Group antenna

Abstract

Group antenna (2, 3, 4, 5') with a feed line comprising: a first branch line (12a) and a second branch line (12b), each extending in one direction, and each comprising a plurality of radiating elements (13a-13l); and a coupling line (11) which is configured to couple or combine the first branch line (12a) and the second branch line (12b), wherein the multitude of radiation elements (13a-13f) provided for the first branch line (12a) are arranged on one side of the first branch line (12a), the multitude of radiation elements (13g-13l) provided for the second branch line (12b) are arranged on one side of the second branch line (12b) that is opposite one side, and a distance from a coupling element (p1), in which the first branch line (12a) and the second branch line (12b) are coupled to the coupling line (11), to a radiating element (13f) that is closest to the coupling element (p1) of the plurality of radiating elements (13a-13f) provided for the first branch line (12a), by an electrical length of (2n-1)λ / 2 (where λ is a wavelength and n is a natural number) greater than a distance from the coupling element (p1) to a radiating element (13l) that is closest to the coupling element (p1) of the plurality of radiating elements (13g-13l) provided for the second branch line (12b), characterized by the fact that the group antenna (2, 3, 4, 5') further comprises a connector (15) which is designed to connect the first and second branch lines (12a, 12b) on the opposite side of the coupling part (p1).

Description

BACKGROUND OF THE INVENTION 1. Technical Field

[0001] Exemplary embodiments of the present invention relate to a group antenna. 2. State of the art

[0002] For this type of antenna, for example, a planar array antenna with a linearly extending feed line and a plurality of radiating antenna elements projecting perpendicularly from the line has been proposed (see JP 2001-111330 A (Patent Reference 1)). Furthermore, a technology / technique has been proposed in which an auxiliary antenna is formed from two element antennas provided at a predetermined distance from each other in the same plane, perpendicular to a main lobe direction of a main antenna, and in which high-frequency signals from the element antennas with the same amplitude and opposite phase are combined at a frequency to be received (see JP 2015-010823 A (Patent Reference 2)).

[0003] With this type of antenna, beamwidth and directivity are used as an index indicating the antenna's performance. However, with the technologies / techniques disclosed in patent literature 1 and 2, it is difficult to design the antenna in such a way that the beamwidth and directivity exhibit the desired width and directivity, which is technically problematic.

[0004] Furthermore, publication WO 2017 / 052 238 A1 discloses an antenna device and a vehicle radar device incorporating it, and publication US 2016 / 0 079 674 A1 discloses a distributor and a planar antenna. INVENTION SUMMARY

[0005] In view of the aforementioned problems, it is therefore an objective of the embodiments of the disclosure to provide a group antenna that can realize the desired beamwidth and directivity relatively easily.

[0006] The aforementioned object of the embodiments of the present invention can be achieved by a group antenna provided with a feed line, comprising: a first branch line and a second branch line, each extending in one direction and each comprising a plurality of radiating elements; and a coupling line configured to couple or combine the first branch line and the second branch line, wherein the plurality of radiating elements provided for the first branch line are provided on one side of the first branch line, the plurality of radiating elements provided for the second branch line are provided on one side of the second branch line opposite the first side, and a distance from a coupling element at which the first and second branch lines are coupled to the coupling line.to a radiating element of the plurality of radiating elements provided for the first branch line, which is closest to the coupling part, by an electrical length of (2n-1)λ / 2 (where λ is a wavelength and n is a natural number) greater than a distance from the coupling part to a radiating element of the plurality of radiating elements provided for the second branch line, which is closest to the coupling part, characterized in that the group antenna further comprises a connector which is configured to connect the first and the second branch lines on the opposite side of the coupling part. BRIEF DESCRIPTION OF THE DRAWING Fig. Figure 1 shows a top view illustrating a group antenna according to a first embodiment; Fig. Figure 2 shows a characteristic representation illustrating an example of the characteristics of the group antenna according to the first embodiment; Fig. Figure 3A shows a top view illustrating a group antenna according to a modification example of the first embodiment; Fig. Figure 3B shows a top view illustrating a group antenna according to a modification example of the first embodiment; Fig. Figure 4 shows a top view illustrating a group antenna according to a second embodiment; Fig. Figure 5 shows a characteristic representation illustrating an example of the characteristics of the group antenna according to the second embodiment; Fig. Figure 6 shows a top view illustrating a group antenna according to a third embodiment; Fig. Figure 7 shows a top view illustrating a group antenna according to a fourth embodiment; Fig. Figure 8A shows a characteristic representation illustrating an example of the properties of the group antenna according to the second embodiment; Fig. Figure 8B shows a characteristic representation illustrating an example of the properties of the group antenna according to the third embodiment; Fig. Figure 8C shows a characteristic representation illustrating an example of the properties of the group antenna according to the fourth embodiment; Fig. 9A shows a top view illustrating a group antenna according to a fifth embodiment; Fig. 9B shows a top view illustrating a group antenna according to the fifth embodiment; and Fig. Figure 10 shows a characteristic representation illustrating an example of the properties of the group antenna according to the fifth embodiment. DETAILED DESCRIPTION OF THE EXAMPLES OF EXECUTION

