阅读说明：本技术 天线、天线系统、阵列天线以及阵列天线系统 (Antenna, antenna system, array antenna and array antenna system ) 是由 小向康文 小林弘晃 高井康充 冈田真一 平松义范 于 2020-04-16 设计创作，主要内容包括：天线(10)具备：天线元件(11),呈环状,两端为开放端,且由导体形成；以及第1接地导体(12),与天线元件(11)的一端的开放端连接,且以围拢天线元件(11)的外周的方式而被配置成封闭的环状。(An antenna (10) is provided with: an antenna element (11) which is annular, has both ends open, and is formed of a conductor; and a 1 st ground conductor (12) connected to the open end of one end of the antenna element (11) and arranged in a closed loop so as to surround the outer periphery of the antenna element (11).)

1. An antenna is provided with:

an antenna element having a ring shape, both ends of which are open ends, the antenna element being formed of a conductor; and

and a 1 st ground conductor connected to the open end of one end of the antenna element and arranged in a closed loop so as to surround an outer periphery of the antenna element.

2. The antenna as set forth in claim 1,

the antenna element is formed in a circular ring shape.

3. The antenna of claim 1 or 2,

the antenna further includes a disturbing element formed of a conductor branched from the antenna element.

4. An antenna system is provided, which is capable of improving the antenna performance,

the antenna system is provided with:

the antenna of any one of claims 1 to 3; and

a control substrate for controlling the operation of the display device,

the control substrate is provided with:

a control circuit that controls the antenna; and

and a 2 nd ground conductor connected to the open end of the one end of the antenna element and the 1 st ground conductor.

5. An array antenna configured by configuring the antenna arrangement of any one of claims 1 to 3 in plural.

6. An array antenna system is provided, which comprises a plurality of antennas,

the array antenna system is provided with:

an array antenna as claimed in claim 5; and

a control substrate for controlling the operation of the display device,

the control substrate is provided with:

a control circuit that controls the array antenna, the control circuit including a phase control unit that controls phases of radio waves output from a plurality of antennas constituting the array antenna; and

and a 2 nd ground conductor connected to the open end of the one end of the antenna element and the 1 st ground conductor.

Technical Field

The present disclosure relates to an antenna, an antenna system, an array antenna and an array antenna system.

Background

A module including a coil antenna formed with a spiral coil pattern for transmitting and receiving signals through contactless communication with a contactless IC card has been disclosed (for example, patent document 1).

(Prior art document)

(patent document)

Japanese patent laid-open No. 2008-269386 of patent document 1

When power is supplied to an antenna provided in a module via a cable such as a coaxial cable, a ground conductor of the cable may be connected to a ground conductor provided in the module. As disclosed in patent document 1, the antenna provided in the module may be connected to the ground conductor provided in the module. In this case, the current leaking from the antenna to the ground conductor of the module flows into the ground conductor of the cable. Accordingly, the radiation characteristics of the antenna may be affected by the cable.

Disclosure of Invention

Thus, the present disclosure provides an antenna or the like capable of improving radiation characteristics.

An antenna according to an aspect of the present disclosure includes: an antenna element having a ring shape, both ends of which are open ends, the antenna element being formed of a conductor; and a 1 st ground conductor connected to the open end of one end of the antenna element and arranged in a closed loop so as to surround an outer periphery of the antenna element.

The antenna and the like according to the present disclosure can improve radiation characteristics.

Drawings

Fig. 1 is a plan view of an antenna system according to embodiment 1.

Fig. 2A is a diagram showing a simulation result of a current distribution of the antenna system according to the comparative example.

Fig. 2B is a diagram showing a simulation result of a current distribution of the antenna system according to embodiment 1.

Fig. 3 is a plan view of the array antenna system according to embodiment 2.

Fig. 4 is a circuit configuration diagram showing an example of the phase control unit according to embodiment 2.

Fig. 5 is a circuit configuration diagram showing an example of a part of the phase control unit according to embodiment 2.

