is connected to the end section of waveguide section 21 opposite the end section on the power supply side. Like waveguide section 21, horn section 22 extends in the X-direction and has a rectangular shape with a cross-section perpendicular to the X-direction. Horn section 22 and waveguide section 21 are connected in the X-direction. Horn section 22 has a height as the distance between E-planes and a width as the distance between H-planes. The width of horn section 22 is greater than the width of waveguide section 21. The height of horn section 22 is equal to the height of waveguide section 21 across its entire length. This equal height is not limited to situations of exactly equal height and can include situations of substantially equal height.The horn section 22 has a configuration in which the waveguide section 21 extends in the Y direction. Such a horn section 22 can also be referred to as an H-plane horn.

[0022] As in Fig. As illustrated in Figure 4, the horn section 22 has a shape in which its width, i.e., its length, widens continuously in the Y-direction. The width of the horn section 22 increases as the distance from the waveguide section 21 increases in the X-direction. The width of the horn section 22 is equal to that of the waveguide section 21 at its boundary with the waveguide section 21 and has a maximum value at the aperture 22, which radiates the electromagnetic waves into space. The height of the aperture 22a is the same as that of the waveguide section 21. The dimensions of the horn section 22 are determined according to the operating frequency. The horn section 22 has a length L in the X-direction, a width W in the Y-direction, and a height H in the Z-direction.

[0023] Waveguide section 21 and horn section 22 contain conductors 30, 31, 40, and 41. Conductors 30, 31, 40, and 41 can be, for example, a metal plate, a metal film such as plating, a conductive foil, a conductive sheet, a via conductor, a through-hole conductor, or the like. Conductors 30 and 31 are arranged to face each other in the Z-direction, which is the vertical direction. Conductors 30 and 31 each have the E-planes on waveguide section 21 and horn section 22, respectively. The distance between conductors 30 and 31 is the distance between the E-planes. This distance is constant over the entire facing region. Conductors 30 and 31 are flat.

[0024] The conductors 40 and 41 are arranged to face each other in the Y-direction, which is the width direction. The conductors 40 and 41 are located between the conductors 30 and 31 in the Z-direction and electrically connect them. The conductors 40 and 41 each have the H-planes on the waveguide section 21 and the horn section 22, respectively. The distance between the conductors 40 and 41 is the distance between the H-planes. As described above, the distance between the conductors 40 and 41 is constant in the waveguide section 21 and widens continuously in the horn section 22.

[0025] The conductors 30, 31, 40, and 41 form a ring-shaped, cylindrical structure with a rectangular cross-section perpendicular to the X-direction. The area enclosed by the conductors 30, 31, 40, and 41 can be hollow, meaning it can be filled with air. A dielectric material can be used instead of air.

[0026] Column section 23 is a column-shaped conductor section. Column section 23 is electrically connected to at least one of the conductors 30, 31 that form the E-plane on horn section 22 and extends in the Z-direction. Due to this connection, column section 23 has the same potential as conductors 30, 31, 40, 41. Column section 23 is located on horn section 22 away from aperture 22a. Column section 23 is also located on horn section 22 away from the H-plane, i.e., conductors 40, 41. Column section 23 can also be described as a projection. The electrical connection is not limited to those formed between different elements such as terminals. For example, conductor 30 and column section 23 can be located on the same metal element, and column section 23 can be a projection with respect to conductor 30.

[0027] The horn antenna 20 according to the present embodiment comprises two column sections 23. As in Fig. 4 and Fig. As shown in Figure 5, the two column sections 23 are arranged in a row in the latitude direction (Y-direction). The two column sections 23 are spaced at intervals of half a wavelength or less, so that electromagnetic waves do not leak between the column sections 23. The column section 23 is located between the aperture 22a and the boundary that lies between the waveguide section 21 and the horn section 22. As shown in Fig. As illustrated in Figure 5, the two column sections 23 are arranged line-symmetrically with respect to the virtual center line CL of the horn antenna 20, parallel to the X-direction. The horn antenna 20 is also arranged line-symmetrically with respect to the center line CL.