[0007] A group antenna according to the embodiments of the invention is described below with reference to the drawing. <Erstes Ausführungsbeispiel>

[0008] A group antenna according to a first embodiment is defined with reference to Fig. 1 and Fig. 2 described. (Configuration)

[0009] An overview of the group antenna according to the first embodiment is provided with reference to Fig. 1 explained. Fig. Figure 1 shows a top view illustrating the array antenna according to the first embodiment. Illustrations of a dielectric substrate and a base plate are omitted. The same applies to Fig. 3A and Fig. 3B, Fig. 4, Fig. 6, Fig. 7 and Fig. 9 to.

[0010] In Fig. 1 is a group antenna 1, a horizontally polarized group antenna. The group antenna 1 is provided with: branch lines 12a and 12b, which are adjacent to each other and extend in one direction (which is a direction vertical to a paper surface); and a coupling line 11, which is configured to couple or combine the branch lines 12a and 12b. The coupling line 11 and the branch lines 12a and 12b form a feed line to the group antenna 1. In the first embodiment, the term "branch lines 12a and 12b, which are adjacent to each other" preferably means "branch lines 12a and 12b, which are adjacent to each other without introducing another feed line (or branch line) between them".

[0011] Branch line 12a is provided with a plurality of radiation elements 13a, 13b, 13c, 13d, 13e and 13f, which project dendritically in a direction intersecting one direction and on the opposite side of branch line 12b. Similarly, branch line 12b is provided with a plurality of radiation elements 13g, 13h, 13i, 13j, 13k and 13l, which project dendritically in a direction intersecting one direction and on the opposite side of branch line 12a. In particular, in the first embodiment, the group antenna 1 is arranged in such a way that the distance from a coupling part p1, in which the branch lines 12a and 12b are coupled to the coupling line 11, to the radiating element 13f is greater by an electrical length of (2n-1)λ / 2 (where n is a natural number) than the distance from the coupling part p1 to the radiating element 13l.The "electrical length" is a length based on an amount of electrical phase change, and a length at which the phase changes by 360° is equivalent to a wavelength.

[0012] In each of the branch lines 12a and 12b, a standing wave is generated from electrical energy directed from the coupling element p1 to a reflection end (hereinafter referred to as a "progressing wave") and from electrical energy directed from the reflection end to the coupling element p1 (hereinafter referred to as a "reflected wave"). The radiating elements 13a, 13b, 13c, 13d, 13e, and 13f are each arranged on parts corresponding to the nodes of the standing wave generated in branch line 12a. Similarly, the radiating elements 13g, 13h, 13i, 13j, 13k, and 13l are each arranged on parts corresponding to the nodes of the standing wave generated in branch line 12b.

