Dual-polarized antenna

Abstract

To provide a polarization shared antenna high in cross polarization discrimination of an antenna.SOLUTION: A polarization shared antenna includes a plurality of antenna units arranged in a row and is capable of sending / receiving a first polarized wave oscillating in a first direction and a second polarized wave oscillating in a second direction orthogonal to the first direction. The plurality of antenna units each include a first antenna element for the first polarized wave and a second antenna element for the second polarized wave. In the antenna units adjacent to each other, each of the first antenna elements radiates the first polarized wave with a phase delayed by a predetermined first phase with respect to the phase of a first input signal, and one of the second antenna elements radiates the second polarized wave with a phase delayed by a predetermined second phase with respect to the phase of a second input signal, and the other of the second antenna elements radiates the second polarized wave with an opposite phase that is a phase delayed by the second phase with respect to the phase of the second input signal.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a dual-polarized antenna capable of transmitting and receiving vertically polarized waves and horizontally polarized waves. [Background technology]

[0002] In 5G communications using the millimeter wave band, it is possible to multiplex two information channels at a single carrier frequency using vertically and horizontally polarized waves that are orthogonal to each other. Conventionally, antennas that use a substrate integrated waveguide (SIW) have been known as dual-polarized antennas that can transmit and receive vertically and horizontally polarized waves (see, for example, Patent Document 1).

[0003] The dual-polarized antenna using SIW disclosed in Patent Document 1 and elsewhere radiates electromagnetic waves parallel to the substrate surface. This type of antenna is called an "endfire type." In contrast, antennas that radiate electromagnetic waves perpendicular to the substrate surface are called "broadside type."

[0004] An end-fire type dual-polarized antenna is suitable for use cases where it is installed on the roof of a vehicle and performs 360-degree beam search while communicating. From the perspective of vehicle design, a low-profile, small-sized array antenna is desirable in order to minimize the protrusion on the roof. Dual-polarized antennas that use SIW are easy to manufacture and are suitable for reducing the height and size of antennas. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2021-517760 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in dual-polarized antennas, the separation between the vertically and horizontally polarized transmission lines tends to become narrower as antennas become thinner and smaller, which may lead to a decrease in communication quality due to the increased likelihood of cross-polarized components leaking from one transmission line (e.g., the vertically polarized transmission line) to the other (e.g., the horizontally polarized transmission line).

[0007] SUMMARY OF THE INVENTION An object of the present invention is to provide a dual polarized antenna having high cross-polarization discrimination. [Means for solving the problem]

[0008] A dual-polarized antenna according to one aspect of the present invention comprises: A dual-polarized antenna has a plurality of antenna units arranged in a row, and is capable of transmitting and receiving a first polarized wave oscillating in a first direction and a second polarized wave oscillating in a second direction orthogonal to the first direction, Each of the plurality of antenna units comprises: a first antenna element for the first polarization; a second antenna element for the second polarization; a transmission line for transmitting an input signal to the first antenna element and the second antenna element; Equipped with In the adjacent antenna units, each of the first antenna elements radiates the first polarized wave with a phase delayed by a predetermined first phase with respect to the phase of a first input signal; One of the second antenna elements radiates the second polarized wave at a phase delayed by a predetermined second phase relative to the phase of the second input signal, and the other of the second antenna elements radiates the second polarized wave at a phase opposite to the second phase delayed by the second phase relative to the phase of the second input signal. [Effects of the Invention]

[0009] According to the present invention, a dual polarized antenna is provided that provides high cross-polarization discrimination of the antenna. [Brief explanation of the drawings]