[0028] Each of the column sections 23 is connected to the ladders 30, 31. As in Fig. As shown in Figure 6, one end of the column section 23, which extends in the Z direction, is connected to conductor 30, and the other end is connected to conductor 31. The height of the column section 23 is equal to the height of the E-level gap, and the column section 23 bridges conductors 30 and 31.

[0029] The horn antenna 20, configured as described above, is attached to the vehicle 10 such that the X direction is substantially parallel to the vehicle front-rear direction and the aperture 22a of the horn section 22 is at the front of the vehicle.

[0030] The following is a configuration of the horn antenna 20 according to Fig. 7, Fig. 8 described. Fig. Figure 7 illustrates that the column section 23 under the conductor 30, the via conductors 40V, 41V and the like are transparent for easier understanding.

[0031] As in Fig. 7, Fig. As illustrated in Figure 8, the horn antenna 20 is arranged on the printed circuit board 50. The printed circuit board 50 comprises a dielectric base material 51. Conductors are arranged in several layers on the base material 51. The thickness direction of the base material 51 is parallel to the Z-direction described above. The inventor of the present application has created a prototype of a horn antenna 20 with this type of configuration.

[0032] The base material 51 can, for example, be a dielectric. The base material 51 can be a single layer or multiple layers of dielectrics. A low-loss material can be used for high-frequency applications. Low-loss materials exhibit an extremely low tangent δ (dielectric loss tangent) in the high-frequency band. For example, a fluorinated resin such as polytetrafluoroethylene (PTFE), polyphenylene ether (PPE), or a combination of the aforementioned resin with a glass fabric or fiber fleece can be used. In this prototype, a base material combining PPE and a glass fabric was used.

[0033] The printed circuit board 50 includes conductors 30 and 31. Conductors 30 and 31 are provided as a single conductive foil (for example, a copper foil). Conductor 30 is arranged on the first surface of the base material 51 in the Z-direction, and conductor 31 is arranged on the second surface opposite the first surface. Conductor 30 covers the entire region of the first surface of the base material 51. Conductor 31 covers the entire region of the second surface of the base material 51. The second surface of the base material 51 is opposite the first surface of the base material 51. The printed circuit board 50 is a double-sided substrate board.

[0034] The printed circuit board 50 includes the column section 23 and conductors 40 and 41. The column section 23 is designed as a via conductor that electrically connects conductors 30 and 31, which have different layers. The base material 51 is formed with a hole 52 that penetrates the Z-direction at the position where the column section 23 is formed. The hole 52 can be referred to as a via. A conductive material is arranged in the hole 52 to form the column section 23. The conductive material can be filled into the hole 52 completely or can be filled only into a portion of the hole 52. For example, a plating film is arranged as the conductive material on the wall surface of the hole 52, and a gap (cavity) can be included within the plating film.

[0035] Conductors 40 and 41 are each configured as via conductors 40V and 41V, similar to column section 23. Several holes 53, penetrating in the Z-direction, are formed in the base material 51 at predetermined intervals along the formation positions of conductors 40 and 41. These holes 53 are spaced at intervals of half a wavelength or less to prevent electromagnetic leakage. The hole 53 can be referred to as a via hole. Conductive material is arranged within the hole 53 to form the via conductors 40V and 41V. Conductive material is also formed at the hole 53 to connect conductors 30 and 31. Several via conductors 40V, electrically connecting conductors 30 and 31, function as conductor 40, which forms the H-plane of the horn antenna 20. Several via conductors 41V, which electrically connect conductors 30, 31, function as conductor 41, which forms the H-plane of the horn antenna 20.The 40V and 41V via conductors can also be referred to as post walls.

[0036] In the present embodiment, the column section 23 and the via conductors 40V, 41V are formed in the same step. The configuration of the column section 23 and the configuration of the via conductors 40V, 41V are essentially identical, and the cross-section perpendicular to the Z-direction is a column body with a substantially perfect circular shape. The diameters of the column section 23 and the via conductors 40V, 41V are identical, as are the materials used. The column section 23 and the via conductors 40V, 41V are formed by metal plating (for example, copper plating).

