CN109565112B

CN109565112B - Antenna device

Info

Publication number: CN109565112B
Application number: CN201780047843.9A
Authority: CN
Inventors: 松本久功; 藤冈孝芳; 谷川原诚
Original assignee: Hitachi Industrial Equipment Systems Co Ltd
Current assignee: Hitachi Industrial Equipment Systems Co Ltd
Priority date: 2016-11-14
Filing date: 2017-06-30
Publication date: 2021-10-22
Anticipated expiration: 2037-06-30
Also published as: TW201818608A; CN109565112A; WO2018087956A1; JP2018082224A; JP6761737B2; TWI663784B

Abstract

The antenna device (1E) is provided with first to n +2 dielectric layers (Sn +2) (2. ltoreq. n), first to n patch electrodes (P1) and a ground electrode (P), wherein the m patch electrode (Pm) (1. ltoreq. m.ltoreq. n-1) has two faces having a size corresponding to the m-th frequency, one of the two faces is in contact with the m-th dielectric layer (Sm), the other of the two faces is in contact with the m + 1-th dielectric layer (Sm +1), the m +1 patch electrode (Pm +1) has two faces having a size corresponding to the m + 1-th frequency, one of the two faces is in contact with the m + 1-th dielectric layer (Sm +1), the other of the two faces is in contact with the m + 2-th dielectric layer (Sm +2), the ground electrode (P) has a face in contact with the n + 1-th dielectric layer (Sn +1) and a face in contact with the n + 2-th dielectric layer (Sn +2), the first dielectric layer (S1) includes a dielectric substrate.

Description

Antenna device

Technical Field

The present disclosure relates to an antenna device.

Background

An antenna device (hereinafter, also referred to as an "antenna") is an important component for determining communication performance of a wireless communication system. There are various types of antennas, and among antennas that realize single-sided directivity, there are patch antennas. For example, patent document 1 discloses a structural example of a patch antenna.

Prior art documents

Patent document

Patent document 1: international publication No. 2004/095639

Disclosure of Invention

Problems to be solved by the invention

Patent document 1 describes a patch antenna having a structure in which a ground conductor portion and a patch conductor portion face each other. In the patch antenna having this structure, the dielectric constant and the dielectric loss tangent (the degree of power loss in the capacitor) of the dielectric such as the printed circuit board supporting the conductor portions such as the ground conductor portion and the patch conductor portion determine the radiation efficiency of the patch antenna. For example, if the dielectric constant is large, the wavelength of the current flowing through the patch conductor portion is shortened, the current density is increased, and the conductor loss is increased. When the dielectric loss tangent is large, the dielectric loss of the electromagnetic wave transmitted through the dielectric material increases.

However, the patch antenna described in patent document 1 has a problem of high assembly cost. In addition, in order to use the patch antenna in a wireless communication system (particularly, a mobile communication system), a patch antenna having wide directivity is required.

The present disclosure has been made in view of the above problems, and an object thereof is to provide a patch antenna technology which is easy in assembly work, can suppress manufacturing cost to a low level, and has a wide directivity.

Means for solving the problems

In order to solve the above problems, one of the representative inventions is to provide an antenna device comprising first to n +2 th dielectric layers (2. ltoreq. n), first to n-th patch electrodes, and a ground electrode, wherein the m-th patch electrode (1. ltoreq. m.ltoreq. n-1) has two surfaces having a size corresponding to the m-th frequency, one of the two surfaces is connected with the m dielectric layer, the other surface of the two surfaces is connected with the m +1 dielectric layer, the m +1 patch electrode has two surfaces with the size corresponding to the m +1 frequency, one of the two surfaces is connected with the (m +1) th dielectric layer, the other surface of the two surfaces is connected with the (m +2) th dielectric layer, the ground electrode has a surface in contact with the (n +1) th dielectric layer and a surface in contact with the (n +2) th dielectric layer, and the first dielectric layer includes a dielectric substrate.

The present specification includes the disclosure of japanese patent application No. 2016-221218, which is the basis of the priority of the present application.

Effects of the invention

According to the present disclosure, a patch antenna technology that is easy in assembly work, can suppress manufacturing cost, and has wide directivity can be provided. Problems, structures, and effects other than those described above will become apparent from the following description of the embodiments.

Drawings

Fig. 1 is a schematic diagram of an antenna device according to embodiment 1.

Fig. 2 is an exploded view of the components included in the antenna device.

Fig. 3 is a cross-sectional view of a plane parallel to the yz plane of the antenna device.

Fig. 4 is a diagram for explaining a support structure of the antenna device.

Fig. 5 is a front view of the upper surface of the first dielectric substrate.

Fig. 6 is a front view of the lower surface of the fourth dielectric substrate.

Fig. 7 is a cross-sectional view of an antenna device mounted with an electronic component for transmitting a high-frequency signal.

Fig. 8 is a diagram showing an internal configuration of an electronic circuit.

Fig. 9 is a schematic diagram showing an antenna device according to embodiment 2.

Fig. 10 is a schematic diagram showing an antenna device according to example 3.