Fig. 6 is a diagram showing an example of phase characteristics of each phase shifter in the phase control unit according to embodiment 2.

Fig. 7 is a diagram showing directivity characteristics when the phase difference of the array antenna according to embodiment 2 is 90 degrees.

Fig. 8 is a diagram showing directivity characteristics when the phase difference of the array antenna according to embodiment 2 is 180 degrees.

Fig. 9 is a diagram showing directivity characteristics of the array antenna according to embodiment 2 when there is no phase difference.

Fig. 10 is a diagram showing directivity characteristics of the array antenna according to embodiment 2 when no phase difference is present in a state of being connected to a cable.

Detailed Description

An antenna according to an aspect of the present disclosure includes: an antenna element having a ring shape, both ends of which are open ends, the antenna element being formed of a conductor; and a 1 st ground conductor connected to the open end of one end of the antenna element and arranged in a closed loop so as to surround an outer periphery of the antenna element.

For example, the following cases exist: a ground conductor (referred to as a 2 nd ground conductor) of a control board provided with a control circuit for controlling an antenna is connected to an open end of one end of an antenna element, and the 2 nd ground conductor is connected to a ground conductor of a cable such as a coaxial cable (for example, an outer conductor of the coaxial cable), and power is supplied to the antenna element via the cable. In this case, a current leaks from the antenna element to the 2 nd ground conductor, and the leaked current flows into the ground conductor of the cable, so that the radiation characteristic of the antenna may be affected by the cable. Then, the first annular ground conductor 1 disposed so as to surround the outer periphery of the antenna element is connected to the open end of one end of the antenna element. Accordingly, current does not easily leak from the antenna element to the 2 nd ground conductor, and thus does not easily flow into the ground conductor of the cable connected to the 2 nd ground conductor. Therefore, the radiation characteristic of the antenna is not easily affected by the cable, so that the radiation characteristic can be improved.

Also, the antenna element may be formed in a circular ring shape.

Thus, the antenna element may be circular ring-shaped.

The antenna may further include a disturbing element formed of a conductor branched from the antenna element.

Accordingly, an electric wave of a circularly polarized wave can be radiated from the antenna by the perturbation element.

An antenna system according to an aspect of the present disclosure includes the antenna and a control board, the control board including: a control circuit that controls the antenna; and a 2 nd ground conductor connected to the 1 st ground conductor and the open end of one end of the antenna element.

Accordingly, an antenna system capable of improving radiation characteristics can be provided.

An array antenna according to an aspect of the present disclosure is configured by arranging a plurality of the above-described antenna arrays.

Accordingly, an array antenna capable of improving radiation characteristics can be provided.

An array antenna system according to an aspect of the present disclosure includes the above-described array antenna and a control board, the control board including a control circuit that controls the array antenna, the control circuit including a phase control unit that controls phases of radio waves output from a plurality of antennas constituting the array antenna; and a 2 nd ground conductor connected to the open end of the one end of the antenna element and the 1 st ground conductor.

Accordingly, an array antenna system capable of improving radiation characteristics can be provided.

The embodiments to be described below are general or specific examples. The numerical values, shapes, components, arrangement positions and connection manners of the components, steps, and the order of the steps shown in the following embodiments are merely examples, and the present disclosure is not limited thereto.

(embodiment mode 1)

Embodiment 1 will be described below with reference to fig. 1 to 2B.

Fig. 1 is a plan view of an antenna system 1 according to embodiment 1.

The antenna system 1 is a system for radiating and receiving electric waves. The antenna system 1 includes an antenna 10 and a control board 20. In addition, the antenna 10 and the control substrate 20 may be formed integrally. The antenna system 1 may be implemented by one substrate 30, as shown in fig. 1, for example. The substrate 30 may be, for example, a printed wiring board, and the antenna 10 and the control substrate 20 may be formed on one substrate 30. In fig. 1, the left side portion of the substrate 30 is referred to as an antenna 10, and the right side portion is referred to as a control substrate 20. The antenna 10 and the control board 20 may not be formed on one board 30, and may be formed separately.

