Patent Application
20200395676
The present invention relates to an array antenna device including a plurality of patch antennas.
It is desirable that array antenna devices used for wireless communication, for example, have a high gain and a high axial ratio even with a weak radio wave when scanning with a beam is performed in a wide-angle direction in order to enable wireless communication over the wide angle. The wide-angle direction is a direction in which a radio wave is transmitted/received at ends of the beam width.
A decrease in the gain and the a decrease in the axial ratio when scanning with the beam is performed in the wide-angle direction are caused by a difference in the amplitude between a vertically polarized wave and a horizontally polarized wave in the wide-angle direction, in addition to surface waves generated in a dielectric substrate on which patch antennas are formed.
An array antenna device disclosed in the following Patent Literature 1 employs a substrate having a low dielectric constant characteristic such as foam as a dielectric substrate in order to suppress a decrease in the gain and a decrease in the axial ratio when scanning with a beam is performed in a wide-angle direction.
A difference in the amplitude between a vertically polarized wave and a horizontally polarized wave in the wide-angle direction can be changed by adjusting the thickness of the substrate having a low dielectric constant characteristic such as foam. In this array antenna device, a screw is used to adjust the thickness of the substrate.
Patent Literature 1: JP 2009-188895 A
Since the array antenna devices are configured as described above, the thickness of the substrate can be adjusted by the screws.
In this example, the amount of adjustment of the thickness of the substrate is proportional to the amount of rotation of the screw, and the amount of rotation of the screw is dependent on the pitch of the screw thread. For this reason, the adjustment accuracy of the thickness of a substrate can be improved as the pitch of a screw thread becomes narrower.
For example in a case where the frequency band of a beam is high such as the Kurz-above (Ka) band or a millimeter wave band, it is necessary to use a screw having a thread pitch in the order of micrometers in order to implement a desired adjustment accuracy.
However, since it is difficult to manufacture a screw having a thread pitch in the order of micrometers, there are cases where the thickness of the substrate cannot be adjusted with high accuracy and the thickness of the substrate cannot be adjusted to a desired thickness. It is a disadvantage in that, as a result, a decrease in the gain and a decrease in the axial ratio cannot be suppressed when scanning with a beam is performed in the wide-angle direction.
The present invention has been devised in order to solve the above disadvantage, and it is an object of the present invention to obtain an array antenna device capable of suppressing a decrease in the gain and a decrease in the axial ratio when scanning with a beam is performed in the wide-angle direction.
An array antenna device according to the present invention includes a first dielectric substrate provided with a first conductor ground plane on a front surface or a back surface thereof, a plurality of patch antennas provided in the first conductor ground plane, a plurality of conductive members, ends of which are connected to the first conductor ground plane to surround the patch antennas individually, and a second conductor ground plane connected to each of other ends of the conductive members, wherein in a case where the first conductor ground plane is provided on the front surface of the first dielectric substrate, a part of the plurality of conductive members penetrates the first dielectric substrate, and a remaining part of the plurality of conductive members functions as spacers for providing an air layer between the first dielectric substrate and the second conductor ground plane, and in a case where the first conductor ground plane is provided on the back surface of the first dielectric substrate, the plurality of conductive members functions as spacers for providing an air layer between the first conductor ground plane and the second conductor ground plane.
According to the present invention, in a case where the first conductor ground plane is formed on the front surface of the first dielectric substrate, a part of the plurality of conductive members penetrates the first dielectric substrate, and the remaining part of the plurality of conductive members functions as spacers for providing an air layer between the first dielectric substrate and the second conductor ground plane, and in a case where the first conductor ground plane is formed on the back surface of the first dielectric substrate, the plurality of conductive members functions as spacers for providing an air layer between the first conductor ground plane and the second conductor ground plane. Therefore, there is an effect of suppressing a decrease in the gain and a decrease in the axial ratio when scanning with a beam is performed in the wide-angle direction.
To describe the present invention further in detail, embodiments for carrying out the present invention will be described below with reference to accompanying drawings.
In
The front surface of the first dielectric substrate 1 is the surface on the upper side in
The first conductor ground plane 2 is a ground plane of copper foil formed on the front surface of the first dielectric substrate 1.
Patch antennas 3-1 to 3-9 are circular patch antennas provided on the first conductor ground plane 2.