[0037] The horn antenna 20, which is in Fig. 7, Fig. Figure 8 illustrates the device, which contains a dielectric material. The present disclosure describes an example in which the conductors 30, 31 are arranged across the entire region of the first and second surfaces of the base material 51. However, this example does not represent a limitation. The metal foil can be patterned to exclude the section outside the via conductors 40V, 41V.

[0038] The following describes the result of a comparison between the configuration having the column section 23, which is an example in the present embodiment (hereinafter referred to simply as a "present example"), and the configuration without the column body, which is a comparison example, based on electromagnetic field simulation. Fig. Figure 9 illustrates a configuration of a horn antenna used in an electromagnetic field simulation.

[0039] In the electromagnetic field simulation, the horn antenna 20 in the present example includes two column sections 23, as shown in Fig. Figure 9 is illustrated, and the column segments 23 are aligned in the Y direction. A training region 23a including the column segments 23, which is defined by a dash-dotted line in Fig. Figure 9 illustrates a rectangular region defined by the outer ends of the two column sections 23 in the Y-direction and the ends of the two column sections 23 in the X-direction. All column sections 23 are located within the formation region 23a. For example, if there is only one column section 23, the formation region 23a is a rectangular region with a length in the X-direction and a length in the Y-direction equal to the diameter of the column section 23.

[0040] The training region 23a is defined such that the length from the center of the training region 23a to the aperture 22a in the X-direction is within the range of 0.4 L to 0.5 L. The horn antenna 20 has a line-symmetrical configuration with respect to the center line CL, and the distance between each end section of the aperture 22a and the training region 23a in the Y-direction is in the range of 0.4 W to 0.425 W. The distance between the end section of the aperture 22a and the training region 23a is defined to be equal. For example, the length of the training region 23a is 0.2 W, and the distance between the training region 23a and the end section of the aperture 22a is 0.4 W. (1) Identical dimensions in the present and comparative examples

[0041] The dimensions of the horn antenna in the present example and the dimensions of the horn antenna in the comparison example are defined identically, and then the electromagnetic field simulation was performed for both examples. In other words, in the present example, column section 23 is added to the horn antenna of the comparison example. Fig. Figure 10 illustrates the reflection characteristics. Fig. 10 The solid line illustrates the present example (with column section 23) and the dashed line shows the comparison example (without column body).

[0042] As in Fig. As illustrated in Figure 10, the frequency at which the damping pole has a greater reflection attenuation S11 differs between the present example and the comparison example. Based on Fig. As shown in section 10, it is obvious that if column section 23 is provided, it can operate at a lower frequency while maintaining the same dimensions. In other words, it is clear that the operating frequency can be shifted to a lower frequency range compared to the configuration without a column body. Therefore, it is evident that the reflection characteristics can be improved. (2) Identical operating frequencies in the present and comparative examples

[0043] The operating frequency of the horn antenna in the present example and the operating frequency of the horn antenna in the comparison example were set identically, and then the electromagnetic field simulation was performed. The operating frequency was set to 85.375 GHz. The operating frequency can also be referred to as the resonant frequency. The gain (antenna amplification or antenna gain) and dimensions of a horn antenna are determined by the wavelength, that is, the operating frequency. By cutting the aperture of the horn section at a point where the electric field strength is high, the electromagnetic waves can be radiated into the external space. [Table 1] Frequenzbandbreite [GHz] Verstärkung [dB] Dimension (width W x length L x height H) [mm 3 ] Ohne Säulenkörper (Vergleichsbeispiel) 1,800 4,25 4,71×3,24×0,9(2,54λε×1,75λε×0,49λε) Ohne Säulenkörper (vorliegendes Beispiel) 2,475 5,76 4,50×2,96×0,50(2,43λε×1,59λε×0,50λε)