[0010] [Figure 1]FIG. 1 is a perspective view showing an external appearance of an antenna device according to an embodiment of the present invention. [Figure 2] FIG. 2 is an exploded perspective view of the antenna device. [Figure 3] FIG. 3 is a front view of the antenna device as seen from the positive side in the X-axis direction. [Figure 4] FIG. 4 is a side view of the antenna device as viewed from the negative side in the Y-axis direction. [Figure 5] 5A and 5B are plan views showing the antenna structure of the antenna main body. [Figure 6] FIG. 6 is a perspective view showing the antenna structure of the antenna main body. [Figure 7] FIG. 7 is a diagram showing the laminated structure of the antenna body. [Figure 8] FIG. 8 is a diagram showing the phases of input signals to adjacent antenna units. [Figure 9] FIG. 9 is a diagram showing the antenna output when there is no coupling between the lines. [Figure 10] FIG. 10 is a diagram showing the horizontally polarized component in the antenna output when the horizontally polarized component is coupled to the vertically polarized input signal. [Figure 11] FIG. 11 is a diagram showing the vertically polarized component in the antenna output when the vertically polarized component is coupled to the horizontally polarized input signal. [Figure 12] 12A and 12B are diagrams showing the intensities of the main polarization component and the cross polarization component in the radiation direction. DETAILED DESCRIPTION OF THE INVENTION

[0011] An antenna device A according to an embodiment of the present invention will be described in detail below with reference to the drawings.

[0012] Antenna device A is a dual-polarized antenna capable of radiating first and second polarized waves that are orthogonal to each other. Antenna device A transmits, for example, vertically and horizontally polarized waves in the 5G millimeter wave band (28 GHz). Antenna device A is an end-fire antenna whose main radiation direction is parallel to the substrate surface.

[0013] In this disclosure, the first direction, which is the vibration direction of the first polarized wave, will be described as the "vertical direction," and the second direction, which is the vibration direction of the second polarized wave, will be described as the "horizontal direction." The description will also be made using a right-handed Cartesian coordinate system in which the direction perpendicular to the substrate surface is the positive direction of the Z axis, and the main radiation direction of the first polarized wave and the second polarized wave is the positive direction of the X axis. Hereinafter, the terms "X-axis direction," "Y-axis direction," and "Z-axis direction" refer to the positive directions of the X axis, Y axis, and Z axis, respectively.

[0014] Fig. 1 is an external perspective view showing an antenna device A according to an embodiment of the present invention. Fig. 2 is an exploded perspective view of the antenna device A. Fig. 3 is a front view of the antenna device A as seen from the positive side in the X-axis direction. Fig. 4 is a side view of the antenna device A as seen from the negative side in the Y-axis direction.

[0015] 1 to 4, the antenna device A includes an antenna main body 1 and an antenna cover 5. In Fig. 3 and Fig. 4, the inside of the antenna main body 1 is shown in a see-through manner.

[0016] The antenna main body 1 is an array antenna having eight antenna units 1A to 1H arranged in a row in the Y-axis direction. Control units 61 and 62 are mounted on the antenna main body 1. The control units 61 and 62 are, for example, beamforming ICs, and perform functions such as adjusting the phase and gain of each antenna connected via a transmission line and amplifying the transmission signal. The control unit 61 controls the power supply to the antenna units 1A to 1D, and the control unit 62 controls the power supply to the antenna units 1E to 1H.

[0017] The antenna cover 5 is an auxiliary member arranged at the end of the antenna main body 1 on the positive side in the X-axis direction. The antenna cover 5 is made of a conductive material such as metal. The antenna cover 5 has a first cover body 51, a second cover body 52, and a third cover body 53. The first cover body 51 and the second cover body 52 are arranged opposite each other in the Z-axis direction and are connected by the third cover body 53. That is, in the XZ cross section, the antenna cover 5 has a substantially U-shape with an opening on the positive side in the X-axis direction.

