Patent Grant
11831076
This application is a National Stage of PCT international application Ser. No. PCT/JP2019/042058 filed on Oct. 25, 2019 which designates the United States, incorporated herein by reference, and which is based upon and claims the benefit of priority from Japanese Patent Application No. 2018-206002 filed on Oct. 31, 2018, the entire contents of which are incorporated herein by reference.
The present disclosure relates to an antenna, a wireless communication module, and a wireless communication device.
In an array antenna, an antenna for multiple-input multiple-output (MIMO), and the like; a plurality of antenna elements are arranged close to each other. When the plurality of antenna elements are arranged close to each other, mutual coupling between the antenna elements can be increased. When the mutual coupling between the antenna elements is increased, radiation efficiency of the antenna elements may decrease.
Therefore, a technique for reducing the mutual coupling between the antenna elements has been proposed (for example, Patent Literature 1).
An antenna according to an embodiment of the present disclosure includes a first antenna element, a second antenna element, a first coupler, and a second coupler. The first antenna element includes a first radiation conductor and a first feeder line and is configured to resonate in a first frequency band. The second antenna element includes a second radiation conductor and a second feeder line and is configured to resonate in a second frequency band. The second feeder line is configured to be coupled to the first feeder line such that a first component is dominant. The first component is one of a capacitance component and an inductance component. The first coupler is configured to couple the first feeder line and the second feeder line such that a second component different from the first component is dominant. The first radiation conductor and the second radiation conductor are arranged at an interval equal to or less than ½ of a resonance wavelength. The second radiation conductor is configured to be coupled to the first radiation conductor with a first coupling method in which one of a capacitive coupling and a magnetic field coupling is dominant. The second coupler is configured to couple the first radiation conductor and the second radiation conductor with a second coupling method different from the first coupling method.
A wireless communication module according to an embodiment of the present disclosure includes the above-described antenna and an RF module. The RF module is configured to be electrically connected to at least one of the first feeder line and the second feeder line.
A wireless communication device according to an embodiment of the present disclosure includes the above-described wireless communication module and a battery. The battery is configured to supply power to the wireless communication module.
There is room for improvement in the conventional technique for reducing mutual coupling between the antenna elements.
The present disclosure relates to providing an antenna, a wireless communication module, and a wireless communication device with reduced mutual coupling between antenna elements.
According to the antenna, the wireless communication module, and the wireless communication device according to an embodiment of the present disclosure, the mutual coupling between the antenna elements can be reduced.
In the present disclosure, a “dielectric material” may include either a ceramic material or a resin material as a composition. The ceramic material includes an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, a glass ceramic sintered body, a crystallized glass obtained by precipitating a crystal component in a glass base material, and microcrystalline sintered body such as mica or aluminum titanate. The resin material includes a material obtained by curing an uncured material such as an epoxy resin, a polyester resin, a polyimide resin, a polyamide-imide resin, a polyetherimide resin, and a liquid crystal polymer.
In the present disclosure, a “conductive material” can include, as a composition, any of a metallic material, a metallic alloy, a cured material of metallic paste, and a conductive polymer. The metallic material includes copper, silver, palladium, gold, platinum, aluminum, chromium, nickel, cadmium lead, selenium, manganese, tin, vanadium, lithium, cobalt, titanium, and the like. The alloy includes a plurality of metallic materials. The metallic paste includes a paste formed by kneading the powder of a metallic material along with an organic solvent and a binder. The binder includes an epoxy resin, a polyester resin, a polyimide resin, a polyamide-imide resin, and a polyetherimide resin. The conductive polymer includes a polythiophene-based polymer, a polyacetylene-based polymer, a polyaniline-based polymer, a polypyrrole-based polymer, and the like.
Hereinafter, a plurality of embodiments of the present disclosure will be described with reference to the drawings. In the components illustrated in
In the embodiments of the present disclosure, a plane on which a first antenna element 31 and a second antenna element 32 illustrated in
As illustrated in
The base 20 is configured to support the first antenna element 31 and the second antenna element 32. The base 20 is a quadrangular prism as illustrated in
The base 20 may include a dielectric material. A relative permittivity of the base 20 may be appropriately adjusted according to a desired resonance frequency of the antenna 10. The base 20 includes an upper surface 21 and a lower surface 22 as illustrated in
The first antenna element 31 is configured to resonate in a first frequency band. The second antenna element 32 is configured to resonate in a second frequency band. The first frequency band and the second frequency band may belong to the same frequency band or different frequency bands, depending on the use of the antenna 10 and the like. The first antenna element 31 can resonate in the same frequency band as the second antenna element 32. The first antenna element 31 can resonate in a frequency band different from that of the second antenna element 32.
The first antenna element 31 may be configured to resonate in the same phase as the second antenna element 32. A first feeder line 51 and a second feeder line 52 may be configured to feed signals that excite the first antenna element 31 and the second antenna element 32 in the same phase. When the first antenna element 31 and the second antenna element 32 are excited in the same phase, the signal fed from the first feeder line 51 to the first antenna element 31 may have the same phase as the signal fed from the second feeder line 52 to the second antenna element 32. When the first antenna element 31 and the second antenna element 32 are excited in the same phase, the signal fed from the first feeder line 51 to the first antenna element 31 may have a different phase from the signal fed from the second feeder line 52 to the second antenna element 32.