[0013] A portion of the electrical energy fed into the coupling line 11 can be successively coupled to and radiated or emitted by each of the radiating elements 13a, 13b, 13c, 13d, 13e, and 13f via the branch line 12a; specifically, an electrical wave or a radio wave can be emitted by each radiating element. Furthermore, the remaining portion of the electrical energy fed into the coupling line 11 can be successively coupled to and emitted by each of the radiating elements 13g, 13h, 13i, 13j, 13k, and 13l via the branch line 12b. (Beamwidth of the array antenna)

[0014] A group antenna of the type disclosed in patent specification 1 is provided, for example, with: a feed line formed on a dielectric substrate and extending linearly; and a plurality of radiating elements directly connected to the feed line and protruding dendritically. The beamwidth of the antenna arrangement changes depending on the width between a left radiating element and a right radiating element of the group antenna (for example, the distance between the center of a radiating element protruding on one side of the feed line and the center of a radiating element protruding on the opposite side of that side of the feed line). Specifically, as the width between the radiating elements increases, the beamwidth decreases; that is, the directivity improves.On the other hand, a smaller width between the radiating elements increases the beam width; namely, the directivity is reduced.

[0015] Furthermore, the propagation speed of an electromagnetic wave in a medium (or dielectric substance) can be determined by the dielectric constant and the magnetic permeability of the medium. The dielectric substance has a relative permeability of approximately 1, and the size of the radiating elements formed on the dielectric substrate can therefore be determined primarily in accordance with the dielectric constant of the dielectric substrate. Consequently, if the dielectric constant of the dielectric substrate is changed, the size of the radiating elements can be changed. In other words, if the dielectric constant of the dielectric substrate is changed, the width between the radiating elements can be changed, and thus the beam width can be changed.

[0016] The dielectric substrate must, however, fulfill certain electrical properties, such as a specific dielectric constant and loss, and mechanical properties, such as strength and coefficient of thermal expansion. It is therefore not easy to change the materials of the dielectric substrate or its composition, and it is difficult to alter the dielectric constant of the dielectric substrate to achieve a desired beam width. Consequently, it is equally difficult to change the size of the emitting elements to achieve a desired beam width.

[0017] The group antenna 1 is provided with the branch lines 12a and 12b as part of the feed line. Therefore, if the distance between the branch lines 12a and 12b is changed, it is possible to change the width between the radiating elements described above without changing the size of the radiating elements 13a to 13l, that is, without changing the dielectric constant of the dielectric substrate. (Characteristics of a group antenna)

[0018] The following are characteristics of group antenna 1 with reference to Fig. 2 explained. Fig. Figure 2 shows a characteristic representation illustrating an example of the properties of the group antenna according to the first embodiment. A solid line in Fig. Figure 2 shows the properties of the group antenna 1 (which exhibits directivity in the horizontal plane). A dotted line in Fig. Figure 2 shows the characteristics of a group antenna according to a comparative example where the feed line is not provided with the branch line (which is, for example, the group antenna of the type disclosed in patent specification 1).

[0019] In Fig. Near 0°, the gain of array antenna 1 (see the solid line) is greater than the gain of the array antenna according to the comparison example (see the dotted line). Conversely, in an area with a relatively large angle, the gain of array antenna 1 is significantly lower than the gain of the array antenna according to the comparison example. In other words, array antenna 1 can be said to have a reduced beamwidth or improved directivity compared to the array antenna according to the comparison example.

[0020] In Fig. 2 are left-right asymmetric properties of the group antenna 1, indicated by the solid line, presumably caused by a difference in cancellation distribution between the left and right radiating elements, in addition to a vertical offset of the left and right radiating elements. (Technical effect)

[0021] According to the group antenna 1, it is possible to achieve the desired beamwidth and directivity without changing the size of the radiating elements 13a to 13l by changing the distance between the branch lines 12a and 12b.

[0022] The array antenna is sometimes used, for example, for vehicle-mounted radar. When mounted on a vehicle, the radar is often located on an emblem, a bumper, the back of a resin cover, or similar surface. In this case, the electromagnetic wave exhibits different transmission properties in a resin material depending on its polarization. If the resin material has a relatively shallow slope (that is, if the resin material is approximately perpendicular to the ground), it is a well-known fact that a horizontally polarized wave traveling at a wide angle onto a horizontal plane has lower transmission attenuation compared to a vertically polarized wave.However, the horizontally polarized array antenna tends to radiate the electromagnetic wave in a lateral direction, and this causes a disturbance of the directional characteristic, which is problematic.