Fig. 11 is a schematic diagram showing an antenna device according to example 4.

Fig. 12 is a diagram showing a design example of an antenna device.

Fig. 13 is a front view of the components of the antenna device.

Fig. 14 is a diagram showing simulation results of antenna characteristics.

Fig. 15 is a diagram showing radiation patterns of the antenna device at two frequencies.

Fig. 16 is a diagram showing an antenna device according to modification 2.

Fig. 17 is a diagram showing the structure of the antenna device of the prior application.

Detailed Description

[ summary ]

The inventors of the present application proposed an antenna device in which a dielectric substrate 203 and a gap G are provided between a patch electrode 201 and a ground electrode 202 as shown in fig. 17 in japanese patent 2016-002177 previously filed. As shown in fig. 17, the antenna device includes a patch electrode 201 sandwiched between two

dielectric substrates

203 and 204, and a ground electrode 202 formed on the dielectric substrate 205. The antenna device having the above-described structure can be easily manufactured, and has high gain and wide directivity, but since it has only one patch electrode 201, signals are received by electromagnetic waves of a single frequency.

However, in order to improve the stability of Positioning in a Global Positioning System such as a GPS (Global Positioning System), an antenna technique for receiving signals using electromagnetic waves of two frequencies is known.

However, it is difficult for conventional antenna devices corresponding to two frequencies to sufficiently satisfy gains and directivities required for high-precision GNSS (Global Navigation Satellite System) used for industrial purposes and the like.

Therefore, the inventors of the present application have improved the antenna device proposed previously, and have proposed an antenna technique for receiving signals using electromagnetic waves of a plurality of frequencies with high gain and wide directivity.

Hereinafter, embodiments of the present disclosure will be described based on the drawings. The embodiments of the present disclosure are not limited to the embodiments described below, and various modifications are possible within the scope of the technical idea. In the drawings, the same reference numerals are used to designate corresponding parts in the drawings used in the description of the embodiments to be described later, and redundant description is omitted.

In the present specification, the term "dielectric layer" may refer to the dielectric substrate itself or an air layer. The dielectric layer also refers to a layer obtained by laminating a dielectric substrate and an air layer. The dielectric layer may include a dielectric substrate and a dielectric other than an air layer.

< example 1>

Fig. 1 is a schematic diagram of an antenna device 1 according to embodiment 1. The antenna device 1 of the present embodiment includes a first dielectric substrate 11, a second dielectric substrate 12, a third dielectric substrate 13, a fourth dielectric substrate 14, a first patch electrode 15, a second patch electrode 16, and a ground electrode 17. The respective components included in the antenna device 1 are arranged substantially in parallel, for example. Further, an air layer G is provided between the third dielectric substrate 13 and the ground electrode 17. Hereinafter, each component included in the antenna device 1 will be described with reference to fig. 2.

Fig. 2 is an exploded view of each component included in the antenna device 1. The first dielectric substrate 11 is a rectangular plate-shaped member having a thickness t1 and having an upper surface 11a and a lower surface 11 b. The second dielectric substrate 12 is a square plate-shaped member having a thickness t2 and having an upper surface 12a and a lower surface 12 b. The third dielectric substrate 13 is a square plate-shaped member having a thickness t3 and having an upper surface 13a and a lower surface 13 b. The fourth dielectric substrate 14 is a square plate-shaped member having an upper surface 14a and a lower surface 14 b.

The material of the first dielectric substrate 11, the second dielectric substrate 12, the third dielectric substrate 13, and the fourth dielectric substrate 14 is FR4, acryl, teflon (registered trademark), or the like. For each substrate, a printed board made of glass epoxy resin is preferably used, but a dielectric such as an acrylic plate, ABS (resin formed by polymerizing acrylonitrile, butadiene, or styrene), or a glass plate may be used.

The size LS of each substrate is slightly larger than the size L of the ground electrode 17, and it is necessary to have a sufficient size in the frequency of use of the antenna device 1. In other words, the size LS of each substrate is sufficiently larger than the sizes of the first patch electrode 15 and the second patch electrode 16. Preferably, the size LS of each substrate is ideally more than 2 times the size of the patch electrode. However, the size of the antenna device 1 can be reduced even further. The size LS of each substrate is preferably about 100 to 300mm when the frequency of use is about 1GHz, for example.

The first dielectric substrate 11, the second dielectric substrate 12, the third dielectric substrate 13, and the fourth dielectric substrate 14 may be different in size from each other. In this case, the size of the fourth dielectric substrate 14 on which the ground electrode 17 is disposed may be set to 2 times the size of the patch electrode according to the above example, and the first dielectric substrate 11, the second dielectric substrate 12, and the third dielectric substrate 13 may be smaller than those on which the first patch electrode 15 and the second patch electrode 16 are disposed.

The first patch electrode 15 is formed of a circular thin plate-like member or film having an upper surface 15a and a lower surface 15 b. The second patch electrode 16 is formed of a circular thin plate-like member or film having an upper surface 16a and a lower surface 16 b. The outer diameters L1 and L2 of the first patch electrode 15 and the second patch electrode 16 are determined by the carrier frequency of the wireless system, as in the case of a normal patch antenna. Usually, the length of one side of the patch electrode is often set based on the length of 1/2 wavelengths of the carrier frequency.