[0018] For example, the antenna cover 5 is attached to the antenna body 1 by inserting and fixing the positive end of the antenna body 1 in the X-axis direction into an opening 53a provided in the third cover body 53. The antenna cover 5 is electrically connected to the ground pattern (reference numeral omitted) of the antenna body 1. The antenna cover 5 is fixed in a manner that ensures DC conduction with the ground of the antenna body 1, for example, by soldering or a conductive adhesive. Note that the antenna cover 5 may be fixed in a manner that does not involve DC conduction, such as by screwing, as long as the opening 53a of the attachment portion is sufficiently close to the ground of the antenna body 1. The provision of the antenna cover 5 improves the antenna gain of the antenna device A.

[0019] 5A and 5B are plan views showing the antenna structure of the antenna main body 1. Fig. 6 is a perspective view showing the antenna structure of the antenna main body 1. In Figs. 5B and 6, portions of the antenna units 1A and 1B are shown enlarged. In Fig. 6, the inside of the antenna structure is shown in a see-through manner.

[0020] As shown in Figures 5A and 5B, each of the antenna units 1A to 1H has a first antenna section 10 and a second antenna section 20. The first antenna section 10 has an antenna structure for vertical polarization. The second antenna section 20 has an antenna structure for horizontal polarization. The antenna units 1A to 1H are formed, for example, by a multilayer printed wiring board.

[0021] The antenna units 1A to 1H are formed, for example, from a multilayer printed wiring board. The antenna units 1A to 1H can be easily manufactured using circuit formation technology for printed wiring boards. Furthermore, the size, shape, position, etc. of the antenna elements in the first antenna section 10 and the second antenna section 20 can be easily controlled, improving element precision.

[0022] The layered structure of the antenna body 1 is shown in Fig. 7. The antenna body 1 has, for example, a first conductor layer M1 to a sixth conductor layer M6, as shown in Fig. 7. The first conductor layer M1 to the sixth conductor layer M6 are formed of metal foil such as copper foil. A dielectric layer D made of a resin material or the like is interposed between each of the first conductor layer M1 to the sixth conductor layer M6. The antenna cover 5 is electrically connected to, for example, the ground patterns (reference numerals omitted) of the first conductor layer M1 and the sixth conductor layer M6.

[0023] The first antenna section 10 includes a first transmission line 11 and a first antenna element 12. The first transmission line 11 is a section that transmits a vertically polarized signal. The first antenna element 12 is a section that radiates a vertically polarized wave.

[0024] The first transmission line 11 is a microstrip line formed on the surface layer of the substrate by the first conductor layer M1.

[0025] The first antenna element 12 includes a waveguide 30 that propagates vertically polarized waves. The waveguide 30 has, for example, a substrate integrated waveguide (SIW) structure. The waveguide 30 is formed by side via groups 31G and 32G, a rear via group 33G, an upper plate 34, and a lower plate 35.

[0026] The side via groups 31G, 32G are each formed of a plurality of side vias 31, 32 arranged in the X-axis direction. The back via group 33G is formed of a plurality of back vias 33 arranged in the Y-axis direction. The side vias 31, 32 and back via 33 are through holes that connect a ground pattern (reference numeral omitted) formed on the first conductor layer M1 to a ground pattern (reference numeral omitted) on the sixth conductor layer M6, and penetrate the second conductor layer M2 to the fifth conductor layer M5. The side vias 31, 32 and back via 33 are electrically connected to the second conductor layer M2, the fourth conductor layer M4 and the fifth conductor layer M5, and are electrically insulated from the third conductor layer M3.

[0027] The upper plate 34 is formed of the ground plane of the second conductor layer M2. The ground plane of the second conductor layer M2 forms a return path for a transmission line (e.g., the first transmission line 11) formed on the surface layer of the substrate. The lower plate 35 is formed of the ground plane of the fifth conductor layer M5.

[0028] A rectangular waveguide having an opening on the positive side in the X-axis direction is formed by the side via groups 31G and 32G, the back via group 33G, the upper plate 34, and the lower plate 35. A first via 36 connected to the first transmission line 11 is inserted near the back via group 33G.