[0023] However, the array antenna 1 can achieve the desired beamwidth by changing the distance between the branch lines 12a and 12b, even though it is a horizontally polarized array antenna. Furthermore, the array antenna 1 can reduce interference with the directional characteristic by decreasing the radiation of the electromagnetic wave in the lateral direction. Therefore, according to the array antenna 1, it is possible to implement a vehicle-mounted radar that uses a horizontally polarized wave and exhibits outstanding transmission properties in a resin material located on the front of the vehicle radar. Examples of variations

[0024] Examples of modifications to the group antenna 1 according to the first embodiment are given below with reference to Fig. 3A and Fig. 3B explained. Fig. 3A and Fig. Figure 3B shows top views illustrating group antennas according to modified examples of the first embodiment.

[0025] In Fig. 3A is a group antenna 1' configured such that the width of one part 14a is greater than the width of the other part of the branch line 12a, and the width of one part 14b is greater than the width of the other part of the branch line 12b, with each part 14a and 14b occupying an area of ​​the respective branch lines 12a and 12b, starting at the reflection end, and having a length corresponding to an electrical length of λ / 4. Such a configuration makes it possible to suppress the amount of electrical energy radiated from the reflection end of each of the branch lines 12a and 12b.

[0026] Furthermore, according to Fig. 3B the group antenna 1' shall be designed in such a way that the branch lines 12a and 12b have the same length (or that the reflection ends are at the same height). <Zweites Ausführungsbeispiel>

[0027] A group antenna according to a second embodiment is described below with reference to Fig. 4 and Fig. 5 explained. The second embodiment differs in part in the form of the group antenna, but is otherwise the same as the first embodiment. Therefore, the same explanation as in the first embodiment is omitted for the second embodiment, and the same parts bear the same reference numerals in the drawing. The following is explained with reference to Fig. 4 and Fig. 5 explains a fundamentally different point of view. (Configuration)

[0028] An overview of the group antenna according to the second embodiment is provided with reference to Fig. 4 explained. Fig. Figure 4 shows a top view illustrating the group antenna according to the second embodiment.

[0029] According to Fig. 4 is a group antenna 2 with a connecting line 15, which is configured to connect the branch lines 12a and 12b on the opposite side of the coupling section 1. The coupling line 11, the branch lines 12a and 12b and the connecting line 15 form a feed line to the group antenna 2.

[0030] In the array antenna 1 according to the first embodiment, the radiating elements are each arranged on the parts corresponding to the nodes of the standing wave generated by the propagating wave and the reflected wave. In the array antenna 2 according to the second embodiment, the radiating elements are each arranged on parts corresponding to the nodes of a standing wave generated by a wave associated with clockwise propagating electrical energy and a wave associated with counterclockwise propagating electrical energy. Hereinafter, the branch lines 12a and 12b and the connecting line 15 are referred to as a “ring line (12a, 12b, 15)” as needed. (Characteristics of a group antenna)

[0031] The following are characteristics of the group antenna 2 with reference to Fig. 5 explained. Fig. Figure 5 shows a characteristic representation illustrating an example of the properties of the group antenna according to the second embodiment. A solid line in Fig. Figure 5 shows the properties of the group antenna 2 (which exhibits directivity in the horizontal plane). A dotted line in Fig. Figure 5 shows the characteristics of group antenna 1.

[0032] In the case of group antenna 2 (see the solid line), the left-right asymmetry characteristics of the directivity in the horizontal plane are improved compared to group antenna 1 (see the dotted line). This may indicate that a difference in the excitation distribution between the left and right radiating elements is reduced because the left and right feed lines are connected in a ring configuration. (Technical effect)

[0033] With group antenna 2, it is also possible to change the desired beamwidth and directivity without changing the size of the radiating elements 13a to 13l by changing the distance between the branch lines 12a and 12b, in other words, by changing the flattening of an oval formed by the branch lines 12a and 12b and the connecting line 15. <Drittes Ausführungsbeispiel>

[0034] A group antenna according to a third embodiment is described with reference to Fig. Section 6 explains. The third embodiment differs in part in the form of the group antenna, but in other parts it is the same as the second embodiment. Thus, the same explanation as in the second embodiment is omitted for the third embodiment, and the same parts bear the same reference numerals in the drawing. With reference to Fig. Section 6 below explains a fundamentally different point of view. (Configuration)

[0035] An overview of the group antenna according to the third embodiment is provided with reference to Fig. 6 explained. Fig. Figure 6 shows a top view illustrating the group antenna according to the third embodiment.