Hereinafter, when the individual patch antennas 3-1 to 3-9 are not distinguished, they may be referred to as the patch antennas 3.
In
Although nine patch antennas 3 are illustrated as an example in
To simplify the drawing, the patch antennas 3-7 to 3-9 are representatively illustrated in
In the first embodiment, an example is illustrated in which each of the patch antennas 3-1 to 3-9 has a circular shape; however, the shape is not limited to a circle and may be, for example, a polygon.
Conductive members 4 each include a first connection conductor 4a and a second connection conductor 4b, and ends of the conductive members 4 are coupled to the first conductor ground plane 2 so as to surround the patch antennas 3-1 to 3-9 individually.
The first connection conductor 4a which is a part of the conductive member 4 is provided so as to penetrate the first dielectric substrate 1, and one end thereof is coupled to the first conductor ground plane 2 at a position surrounding any of the patch antennas 3-1 to 3-9.
The second connection conductor 4b, which is the remaining part of the conductive member 4, is a copper core ball that conducts between the other end of the first connection conductor 4a and a second conductor ground plane 5.
The second connection conductor 4b functions as a spacer for providing an air layer 6 between the first dielectric substrate 1 and the second conductor ground plane 5.
Although the example in which the second connection conductor 4b is a copper core ball is illustrated here, the second connection conductor 4b is not limited to a sphere and may be, for example, a cube or a rectangular parallelepiped.
A land 4c is a portion where the first connection conductor 4a and the second connection conductor 4b are coupled by solder.
The second conductor ground plane 5 is a ground plane of copper foil coupled to each of the other ends of second connection conductors 4b in a plurality of conductive members 4.
The air layer 6 is a layer between the first dielectric substrate 1 and the second conductor ground plane 5 formed by the second connection conductors 4b.
Next, the operation will be described.
In the array antenna device according to the first embodiment, the patch antennas 3-1 to 3-9 are formed by removing the first conductor ground plane 2 in the annular shapes like in the conductor-cut-out portions 2a illustrated in
The plurality of conductive members 4 is provided in the first dielectric substrate 1 in such a manner that ends of the conductive members 4 surround the patch antennas 3-1 to 3-9 individually.
Specifically, the conductive members 4 each include a first connection conductor 4a and a second connection conductor 4b, and the first connection conductors 4a are provided so as to penetrate the first dielectric substrate 1 with the ends thereof coupled to the first conductor ground plane 2 at positions surrounding one patch antenna 3 out of the patch antennas 3-1 to 3-9.
An end of a second connection conductor 4b is coupled to the other end of a first connection conductor 4a, and the other end of the second connection conductor 4b is coupled to the second conductor ground plane 5.
Here, the second connection conductor 4b functions as a spacer for providing the air layer 6 between the first dielectric substrate 1 and the second conductor ground plane 5.
The size of the air layer 6, which is the length of an interval between the first dielectric substrate 1 and the second conductor ground plane 5, corresponds to the diameter of the second connection conductor 4b which is a copper core ball.
By providing the air layer 6 between the first dielectric substrate 1 and the second conductor ground plane 5, a low dielectric constant substrate can be equivalently implemented.
In addition, a difference in the amplitude between a vertically polarized wave and a horizontally polarized wave in the wide-angle direction can be reduced by adjusting the size of the air layer 6.
In order to suppress a decrease in the gain and a decrease in the axial ratio when scanning with a beam is performed in the wide-angle direction, it is only required to adjust the size of the air layer 6 in such a manner that a difference in the amplitude between a vertically polarized wave and a horizontally polarized wave in the wide-angle direction is reduced.
Since the size of the air layer 6 corresponds to the diameter of the second connection conductor 4b, it is only required to use a second connection conductor 4b having a diameter that allows a difference in the amplitude between the vertically polarized wave and the horizontally polarized wave in the wide-angle direction to be reduced.
However, in a case where the frequency band of the beam is high such as the Ka band or a millimeter wave band, the size of the air layer 6 needs to be adjusted in the order of micrometers, and thus it is necessary to use second connection conductors 4b manufactured with accuracy in the order of micrometers.