Based on the wavelength in free space, the length of one side of the patch electrode is, for example, about 140mm in the case of the 920MHz band and about 78mm in the case of the 1.6GHz band. However, since the antenna device 1 is affected by the dielectric constant of the dielectric substrate supporting each electrode and the wavelength is shortened, the actual size of the patch electrode is about a fraction% to several tens% of the size based on the wavelength in the free space.

In the present embodiment, the outer diameter L1 of the first patch electrode 15 is smaller than the outer diameter L2 of the second patch electrode 16. In other words, the wavelength of the electromagnetic wave received or radiated by the first patch electrode 15 is shorter than the wavelength of the electromagnetic wave received or radiated by the second patch electrode 16. Alternatively, the frequency of the electromagnetic wave received or radiated by the first patch electrode 15 is higher than the frequency of the electromagnetic wave received or radiated by the second patch electrode 16.

The shape of the first patch electrode 15 and the second patch electrode 16 may be other than a circular shape as long as desired characteristics can be obtained. The first patch electrode 15 and the second patch electrode 16 may have a regular n-sided shape (n is 4 or more), for example. The first patch electrode 15 and the second patch electrode 16 are formed as plate-like members or thin films of copper, aluminum, gold, or the like.

The ground electrode 17 is a rectangular thin plate-like member or film having an upper surface 17a and a lower surface 17b. The ground electrode 17 is formed as a plate-like member or thin film of copper, aluminum, gold, or the like. The ground electrode 17 is formed substantially on the entire upper surface 14a of the fourth dielectric substrate 14. Therefore, the ground electrode 17 has a larger size in plan view than the first patch electrode 15 and the second patch electrode 16. The air layer G has a thickness dg, and is provided by, for example, providing a rod at the four corners of the antenna device and separating the third dielectric substrate 13 from the ground electrode 17. The effective dielectric constant of the dielectric layer can be adjusted by providing the air layer G.

Fig. 3 is a cross-sectional view of a plane parallel to the yz plane of the antenna device 1. As shown in fig. 3, the lower surface 11b of the first dielectric substrate 11 is in contact with the upper surface 12a of the second dielectric substrate 12, and the first patch electrode 15 is sandwiched between the first dielectric substrate 11 and the second dielectric substrate 12. The lower surface 12b of the second dielectric substrate 12 is in contact with the upper surface 13a of the third dielectric substrate 13, and the second patch electrode 16 is sandwiched between the second dielectric substrate 12 and the third dielectric substrate 13.

The ground electrode 17 faces the lower surface 13b of the third dielectric substrate 13 through an air layer G. The ground electrode 17 is disposed so as to cover the upper surface 14a of the fourth dielectric substrate. In the present embodiment, the ground electrode 17 is in contact with the upper surface 14a of the fourth dielectric substrate, but the ground electrode 17 may be separated from the upper surface 14a of the fourth dielectric substrate.

The antenna device 1 can design the operating gain and the bandwidth by using the thickness t1 of the first dielectric substrate 11, the thickness t2 of the second dielectric substrate 12, the thickness t3 of the third dielectric substrate 13, and the thickness dg of the air layer G as design parameters. t1, t2, t3 and dg are designed within the following ranges.

[ mathematical expression 1]

Here, λ is a wavelength λ 1 in a free space of an electromagnetic wave radiated or received by the first patch electrode 15, a wavelength λ 2 in a free space of an electromagnetic wave radiated or received by the second patch electrode 16, or an average value of λ 1 and λ 2. The upper expression is a condition for the antenna device 1 to operate as a micro antenna, and the lower expression is a condition for satisfying a design requirement. The values of the parameters are, for example, values corresponding to the applied wireless communication system.

Fig. 4 is a diagram for explaining a support structure of the antenna device 1. In the case of fig. 4, the first dielectric substrate 11, the second dielectric substrate 12, and the third dielectric substrate 13 are supported and fixed by the rods (column portions) 8 and the screws 9 arranged at four corners. As shown in fig. 4, by disposing the rods 8 and the screws 9 at the four corners of each substrate, it is possible to support the substrate while suppressing a decrease in antenna characteristics while avoiding adverse effects on electromagnetic waves radiated from the first patch electrode 15 and the second patch electrode 16. The rod 8 and the screw 9 are preferably made of resin, but may be made of metal when strength is required.

However, the positions of the rods 8 and the screws 9 may be set to any positions that do not adversely affect the electromagnetic waves radiated from the first patch electrode 15 and the second patch electrode 16, and may be set to any positions on the edge portions of the respective substrates, for example. For example, it is considered that the input impedance at the center portion in the planar direction of the first patch electrode 15 and the second patch electrode 16 is 0, and theoretically, even if the first patch electrode and the second patch electrode are in contact with a conductor or a dielectric, the influence on the antenna characteristics is small, and therefore, the rod 8 and the screw 9 can be arranged.