The first antenna element 31 may be configured to resonate in a phase different from that of the second antenna element 32. The first feeder line 51 and the second feeder line 52 may be configured to feed signals that excite the first antenna element 31 and the second antenna element 32 in different phases. When the first antenna element 31 and the second antenna element 32 are excited in different phases, the signal fed from the first feeder line 51 to the first antenna element 31 may have the same phase as the signal fed from the second feeder line 52 to the second antenna element 32. When the first antenna element 31 and the second antenna element 32 are excited in different phases, the signal fed from the first feeder line 51 to the first antenna element 31 may have a different phase from the signal fed from the second feeder line 52 to the second antenna element 32.
As illustrated in
The first radiation conductor 41 illustrated in
Each of the first radiation conductor 41 and the second radiation conductor 42 may include a conductive material. Each of the first radiation conductor 41, the second radiation conductor 42, the first feeder line 51, the second feeder line 52, the first ground conductor 61, the second ground conductor 62, the first coupler 70, and the second coupler 73 may include the same conductive material, or may include different conductive materials.
The first radiation conductor 41 and the second radiation conductor 42 may have a flat plate shape as illustrated in
In the present embodiment, the first radiation conductor 41 and the second radiation conductor 42 have the same rectangular shape. However, the first radiation conductor 41 and the second radiation conductor 42 may have any shape. In addition, the first radiation conductor 41 and the second radiation conductor 42 may have different shapes.
A longitudinal direction of the first radiation conductor 41 and the second radiation conductor 42 is along the Y direction. A lateral direction of the first radiation conductor 41 and the second radiation conductor 42 is along the X direction. The first radiation conductor 41 includes a long side 41a and a short side 41b. The second radiation conductor 42 includes a long side 42a and a short side 42b.
The first radiation conductor 41 and the second radiation conductor 42 are arranged so that the long side 41a and the long side 42a face each other. However, the arrangement of the first radiation conductor 41 and the second radiation conductor 42 is not limited thereto. For example, the first radiation conductor 41 and the second radiation conductor 42 may be arranged side by side so that a portion of the long side 41a and a portion of the long side 42a face each other. For example, the first radiation conductor 41 and the second radiation conductor 42 may be arranged to be shifted in the Y direction.
The first radiation conductor 41 and the second radiation conductor 42 may be arranged side by side so that the short side 41b and the short side 42b face each other. However, the arrangement of the first radiation conductor 41 and the second radiation conductor 42 is not limited thereto. For example, the first radiation conductor 41 and the second radiation conductor 42 may be arranged side by side so that a portion of the short side 41b and a portion of the short side 42b face each other. For example, the first radiation conductor 41 and the second radiation conductor 42 may be arranged with the short side 41b and the short side 42b facing each other being shift from each other.
The first radiation conductor 41 and the second radiation conductor 42 are arranged at an interval equal to or less than ½ of the resonance wavelength of the antenna 10. In the present embodiment, as illustrated in
A current can flow through the first radiation conductor 41 along the Y direction. When the current flows through the first radiation conductor 41 along the Y direction, a magnetic field surrounding the first radiation conductor 41 changes in the XZ plane. A current can flow through the second radiation conductor 42 along the Y direction. When the current flows through the second radiation conductor 42 along the Y direction, a magnetic field surrounding the second radiation conductor 42 changes in the XZ plane. The magnetic field surrounding the first radiation conductor 41 and the magnetic field surrounding the second radiation conductor 42 interact with each other. For example, when the first radiation conductor 41 and the second radiation conductor 42 are excited in the same phase or phases close to each other, most of the currents flowing through the first radiation conductor 41 and the second radiation conductor 42 can flow in the same direction. Examples of the phases close to each other include cases where both phases are within ±60°, within ±45°, and within ±30°. When most of the currents flowing through the first radiation conductor 41 and the second radiation conductor 42 flow in the same direction, magnetic field coupling between the first radiation conductor 41 and the second radiation conductor 42 can be large. The first radiation conductor 41 and the second radiation conductor 42 can be configured so that the magnetic field coupling becomes large by flowing most of the flowing currents in the same direction.
When the resonance frequencies of the first radiation conductor 41 and the second radiation conductor 42 are the same or close to each other, the first radiation conductor 41 and the second radiation conductor 42 may be configured so that a coupling occurs at the time of resonance. The coupling at the time of resonance can be referred to as “even mode” and “odd mode”. The even mode and the odd mode are also collectively referred to as the “even-odd mode”. When the first radiation conductor 41 and the second radiation conductor 42 resonate in the even-odd mode, each of the first radiation conductor 41 and the second radiation conductor 42 resonates at a resonance frequency different from the case where they do not resonate in the even-odd mode. In many cases in which the first radiation conductor 41 and the second radiation conductor 42 are coupled, magnetic field coupling and electric field coupling occur at the same time. If one of the magnetic field coupling and the electric field coupling becomes dominant, the coupling between the first radiation conductor 41 and the second radiation conductor can finally be regarded as the dominant one of the magnetic field coupling or the electric field coupling.