Since it is easier to manufacture copper core balls with high accuracy as compared to manufacturing screws having a narrow thread pitch, it is easy to manufacture copper core balls with accuracy in the order of micrometers. Thus, it is possible to use second connection conductors 4b having a desired diameter.
The example in which the patch antennas 3-1 to 3-9 are formed is illustrated in the first embodiment. Focusing on three adjacent patch antennas 3 out of the patch antennas 3-1 to 3-9, it is desirable that the three patch antennas 3 are disposed in such a manner that a distance between the centers of each pair of the three patch antennas 3 approximately equals a half the wavelength of a frequency of the beam to be transmitted and received.
For example, focusing on the patch antenna 3-2, 3-3, and 3-6 as three adjacent patch antennas 3, the patch antennas 3-2, 3-3, and 3-6 are disposed in such a manner that lines connecting the centers of the three patch antennas become an equilateral triangle A.
The distance between the center of patch antenna 3-2 and the center of patch antenna 3-3 is approximately half the wavelength of the frequency of the beam, and the distance between the center of patch antenna 3-3 and the center of patch antenna 3-6 is approximately half the wavelength of the frequency of the beam. The distance between the center of patch antenna 3-6 and the center of patch antenna 3-2 is approximately half the wavelength of the frequency of the beam.
The radius r of the patch antennas 3-1 to 3-9 is expressed as the following equation (1), using an effective dielectric constant εr calculated from the first dielectric substrate 1 and the air layer 6.
In equation (1), c represents the speed of light, and f represents the frequency of the beam.
The effective dielectric constant εr is expressed as the following equation (2), where the thickness of the first dielectric substrate 1 is denoted by t1, a dielectric constant of the first dielectric substrate 1 is denoted by εr1, the thickness of the air layer 6 is denoted by t2, and the dielectric constant of the air layer 6 is denoted by εr2.
The conductive members 4 are disposed at positions surrounding the patch antennas 3-1 to 3-9 individually.
As one of the positions where the conductive members 4 are disposed, for example, the center of gravity of the equilateral triangle A, which is a position equidistant from the patch antennas 3-2, 3-3, and 3-6 is conceivable.
The diameter of the conductor-cut-out portions 2a surrounding the patch antennas 3-1 to 3-9 is determined in such a manner that an equivalent patch radius from the center of the patch antennas 3-1 to 3-9 (hereinafter referred to as “effective radius”) results in an axial ratio characteristic of approximately 0 dB in a target maximum angle of the beam scanning angle. As the target maximum angle of the beam scanning angle, for example, a beam scanning angle of ±60 degrees is conceivable.
An effective radius is an electrical radius of the patch antennas 3 in consideration of the spread of an electric field B generated in the patch antennas 3 when the power is being fed as illustrated in
It is known that the axial ratio of the patch antennas 3-1 to 3-9 can be adjusted by the effective radius.
Specifically, in the case where the effective dielectric constant εr is about 1.3 and when the effective radius of the patch antennas 3-1 to 3-9 is about 0.26λ, the axial ratio in the wide-angle direction is obtained as 0 dB, and a resonance characteristic is obtained at the frequency of the beam. Symbol λ represents the wavelength at the frequency of a beam used.
Therefore, the first conductor ground plane 2 positioned between about 0.26λ away from the center of the patch antennas 3-1 to 3-9 and the perimeters of the patch antennas 3-1 to 3-9 is each cut out into an annual shape.
Note that there are cases where conductor-cut-out portions 2a of adjacent patch antennas 3 overlap with each other since the radius r of the adjacent patch antennas 3 is large and thus intervals in the arrangement of the adjacent patch antenna 3 become narrow. Since it is only required that adjacent patch antennas 3 do not overlap with each other, conductor-cut-out portions 2a of the adjacent patch antennas 3 may overlap with each other.
As apparent from the above, according to the first embodiment, parts of the plurality of conductive members 4 penetrate the first dielectric substrate 1 while the remaining parts of the plurality of conductive members 4 function as spacers for providing the air layer 6 between the first dielectric substrate 1 and the second conductor ground plane 5, thereby exercising effects of suppressing a decrease in the gain and a decrease in the axial ratio when scanning with a beam is performed in the wide-angle direction.