When the rod 8 is provided at the center portion of the first patch electrode 15 and the second patch electrode 16 as described above, the substrate can be less bent due to the hollow structure, and high antenna performance can be maintained. In particular, under severe use conditions such as industrial use, it is assumed that a large number of mechanical impacts are applied, and such a structure for improving strength is sometimes required. In fig. 4, four rods 8 are provided, but the number of rods may be increased or decreased depending on the required strength, cost, and the like.

[ details of the antenna device 1]

In the above description, the lead wires connected to the electrodes of the antenna device 1 are omitted. In practice, in order to operate the antenna device 1, it is necessary to electrically insulate the first patch electrode 15 and the second patch electrode 16 from the ground electrode 17 and supply power to the first patch electrode 15 and the second patch electrode 16. Hereinafter, a method of connecting a power feeding lead wire and a grounding lead wire required for actually using the antenna device 1 will be described.

Fig. 5 is a front view of the upper surface 11a of the first dielectric substrate 11. As shown in fig. 5, a first signal pad 11d for electrically connecting to the first patch electrode 15 and the second patch electrode 16 and a through hole 11c penetrating the first signal pad 11d are provided on the upper surface 11a of the first dielectric substrate 11. The via hole 11c is covered with a conductive via wiring, and the first patch electrode 15 and the second patch electrode 16 are electrically connected to the signal line 2 (see fig. 7) penetrating the via hole 11 c. The signal line 2 can be fixed by welding to the first signal pad portion 11d. In addition, the through hole 11c is provided at a position deviated from the center portion of the first dielectric substrate 11.

Fig. 6 is a front view of the lower surface 14b of the fourth dielectric substrate 14. As shown in fig. 6, a ground pad portion 14d for electrical connection to the ground electrode 17 is formed on the lower surface 14b of the fourth dielectric substrate 14. The ground pad portion 14d is formed with a through hole 14c and a plurality of via wirings 14e. The via wiring 14e is formed to surround the through hole 14 c. The ground electrode 17 is electrically connected to a lead wire for grounding via the grounding pad portion 14d. The through hole 14c is provided at a position deviated from the center of the fourth dielectric substrate 14, similarly to the through hole 11c provided in the first dielectric substrate 11.

A second signal pad portion 14g is formed on the inner side of the ground pad portion 14d with a gap portion 14f therebetween, which is not shown in fig. 6. That is, the ground pad portion 14d and the second signal pad portion 14g are separated by the gap portion 14f. Therefore, the ground pad portion 14d and the second signal pad portion 14g are not electrically connected. In other words, the ground pad portion 14d is insulated from the second signal pad portion 14g. The through hole 14c is provided in the second signal pad portion 14g.

Similarly, through holes 12c, 13c, 15c, 16c, and 17c are also provided in the second dielectric substrate 12, the third dielectric substrate 13, the first patch electrode 15, the second patch electrode 16, and the ground electrode 17. The antenna device 1 is designed such that the positions of the through holes are aligned to form one through hole when the dielectric substrates face the electrodes. The signal line 2 is inserted into the through hole, and the first patch electrode 15 and the second patch electrode 16 are electrically connected to the signal line 2 and supplied with power.

In addition, the diameter of the through hole 17c provided in the ground electrode 17 is designed to be larger than the diameter of the through hole 14c provided in the fourth dielectric substrate 14. This prevents the signal line 2 from contacting the ground electrode 17 and causing a short circuit.

Fig. 7 is a cross-sectional view of the antenna device 1 mounted with an electronic component for transmitting a high-frequency signal. The cross section is a cut surface when cut along the line AB shown in fig. 5 and 6. In the antenna device 1, the feeding point 3 is provided at a position corresponding to a position above the first patch electrode 15 on the upper surface 11a of the first dielectric substrate 11, and a high-frequency signal is input and output through the feeding point 3.

The feeding point 3 is in contact with, for example, a portion of the solder 4 bonded to fix the signal line 2 to the first signal pad portion 11d. In the case of the present embodiment, the impedance of the power feeding point 3 is 50 Ω. The supply point 3 is selected to be the position into which the high-frequency signal efficiency enters best. In the case of the present embodiment, as described above, the feeding point 3 is selected to be a position slightly deviated from the centers of the first patch electrode 15 and the second patch electrode 16.

As described above, the signal line 2 penetrates the through hole provided in each dielectric substrate and is fixed to the first signal pad portion 11d and the second signal pad portion 14g by the solder 4. The inner sides of the through holes 11c and 12c provided in the first dielectric substrate 11 and the second dielectric substrate 12 are covered with a conductor, and the signal line 2 is electrically connected to the first patch electrode 15 and the second patch electrode 16.

On the other hand, the diameter of the through hole 17c provided in the ground electrode 17 is designed to be slightly larger than the diameter of the through hole 14c provided in the fourth dielectric substrate 14, and the signal line 2 is insulated from the ground electrode 17 without contacting it. That is, the first patch electrode 15 and the second patch electrode 16 are electrically connected to the second signal pad portion 14g via the signal line 2, and are electrically insulated from the ground electrode 17. The ground electrode 17 is electrically connected to the ground pad portion 14d through the plurality of via wirings 14e, and is electrically insulated from the second signal pad portion 14g.