[0036] According to Fig. 6 is a group antenna 3 with a dummy line 16 provided, which is connected to the connecting line 15 and has the same effect as a λ / 4 short-circuit dummy line (short circuit). The dummy line 16 can be a dummy line that is short-circuited between the dummy line 16 and the base plate using a via (or a through-hole), or it can be a dummy line that acts like a short-circuit dummy line without the use of a via. In Fig. Figure 6 illustrates a T-shaped dummy line as an example of the dummy line 16, which has the same effect as the λ / 4 short-circuit dummy line. In the T-shaped dummy line, a conductor with an electrical length of λ / 4 extends from the connecting conductor 15, and a bridge of a size that allows the connecting conductor to be equivalently short-circuited is connected to its end. However, the dummy line 16 is not limited to the T-shaped dummy line; various existing embodiments can be applied to it. From the perspective of manufacturing the array antenna 3, the dummy line 16 can preferably be a dummy line without a via. (Technical effect)

[0037] In a bend in the feed line, such as connecting line 15, electrical energy tends to be radiated unnecessarily. This unnecessary radiation is more pronounced the smaller the radius of curvature of the bent section and can lead to a disturbance in the directivity. According to the group antenna 3, it is possible to prevent the unnecessary radiation of electrical energy originating from connecting line 15 by connecting the dummy line 16 to connecting line 15. <Viertes Ausführungsbeispiel>

[0038] A group antenna according to a fourth embodiment is described with reference to Fig. 7 and Fig. 8A to Fig. 8C explained. The fourth embodiment differs in part in the form of the group antenna, but is otherwise the same as the third embodiment. Thus, the same explanation as for the third embodiment is omitted in the fourth embodiment, and the same parts bear the same reference numerals in the drawing. With reference to Fig. 7 and Fig. 8A to Fig. Section 8C below explains a fundamentally different point of view. (Configuration)

[0039] An overview of the group antenna according to the fourth embodiment is provided with reference to Fig. 7 explained. Fig. Figure 7 shows a top view illustrating the group antenna according to the fourth embodiment.

[0040] According to Fig. A group antenna 4 is provided with a dummy line 17 for impedance matching, which is connected to the connecting line 11. Various conventional configurations can be applied to an impedance matching procedure, and a detailed explanation is therefore omitted. The position and size of the dummy line 17 can vary depending on the impedance of the group antenna 4. (Technical effect)

[0041] The influence of the ring line (12a, 12b, 15) from each of the group antennas 2, 3 and 4 on the group antenna is determined with reference to Fig. 8A to Fig. 8C explained. Fig. 8A to Fig. Figures 8C are characteristic representations illustrating examples of the properties of the group antennas according to the second to fourth embodiments. An upper part in Fig. Figure 8A shows a Smith chart. A lower part in Fig. 8A to Fig. Figure 8C shows a representation that indicates a relationship between a frequency and a return loss (or reflection coefficient). Fig. Figure 8A shows a Smith chart and a diagram illustrating the relationship between a frequency and a return loss for the group antenna 2 according to the second embodiment. Fig. Figure 8B shows a Smith chart and a diagram illustrating the relationship between a frequency and a return loss for the group antenna 3 according to the third embodiment. Fig. Figure 8C shows a Smith chart and a diagram illustrating the relationship between a frequency and a return loss for the group antenna 4 according to the fourth embodiment.

[0042] In the group antenna 2, a reactance component is mainly changed by the ring line (12a, 12b, 15) to cause an impedance deviation, and according to Fig. 8A shifts a frequency that allows for low return loss from a desired frequency (which in this case is 76.5 gigahertz (GHz)). The dummy line 16 is not designed to change the reactance of the ring line (12a, 12b, 15) of the array antenna 3. Therefore, even with the array antenna 3 provided by the dummy line 16, according to Fig. 8B the frequency that allows low return loss is still shifted from the desired frequency.