[0044] As shown in Table 1, the dimensions of the present example (width W x length L x height H) are 4.50 mm x 2.96 mm x 0.50 mm. The gain is 5.76 dB. On the other hand, the dimensions of the comparison example are 4.71 mm x 3.24 mm x 0.90 mm. The gain is 4.25 dB. When the wavelength λε is applied, the dimensions of the present example are 2.43λε × 1.59λε × 0.50λε, and the dimensions of the comparison example are 2.54λε × 1.75λε × 0.49λε. The wavelength λε is a value obtained by the square root of the “value of (300 [mm / s] / 87.375 [GHz]) divided by the value of the dielectric constant of the base material 51”, and the wavelength λε is expressed in millimeters [mm]. (2-1) Comparison regarding electric field distribution

[0045] Fig. Figure 11 shows the electric field distribution in the present example and Fig. Figure 12 shows the electric field distribution in the comparison example. Fig. 11, Fig. Figure 12 illustrates the change over time. The phase shift occurs in the sequence (a), (b), (c), and (d), which is shown in Fig. 11, Fig. 12 are illustrated. In Fig. 12 are the elements that are identical to or refer to the present example (in other words, the present embodiment), designated by adding “r” to the reference numerals in the present embodiment.

[0046] In the present example, the column section 23, which is arranged at the horn section 22, has the same potential (ground potential) as the conductors 30, 31, 40, 41. Therefore, the column section 23 acts as a wall that cancels out the electric field. The column section 23 cancels out the electric field that is reflected, for example, by the conductors 40, 41, which form the H-plane, towards the column section 23. As in Fig. As illustrated in Figure 11, column section 23 and its surroundings are zero points. The electric field is deflected around column section 23. Column section 23 cancels the reflection from aperture 22 due to the electric field being deflected around column section 23. Therefore, it is possible to ensure the reflection characteristics.

[0047] In the comparative example, since the column body is not included, the electric field strength at the position corresponding to the column body is higher, as in Fig. Figure 12 shows that it is necessary to provide an aperture 22ar at a position where the electric field strength is higher and reflection from aperture 22ar can be eliminated due to the higher electric field at the position corresponding to the column body. By fulfilling these conditions, it is possible to radiate the electromagnetic waves from aperture 22ar of the horn section 22r while ensuring the reflection characteristics. To fulfill these conditions, aperture 22ar must be located away from the position corresponding to the column body.

[0048] In the present example, it is possible to set the position where the electric field strength is higher in the comparison example to the zero point by providing column section 23. Consequently, the electric field distribution varies, and the position where aperture 22a is located and the electric field strength is higher is closer to waveguide section 21 compared to the comparison example. That is, aperture 22a approaches waveguide section 21. Therefore, the dimension of horn section 22 becomes smaller even at the same operating frequency. If the dimensions are identical, the operating frequency shifts into the lower frequency range. (2-2) Comparison regarding reflection characteristics

[0049] Fig. Figure 13 illustrates the reflection characteristics. Fig. Figure 13 illustrates the present example (with column section 23) with a solid line and illustrates the comparison example (without the column body) with a dashed line. As in Fig. As shown in Figure 13, attenuation poles are generated at essentially identical frequencies. Therefore, it is evident that the reflection characteristics can be improved by providing column section 23. As illustrated in Table 1, the frequency bandwidth, which is the bandwidth of the reflection attenuation S11 = -10 dB, is 1.8 GHz in the comparison example and 2.475 GHz in the present example. When column section 23 is provided, the frequency bandwidth is broadened. Therefore, based on Fig. 13 and Table 1 obviously show that the reflection characteristics can be improved by providing the column section 23. (2-3) Comparison regarding radiation characteristics or directivity

[0050] Fig. Figure 14 illustrates the radiation characteristics or directional effect. Fig. Figure 14 illustrates the present example (with column section 23) with a solid line and illustrates the comparison example (without the column body) with a dashed line. Fig. Figure 14 illustrates the reflection characteristics at an XY plane. As in Fig. As shown in Figure 14, a larger side lobe is generated in the comparison example. On the other hand, in the present example, the side lobes disappear and only the main ray exists. Therefore, based on Fig. 14. It is evident that the reflection characteristics can be improved by providing the column section 23. Since side lobes are not generated, the gain can be improved compared to the reference example.