The second radiation conductor 42 is configured to be coupled to the first radiation conductor 41 with a first coupling method in which one of the capacitive coupling and the magnetic field coupling is dominant. In the present embodiment, the first radiation conductor 41 and the second radiation conductor 42 are the microstrip type antennas, and the long side 41a and the long side 42a face each other. The mutual influence of the magnetic field surrounding the first radiation conductor 41 and the magnetic fields surrounding the second radiation conductor 42 is more dominant than the mutual influence due to the electric field between the first radiation conductor 41 and the second radiation conductor 42. The coupling between the first radiation conductor 41 and the second radiation conductor 42 can be considered as the magnetic field coupling. Therefore, in the present embodiment, the second radiation conductor 42 is configured to be coupled to the first radiation conductor 41 with the first coupling method in which the magnetic field coupling is dominant.
The first feeder line 51 illustrated in
The second feeder line 52 illustrated in
The first feeder line 51 is configured to supply power to the first radiation conductor 41. The first feeder line 51 is configured to supply the power from the first radiation conductor 41 to an external device or the like. The second feeder line 52 is configured to supply power to the second radiation conductor 42. The second feeder line 52 is configured to supply the power from the second radiation conductor 42 to an external device or the like.
The first feeder line 51 and the second feeder line 52 may include a conductive material. Each of the first feeder line 51 and the second feeder line 52 may be a through-hole conductor, a via conductor, or the like. The first feeder line 51 and the second feeder line 52 may be located in the base 20 as illustrated in
As illustrated in
As illustrated in
The magnetic field surrounding the first feeder line 51 and the magnetic field surrounding the second feeder line 52 can interfere with each other. For example, when most of the currents flowing through the first feeder line 51 and the second feeder line 52 flow in the same direction, the magnetic field surrounding the first feeder line 51 and the magnetic field surrounding the second feeder line 52 constructively interfere with each other in a macroscopic manner. The first feeder line 51 and the second feeder line 52 can be magnetically coupled by interference between the magnetic field surrounding the first feeder line 51 and the magnetic field surrounding the second feeder line 52.
The second feeder line 52 is configured to be coupled to the first feeder line 51 such that a first component is dominant. The first component is one of the capacitance component and the inductance component. The first feeder line 51 and the second feeder line 52 can be magnetically coupled by interference between the magnetic field surrounding the first feeder line 51 and the magnetic field surrounding the second feeder line 52. The second feeder line 52 is configured to be coupled to the first feeder line 51 such that the inductance component serving as the first component is dominant.
The first ground conductor 61 illustrated in
The first ground conductor 61 and the second ground conductor 62 may include a conductive material. The first ground conductor 61 and the second ground conductor 62 may have a flat plate shape. The first ground conductor 61 and the second ground conductor 62 are located on the lower surface 22 of the base 20. The first ground conductor 61 and the second ground conductor 62 may be located partially in the base 20.
The first ground conductor 61 may be connected to the second ground conductor 62. For example, the first ground conductor 61 may be configured to be electrically connected to the second ground conductor 62. The first ground conductor 61 and the second ground conductor 62 may be formed integrally as illustrated in
The first ground conductor 61 and the second ground conductor 62 extend along the XY plane, as illustrated in
The first coupler 70 is configured to couple the first feeder line 51 and the second feeder line 52 such that a second component different from the first component is dominant. When the first component is an inductance component, the second component is a capacitance component. The first coupler 70 is configured to couple the first feeder line 51 and the second feeder line 52 such that the capacitance component serving as the second component is dominant.
For example, the first coupler 70 includes the first conductor 71 and the second conductor 72, as illustrated in
When the first feeder line 51 directly feeds power to the first radiation conductor 41 and the second feeder line 52 directly feeds power to the second radiation conductor 42, in the coupling between the first feeder line 51 and the second feeder line 52, the inductance component may be dominant. The inductance component in the coupling between the first feeder line 51 and the second feeder line 52 forms a parallel circuit with the capacitance component due to the first coupler 70. In the antenna 10, an anti-resonance circuit including the inductance component and the capacitance component is configured. The anti-resonance circuit can cause an attenuation pole in transmission characteristics between the first antenna element 31 and the second antenna element 32. The transmission characteristics are characteristics of power transmitted from the first feeder line 51, which is an input port of the first antenna element 31, to the second feeder line 52, which is an input port of the second antenna element 32. By causing the attenuation pole in the transmission characteristics, the interference between the first antenna element 31 and the second antenna element 32 can be reduced in the antenna 10.
In this way, the first coupler 70 is configured to couple the first feeder line 51, which is the input port of the first antenna element 31, and the second feeder line 52, which is the input port of the second antenna element 32, such that the second component is dominant. The second component is different from the first component, which is dominant in the coupling between the first feeder line 51 itself and the second feeder line 52 itself. The first component and the second component forms a parallel circuit, so that the antenna 10 has an anti-resonance circuit at the input port.