The antenna 10 includes an antenna element 11, a 1 st ground conductor 12, a perturbation element 13, and a feeding point 14.

The antenna element 11 is a loop-shaped radiating element formed of a conductor having both ends opened. The antenna element 11 is formed on the substrate 30 as a conductor pattern, for example. In fig. 1, in order to facilitate recognition of the shape of the antenna element 11, hatching is added to the antenna element 11 with diagonal lines extending from the upper right to the lower left. The antenna element 11 is formed in a circular ring shape, for example. The antenna element 11 is not limited to a circular shape as long as it has an annular shape, and may have a polygonal shape. Although the loop antenna element 11 of 1 circumference is shown as the loop antenna element 11 in fig. 1, the antenna element 11 is not limited to a loop of 1 circumference, and may be a loop of 1 circumference or more (i.e., a spiral shape). The open end of one end of the antenna element 11 is connected to the 1 st ground conductor 12 and a 2 nd ground conductor 21 described later. The other end of the antenna element 11 has an open end connected to the feeding point 14.

The 1 st ground conductor 12 is a ring-shaped ground conductor connected to the open end of one end of the antenna element 11 and arranged to close around the outer periphery of the antenna element 11. The 1 st ground conductor 12 is formed on the substrate 30 as a conductor pattern, for example. In fig. 1, dots are added to the 1 st ground conductor 12 in order to facilitate recognition of the shape of the 1 st ground conductor 12. In order to facilitate recognition of the loop shape of the 1 st ground conductor 12, a broken line is added to a boundary between the 1 st ground conductor 12 and a 2 nd ground conductor 21 described later. For example, the 1 st ground conductor 12 and the 2 nd ground conductor 21 described later may be connected to the substrate 30 without any break. For example, the 1 st ground conductor 12 is disposed along the antenna element 11. For example, since the antenna element 11 is formed in a circular ring shape, the 1 st ground conductor 12 is formed in a circular ring shape along the outer periphery of the ring shape. The 1 st ground conductor 12 may not be annular but may be formed in a polygonal annular shape as long as it is arranged so as to close the outer periphery of the antenna element 11. For example, when the antenna element 11 has a square annular shape, the 1 st ground conductor 12 may be formed in a square annular shape along the outer periphery of the antenna element 11.

The disturbing element 13 is a radiating element constituted by a conductor branched from the antenna element 11. The perturbation elements 13 are formed as conductor patterns on the substrate 30, for example. In fig. 1, in order to facilitate recognition of the shape of the disturbance element 13, the disturbance element 13 is hatched with oblique lines extending in the direction from the upper left to the lower right. The perturbation element 13 is formed to branch from the loop-shaped antenna element 11 and extend to the inside of the loop, but may be formed to extend to the outside of the loop. Furthermore, although the disturbing element 13 has a linear shape, it is not limited to the linear shape and may have a curved shape. An electric wave of a circularly polarized wave can be radiated from the antenna 10 by the perturbation element 13. For example, a right-hand circularly polarized wave directed to the near side on the paper surface of fig. 1 can be radiated, and a left-hand circularly polarized wave directed to the far side on the paper surface of fig. 1 can be radiated. When the antenna 10 radiates a linearly polarized radio wave, the disturbing element 13 may not be provided.

The feeding point 14 is provided, for example, at the open end of the other end of the antenna element 11, for supplying high-frequency power to the antenna element 11, and transmits the generated high-frequency power to a receiver or the like by receiving radio waves with the antenna element 11. For example, the feeding point 14 is connected to an input/output IF (interface) 23 as described later, and the input/output IF (interface) 23 is connected to a cable such as a coaxial cable via the control circuit 22. Although fig. 1 shows that the feeding point 14 is provided at the open end of the other end of the antenna element 11, it may be provided at a position of the antenna element 11 that is offset from the open end, instead of the open end.