Since the remaining parts of the conductive members 4 functioning as spacers are the second connection conductor 4b that can be manufactured with accuracy in the order of micrometers, the size of the air layer 6 can be adjusted in the order of micrometers, thereby suppressing a decrease in the gain and a decrease in the axial ratio when scanning with a beam is performed in the wide-angle direction.
The example is illustrated in the first embodiment in which the first conductor ground plane 2 is formed on the front surface of the first dielectric substrate 1; however as illustrated in
A conductive member 4 illustrated in
The first connection conductor 4d is a copper core ball one end of which is coupled to a first conductor ground plane 2 at a position surrounding any one of patch antennas 3-1 to 3-9, and the other end of which is coupled to a second conductor ground plane 5.
The first connection conductor 4d functions as a spacer for providing an air layer 6 between the first conductor ground plane 2 and the second conductor ground plane 5.
Since the air layer 6 is provided also in the array antenna device illustrated in
Therefore, also in the array antenna device illustrated in
The first embodiment has illustrated the array antenna device including the first dielectric substrate 1, whereas in a second embodiment an array antenna device including a first dielectric substrate 1 and a second dielectric substrate 7 will be described.
A plan view of the array antenna device of the second embodiment is illustrated in
In
The second dielectric substrate 7 is disposed between the first dielectric substrate 1 and a second conductor ground plane 5.
Conductive members 4 each include a first connection conductor 4a, a second connection conductor 4e, and a third connection conductor 4f, and ends of the conductive members 4 are coupled to the first conductor ground plane 2 so as to surround each of patch antennas 3-1 to 3-9.
A second connection conductor 4e which is a part of a conductive member 4 is provided so as to penetrate the second dielectric substrate 7, and one end thereof is coupled to the second conductor ground plane 5.
A third connection conductor 4f, which is the remaining part of the conductive member 4, is a copper core ball that conducts between the other end of the first connection conductor 4a and the other end of the second connection conductor 4e.
The third connection conductor 4f functions as a spacer for providing an air layer 6 between the first dielectric substrate 1 and the second dielectric substrate 7.
Although the example in which the third connection conductor 4f is a copper core ball is illustrated here, the third connection conductor 4f is not limited to a sphere and may be, for example, a cube, or a rectangular parallelepiped.
A land 4g is a portion where the second connection conductor 4e and the third connection conductor 4f are coupled by solder.
Although the second dielectric substrate 7 is included in addition to the first dielectric substrate 1 in the second embodiment, since the air layer 6 is provided, a low dielectric constant substrate can be equivalently implemented like in the first embodiment.
Thus, like in the first embodiment described above, it is possible to suppress a decrease in the gain and a decrease in the axial ratio when scanning with a beam is performed in the wide-angle direction.
In the second embodiment, however, since the second dielectric substrate 7 is included in addition to the first dielectric substrate 1, the effective dielectric constant εr is calculated from the first dielectric substrate 1, the second dielectric substrate 7, and the air layer 6.
The effective dielectric constant εr is expressed as the following equation (3), where the thickness of the first dielectric substrate 1 is denoted by t1, the dielectric constant of the first dielectric substrate 1 is denoted by εr1, the thickness of the air layer 6 is denoted by t2, the dielectric constant of the air layer 6 is denoted by εr2, the thickness of the second dielectric substrate 7 is denoted by t3, the dielectric constant of the second dielectric substrate 7 is denoted by εr3.
The example is illustrated in the second embodiment in which the first conductor ground plane 2 is formed on the front surface of the first dielectric substrate 1; however as illustrated in
The conductive members 4 illustrated in
The first connection conductor 4h is a copper core ball one end of which is coupled to a first conductor ground plane 2 at a position surrounding any one of patch antennas 3-1 to 3-9.
The first connection conductor 4h functions as a spacer for providing an air layer 6 between the first conductor ground plane 2 and a second dielectric substrate 7.
Since the air layer 6 is provided also in the array antenna device illustrated in
Therefore, also in the array antenna device illustrated in
In the third embodiment, an array antenna device including first striplines 13, second striplines 15, and slots 17 as feed line portions 10 will be described.
A plan view of the array antenna device of the third embodiment is illustrated in
In
A second dielectric substrate 11 is disposed on, out of the two planes of a second conductor ground plane 5, a plane opposite to the plane to which conductive members 4 are coupled.