[0043] In the case of the group antenna 4, which is provided with the reactive line 17 for impedance matching, the impedance deviation caused by the ring line (12a, 12b, 15) is eliminated, and according to Fig. 8C allows the return loss to be reduced at the desired frequency.

[0044] The reactive line 17 can also be provided for impedance matching for the group antenna 1 according to the first embodiment. <Fünftes Ausführungsbeispiel>

[0045] Group antennas according to a fifth embodiment are described below with reference to Fig. 9A, Fig. 9B and Fig. 10 explained. The fifth embodiment differs in part in the form of the group antenna, but in other parts it is the same as the first embodiment. Thus, in the fifth embodiment, the same explanations as in the first embodiment are omitted, and the same parts bear the same reference numerals in the drawing. With reference to Fig. 9A, Fig. 9B and Fig. Section 10 below explains a fundamentally different point of view. (Configuration)

[0046] An overview of the group antennas according to the fifth embodiment is given below with reference to Fig. 9A and Fig. 9B explained. Fig. 9A and Fig. Figure 9B shows top views illustrating the group antennas according to the fifth embodiment.

[0047] According to Fig. 9a The branch line 12a of a group antenna 5 is provided with a plurality of radiating elements that are dendritically directed in a direction that intersects a direction (which is a vertical direction onto a paper surface) and project on the side of branch line 12b. In the same way, branch line 12b is provided with a plurality of radiating elements that are dendritically directed in the direction that intersects the direction and project on the side of branch line 12a.

[0048] In the group antenna 5, the reflection ends of the branch lines 12a and 12b are wider than the other part; however, the shape of the reflection ends is not limited to this example. Furthermore, the other side of the coupling part p1 of the branch lines 12a and 12b can be connected by the connecting line 15 according to Fig. 9B should be connected. A 5' group antenna according to Fig. 9B is provided with the dummy line 16, but can also be provided without it. The group antenna 5' can likewise be provided with a dummy line for impedance matching. (Characteristics of a group antenna)

[0049] The following are characteristics of the group antenna 5 with reference to Fig. 10 explained. Fig. Figure 10 shows a characteristic representation illustrating an example of the properties of the group antenna according to the fifth embodiment. A solid line in Fig. Figure 10 shows the properties of the group antenna 5 (which exhibits a directivity in the horizontal plane). A dotted line in Fig. Figure 10 shows the properties of the group antenna according to the comparative example, in which the feed line is not provided with the branch line (which is, for example, the group antenna of the type disclosed in patent specification 1).

[0050] According to Fig. 10. The gain of array antenna 5 (see the solid line) is lower near 0° than the gain of the array antenna according to the comparison example (see the dotted line). On the other hand, in an area with a relatively large angle, the gain of array antenna 5 is greater than the gain of the array antenna according to the comparison example. In other words, it can be said that array antenna 5 has a wider beamwidth compared to the array antenna according to the comparison example. (Technical effect)

[0051] According to the group antennas 5 and 5', it is possible to achieve the desired beamwidth and directivity without changing the size of the radiating elements by changing the distance between the branch lines 12a and 12b.

[0052] Various embodiments of the present invention, derived from the embodiments and modifications explained above, are explained below.

[0053] A group antenna according to one embodiment of the invention is provided with a feed line comprising: a first branch line and a second branch line, each extending in one direction and each comprising a plurality of radiating elements; and a coupling line configured to couple or combine the first branch line and the second branch line, wherein the plurality of radiating elements provided for the first branch line are arranged on one side of the first branch line, the plurality of radiating elements provided for the second branch line are arranged on one side of the second branch line opposite one side, and a distance from a coupling element, at which the first and second branch lines are coupled to the coupling line, to a radiating element,The coupling element that is closest to the multiple of radiating elements provided for the first branch line is greater by an electrical length of (2n-1)λ / 2 (where λ is a wavelength and n is a natural number) than the distance from the coupling element to a radiating element that is closest to the multiple of radiating elements provided for the second branch line. In the embodiments described above, branch lines 12a and 12b correspond to examples of the first and second branch lines, respectively, and coupling line 11 corresponds to an example of the coupling line.