The control board 20 includes a 2 nd ground conductor 21, a control circuit 22, and an input/output IF 23.

The 2 nd ground conductor 21 is a ground conductor connected to the 1 st ground conductor 12 and an open end of one end of the antenna element 11. The 2 nd ground conductor 21 is formed on the control substrate 20 (substrate 30) as an overall pattern, for example. In fig. 1, dots different from those of the 1 st ground conductor 12 are added to the 2 nd ground conductor 21 in order to facilitate recognition of the shape of the 2 nd ground conductor 21.

The control circuit 22 is a circuit for controlling the antenna 10. The components of the control circuit 22 may be provided only on one main surface of the control board 20, may be provided on both surfaces, or may be provided in an inner layer when the control board 20 (board 30) is a multilayer board. The control circuit 22 includes, for example, an impedance matching circuit, a filter circuit, a switching circuit, or the like.

The input/output IF23 is an interface to which a cable such as a coaxial cable is connected, and is a coaxial connector in the case where the cable is a coaxial cable. The input/output IF23 is connected to, for example, an RFIC (radio Integrated Circuit) or the like via a cable. For example, when the cable is a coaxial cable and the input/output IF23 is a coaxial connector, the coaxial cable is connected to the coaxial connector, and the inner conductor of the coaxial cable is connected to the feeding point 14 via the control circuit 22. Accordingly, at the time of transmission, high-frequency power from the RFIC or the like can be supplied to the antenna element 11, and at the time of reception, high-frequency power from the antenna element 11 can be transmitted to the RFIC or the like. The outer conductor (ground conductor) of the coaxial cable is connected to the 2 nd ground conductor 21.

The present disclosure is characterized in that the 1 st ground conductor 12 is connected to an open end of one end of the antenna element 11, and the 1 st ground conductor 12 is arranged in a closed loop shape so as to surround an outer periphery of the antenna element 11. The effect achieved by providing the antenna 10 with the first ground conductor 12 will be described with reference to fig. 2A and 2B.

Fig. 2A shows a simulation result of a current distribution of the antenna system according to the comparative example. Fig. 2B shows a simulation result of the current distribution of the antenna system 1 according to embodiment 1. In fig. 2A and 2B, lighter color indicates more concentrated current.

In the antenna system according to the comparative example, the 1 st ground conductor 12 is not provided. Therefore, by comparing fig. 2A and fig. 2B, the effect of providing the 1 st ground conductor 12 can be confirmed.

As shown in fig. 2A, when the 1 st ground conductor 12 is not provided, the current is concentrated in the portion circled by the broken line a in the 2 nd ground conductor 21, and it is understood that the current flowing from the antenna element 11 to the 2 nd ground conductor 21 increases. For example, when the ground conductor of the cable is connected to the 2 nd ground conductor 21, the current leaking from the antenna element 11 to the 2 nd ground conductor 21 flows into the ground conductor of the cable. Accordingly, the radiation characteristic of the antenna 10 is affected by the cable (e.g., radiation noise from the cable), and there is a possibility that the radiation characteristic may be deteriorated.

As shown in fig. 2B, in the case of the antenna system 1 including the 1 st ground conductor 12, it is understood that the current is not concentrated in the portion circled by the broken line a in the 2 nd ground conductor 21, but is concentrated in the portion circled by the broken line B in the 1 st ground conductor 12. That is, the 1 st ground conductor 12 is provided, whereby the current can be suppressed from flowing from the antenna element 11 to the 2 nd ground conductor 21.