A third conductor ground plane 12 is a ground plane of copper foil disposed on, out of the two planes of the second dielectric substrate 11, a plane opposite to the plane on which the second conductor ground plane 5 is disposed.
A first stripline 13 is provided at a position facing one patch antenna 3 out of the patch antennas 3-1 to 3-9 inside the second dielectric substrate 11.
A second stripline 15 is provided at a position facing one patch antenna 3 out of the patch antennas 3-1 to 3-9 inside the second dielectric substrate 11.
A via 14 is a connecting member for electrically connecting a first stripline 13 and an adjustment circuit for, for example, adjusting the phase and the amplitude of signals.
A via 16 is a connecting member for electrically connecting a second stripline 15 and an adjustment circuit for, for example, adjusting the phase and the amplitude of signals.
A slot 17 is included in the second conductor ground plane 5 at a position facing one patch antenna 3 out of the patch antennas 3-1 to 3-9.
The slot 17 excites the patch antenna 3 at the opposite position when power is fed from the first stripline 13 and the second stripline 15.
The explanatory diagram of
In
One end of the first stripline 13 is coupled to the via 14.
The first stripline 13 is branched into two on the way, and two branch lines 13a of the first stripline 13 are disposed in parallel so as to maintain the symmetry of the first stripline 13.
One end of the second stripline 15 is coupled to the via 16.
The second stripline 15 is branched into two on the way, and two branch lines 15a of the second stripline 15 are disposed in parallel so as to maintain the symmetry of the second stripline 15.
The shape of the slot 17 is substantially cruciform, and the center 17a of the slot 17 substantially coincides with the center of a patch antenna 3 at the opposite position.
Also, at the midpoints of the two branch lines 13a, the length from a midpoint 13b at a position overlapping with the slot 17 to a tip 13c is approximately a quarter of the wavelength of a frequency of the beam in order to enhance the feeding efficiency of the slot 17.
At the midpoints of the two branch lines 15a, the length from a midpoint 15b at a position overlapping with the slot 17 to a tip 15c is approximately a quarter of the wavelength of a frequency of the beam in order to enhance the feeding efficiency of the slot 17.
Next, the operation will be described.
The first stripline 13 in the feed line portion 10 is fed with, for example, a first polarized wave, and the second stripline 15 is fed with a second polarized wave orthogonal to the first polarized wave.
The slot 17 in the feed line portion 10 has a cross slot structure in which orthogonal polarized waves can be excited, and the first polarized wave and the second polarized wave are fed with power in a contactless manner from the first stripline 13 and the second stripline 15.
The slot 17 is coupled to the patch antenna 3 at the opposite position and excites the patch antenna 3 at the opposite position when the first polarized wave and the second polarized wave are fed with power in a contactless manner from the first stripline 13 and the second stripline 15.
As a result, the slot 17 and the patch antenna 3 operate as an antenna.
Since the patch antennas 3 are excited using the slots 17 in the third embodiment, it is possible to implement an array antenna device in which cross polarization is suppressed.
Moreover, since polarized waves orthogonal to each other are fed to the first striplines 13 and the second striplines 15, a circularly polarized wave can be radiated from the patch antennas 3.
The example is illustrated in the third embodiment in which the first conductor ground plane 2 is formed on the front surface of the first dielectric substrate 1; however as illustrated in
In
Even in a case where the first conductor ground plane 2 is formed on the back surface of the first dielectric substrate 1, a slot 17 can excite a patch antenna 3 at the opposite position like in the case where the first conductor ground plane 2 is formed on the front surface of the first dielectric substrate 1.
The example has been illustrated in the third embodiment in which the first stripline 13 and the second stripline 15 are each branched into two on the way; however, the present invention is not limited to those branching into two, and a first stripline 13 and a second stripline 15 may be linear as illustrated in
In
However, this is merely an example, and for example as illustrated in
In a fourth embodiment, an array antenna device including first striplines 23, second striplines 24, and slots 17 as feed line portions will be described.
A plan view of the array antenna device of the fourth embodiment is illustrated in
In
A third dielectric substrate 21 is disposed on, of the two planes of a second conductor ground plane 5, a plane opposite to the plane to which conductive members 4 are coupled.