[0051] The horn antenna 20 according to the present embodiment includes the column section 23 within the horn section 22. The column section 23 is electrically connected to at least one of the conductors 30, 31 that form the E-plane. The column section 23 has the same potential as the conductors 30, 31, 40, 41. The column section 23 acts as a wall that cancels out the electric field. The column section 23 and its surroundings become zero points, and the electric field distribution varies with respect to the configuration in which the column section is not included. Consequently, the operating frequency shifts to a lower frequency range with respect to the configuration in which the column section is not included. If the operating frequencies are identical in both the present example and the comparison example, it is possible to miniaturize the physical dimensions compared to the configuration without the column section.Therefore, it is possible to provide the horn antenna 20 with a smaller dimension.

[0052] Column section 23 is configured to include horn section 22, which has an H-plane horn configuration. It is possible to reduce the length L (in other words, the horn length) in the X-direction and the width W (the length in the Y-direction). The X-direction is the direction of transmission of electromagnetic waves. The dimensions can be reduced in three directions: height H, horn length L, and width W.

[0053] As in Fig. 7, Fig. As illustrated in Figure 8, the horn antenna 20 is arranged on the circuit board 50. The column section 23 is designed as a via conductor, formed by placing a conductive material in the holes 52 of the dielectric base material 51. Due to the wavelength shortening effect of the dielectric, it is possible to miniaturize the horn antenna 20. Since the horn antenna 20 can be miniaturized by providing the column section 23, it is possible to reduce tan δ (dielectric loss tangent).

[0054] As in, for example, Fig. As illustrated in Figure 4, several column sections 23 can be aligned in the lateral direction (in other words, the Y-direction) in a multi-column-section configuration. If a via conductor is used as the column section 23, the length of the training region 23a in the X-direction can be shortened compared to the configuration in which the column section 23, which has a large diameter, is used. Therefore, it is also possible to reduce the length L of the horn section 22 and the dimensions of the horn antenna 20 in the X-direction.

[0055] The horn antenna 20 according to the present embodiment is suitable for transmitting and / or receiving electromagnetic E-band waves, based on the simulation result mentioned above. (Other embodiments)

[0056] While the disclosure in this specification and the drawings has been described with reference to their embodiments, it is to be understood that the disclosure is not limited to these embodiments and constructions. The present disclosure is intended to cover different modifications and equivalent arrangements. Furthermore, in addition to the various combinations and configurations, other combinations and configurations, including more, fewer, or only a single element, also fall within the spirit and scope of the present disclosure.

[0057] The present disclosure in this specification and the drawings describes an example of the use of the horn antenna 20 in road-to-vehicle communication. However, there is no limitation thereto. The frequency used in the present application is not limited to the E-band (60 GHz to 90 GHz). The present application can be applied to wireless communication using radio frequency signals in a microwave band (3 GHz to 30 GHz) and a millimeter wave band (30 GHz to 300 GHz). The present disclosure can be applied not only to a vehicle but can, for example, be applied to consumer products.

[0058] The present disclosure describes an example of the horn antenna 20 with the printed circuit board 50. However, the present disclosure is not limited to this example. For instance, the horn antenna 20 can be formed on a metal plate by stamping, bending, joining, or the like. The conductors 30, 31, 40, 41 and the column section 23 described above can likewise be formed by processing a metal plate. When the printed circuit board 50 is used, it is possible to miniaturize the horn antenna 20.

[0059] The cross-sectional shape of column section 23 need not be restricted to a perfect circle. As in Fig. As illustrated in Figure 15, one configuration can include column section 23, which has a longer side in one direction. For example, column section 23 can have a cross-sectional surface with an elliptical shape, where the Y-direction is the longitudinal direction and the X-direction is the transverse direction. An elliptical, trapezoidal, or polygonal shape can also be used.