As described above, when the 2 nd ground conductor 21 of the control board 20 is connected to the open end of one end of the antenna element 11, and the 2 nd ground conductor 21 is connected to a ground conductor of a cable such as a coaxial cable (for example, an outer conductor of the coaxial cable), the antenna element 11 may be fed with power through the cable. In this case, a current leaks from the antenna element 11 to the 2 nd ground conductor 21, and the leaked current flows into the ground conductor of the cable, so that the radiation characteristic of the antenna 10 may be affected by the cable. Then, the 1 st ground conductor 12, which is disposed in a loop shape so as to surround the outer periphery of the antenna element 11, is connected to the open end of one end of the antenna element 11. Accordingly, current does not easily leak from the antenna element 11 to the 2 nd ground conductor 21, and current does not easily flow into the ground conductor of the cable connected to the 2 nd ground conductor 21. Therefore, the radiation characteristics of the antenna 10 are not easily affected by the cable, so that the radiation characteristics can be improved.

(embodiment mode 2)

Next, embodiment 2 will be described with reference to fig. 3 to 10. In embodiment 2, an array antenna 100 and an array antenna system 2 including the array antenna 100 will be described, where the array antenna 100 is configured by arranging a plurality of antennas 10 according to embodiment 1.

Fig. 3 is a plan view of the array antenna system 2 according to embodiment 2.

The array antenna system 2 is a system for radiating and receiving electric waves. The array antenna system 2 includes an array antenna 100 and a control board 200. In the array antenna system 2, the directivity of the array antenna 100 can be controlled. That is, it is possible to transmit and receive radio waves to and from an object arranged in a specific direction with respect to the array antenna 100. In addition, the array antenna 100 and the control substrate 200 may be formed as one body. For example, as shown in fig. 3, the array antenna system 2 may be implemented by one substrate 300. The substrate 300 may be, for example, a printed wiring board, and the array antenna 100 and the control substrate 200 may be formed on one substrate 300. In fig. 3, the lower portion of the substrate 300 is referred to as an array antenna 100, and the upper portion is referred to as a control substrate 200. The array antenna 100 and the control board 200 may be formed separately from each other, instead of being formed on one board 300.

The array antenna 100 is configured by arranging a plurality of antennas 10 according to embodiment 1, and includes, for example, 4 antennas 10. Here, the 4 antennas 10 are antennas 10a to 10 d. That is, the antennas 10a to 10d each include: antenna element 11, 1 st ground conductor 12, perturbing element 13, and feed point 14. The antenna element 11, the 1 st ground conductor 12, and the disturbing element 13 of each of the antennas 10a to 10d are formed on the substrate 300 as, for example, a conductor pattern. As described later, the feeding point 14 of each of the antennas 10a to 10d is connected to an input/output IF230 connected to a cable such as a coaxial cable via a control circuit 220. The number of antennas 10 included in the array antenna 100 is not limited to 4, and may be 2, 3, or 5 or more.

The control board 200 includes: a 2 nd ground conductor 210, a control circuit 220, and an input-output IF 230.

The 2 nd ground conductor 21.0 is a ground conductor connected to the open end of one end of the antenna element 11 of each of the antennas 10a to 10d and the 1 st ground conductor 12 of each of the antennas 10a to 10 d. The 2 nd ground conductor 210 is formed on the control substrate 200 (substrate 300) as an overall pattern, for example. In fig. 3, dots different from those of the 1 st ground conductor 12 are added to the 2 nd ground conductor 210 in order to facilitate recognition of the shape of the 2 nd ground conductor 210.

The control circuit 220 is a circuit for controlling the array antenna 100. The components of the control circuit 220 may be provided only on one main surface of the control board 200, may be provided on both surfaces, or may be provided in an inner layer when the control board 200 (board 300) is a multilayer board. The control circuit 220 includes, for example, an impedance matching circuit, a filter circuit, a switching circuit, or the like. The control circuit 220 includes, for example, a phase control unit 227 (see fig. 4 described later) and controls the phases of radio waves output from the plurality of antennas 10a to 10d constituting the array antenna 100.