The second coupler 73 is configured to couple the first radiation conductor 41 and the second radiation conductor 42 with a second coupling method different from the first coupling method. When the first coupling method is a coupling method in which magnetic field coupling is dominant, the second coupling method is a coupling method in which capacitive coupling is dominant. The second coupler 73 is configured to couple the first radiation conductor 41 and the second radiation conductor 42 with the second coupling method in which the capacitive coupling is dominant.
For example, the second coupler 73 may include a conductive material. The second coupler 73 is located in the base 20 as illustrated in
The electric field is large at both ends of the first radiation conductor 41 and both ends of the second radiation conductor 42. When most of the currents flowing through the first radiation conductor 41 and the second radiation conductor 42 flow in an inverse direction, a potential difference between the first radiation conductor 41 and the second radiation conductor 42 becomes large. The magnitude of the capacitive coupling with the second coupling method changes depending on the position where the second coupler 73 faces each of the first radiation conductor 41 and the second radiation conductor 42. The magnitude of the capacitive coupling with the second coupling method can be adjusted by the position and the area where the second coupler 73 faces each of the first radiation conductor 41 and the second radiation conductor 42.
The second feeder line 52 is configured to be coupled to the first feeder line 51 such that the inductance component serving as the first component is dominant. The first coupler 70 is configured to couple the first feeder line 51 and the second feeder line 52 such that the capacitance component serving as the second component is dominant. A coupling coefficient K1 due to the capacitance component and the inductance component between the first feeder line 51 and the second feeder line 52 can be calculated by using a coupling coefficient Ke1 and a coupling coefficient Km1. The coupling coefficient Ke1 is a coupling coefficient due to the capacitance component between the first feeder line 51 and the second feeder line 52. The coupling coefficient Km1 is a coupling coefficient due to an inductance component between the first feeder line 51 and the second feeder line 52. For example, the relationship between the coupling coefficient K1 and the coupling coefficients Ke1 and Km1 is expressed by Equation:
K1=(Ke12−Km12)/(Ke12+Km12).
The coupling coefficient Km1 can be determined according to the configuration of the first feeder line 51 and the second feeder line 52. For example, the coupling coefficient Km1 can change in response to a change in a length of a gap g2 between the first feeder line 51 and the second feeder line 52 illustrated in
The second radiation conductor 42 is configured to be coupled to the first radiation conductor 41 with the first coupling method in which the magnetic field coupling is dominant. The second coupler 73 is configured to couple the first radiation conductor 41 and the second radiation conductor 42 with the second coupling method in which the capacitive coupling is dominant. A coupling coefficient K2 due to the capacitive coupling and the magnetic field coupling between the first radiation conductor 41 and the second radiation conductor 42 can be calculated by using a coupling coefficient Ke2 and a coupling coefficient Km2. The coupling coefficient Ke2 is a coupling coefficient of the capacitive coupling between the first radiation conductor 41 and the second radiation conductor 42. The coupling coefficient Km2 is a coupling coefficient of the magnetic field coupling between the first radiation conductor 41 and the second radiation conductor 42. For example, the relationship between the coupling coefficient K2 and the coupling coefficients Ke2 and Km2 is expressed by Equation:
K2=(Ke22−Km22)/(Ke22+Km22).
The coupling coefficient Km2 can be determined according to the configuration of the first radiation conductor 41 and the second radiation conductor 42. For example, a configuration in which the first radiation conductor 41 and the second radiation conductor 42 are arranged in the Y direction as illustrated in
<Simulation Result>
The reflection coefficient S11 indicates a ratio of the power that is reflected by the first radiation conductor 41 and returns to the first feeder line 51 among the power supplied from the first feeder line 51 to the first radiation conductor 41. In the present embodiment, the reflection coefficient S11 can have one local minimum value by reducing the mutual coupling between the first radiation conductor 41 and the second radiation conductor 42, which will be described in detail later. The reflection coefficient S11 takes a local minimum value of about −11 dB (decibel) in the vicinity of a frequency of 28 GHz.
The transmission coefficient S21 indicates a ratio of the power transmitted to the second feeder line 52 among the power supplied to the first feeder line 51. In the present embodiment, a peak value of the transmission coefficient S21 can be reduced by reducing the mutual coupling between the first feeder line 51 and the second feeder line 52, which will be described in detail later. The transmission coefficient S21 has a peak value of about −12 dB in the vicinity of the frequency of 28 GHz.
It is assumed that: a coupling coefficient due to a capacitance component and an inductance component between the first feeder line 51 and the second feeder line 52 in the comparative example is a coupling coefficient Kx1; a coupling coefficient due to the capacitance component between the first feeder line 51 and the second feeder line 52 is Kex1; and a coupling coefficient due to the inductance component between the first feeder line 51 and the second feeder line 52 is a coupling coefficient Kmx1. In the same as or similar to the present embodiment, even in the comparative example, the coupling coefficient Kx1 can be calculated by using the coupling coefficient Kex1 and the coupling coefficient Kmx1. For example, the relationship between the coupling coefficient Kx1 and the coupling coefficients Kex1 and Kmx1 is expressed by Equation:
Kx1=(Kex12−Kmx12)/(Kex12+Kmx12).