[0060] The number of column sections 23 need not be limited to the preceding example described in the present disclosure. As in Fig. 15, Fig. As illustrated in Figure 16, one configuration can include column section 23, which has a longer side in one direction. The cross-section of column section 23, which is shown in Figure 16, is shown in Figure 16. Fig. Figure 16 shows an elongated circular shape. In this configuration, the diameter of a column section 23 can be equal to the length of the training area 23a, which has two column sections 23, in the Y-direction.

[0061] As in Fig. As illustrated in Figure 17, the horn antenna 20 can include three or more column sections 23. Although not illustrated, three or more column sections 23 can be arranged in a row along the Y-direction. As shown in Fig. As illustrated in Figure 17, several column sections 23 can be arranged, with the positions arranged along the X-direction. Fig. Figure 17 illustrates that two column sections 23 are aligned in the Y direction, with the remaining column section 23 positioned at an intermediate position between the two column sections 23. The intermediate position is a position offset relative to the aperture 22a.

[0062] The present disclosure describes an example in which the column section 23 is connected to both conductors 30, 31, each forming the E-planes. However, there is no limitation thereon. In other words, the height of the column section 23 need not be limited to the height equal to the distance between the E-planes. The column section 23 is electrically connected to at least one of the conductors 30, 31 that form the E-plane. For example, in an example that is in Fig.As illustrated in Figure 18, the column section 23 is connected only to the conductor 31. The height of the column section 23 is shorter than the distance between the E-levels. Since the inventor of the present application confirmed the result based on the electromagnetic field simulation, it is equally possible to achieve the same effect even if the height of the column section 23 is 0.8 H as shown in the configuration where the height of the column section 23 is equal to the distance between the E-levels. The column section 23 has the same potential as the conductors 30, 31, 40, and 41. The column section 23 acts as a wall that cancels out the electric field. Therefore, it is possible to have the same advantageous effect even if the height of the column section 23 is shorter than the distance between the E-levels.

[0063] Column section 23 can be displaced away from aperture 22a in a region within horn section 22, in other words, a region surrounded by conductors 30, 31, 40, 41 of horn section 22. Therefore, it is possible to shift the column section to a position where the electric field strength is higher in the X direction.

Claims

[1] Horn antenna, comprising: a waveguide section (21); a horn section (22) connected to one end of the waveguide section (21) and having a height as the distance between E-planes and a width as the distance between H-planes, wherein the width of the horn section (22) is greater than the width of the waveguide section (21) and the height of the horn section (22) is equal to the height of the waveguide section (21); and Column sections (23) which are electrically connected to at least one of conductors (30, 31) which each form the E-planes on the horn section (22) and are arranged at a position away from an aperture (22a) of the horn section (22) within the horn section (22), wherein two of the column sections (23) are separated by half a wavelength or less. [2] Horn antenna according to claim 1, wherein each of the waveguide section (21), the horn section (22) and the column section (23) includes a dielectric base material (51), and the conductors (30, 31) which are arranged in several layers on the dielectric base material (51), wherein the dielectric base material (51) has a hole (52) which is connected to at least one of the conductors (30, 31) on the horn section (22), and wherein the column sections (23) are formed from a conductive material which is arranged in the hole (52). [3] Horn antenna according to claim 2, wherein the column sections (23) are aligned in one direction along the width of the horn section (22). [4] Having a horn antenna: a waveguide section (21); a horn section (22) connected to one end of the waveguide section (21) and having a height as the distance between E-planes and a width as the distance between H-planes, wherein the width of the horn section (22) is greater than the width of the waveguide section (21) and the height of the horn section (22) is equal to the height of the waveguide section (21); and a column section (23) which is electrically connected to at least one of conductors (30, 31) which each form the E-planes on the horn section (22) and is arranged at a position away from an aperture (22a) of the horn section (22) within the horn section (22), wherein a cross-sectional shape of one column section (23) is a perfect circular shape, an elliptical shape, a trapezoidal shape or a polygonal shape.

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