The input/output IF230 is an interface to be connected to a cable such as a coaxial cable, and is a coaxial connector in the case where the cable is a coaxial cable. The input/output IF230 is connected to, for example, an RFIC via a cable. For example, when the cable is a coaxial cable and the input/output IF230 is a coaxial connector, the coaxial cable is connected to the coaxial connector, and the inner conductor of the coaxial cable is connected to the feeding point 14 of each of the antennas 10a to 10d via the control circuit 220. Accordingly, it is possible to supply high-frequency power from the RFIC or the like to the antenna element 11 of each of the antennas 10a to 10d at the time of transmission, and to transmit high-frequency power from the antenna element 11 of each of the antennas 10a to 10d to the RFIC or the like at the time of reception. The outer conductor (ground conductor) of the coaxial cable is connected to the 2 nd ground conductor 210.

Here, the phase control unit 227 will be described with reference to fig. 4 to 6.

Fig. 4 is a circuit configuration diagram showing an example of the phase control unit 227 according to embodiment 2. Fig. 4 shows an input/output IF230 and antennas 10a to 10d in addition to the phase control unit 227. The input/output IF230 in fig. 4 represents, for example, a terminal connected to the inner conductor of the coaxial cable. A portion of the input/output IF230 connected to the outer conductor (ground conductor) of the coaxial cable is connected to the 2 nd ground conductor 210 (not shown in fig. 4). The control circuit 220 may include other circuits such as an impedance matching circuit and a filter circuit in addition to the phase control unit 227, and the other circuits are not shown in fig. 4.

For example, the directivity of the array antenna 100 can be controlled by applying a phase difference to the high-frequency signal transmitted to each of the antennas 10a to 10d via the input/output IF 230.

The phase control unit 227 is configured to control the directivity of the array antenna 100, and the phase control unit 227 includes: switches SW11 and SW12 provided corresponding to the antenna 10a, and phase shifters α 1 to α n (n is an integer of 2 or more); switches SW21 and SW22 and phase shifters β 1 to β n provided corresponding to the antenna 10 b; switches SW31 and SW32 and phase shifters γ 1 to γ n provided corresponding to the antenna 10 c; switches SW41 and SW42 provided corresponding to the antenna 10d, and phase shifters δ 1 to δ n.

The switch SW11 is an spnt (single Pole n through) switch, and the common terminal is connected to the input/output IF230, and the selection terminal is connected to the phase shifters α 1 to α n. The switch SW21 is an SPnT switch, and the common terminal is connected to the input/output IF230, and the selection terminal is connected to the phase shifters β 1 to β n. The switch SW31 is an SPnT switch, and the common terminal is connected to the input/output IF230, and the selection terminal is connected to the phase shifters γ 1 to γ n. The switch SW41 is an SPnT switch, and the common terminal is connected to the input/output IF230, and the selection terminal is connected to the phase shifters δ 1 to δ n.

The phase shifters α 1 to α n, β 1 to β n, γ 1 to γ n, and δ 1 to δ n are phase matching circuits. The phase shifters α 1 to α n, β 1 to β n, γ 1 to γ n, and δ 1 to δ n are circuits formed of impedance elements such as inductors and capacitors, and the amount of phase adjustment is determined according to the connection mode of each impedance element and the element parameter.

The switch SW12 is an SPnT switch, and the common terminal is connected to the feeding point 14 of the antenna 10a, and the selection terminal is connected to the phase shifters α 1 to α n. The switch SW22 is an SPnT switch, and the common terminal is connected to the feeding point 14 of the antenna 10b, and the selection terminal is connected to the phase shifters β 1 to β n. The switch SW32 is an SPnT switch, and the common terminal is connected to the feeding point 14 of the antenna 10c, and the selection terminal is connected to the phase shifters γ 1 to γ n. The switch SW42 is an SPnT switch, and the common terminal is connected to the feed point 14 of the antenna 10d, and the selection terminal is connected to the phase shifters δ 1 to δ n.