The antenna 10X of the comparative example does not have the first coupler 70. In the antenna 10X of the comparative example, the degree to which the coupling coefficient Kmx1 and the coupling coefficient Kex1 cancel each other cannot be adjusted. In the antenna 10X of the comparative example, the coupling coefficient Kx1 cannot be adjusted because the degree to which the coupling coefficient Kmx1 and the coupling coefficient Kex1 cancel each other cannot be adjusted. In the antenna 10X of the comparative example, the mutual coupling between the first feeder line 51 and the second feeder line 52 can be larger than that of the antenna 10. In contrast, since the antenna 10 has the first coupler 70, the coupling coefficient K1 can be adjusted to make it smaller.
It is assumed that: a coupling coefficient due to the capacitive coupling and the magnetic field coupling between the first radiation conductor 41 and the second radiation conductor 42 in the comparative example is a coupling coefficient Kx2; a coupling coefficient of the capacitive coupling between the first radiation conductor 41 and the second radiation conductor 42 is a coupling coefficient Kex2; and a coupling coefficient of the magnetic field coupling between the first radiation conductor 41 and the second radiation conductor 42 is a coupling coefficient Kmx2. Same as or similar to the present embodiment, even in the comparative example, the coupling coefficient Kx2 can be calculated by using the coupling coefficient Kex2 and the coupling coefficient Kmx2. For example, the relationship between the coupling coefficient Kx2 and the coupling coefficients Kex2 and Kmx2 is expressed by Equation:
Kx2=(Kex22−Kmx22)/(Kex22+Kmx22).
The antenna 10X of the comparative example does not have the second coupler 73. In the antenna 10X of the comparative example, the degree to which the coupling coefficient Kmx2 and the coupling coefficient Kex2 cancel each other cannot be adjusted. The antenna 10X of the comparative example cannot adjust the coupling coefficient Kx2 because the degree to which the coupling coefficient Kmx2 and the coupling coefficient Kex2 cancel each other cannot be adjusted. In the antenna 10X of the comparative example, the mutual coupling between the first radiation conductor 41 and the second radiation conductor 42 can be larger than that of the antenna 10. In contrast, since the antenna 10 has the second coupler 73, the coupling coefficient K2 can be adjusted to make it smaller.
In general, coupling occurs when resonators with the same resonance frequency approach each other. In the antenna 10X of the comparative example, the even-odd mode occurs because the mutual coupling between the first radiation conductor 41 and the second radiation conductor 42 is large. The antenna 10X of the comparative example resonates at different resonance frequencies in the even mode and the odd mode. In the antenna 10X of the comparative example, the radiation efficiency of electromagnetic waves can be lowered by resonating in the even-odd modes of different resonance frequencies.
<Simulation Result>
A broken line indicates a reflection coefficient S11x of the antenna 10X according to the comparative example. A solid line indicates a transmission coefficient S21x of the antenna 10X according to the comparative example.
The reflection coefficient S11x takes a local minimum value of about −9 dB in the vicinity of the frequency of 27 GHz. The reflection coefficient S11x takes a local minimum value of about −10 dB in the vicinity of the frequency of 29 GHz. In the comparative example, the reflection coefficient S11x takes two local minimum values.
The fact that the reflection coefficient S11x takes the two minimum values indicates that the antenna 10X has two resonance frequencies. The two resonance frequencies of the antenna 10X are caused by the even and odd modes. The resonance of the antenna 10X in the even-odd mode indicates that the mutual coupling between the first antenna element 31 and the second antenna element 32 is large. Since each of the first antenna element 31 and the second antenna element 32 resonates in the even-odd mode, the radiation efficiency of electromagnetic waves by each of the first radiation conductor 41 and the second radiation conductor 42 becomes low.
The transmission coefficient S21x has a peak value of about −5 dB in a frequency range from 27 GHz to 29 GHz. The peak value of the transmission coefficient S21x is larger than that of the transmission coefficient S21 of the present embodiment illustrated in
In contrast to such a comparative example, the antenna 10 has the first coupler 70, as illustrated in
In contrast to such a comparative example, in the present embodiment, the antenna 10 has the second coupler 73 as illustrated in
The antenna 10 has the first coupler 70 that reduces the mutual coupling between the first feeder line 51 and the second feeder line 52, and the second coupler 73 that reduces the mutual coupling between the first radiation conductor 41 and the second radiation conductor 42. The antenna 10 separately reduces the two mutual couplings by the first coupler 70 and the second coupler 73, which are different couplers. The first coupler 70 and the second coupler 73 are independent of each other. By having the first coupler 70 and the second coupler 73, the antenna 10 can increase the flexibility in design for reducing the mutual coupling.
As illustrated in
As illustrated in
The first radiation conductor 41 and the second radiation conductor 42 are arranged to be shifted in the long side direction, that is, in the Y direction. By arranging the first radiation conductor 41 and the second radiation conductor 42 so as to be shifted in the Y direction, a portion of the long side 41a and a portion of the long side 42a face each other. A gap g3 is generated when a portion of the long side 41a and a portion of the long side 42a face each other. A coupling coefficient Km3 of the magnetic field coupling between the first radiation conductor 41 and the second radiation conductor 42 depends on a length of the gap g3 in the Y direction. The length of the gap g3 in the Y direction corresponds to an interval d1 illustrated in
By arranging the first radiation conductor 41 and the second radiation conductor 42 so as to be shifted in the Y direction, the interval d1 between the short side 41b and the short side 42b can be brought close to each other.