[0029] The first via 36 is a through hole that connects the first conductor layer M1 and the sixth conductor layer M6, and penetrates the second conductor layer M2 to the fifth conductor layer M5. The first via 36 is electrically insulated from the second conductor layer M2 to the fifth conductor layer M5. An electromagnetic field is induced around the first via 36 and propagates within the waveguide 30. The electromagnetic field is then radiated as a vertically polarized wave from the opening of the waveguide 30.

[0030] The second antenna section 20 includes a second transmission line 21 and a second antenna element 22. The second transmission line 21 is a section that transmits a horizontally polarized signal. The second antenna element 22 is a section that radiates a horizontally polarized wave.

[0031] The second transmission line 21 is a microstrip line formed on the surface layer of the substrate by the first conductor layer M1. The second transmission line 21 is disposed close to the first transmission line 11 and substantially parallel to it.

[0032] The second antenna element 22 includes a radiating portion 23 and a signal converting portion 24. The radiating portion 23 has, for example, a dipole antenna structure. The signal converting portion 24 converts the single-ended signal from the second transmission line 21 into a differential signal.

[0033] The radiation portion 23 is formed by the fourth conductor layer M4. The radiation portion 23 has a linear shape and extends to the positive side and negative side in the Y-axis direction across a slot 24B formed in the fourth conductor layer M4.

[0034] The signal conversion unit 24 is composed of a relay line 24A formed on the third conductor layer M3 and a slot 24B formed on the fourth conductor layer M4. The relay line 24A is a microstrip line and is connected to the second transmission line 21 via a second via 25. The second via 25 is a through hole that connects the first conductor layer M1 and the third conductor layer M3 and penetrates the second conductor layer M2. The second via 25 is electrically insulated from the second conductor layer M2.

[0035] The relay line 24A has a substantially L-shape, extends from the connection with the second via 25 to the positive side in the X-axis direction, and bends and extends in the Y-axis direction. In Fig. 6, the relay line 24A of the antenna unit 1A bends and extends to the positive side in the Y-axis direction, and the relay line 24A of the antenna unit 1B bends and extends to the negative side in the Y-axis direction. That is, the relay lines 24A of the adjacent antenna units 1A and 1B are bent in opposite directions. The slot 24B is formed along the X-axis direction from the edge of the fourth conductor layer M4 (the spaced apart portion of the radiation portion 23).

[0036] If the bending directions of the relay line 24A are not opposite between adjacent antenna units 1A and 1B, the conversion from a single-ended signal to a differential signal will not be complete, resulting in a slight bias in the current flowing through the left and right arms of the second antenna element 22, which has a dipole structure. Furthermore, the biased power supply direction will result in poor symmetry and tilted beams of the array antenna. Therefore, in this embodiment, the bending directions of the relay line 24A are opposite between adjacent antenna units 1A and 1B.

[0037] The relay line 24A and the slot 24B are arranged perpendicular to each other in a plan view seen from the Z-axis direction, and are electromagnetically coupled without contact. The signal conversion unit 24 is a microstrip-to-slot converter, and the power feeding directions of the signal conversion units 24 of adjacent antenna units 1A and 1B are opposite.

[0038] The electromagnetic field formed around the relay line 24A induces an electromagnetic field in the slot 24B of the ground pattern of the fourth conductor layer M4. As a result, the single-ended signal from the second transmission line 21 is converted into a differential signal and transmitted to the radiation portion 23. The signal is then radiated from the radiation portion 23 as a horizontally polarized wave.

[0039] In antenna device A, when the phases of the input signals are the same, the horizontally polarized waves radiated from adjacent antenna units 1A to 1H (for example, first antenna unit 1A and second antenna unit 1B) are in opposite phases. On the other hand, when the phases of the input signals are the same, the vertically polarized waves radiated from adjacent antenna units 1A to 1H are in the same phase. That is, in antenna units 1A and 1B, each first antenna element 12 radiates a vertically polarized wave with a phase delayed by a predetermined phase (first phase) from the phase of the input signal. One of second antenna elements 22 radiates a horizontally polarized wave with a phase delayed by a predetermined phase (second phase) from the phase of the input signal, and the other second antenna element 22 radiates a horizontally polarized wave with a phase that is the opposite of the phase delayed by the predetermined phase (second phase) from the phase of the input signal.