[0054] The beamwidth and directivity of a multi-element antenna depend on the width between the radiating elements in a direction that intersects the feed line. One possible method for changing the width between the radiating elements is to change their size. However, changing the size of the radiating elements would require altering the materials of the dielectric substrate on which the multi-element antenna is mounted, its composition, and similar factors, thereby changing the dielectric constant, which is not practical.

[0055] The array antenna, as designed, is provided with a first and a second branch line, which are adjacent to each other and each extend in one direction as part of the feed line. The distance between the first and second branch lines can be varied as desired. Thus, by changing the distance between the first and second branch lines, the width between the radiating elements can be changed without altering the size of the radiating elements. Therefore, with this array antenna, it is relatively easy to achieve the desired beamwidth and directivity.

[0056] In the aforementioned embodiments, the connecting line 15 corresponds to an example of the connector. According to this design, it is possible, for example, to improve the left-right symmetry of the directivity associated with the array antenna in the horizontal plane.

[0057] In this configuration, the array antenna can be provided with a dummy line on the connector, which has the same effect as a λ / 4 short-circuit dummy line. Such a configuration makes it possible to prevent unnecessary radiation of electrical energy originating from the connector. In the aforementioned embodiments, the dummy line 16 corresponds to an example of a dummy line that has the same effect as a λ / 4 short-circuit dummy line (short circuit).

[0058] In a further embodiment of the array antenna, the coupling line includes a dummy line for impedance matching. In the aforementioned embodiments, the dummy line 17 corresponds to an example of a dummy line for impedance matching. According to this embodiment, it is possible to easily match the impedance connected to the array antenna.

[0059] The present invention can be implemented in other specific embodiments without departing from the spirit or essential characteristics thereof. The present embodiments and examples must therefore be regarded in every respect as illustrative and not as limiting, the scope of the invention being indicated more by the following claims than by the preceding description, and any modifications falling within the scope and equivalence of the claims must therefore be considered as included therein.

[0060] A group antenna is provided with a feed line comprising a first branch line and a second branch line, as well as a coupling line. Radiating elements provided for the first branch line are arranged on one side of the first branch line. Radiating elements provided for the second branch line are provided on the opposite side of the second branch line. The distance from a coupling element, where the first and second branches are coupled to the coupling line, to a radiating element that is closest to the coupling element among the multiple radiating elements provided for the first branch line, is greater by an electrical length of (2n-1)λ / 2 than the distance from the coupling element to a radiating element that is closest to the coupling element among the multiple radiating elements provided for the second branch line.

Claims

[1] Group antenna (2, 3, 4, 5') with a feed line comprising: a first branch line (12a) and a second branch line (12b), each extending in one direction, and each comprising a plurality of radiating elements (13a-13l); and a coupling line (11) which is configured to couple or combine the first branch line (12a) and the second branch line (12b), wherein the multitude of radiation elements (13a-13f) provided for the first branch line (12a) are arranged on one side of the first branch line (12a), the multitude of radiation elements (13g-13l) provided for the second branch line (12b) are arranged on one side of the second branch line (12b) that is opposite one side, and a distance from a coupling element (p1), in which the first branch line (12a) and the second branch line (12b) are coupled to the coupling line (11), to a radiating element (13f) that is closest to the coupling element (p1) of the plurality of radiating elements (13a-13f) provided for the first branch line (12a), by an electrical length of (2n-1)λ / 2 (where λ is a wavelength and n is a natural number) greater than a distance from the coupling element (p1) to a radiating element (13l) that is closest to the coupling element (p1) of the plurality of radiating elements (13g-13l) provided for the second branch line (12b), characterized by , that the group antenna (2, 3, 4, 5') further comprises a connector (15) which is designed to connect the first and second branch lines (12a, 12b) on the opposite side of the coupling part (p1). [2] Group antenna (2, 3, 4, 5') according to claim 2, with a dummy line on the connector (15) which has the same effect as a λ / 4 short-circuit dummy line (16). [3] Group antenna (2, 3, 4, 5') according to claim 1 or 2, wherein the coupling line (11) comprises a dummy line (17) for impedance matching.

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