When the antenna device 1 is configured as described above, the signal line 2 can be soldered to the upper surface 11a side of the first dielectric substrate 11 (the outside of the antenna device 1) and the lower surface 14b side of the fourth dielectric substrate (the outside of the antenna device 1) when the antenna device 1 is assembled, and the assembly operation can be easily performed.

Further, referring to fig. 7, the grounding pad portion 14d and the second signal pad portion 14g will be described. The microstrip line 14h is formed in the second signal pad portion 14g, and can be connected to the electronic circuit 5 including a low-noise amplifier circuit, for example.

Since the ground pad portion 14d and the second signal pad portion 14g do not contact each other with the gap portion 14f therebetween, the ground pad portion 14d is formed in コ -shape so as to surround the second signal pad portion 14g, as shown in fig. 7. Since the ground pad portion 14d and the second signal pad portion 14g have the above-described shapes, the microstrip line 14h can transmit a high-frequency signal. The gap 14f is designed to set the characteristic impedance of the microstrip line 14h to a desired value (typically 50 Ω).

In the example shown in fig. 7, the ground pad portion 14d is connected to the ground terminal 5a1 of the electronic circuit 5 (circuit element), and the second signal pad portion 14g is connected to the signal terminal (input terminal) 5a2 of the electronic circuit 5 (circuit element) via the microstrip line 14h. In addition, since the ground electrode 17 is formed on the upper surface 14a of the fourth dielectric substrate 14, the electronic circuit 5 disposed on the lower surface 14b thereof is separated from the antenna portion in terms of electromagnetic field.

Fig. 8 is a diagram showing an internal configuration of the electronic circuit 5. Fig. 8 shows an example of the configuration of the electronic circuit 5 when an active antenna using a low noise amplifier is configured. The electronic circuit 5 includes, in order from the input side, an antenna terminal 5a connected to an electrode 6 (a portion excluding the electronic circuit 5 in fig. 7), an output terminal 5b, a Low Noise Amplifier (LNA)5c, a Band Pass Filter (BPF)5d, and a Bias (Bias Tee) 5e. The output terminal 5b is connected to a demodulation IC7 (demodulator) or the like as an external receiving circuit.

[ Effect of the antenna device 1 according to example 1]

As described above, the antenna device 1 includes the first patch electrode 15 and the second patch electrode 16, and is an antenna device corresponding to a plurality of frequencies. The antenna device 1 according to embodiment 1 has a structure in which the upper surface 15a of the first patch electrode 15 is in contact with the first dielectric substrate 11. Thus, the antenna device 1 can adjust the wavelength shortening rate of the current flowing through the first patch electrode 15 to increase the directivity.

In addition, in the antenna device 1, by adjusting the wavelength shortening factor, the size of one side of the first patch electrode 15 can be reduced as compared with an antenna device not having the first dielectric substrate 11, and as a result, the antenna device 1 can be downsized. Further, since the antenna device 1 can reduce the area of the first patch electrode 15, it acts in a direction in which the beam forming effect of the electromagnetic field radiated by the current flowing through the first patch electrode 15 is weakened, and the directivity can be enlarged.

Since the antenna device 1 is wide-directivity, it is suitable for use in, for example, a wireless communication system. In particular, in a mobile communication system, since the positional relationship (direction) between a transmitter and a receiver cannot be determined in many cases, the antenna device 1 having wide directivity is suitably used in the mobile communication system.

In the manufacturing process of the antenna device 1, the signal line 2 can be fixed to the first dielectric substrate 11 and the fourth dielectric substrate 14 by soldering on the upper surface 11a side (outer side) of the first dielectric substrate 11 and the lower surface 14b side (outer side) of the fourth dielectric substrate. That is, the soldering work can be performed on the outer surfaces of the two printed boards, and the soldering work can be easily performed. This facilitates the assembly work of the antenna device 1, contributing to reduction in manufacturing cost.

In the antenna device 1 according to embodiment 1, the outer diameter of the first patch electrode 15 is smaller than the outer diameter of the second patch electrode 16. Thereby, the antenna device 1 can obtain high-gain antenna performance.

In the antenna device 1 according to embodiment 1, as shown in formula 1, the thickness of each component is designed according to the electromagnetic wave to be radiated or received. Thus, the operation gain of the antenna device 1 increases.

< example 2>

Fig. 9 is a schematic diagram of an antenna device 1A according to embodiment 2. In the case of fig. 9, the rod 8 and the screw 9 are also omitted. The antenna device 1A according to embodiment 2 differs from embodiment 1 in that a coaxial connector 10 is mounted on the lower surface 14b of the fourth dielectric substrate 14, instead of having connection terminals for connecting the ground pad portion 14d and the second signal pad portion 14g to the electronic circuit 5. The antenna device 1A is manufactured as a single patch antenna, for example, and shipped as a product.