[0040] Therefore, for example, when the peak of the antenna gain is set in the X direction (front), the horizontally polarized input signals (second input signals) of adjacent antenna units 1A to 1H are controlled to be alternately inverted and have opposite phases (see FIG. 8). Also, the vertically polarized input signals (first input signals) of adjacent antenna units 1A to 1H are controlled to have the same phase. As a result, the horizontally polarized waves and vertically polarized waves radiated from adjacent antenna units 1A to 1H all have the same phase in the radiation direction, and the adjacent antenna outputs reinforce each other, improving the antenna gain.

[0041] Below, we will specifically explain the antenna output when the control unit 61 controls transmission to the first to fourth antenna units 1A to 1D, taking as an example a case where the peak of the antenna gain is set in the +X direction. In each of the antenna units 1A to 1D, the first transmission line 11 for vertical polarization and the second transmission line 21 for horizontal polarization are formed of microstrip lines and are arranged close to each other. Because the first transmission line 11 and the second transmission line 21 have the same transmission mode, isolation is lower than when the transmission modes between the lines are different.

[0042] 9 to 11, the phases of the vertically polarized waves V1 to V4 and the horizontally polarized waves H1 to H4 of the first to fourth antenna units 1A to 1D are shown as the phases of the BFIC output (input signal) output from the control unit 61, the transmission signal in the transmission path, and the antenna output (output signal) from the antenna element.

[0043] FIG. 9 is a diagram showing the antenna output when there is no coupling between the lines.

[0044] 9, for vertically polarized waves V1 to V4, the BFIC output (first input signal), the transmission signal, and the antenna output are all in phase. By having the antenna outputs in phase, a high antenna gain can be obtained in the radiation direction.

[0045] On the other hand, the horizontally polarized waves H1 to H4 are controlled so that the BFIC outputs (second input signals) are in opposite phases in adjacent antenna units 1A to 1H (for example, the first antenna unit 1A and the second antenna unit 1B). The signals are transmitted as is through the transmission line, so the opposite phases are maintained. Ultimately, in adjacent antenna units 1A to 1H, one signal is maintained in phase while the other signal is inverted and converted to an opposite phase by the second antenna element 22, so the antenna outputs are in phase. Having the antenna outputs in phase enables high antenna gain to be obtained in the radiation direction.

[0046] FIG. 10 is a diagram showing the horizontally polarized component in the antenna output when the horizontally polarized component is coupled to the vertically polarized input signal.

[0047] As shown in FIG. 10, in antenna units 1A-1D, horizontally polarized signals may leak between first transmission line 11 for vertical polarization and second transmission line 21 for horizontal polarization, resulting in coupling of horizontally polarized components with vertically polarized signals. Because the BFIC outputs of horizontally polarized waves H1-H4 are out of phase, the coupled horizontally polarized components are out of phase in first transmission line 11. Because the phase of the transmission signal is maintained in first antenna element 12 for vertical polarization, the antenna outputs of adjacent antenna units 1A-1H are out of phase. Therefore, the horizontally polarized components included in the antenna outputs are canceled out between adjacent antenna units 1A-1H in the radiation direction, reducing the gain of the cross-polarized components in the radiation direction. As a result, cross-polarization discrimination is improved.

[0048] FIG. 11 is a diagram showing the vertically polarized component in the antenna output when the vertically polarized component is coupled to the horizontally polarized input signal.