A coupling coefficient Ke3 of the capacitive coupling between the first radiation conductor 41 and the second radiation conductor 42 depends on the interval d1 between the short side 41b and the short side 41b illustrated in
A coupling coefficient K3 due to the capacitive coupling and the magnetic field coupling between the first radiation conductor 41 and the second radiation conductor 42 can be reduced by canceling the coupling coefficient Km3 and the coupling coefficient Ke3 each other. In the antenna 110, the interval d1 illustrated in
The second feeder line 52 illustrated in
The first coupler 170 illustrated in
A coupling coefficient K4 due to the capacitance component and the inductance component between the first feeder line 51 and the second feeder line 52 can be reduced by canceling a coupling coefficient Km4 and a coupling coefficient Ke4 each other. The coupling coefficient Km4 is a coupling coefficient due to the inductance component between the first feeder line 51 and the second feeder line 52. The coupling coefficient Ke4 is a coupling coefficient due to the capacitance component between the first feeder line 51 and the second feeder line 52. By appropriately configuring the first coupler 170 in the same as or similar to the configuration illustrated in
Other configurations and effects of the antenna 110 are the same as or similar to the configurations and effects of the antenna 10 illustrated in
As illustrated in
The third coupler 74 is configured to couple the first radiation conductor 41 and the second feeder line 52.
The third coupler 74 may be configured to couple the first radiation conductor 41 and the second feeder line 52 such that one of the capacitance component and the inductance component is dominant, depending on the configuration of the first radiation conductor 41 and the second feeder line 52. In the present embodiment, the third coupler 74 is configured to couple the first radiation conductor 41 and the second feeder line 52 such that the capacitance component serving as the second component is dominant.
For example, the third coupler 74 may include a conductive material. The third coupler 74 is located in the base 20. The third coupler 74 is separated from each of the first radiation conductor 41 and the second radiation conductor 42 in the Z direction. The third coupler 74 may be L-shaped, as illustrated in
A coupling coefficient K5 due to the capacitance component and the inductance component between the first radiation conductor 41 and the second feeder line 52 can be reduced by canceling a coupling coefficient Ke5 and a coupling coefficient Km5 each other. The coupling coefficient Ke5 is a coupling coefficient due to the capacitance component between the first radiation conductor 41 and the second feeder line 52. The coupling coefficient Km5 is a coupling coefficient due to the inductance component between the first radiation conductor 41 and the second feeder line 52. Depending on the frequency used in the antenna 210 and the configuration of the antenna 210, the coupling coefficient Km5 may be larger than the coupling coefficient Ke5. In such a configuration, the degree to which the coupling coefficient Ke5 and the coupling coefficient Km5 cancel each other can be changed by appropriately configuring the third coupler 74. By appropriately configuring the third coupler 74, the coupling coefficient Ke5 and the coupling coefficient Km5 can cancel each other, and the coupling coefficient K5 can be reduced. By reducing the coupling coefficient K5, the mutual coupling between the first radiation conductor 41 and the second feeder line 52 can become smaller.
The fourth coupler 75 is configured to couple the second radiation conductor 42 and the first feeder line 51. The fourth coupler 75 may be configured to couple the second radiation conductor 42 and the first feeder line 51 such that one of the capacitance component and the inductance component is dominant, depending on the configuration of the second radiation conductor 42 and the first feeder line 51. In the present embodiment, the fourth coupler 75 is configured to couple the second radiation conductor 42 and the first feeder line 51 such that the capacitance component serving as the second component is dominant.
For example, the fourth coupler 75 may include a conductive material. The fourth coupler 75 is located in the base 20. The fourth coupler 75 is separated from each of the first radiation conductor 41 and the second radiation conductor 42 in the Z direction. The fourth coupler 75 may be L-shaped, as illustrated in
A coupling coefficient K6 due to the capacitance component and the inductance component between the second radiation conductor 42 and the first feeder line 51 can be reduced by canceling a coupling coefficient Ke6 and a coupling coefficient Km6 each other. The coupling coefficient Ke6 is a coupling coefficient due to the capacitance component between the second radiation conductor 42 and the first feeder line 51. The coupling coefficient Km6 is a coupling coefficient due to the inductance component between the second radiation conductor 42 and the first feeder line 51. Depending on the frequency used in the antenna 210 and the configuration of the antenna 210, the coupling coefficient Km6 may be larger than the coupling coefficient Ke6. In such a configuration, the degree to which the coupling coefficient Ke6 and the coupling coefficient Km6 cancel each other can be changed by appropriately configuring the third coupler 74. By appropriately configuring the fourth coupler 75, the coupling coefficient Ke6 and the coupling coefficient Km6 can cancel each other, and the coupling coefficient K6 can be reduced. By reducing the coupling coefficient K6, the mutual coupling between the second radiation conductor 42 and the first feeder line 51 can become smaller.