A third conductor ground plane 22 is a ground plane of copper foil disposed on, of the two planes of the third dielectric substrate 21, a plane opposite to the plane on which the second conductor ground plane 5 is disposed.
Of the two planes of a second dielectric substrate 7, a first stripline 23 is provided at a position facing one patch antenna 3 out of the patch antennas 3-1 to 3-9 on a plane opposite to the plane on which the second conductor ground plane 5 is disposed.
A second stripline 24 is provided at a position facing one patch antenna 3 out of the patch antennas 3-1 to 3-9 inside the third dielectric substrate 21.
The positional relationship among a first stripline 23, a second stripline 24, and a slot 17 in the array antenna device illustrated in
Next, the operation will be described.
A first stripline 23 in a feed line portion is fed with, for example, a first polarized wave, and a second stripline 24 is fed with a second polarized wave orthogonal to the first polarized wave.
A slot 17 in the feed line portion has a cross slot structure in which the polarized waves orthogonal to each other can be excited, and the first polarized wave and the second polarized wave are fed with power in a contactless manner from the first stripline 23 and the second stripline 24.
The slot 17 is coupled to a patch antenna 3 at the opposite position and excites the patch antenna 3 at the opposite position when the first polarized wave and the second polarized wave are fed with power in a contactless manner from the first stripline 23 and the second stripline 24.
As a result, the slot 17 and the patch antenna 3 operate as an antenna.
Since the patch antennas 3 are excited using the slots 17 in the fourth embodiment, it is possible to implement an array antenna device in which cross polarization is suppressed.
Moreover, since polarized waves orthogonal to each other are fed to the first striplines 23 and the second striplines 24, a circularly polarized wave can be radiated from the patch antennas 3.
The example is illustrated in the fourth embodiment in which the first conductor ground plane 2 is formed on the front surface of the first dielectric substrate 1; however as illustrated in
In
In a fifth embodiment, an array antenna device including an adjustment circuit 32 for adjusting the phase and the amplitude of signals transmitted or received by patch antennas 3-1 to 3-9 will be described.
A plan view of the array antenna device of the fifth embodiment is illustrated in
In
A third dielectric substrate 31 is disposed on, of the two planes of a third conductor ground plane 12, a plane opposite to the plane on which a second dielectric substrate 11 is disposed.
An adjustment circuit 32 is disposed on, of the two planes of the third dielectric substrate 31, a plane opposite to the plane on which the third conductor ground plane 12 is disposed and is electrically coupled to a first stripline 13 via a via 14 and to a second stripline 15 via a via 16.
The adjustment circuit 32 is an integrated circuit (IC) for adjusting the phase and the amplitude of a signal transmitted or received by one patch antenna 3 out of patch antennas 3-1 to 3-9 that is provided at the opposite position.
The example is illustrated in
Moreover, as illustrated in
Since the array antenna device illustrated in
An adjustment circuit 32 is electrically coupled to a first stripline 23 via a via 14 and is electrically coupled to a second stripline 24 via a via 16.
With the array antenna device including the adjustment circuits 32, an array antenna device capable of beam scanning in a desired direction can be implemented.
In a sixth embodiment, each of the patch antennas 3-1 to 3-9 formed in a first conductor ground plane 2 is a first patch antenna.
In the sixth embodiment, an array antenna device will be described in which second patch antennas 8-1 to 8-9 are provided on, of the two planes of a second dielectric substrate 7, a plane to which a plurality of conductive members 4 is coupled.
A plan view of the array antenna device of the sixth embodiment is illustrated in
In
The second patch antennas 8-1 to 8-9 are provided on, of the two planes of the second dielectric substrate 7, the plane to which the plurality of conductive members 4 is coupled.
Only the second patch antennas 8-7 to 8-9 are illustrated in
The second patch antennas 8-1 to 8-9 are disposed at positions overlapping with the patch antennas 3-1 to 3-9, respectively, when viewed from the first dielectric substrate 1 toward the second dielectric substrate 7 side.
The second patch antennas 8-1 to 8-9 perform multiple resonance with the patch antennas 3-1 to 3-9, respectively.
Since the array antenna device of the sixth embodiment includes the second patch antennas 8-1 to 8-9, the resonance frequency of the antenna is expanded than that of the array antenna device of the first embodiment. Therefore, the array antenna device of the sixth embodiment is capable of performing beam scanning at a wide angle over a broadband as compared with the array antenna device of the first embodiment.