[0049] As shown in FIG. 11, in antenna units 1A-1D, vertically polarized signals may leak between first transmission line 11 for vertical polarization and second transmission line 21 for horizontal polarization, resulting in coupling of vertically polarized components with horizontally polarized signals. Because the BFIC outputs of vertically polarized waves V1-V4 are in phase, the coupled vertically polarized components are in phase on second transmission line 21. In adjacent antenna units 1A-1H, one of the signals is maintained in phase while the other is inverted and converted to an opposite phase by second antenna element 22 for horizontal polarization, resulting in opposite-phase antenna outputs. Therefore, the vertically polarized components included in the antenna outputs are canceled out between adjacent antenna units 1A-1H, reducing the gain of the cross-polarized components in the radiation direction and improving cross-polarization discrimination.

[0050] 12A and 12B are diagrams showing the intensities of cross-polarized components in the radiation direction, where Fig. 12A shows the measurement results for antenna device A according to the embodiment, and Fig. 12B shows the measurement results for a conventional antenna device.

[0051] 12A, in antenna device A, the intensity of the cross-polarized component is reduced in the main radiation direction (0 [deg]). In the conventional antenna device, the cross-polarized component is also output in phase, so that the intensity is high in the main radiation direction, just like the polarized component.

[0052] As described above, the antenna device A according to one aspect of the present invention has the following features either singly or in appropriate combination.

[0053] That is, the antenna device A (dual-polarized antenna) has a plurality of antenna units 1A-1H arranged in a row, and is a dual-polarized antenna capable of transmitting and receiving vertically polarized waves (first polarization) that oscillate in the vertical direction (first direction) and horizontally polarized waves (second polarization) that oscillate in the horizontal direction (second direction) orthogonal to the vertical direction. Each of the plurality of antenna units 1A-1H includes a first antenna element 12 for vertically polarized waves and a second antenna element 22 for horizontally polarized waves. In adjacent antenna units 1A-1H, each of the first antenna elements 12 radiates vertically polarized waves with a phase delayed by a predetermined first phase from the phase of a first input signal, one of the second antenna elements 22 radiates horizontally polarized waves with a phase delayed by a predetermined second phase from the phase of the second input signal, and the other of the second antenna elements 22 radiates horizontally polarized waves with a phase opposite to the phase delayed by the second phase from the phase of the second input signal.

[0054] According to the antenna device A, by controlling the horizontally polarized input signal to have an opposite phase, even if cross-polarized components are coupled between the transmission lines, the influence of the radiation characteristics due to the cross-polarized components can be reduced, improving the accuracy of cross-identification. Furthermore, since the transmission lines to the first antenna element 12 and the second antenna element 22 can be formed using microstrip lines, the transmission lines can be simplified and the mounting area can be reduced. Furthermore, the end-fire type allows for easy miniaturization and low profile, which is particularly useful when installed close to a metal member such as a vehicle roof.

[0055] In addition, in the antenna device A, the second antenna element 22 has a signal conversion section 24 that converts a single-ended signal into a differential signal, and the signal conversion sections 24 of adjacent antenna units 1A to 1H feed single-ended signals in opposite directions. Specifically, the signal conversion section 24 has a relay line 24A and a slot 24B that are electromagnetically coupled without contact, and the signal conversion sections 24 of adjacent antenna units 1A to 1H have relay lines 24A extending in opposite directions relative to the slots 24B. This makes it easy to realize a configuration in which, in adjacent antenna units 1A to 1H, one of the second antenna elements 22 radiates a horizontally polarized wave in phase with the input signal, and the other of the second antenna elements 22 radiates a horizontally polarized wave in opposite phase to the input signal.

[0056] The antenna device A also includes a first transmission line 11 that transmits a first input signal to a first antenna element 12 and a second transmission line 21 that transmits a second input signal to a second antenna element 22, and the first transmission line 11 and the second transmission line 12 are microstrip lines. This allows the dual-polarized antenna to be miniaturized. Although the line-to-line isolation decreases, high cross-polarization discrimination is ensured.