Other configurations and effects of the antenna 210 are the same as or similar to the configurations and effects of the antenna 10 illustrated in
The configurations and effects of the antenna 310 are the same as or similar to the configurations and effects of the antenna 10 illustrated in
The antenna 410 can be an array antenna. The antenna 410 may be a linear array antenna.
The antenna 410 has the base 20 and n (n: 3 or more integers) antenna elements as a plurality of antenna elements. In the present embodiment, the antenna 410 has four antenna elements (n=4), that is, a first antenna element 431, a second antenna element 432, a third antenna element 433, and a fourth antenna element 434.
The antenna 410 may appropriately have the first coupler 70 illustrated in
The first antenna element 431 may be the first antenna element 31 illustrated in
The second antenna element 432 may be the second antenna element 32 illustrated in
The third antenna element 433 is configured to resonate in a first frequency band or a second frequency band depending on the use of the antenna 410 and the like. The third antenna element 433 may have the same or similar configuration as the first antenna element 431 or the second antenna element 432. The third antenna element 433 has a third radiation conductor 443 and a third feeder line 53. The third radiation conductor 443 may have the same or similar configuration as the first radiation conductor 41 or the second radiation conductor 42 illustrated in
The fourth antenna element 434 is configured to resonate in a first frequency band or a second frequency band depending on the use of the antenna 410 and the like. The fourth antenna element 434 may have the same or similar configuration as the first antenna element 431 or the second antenna element 432. The fourth antenna element 434 has a fourth radiation conductor 444 and a fourth feeder line 54. The fourth radiation conductor 444 may have the same or similar configuration as the first radiation conductor 41 or the second radiation conductor 42 illustrated in
The first antenna element 431 to the fourth antenna element 434 may be configured to resonate in the same phase. The first feeder line 51 to the fourth feeder line 54 may be configured to feed signals that respectively excite the first antenna element 431 to the fourth antenna element 434 in the same phase. When exciting the first antenna element 431 to the fourth antenna element 434 in the same phase, the signals fed from the first feeder line 51 to the fourth feeder line 54 to the first antenna element 431 to the fourth antenna element 434 may have the same phase. When exciting the first antenna element 431 to the fourth antenna element 434 in the same phase, the signals fed from the first feeder line 51 to the fourth feeder line 54 to the first antenna element 431 to the fourth antenna element 434 may have different phases.
The first antenna element 431 to the fourth antenna element 434 may be configured to resonate in different phases. The first feeder line 51 to the fourth feeder line 54 may be configured to feed signals that respectively excite the first antenna element 431 to the fourth antenna element 434 in different phases. When exciting the first antenna element 431 to the fourth antenna element 434 in different phases, the signals fed from the first feeder line 51 to the fourth feeder line 54 to the first antenna element 431 to the fourth antenna element 434 may have the same phase. When exciting the first antenna element 431 to the fourth antenna element 434 in different phases, the signals fed from the first feeder line 51 to the fourth feeder line 54 to the first antenna element 431 to the fourth antenna element 434 may have different phases.
The first antenna element 431, the second antenna element 432, the third antenna element 433, and the fourth antenna element 434 are arranged along the X direction. The first antenna element 431, the second antenna element 432, the third antenna element 433, and the fourth antenna element 434 may be arranged at intervals equal to or less than ¼ of the resonance wavelength of the antenna 410 in the X direction. In the present embodiment, the first radiation conductor 441, the second radiation conductor 442, the third radiation conductor 443, and the fourth radiation conductor 444 are arranged along the X direction with an interval D1. The interval D1 is equal to or less than ¼ of the resonance wavelength of the antenna 410.
In a configuration in which the fourth antenna element 434 serving as an n-th antenna element resonates at the first frequency, the fourth radiation conductor 444 serving as an n-th radiation conductor may be arranged with the first radiation conductor 441 in the X direction at an interval equal to or less than ½ of the resonance wavelength of the antenna 410. In the present embodiment, the first radiation conductor 441 and the fourth radiation conductor 444 are arranged along the X direction with an interval D2. The interval D2 is equal to or less than ½ of the resonance wavelength of the antenna 410. The fourth radiation conductor 444 may be configured to be directly or indirectly coupled to the second radiation conductor 442.
The first antenna element 431 and the second antenna element 432 that are adjacent to each other may be shift in the Y direction. When the first antenna element 431 and the second antenna element 432 that are adjacent to each other are shift in the Y direction, the antenna 410 may have the first coupler 70 illustrated in
The antenna 510 can be an array antenna. The antenna 510 may be a planar array antenna.