In the array antenna device illustrated in
However, this is merely an example, and the second patch antennas 8-1 to 8-9 may be used in the array antenna device in which the first conductor ground plane 2 is formed on the back surface of the first dielectric substrate 1 as illustrated in
In a seventh embodiment, an array antenna device will be described in which an air layer 6 is a first air layer, third connection conductors 4f are first spacers, and second spacers for forming a second air layer 9 between a second conductor ground plane 5 and a second dielectric substrate 7 are included.
A plan view of the array antenna device of the seventh embodiment is illustrated in
In
Fourth connection conductors 4i function as the second spacers that form the second air layer 9 between the second conductor ground plane 5 and the second dielectric substrate 7.
A land 4j is a portion where a second connection conductor 4e and the fourth connection conductor 4i are coupled by solder.
Since the array antenna device of the seventh embodiment includes the second patch antennas 8-1 to 8-9, the resonance frequency of the antenna is expanded than that of the array antenna device of the first embodiment. Therefore, the array antenna device of the seventh embodiment is capable of performing beam scanning at a wide angle over a wide band as compared with the array antenna device of the first embodiment.
Furthermore, since the array antenna device of the seventh embodiment includes the second air layer 9, better axial ratio characteristics in the wide-angle direction can be obtained than in the array antenna device of the first embodiment.
In the array antenna device illustrated in
However, this is merely an example, and the second air layer 9 may be formed in the array antenna device in which the first conductor ground plane 2 is formed on the back surface of the first dielectric substrate 1 as illustrated in
In the eighth embodiment, an array antenna device will be described in which first striplines 13 and second striplines 15 are wired in the same plane, and each of the first striplines 13 and the second striplines 15 excites patch antennas 3-1 to 3-9.
A plan view of the array antenna device of the eighth embodiment is illustrated in
In the array antenna device illustrated in
One end of a via 18 is coupled to a first stripline 13, and the other end protrudes from the array antenna device.
One end of a via 19 is coupled to a second stripline 15, and the other end protrudes from the array antenna device.
The vias 18 and the vias 19 have the same length.
In
The second stripline 15 is also disposed in such a manner that a midpoint 15d overlaps with a slot extending in the longitudinal direction in the drawing of a slot 17 in
Since the first striplines 13 and the second striplines 15 are wired on the same plane in the array antenna device of the eighth embodiment, the impedance characteristics of the antenna seen from the input side are substantially the same. Therefore, the array antenna device of the eighth embodiment has better symmetry and better axial ratio characteristics than the array antenna device of the third and fourth embodiments.
Note that the present invention may include a flexible combination of the respective embodiments, a modification of any component of the embodiments, or an omission of any component in the embodiments within the scope of the present invention.
The present invention is suitable for an array antenna device including a plurality of patch antennas.
1: First dielectric substrate, 2: First conductor ground plane, 2a: Conductor-cut-out portion, 3-1 to 3-9: Patch antenna, 4: Conductive member, 4a: First connection conductor, 4b: Second connection conductor, 4c: Land, 4d: First connection conductor, 4e: Second connection conductor, 4f: Third connection conductor, 4g: Land, 4h: First connection conductor, 4i: Fourth connection conductor, 4j: Land, 5: Second conductor ground plane, 6: Air layer, 7: Second dielectric substrate, 8-1 to 8-9: Second patch antenna, 9: Second air layer, 10: Feed line portion, 11: Second dielectric substrate, 12: Third conductor ground plane, 13: First stripline, 13a: Branch line, 13b: Midpoint, 13c: Tip, 13d: Midpoint, 14, 16: Via, 15: Second stripline, 15a: Branch line, 15b: Midpoint, 15c: Tip, 15d: Midpoint, 17: Slot, 17a: Slot center, 18, 19: Via, 21: Third dielectric substrate, 22: Third conductor ground plane, 23: First stripline, 24: Second stripline, 31: Third dielectric substrate, 32: Adjustment circuit.
| Number | Date | Country | Kind |
|---|---|---|---|
| PCT/JP2017/035232 | Sep 2017 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2018/019225 | 5/18/2018 | WO | 00 |