[0057] The antenna device A also includes control units 61 and 62 that adjust the phase of each transmission line, and the control units 61 and 62 output second input signals of opposite phases to the second antenna elements 22 of adjacent antenna units 1A to 1H. The control units 61 and 62 set the phase of the input signals to each of the antenna units 1A to 1H, for example, so that the antenna gain has a peak at a desired angle. At this time, adjacent antenna units 1A to 1H output input signals of opposite phases to the set phase calculated from the angle at which the peak is to be achieved to the second antenna elements 22. As a result, the horizontally polarized waves and vertically polarized waves radiated from adjacent antenna units 1A to 1H are all in phase in the set angular direction, and the adjacent antenna outputs reinforce each other, improving the antenna gain.

[0058] The invention made by the inventor has been specifically described above based on an embodiment, but the present invention is not limited to the above embodiment and can be modified within the scope of the gist thereof.

[0059] For example, in the embodiment, the first transmission line 11 and the second transmission line 21 are formed of microstrip lines, but the first transmission line 11 and the second transmission line 21 may be other strip lines or coplanar lines.

[0060] In addition, in the embodiment, a dipole antenna is applied to the second antenna element 22 for horizontal polarization, but another antenna structure such as a Yagi antenna may be applied to the second antenna element 22. In addition to the substrate integrated waveguide shown in the embodiment, another antenna structure such as a dipole antenna formed in the vertical direction using vias may be applied to the first antenna element 12 for vertical polarization.

[0061] Furthermore, in the embodiment, a transmitting antenna that radiates horizontally polarized waves and vertically polarized waves has been described as an example, but the polarized antenna of the present invention can be applied to any antenna that has the function of transmitting or receiving horizontally polarized waves and vertically polarized waves, or both.

[0062] Furthermore, the dual polarized antenna of the present invention may be provided with a plurality of antenna units, and the number of antenna units is not particularly limited.

[0063] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0064] 1 Antenna body 1A~1H Antenna unit 11 First transmission line 12 First antenna element 21 Second transmission line 22 Second antenna element A Antenna device (polarized dual antenna)

Claims

1. A dual-polarized antenna having a plurality of antenna units arranged in a row, capable of transmitting and receiving a first polarized wave oscillating in a first direction and a second polarized wave oscillating in a second direction orthogonal to the first direction, Each of the plurality of antenna units comprises: a first antenna element for the first polarization; a second antenna element for the second polarization; a transmission line that transmits an input signal to the first antenna element and the second antenna element, In the adjacent antenna units, each of the first antenna elements radiates the first polarized wave with a phase delayed by a predetermined first phase with respect to the phase of a first input signal; one of the second antenna elements radiates the second polarized wave at a phase delayed by a predetermined second phase with respect to the phase of a second input signal, and the other of the second antenna elements radiates the second polarized wave at a phase opposite to the second phase delayed by the predetermined second phase with respect to the phase of the second input signal; Dual polarized antenna.

2. the second antenna element has a signal conversion unit that converts a single-ended signal into a differential signal; The signal conversion units of the adjacent antenna units have opposite feeding directions of the single-ended signals. The dual-polarized antenna according to claim 1 .

3. the signal conversion unit has a relay line and a slot that are electromagnetically coupled in a non-contact manner, The signal conversion units of the adjacent antenna units have the relay lines extending in opposite directions relative to the slot. The dual-polarized antenna according to claim 2 .

4. The transmission line includes a first transmission line that transmits a first input signal to the first antenna element, and a second transmission line that transmits a second input signal to the second antenna element; the first transmission line and the second transmission line are microstrip lines. The polarized antenna according to claim 1 .

5. A control unit that adjusts the phase of each of the transmission lines, The control unit transmits an input signal of an opposite phase to the second antenna element of the adjacent antenna unit. The polarized antenna according to claim 1 .

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