The coaxial connector 10 has a signal terminal 10a and a ground terminal 10b. The signal line 2 penetrates through the through holes 11c to 17c provided in the dielectric substrates and the conductors, as in the case of the antenna device 1 of example 1. Unlike the antenna device 1 according to embodiment 1, the lower end of the signal line 2 included in the antenna device 1A according to embodiment 2 is exposed as the signal terminal 10a of the coaxial connector 10 attached to the lower surface 14b of the fourth dielectric substrate 14. The signal line 2 is electrically insulated from the ground electrode 17 as in the case of example 1.

As shown in fig. 9, in the antenna device 1A according to example 2, the ground terminal 10b of the coaxial connector 10 is electrically connected to the ground pad portion 14d and the via wiring 14e via the solder 4 on the lower surface 14b of the fourth dielectric substrate 14. The ground electrode 17 provided on the upper surface 14a of the fourth dielectric substrate 14 and the ground pad portion 14d provided on the lower surface 14b are electrically connected to each other through a plurality of via wirings 14e. That is, the ground electrode 17 is electrically connected to the ground terminal 10b of the coaxial connector 10.

In the case of the antenna device 1A according to embodiment 2, when the antenna device 1A is assembled, the signal terminal 10a (i.e., the signal line 2) of the coaxial connector 10 can be soldered to the upper surface 11A side (outside) of the first dielectric substrate 11, and the ground terminal 10b of the coaxial connector 10 can be soldered to the lower surface 14b side (outside) of the fourth dielectric substrate 14.

That is, the welding operation can be performed on the outer surfaces of the two substrates, and the operation can be easily performed. In particular, the coaxial connector 10 can be soldered from the outside of the longitudinal laminated structure of the antenna device 1A, and the antenna device 1A can be easily assembled. As a result, as in the case of embodiment 1, the antenna device 1A can be easily assembled and the manufacturing cost can be reduced.

< example 3>

Fig. 10 is a schematic diagram showing an antenna device 1B according to embodiment 3. The antenna device 1B according to example 3 is configured such that the signal line 2 penetrates the second dielectric substrate 12, the third dielectric substrate 13, and the fourth dielectric substrate 14, but does not penetrate the first dielectric substrate 11. In example 3, the power feeding point 3 is directly connected to the first patch electrode 15 via a Conductive material (Conductive Matching). As the conductive material, a material such as silver paste or conductive adhesive, or a conductive double-sided tape such as copper tape or aluminum tape can be used. Of course, solder is also possible.

< example 4>

Fig. 11 is a schematic diagram of an antenna device 1C according to embodiment 4. The antenna device 1C shown in fig. 11 has two

feeding points

3A and 3B on the upper surface 11a of the first dielectric substrate 11. These two

feed points

3A and 3B are feed points capable of receiving orthogonal polarized wave components, and can be used as polarization-oriented diversity antennas. Further, by combining the signals received at feeding point 3A and feeding point 3B so as to be 90 degrees out of phase, an antenna capable of receiving circularly polarized waves can also be configured. In the present embodiment, although the description has been made assuming a reception antenna, the same discussion can be directly applied to a transmission antenna.

< design example of antenna device >

Hereinafter, a specific design example of the antenna device will be described. Here, a case of using the antenna device for GPS will be described. For example, the first patch electrode 15 and the second patch electrode 16 are respectively sized so that the center frequencies are 1.59GHz and 1.275 GHz.

Fig. 12 is a diagram showing a design example of the antenna device 1D. In the antenna device 1D shown in fig. 12, in example 1, the second dielectric substrate 12 was replaced with a second dielectric layer 120 in which a dielectric substrate 12A and an air layer 12B were stacked, and the third dielectric substrate 13 was replaced with a third dielectric layer 130 in which two dielectric substrates 13A and 13B and an air layer 13C were stacked. The dimensions of the respective components are shown below.

Dielectric substrate 11: 150mm X150 mm, thickness 1mm, raw material FR4

Dielectric substrate 12A: 150mm x 150mm, thickness 2mm, raw material FR4

Dielectric substrate 13A: 150mm x 150mm, thickness 2mm, raw material FR4

Dielectric substrate 13B: 150mm x 150mm, thickness 2mm, raw material FR4

Dielectric substrate 14: 150mm x 150mm, thickness 2mm, raw material FR4

Air layer 12B: thickness of 2mm

Air layer 13C: thickness of 2mm

First patch electrode 15: phi 90mm, circular shape

Second patch electrode 16: phi 105mm, circular shape

Ground electrode 17: 148mm X148 mm, square shape

Fig. 13 is a front view of the components of the antenna device 1D. As shown in fig. 13, the first patch electrode 15 and the second patch electrode 16 are circular, and the ground electrode 17 and each dielectric substrate are square. In the case of the above design values, the simulation results of the antenna characteristics and the radiation pattern shown in the antenna device 1D are shown in fig. 14 and 15.

Fig. 14 is a diagram showing simulation results of antenna characteristics. As shown in fig. 14, it is understood that the antenna device 1D has a reduced reflection loss at frequencies in the vicinity of 1.28GHz and 1.59GHz, and can realize a dual-band antenna.