Each switch is controlled in accordance with an instruction from the RFIC or an instruction from an integrated circuit such as a microcomputer included in the control circuit 220. By controlling the switches, it is possible to control which phase shifter the high-frequency signal from the input/output IF230 passes through, that is, it is possible to set the adjustment amount of the phase of the high-frequency signal to the adjustment amount corresponding to the phase shifter to be passed through. Accordingly, the phase of the high-frequency signal transmitted to each of the antennas 10a to 10d constituting the array antenna can be shifted, and the directivity of the array antenna 100 can be controlled.

Here, a more detailed configuration of the phase control unit 227 will be described with reference to fig. 5 focusing on the switch SW11, the phase shifters α 1 to α n, and the switch SW 12.

Fig. 5 is a circuit configuration diagram showing an example of a part of the phase control unit 227 according to embodiment 2. In fig. 5, the switches SW11 and SW21 are SP4T switches, and the phase shifters α 1 to α 4 (that is, n is 4) are shown.

As shown in fig. 5, the phase shifters α 1 to α 4 are implemented by, for example, a pi-type LC circuit. The number and connection method of the inductors and capacitors are not limited to those shown in fig. 5.

For example, when the phase of the high-frequency signal transmitted to the antenna 10a is adjusted by an amount corresponding to the phase shifter α 1, the switch SW11 and the switch SW12 are controlled so that the common terminal of the switch SW11 and the switch SW12 is connected to the uppermost selection terminal among the selection terminals shown in fig. 5. For each of the phase shifters α 1 to α 4, the phase characteristics shown in fig. 6 can be realized, for example, by adjusting parameters of the inductors and capacitors constituting each of the phase shifters α 1 to α 4.

Fig. 6 is a diagram showing an example of phase characteristics of the phase shifters α 1 to α 4 in the phase control unit 227 according to embodiment 2. The High-frequency signals transmitted to the antennas 10a to 10d are, for example, radio signals in the uhf (ultra High frequency) band, and the phases α 1 to α 4 of the phase shifters of 0.92GHz are focused.

As shown in fig. 6, each phase shifter can shift the phase in 0.92GHz as follows: phase shifter α 1 can shift the phase of the signal passing through phase shifter α 1 by 38 degrees, phase shifter α 2 can shift the phase of the signal passing through phase shifter α 2 by-9 degrees, phase shifter α 3 can shift the phase of the signal passing through phase shifter α 3 by-103 degrees, and phase shifter α 4 can shift the phase of the signal passing through phase shifter α 4 by-143 degrees. The phase of the signal passing through the phase shifters β 1 to β 4, γ 1 to γ 4, and δ 1 to δ 4 can be shifted in the same manner as the phase shifters α 1 to α 4.

Next, as will be described with reference to fig. 7 to 9, the directivity can be controlled by shifting the phase.

Fig. 7 is a diagram showing directivity characteristics when the phase difference of the array antenna 100 according to embodiment 2 is 90 degrees.

Fig. 8 is a diagram showing directivity characteristics when the phase difference of the array antenna 100 according to embodiment 2 is 180 degrees.

Fig. 9 is a diagram showing directivity characteristics of the array antenna 100 according to embodiment 2 when there is no phase difference.

For example, each switch is controlled so that the phase difference between the high-frequency signal transmitted to the antenna 10a and the high-frequency signal transmitted to the antenna 10b becomes 90 degrees, the phase difference between the high-frequency signal transmitted to the antenna 10b and the high-frequency signal transmitted to the antenna 10c becomes 90 degrees, and the phase difference between the high-frequency signal transmitted to the antenna 10c and the high-frequency signal transmitted to the antenna 10d becomes 90 degrees. Accordingly, as shown in fig. 7, the tilt angle of the array antenna 100 can be made, for example, approximately 30 degrees.