Fig. 15 is a diagram showing radiation patterns of the antenna device 1D at two frequencies. In fig. 15, the operation gain of the antenna device is expressed in dB. As shown in fig. 15, the antenna device 1D has high gain and wide directivity in both of the two frequencies.

As described above, the antenna devices 1, 1A to 1D according to the embodiments have high gain and wide directivity, and are most suitable for GNSS corresponding to a plurality of frequencies. The antenna device is expected to be used in industrial applications requiring high-precision positioning, and is effectively applicable to fields such as agriculture, civil engineering, railways, and disaster prevention. Specifically, the antenna device can be effectively applied to, for example, running guidance of agricultural machinery in a large-scale agricultural land, control of a heavy machine in a construction site, driver support of a railway, and constant monitoring of an inclined land where there is a risk of occurrence of a hill collapse or a cliff collapse.

The present disclosure is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiments are described in detail to explain the present disclosure easily and understandably, and are not limited to having all the structures described.

Further, a part of the structure of one embodiment may be replaced with the structure of another embodiment, and the structure of another embodiment may be added to the structure of one embodiment. Further, a part of the configuration of each embodiment can be added, deleted, or replaced with another configuration. In addition, the respective members and the relative dimensions shown in the drawings are simplified and idealized for easy understanding of the present disclosure, and may be different from actual mounting.

< modification 1>

In the above description of the embodiment, the case where the first dielectric substrate 11 and the fourth dielectric substrate 14 of the antenna device 1 are supported by the rod 8 and the screw 9 at the respective four corners has been described. However, if the signal line 2 formed of a conductor member having high rigidity is bonded to each substrate with high bonding force by the solder 4, the antenna device 1 may not be provided with the rod 8 and the screw 9 at the four corners.

< modification 2>

In the above description of the embodiment, the antenna device 1 includes two patch electrodes corresponding to different frequencies. The antenna device 1 may include three or more patch electrodes corresponding to a plurality of frequencies.

Fig. 16 is a diagram showing an antenna device 1E according to modification 2. The antenna device 1E shown in fig. 16 includes first to n +2 th dielectric layers Sn +2 (2. ltoreq. n), first to n-th patch electrodes Pn and a ground electrode P, the m-th patch electrode (1. ltoreq. m.ltoreq. n-1) having two surfaces having a size corresponding to the m-th frequency, one of the two surfaces being in contact with the m-th dielectric layer, the other of the two surfaces being in contact with the m + 1-th dielectric layer, the m + 1-th patch electrode having two surfaces having a size corresponding to the m + 1-th frequency, one of the two surfaces being in contact with the m + 1-th dielectric layer, the other of the two surfaces being in contact with the m + 2-th dielectric layer, the ground electrode P having a surface in contact with the n + 1-th dielectric layer Sn +1 and a surface in contact with the n + 2-th dielectric layer Sn +2, and the first dielectric layer S1 includes a dielectric substrate.

The antenna device 1E having the above-described structure can correspond to three or more frequencies. Here, the dielectric layers S2 to Sn +2 may include only a dielectric substrate, a dielectric substrate and an air layer, or only an air layer. Since the first dielectric layer S1 includes the dielectric substrate, the antenna device 1E is an antenna device having a wide directivity due to the wavelength shortening effect.

Further, in the antenna device 1, the n patch electrodes are arranged so as to become larger in size as going to the ground electrode P. Thus, the antenna device 1E has high gain and wide directivity.

In the antenna device 1E, when the first dielectric layer S1 to the nth dielectric layer Sn are dielectric substrates having thicknesses of t1 to tn, respectively, and the (n +1) th dielectric layer Sn +1 is composed of a dielectric substrate having a thickness of tn +1 and an air layer G having a thickness of dg, the relationship shown in the following equation may be satisfied.

[ mathematical expression 2]

Here, the dielectric substrate included in the (n +1) -th dielectric layer is in contact with the surface of the (n) -th patch electrode Pn, and the air layer G is in contact with the surface of the ground electrode P. Further, λ is an average value of a wavelength λ m in a free space of the electromagnetic wave radiated or received by the m-th patch electrode Pm, a wavelength λ n or λ 1 to λ n in a free space of the electromagnetic wave radiated or received by the n-th patch electrode Pn. λ may be a central value of λ 1 to λ n. The upper expression is a condition for the antenna device 1 to operate as a micro antenna, and the lower expression is a condition for satisfying a design requirement. The values of the parameters are, for example, values corresponding to the applied wireless communication system. The antenna device 1E satisfies the relationship expressed by the above equation, thereby increasing the operation gain.

< modification 3>

In the column of the design example of the antenna device, the antenna device 1D has two air layers 12B and 13C. The air layer 12B and the air layer 13C may be formed of different dielectrics. The air layers 12B and 13C may be spacers having an appropriate dielectric constant, for example, in order to achieve desired radiation characteristics.

Description of the reference numerals

An antenna device

A signal line

A power supply point

Solder

An electronic circuit

An antenna terminal

Output terminal

Low noise amplifier

A band pass filter

Biaser

An antenna

Demodulation IC

Rod

9

Coaxial connector

Signal terminal

10b

A first dielectric substrate

A second dielectric substrate

A third dielectric substrate

A fourth dielectric substrate

A first patch electrode

A second patch electrode

A ground electrode

12B, 13C, g

11a, 12a, 13a, 14a, 15a, 16a, 17a

11b, 12b, 13b, 14b, 15b, 16b, 17b

11c, 12c, 13c, 14c, 15c, 16c, 17c

A pad portion for a first signal

14d

Via routing

14f

A pad section for a second signal

Microstrip line 14h

A second dielectric layer

A third dielectric layer

All publications and patent documents cited in this specification are incorporated herein by reference as if fully set forth.

Claims

1. An antenna device is provided with:

first to n +2 th dielectric layers;

first to nth patch electrodes; and

a ground electrode is arranged on the upper surface of the shell,

an m-th patch electrode having two surfaces having a size corresponding to an m-th frequency, one of the two surfaces being in contact with the m-th dielectric layer, the other of the two surfaces being in contact with the m + 1-th dielectric layer,

the m +1 th patch electrode has two surfaces having a size corresponding to the m +1 th frequency, one of the two surfaces is in contact with the m +1 th dielectric layer, and the other of the two surfaces is in contact with the m +2 th dielectric layer,

the ground electrode has a surface in contact with the (n +1) th dielectric layer and a surface in contact with the (n +2) th dielectric layer,

the first dielectric layer comprises a dielectric substrate,

n is an integer of 2 or more, m is an integer of 1 or more and less than n,

the first to nth dielectric layers are each composed of a dielectric substrate having a thickness of t1 to tn, the n +1 th dielectric layer is composed of a dielectric substrate having a thickness of tn +1 and an air layer having a thickness of dg,

the dielectric substrate included in the (n +1) th dielectric layer is in contact with the other surface of the n-th patch electrode,

the air layer included in the (n +1) th dielectric layer is in contact with the ground electrode,

and satisfies the following relationship:

[ mathematical expression 1]

Here, λ is an average value of a wavelength λ m in a free space of the electromagnetic wave radiated or received by the m-th patch electrode Pm, a wavelength λ n in a free space of the electromagnetic wave radiated or received by the n-th patch electrode Pn, or λ 1 to λ n.

2. The antenna device of claim 1,

the one surface of the first patch electrode is in contact with the dielectric substrate included in the first dielectric layer.

3. The antenna device of claim 1,

the outer diameter of the m-th patch electrode is smaller than the outer diameter of the m + 1-th patch electrode, and the m-th frequency is higher than the m + 1-th frequency.

4. The antenna device of claim 1,

the antenna device further includes:

a dielectric substrate comprised by the n +2 th dielectric layer;

a first pad portion formed on an upper surface of the dielectric substrate included in the first dielectric layer;

a second pad portion formed on a lower surface of the dielectric substrate included in the n +2 th dielectric layer and a third pad portion electrically insulated from the second pad portion;

a conductor part penetrating the first to n +2 th dielectric layers, the first to n-th patch electrodes, and the ground electrode,

the first pad portion, the third pad portion, and the first to nth patch electrodes are electrically connected via the conductor portion,

the second pad part and the ground electrode are electrically connected,

the ground electrode is electrically insulated from the conductor portion.

5. The antenna device of claim 4,

the diameter of the through hole through which the conductor portion provided in the ground electrode penetrates is larger than the diameter of the through hole through which the conductor portion provided in the dielectric substrate included in the n +2 th dielectric layer penetrates.

6. An antenna device is provided with:

a first dielectric layer comprising a dielectric substrate;

a second dielectric layer;

a third dielectric layer;

a fourth dielectric layer;

a first patch electrode having two surfaces having a size corresponding to a first frequency, one of the two surfaces being in contact with the first dielectric layer, and the other of the two surfaces being in contact with the second dielectric layer;

a second patch electrode having two surfaces having a size corresponding to a second frequency, one of the two surfaces being in contact with the second dielectric layer, and the other of the two surfaces being in contact with the third dielectric layer; and

a ground electrode having a surface in contact with the third dielectric layer and a surface in contact with the fourth dielectric layer,

the first dielectric layer is composed of a dielectric substrate with a thickness of t1, the second dielectric layer is composed of a dielectric substrate with a thickness of t2, the third dielectric layer is composed of a dielectric substrate with a thickness of t3 and an air layer with a thickness of dg,

the dielectric substrate included in the third dielectric layer is in contact with the other surface of the second patch electrode,

the air layer included in the third dielectric layer is in contact with the ground electrode,

and satisfies the following relationship:

[ mathematical expression 2]

Here, λ is a wavelength λ 1 in a free space of the electromagnetic wave radiated or received by the first patch electrode, a wavelength λ 2 in a free space of the electromagnetic wave radiated or received by the second patch electrode, or an average value of λ 1 and λ 2.