For example, each switch is controlled so that the phase difference between the high-frequency signal transmitted to the antenna 10a and the high-frequency signal transmitted to the antenna 10b becomes 180 degrees, the phase difference between the high-frequency signal transmitted to the antenna 10b and the high-frequency signal transmitted to the antenna 10c becomes 180 degrees, and the phase difference between the high-frequency signal transmitted to the antenna 10c and the high-frequency signal transmitted to the antenna 10d becomes 180 degrees. Accordingly, as shown in fig. 8, the tilt angle of the array antenna 100 can be set to, for example, 60 degrees.

Then, for example, each switch is controlled so that the phase difference between the high-frequency signal transmitted to the antenna 10a and the high-frequency signal transmitted to the antenna 10b becomes 0 degree, the phase difference between the high-frequency signal transmitted to the antenna 10b and the high-frequency signal transmitted to the antenna 10c becomes 0 degree, and the phase difference between the high-frequency signal transmitted to the antenna 10c and the high-frequency signal transmitted to the antenna 10d becomes 0 degree. In this case, as shown in fig. 9, the tilt angle of the array antenna 100 can be set to, for example, 0 degree (that is, directivity can be not controlled).

In this way, the phase control unit 227 applies a phase difference to the high-frequency signal transmitted to each of the antennas 10a to 10d, thereby controlling the directivity of the array antenna 100.

In addition, fig. 7 to 9 show the directional characteristics of the array antenna 100 in a state where no cable is connected. Then, the influence on the directivity characteristics when the cable is connected will be described with reference to fig. 10, focusing on the array antenna 100 in the case where there is no phase difference (i.e., in the state of fig. 9), for example.

Fig. 10 is a diagram showing directivity characteristics of the array antenna 100 according to embodiment 2 when no phase difference is present in a state where a cable is connected.

The gain of the array antenna 100 when there is no phase difference is 6.33dBi as shown in fig. 9 in a state where no cable is connected, 5.08dBi as shown in fig. 10 in a state where a cable is connected, and the gain is slightly reduced in a state where a cable is connected. However, this gain difference includes a gain difference of about 1dB due to the loss of the cable itself and the loss of the feeder line, and is substantially about 0.3 dB. Therefore, it is known that there is almost no influence of radiation noise from the cable, for example, as influence of the cable other than the loss of the cable itself and the loss of the power supply line.

This is because, as described in embodiment 1, the loop-shaped first ground conductor 12 disposed so as to surround the outer periphery of the antenna element 11 is connected to the open end of one end of the antenna element 11 of each of the antennas 10a to 10 d. That is, current does not easily leak from the antenna element 11 of each of the antennas 10a to 10d to the 2 nd ground conductor 210, and thus current does not easily flow into the ground conductor of the cable connected to the 2 nd ground conductor 210. Therefore, the radiation characteristics of the array antenna 100 are hardly affected by the cable, and as shown in fig. 10, the radiation characteristics can be improved.

The antenna 10, the antenna system 1, the array antenna 100, and the array antenna system 2 according to one or more embodiments have been described above based on the embodiments, but the present disclosure is not limited to the above embodiments. The embodiment obtained by performing various modifications that can be conceived by a person skilled in the art to the above-described embodiments and the embodiment constructed by combining the constituent elements in different embodiments are included in the scope of one or more embodiments within a scope not departing from the gist of the present disclosure.

The present disclosure can be used for an apparatus, a system, or the like of an antenna provided therein.

Description of the symbols

1 antenna system

2-array antenna system

10. 10a, 10b, 10c, 10d antenna

11 antenna element

12 st earth conductor

13 perturbing member

14 feeding point

20. 200 control substrate

21. 210 nd 2 nd ground conductor

22. 220 control circuit

23. 230 input-output IF

30. 300 base plate

100 array antenna

227 phase control unit

SW11, SW12, SW21, SW22, SW31, SW32, SW41 and SW42 switches

α 1, α 2, α 3, α 4, α n, β 1, β 2, β n, γ 1, γ 2, γ n, δ 1, δ 2, δ n phase shifters.