The antenna 510 has the base 20, a first antenna element group 81, and a second antenna element group 82. The antenna 510 may further include second couplers 571, 572, 573, 574, 575, 576, and 577. The antenna 510 may appropriately include the first coupler 70 illustrated in
Each of the first antenna element group 81 and the second antenna element group 82 extends along the X direction. The first antenna element group 81 and the second antenna element group 82 are arranged along the Y direction. Each of the first antenna element group 81 and the second antenna element group 82 may have the same or similar configuration as an antenna element group illustrated in
The first antenna element group 81 includes antenna elements 531, 532, 533, and 534. Each of the antenna elements 531 to 543 may have the same or similar configuration as the first antenna element 31 illustrated in
The second antenna element group 82 includes antenna elements 535, 536, 537, and 538. Each of the antenna elements 535 to 538 may have the same or similar configuration as the first antenna element 31 illustrated in
The antenna elements 531 to 538 may be configured to resonate in the same phase. Feeder lines of the antenna elements 531 to 538 may be configured to feed signals that excite the antenna elements 531 to 538 in the same phase. When the antenna elements 531 to 538 are excited in the same phase, the signals fed from the feeder lines of the antenna elements 531 to 538 to the antenna elements 531 to 538 may have the same phase. When the antenna elements 531 to 538 are excited in the same phase, the signals fed from the feeder lines of the antenna elements 531 to 538 to the antenna elements 531 to 538 may have different phases.
The antenna elements 531 to 538 may be configured to resonate in different phases. The feeder lines of the antenna elements 531 to 538 may be configured to feed the signals that excite the antenna elements 531 to 538 in different phases. When the antenna elements 531 to 538 are excited in different phases, the signals fed from the feeder lines of the antenna elements 531 to 538 to the antenna elements 531 to 538 may have the same phase. When the antenna elements 531 to 538 are excited in different phases, the signals fed from the feeder lines of the antenna elements 531 to 538 to the antenna elements 531 to 538 may have different phases.
In the first antenna element group 81, the antenna elements 531 to 534 are arranged along the X direction. The antenna elements 531 to 534 may be arranged to be shifted in the Y direction. Of the antenna elements 531 to 534, the antenna element 533 protrudes toward the second antenna element group 82.
In the second antenna element group 82, the antenna elements 535 to 538 are arranged along the X direction. The antenna elements 535 to 538 may be arranged to be shifted in the Y direction. Of the antenna elements 535 to 538, the antenna element 537 protrudes toward the first antenna element group 81.
At least one antenna element of the first antenna element group 81 is configured to be coupled to at least one antenna element of the second antenna element group 82 with the first coupling method or the second coupling method. In the present embodiment, the radiation conductor 543 of the antenna element 533 of the first antenna element group 81 is configured to be coupled to the radiation conductor 547 of the antenna element 537 of the second antenna element group 82 with the second coupling method in which the capacitance coupling is dominant. For example, a short side 543b of the radiation conductor 543 and a short side 547b of the radiation conductor 547 face each other. The short side 543b and the short side 547b facing each other can configure a capacitor via the base 20. By configuring the capacitor, the radiation conductor 543 of the antenna element 533 is configured to be coupled to the radiation conductor 547 of the antenna element 537 with the second coupling method in which the capacitive coupling is dominant.
The first antenna element group 81 includes the radiation conductors 541, 542, 543, and 544 as a first radiation conductor group 91. The second antenna element group 82 includes the radiation conductors 545, 546, 547, and 548 as a second radiation conductor group 92.
In the first radiation conductor group 91, the radiation conductor 541 and the radiation conductor 542 that are adjacent to each other are configured to be coupled with the first coupling method in which the magnetic field coupling is dominant, in the same as or similar to the first radiation conductor 41 and the second radiation conductor 42 illustrated in
In the second radiation conductor group 92, the radiation conductor 545 and the radiation conductor 546 that are adjacent to each other are configured to be coupled with the first coupling method in which the magnetic field coupling is dominant, in the same as or similar to the first radiation conductor 41 and the second radiation conductor 42 illustrated in
The second coupler 571 is configured to couple the radiation conductor 541 and the radiation conductor 542 that are adjacent to each other with the second coupling method in which the capacitive coupling is dominant, in the same as or similar to the second coupler 73 illustrated in
In the same as or similar to the second coupler 571, the second coupler 572 is configured to couple the radiation conductor 542 and the radiation conductor 543 that are adjacent to each other with the second coupling method in which the capacitive coupling is dominant. The second coupler 573 is configured to couple the radiation conductor 543 and the radiation conductor 544 that are adjacent to each other with the second coupling method in which the capacitive coupling is dominant. The second coupler 574 is configured to couple the radiation conductor 545 and the radiation conductor 546 that are adjacent to each other with the second coupling method in which the capacitive coupling is dominant. The second coupler 575 is configured to couple the radiation conductor 546 and the radiation conductor 547 that are adjacent to each other with the second coupling method in which the capacitive coupling is dominant. The second coupler 576 is configured to couple the radiation conductor 547 and the radiation conductor 548 that are adjacent to each other with the second coupling method in which the capacitive coupling is dominant. Such a configuration can reduce the mutual coupling between adjacent radiation conductors.
The second coupler 577 is configured to magnetically couple the radiation conductor 543 of the first radiation conductor group 91 and the radiation conductor 547 of the second radiation conductor group 92. The second coupler 577 may include a coil or the like.
Since the second coupler 577 magnetically couples the radiation conductor 543 and the radiation conductor 547, the mutual coupling between the radiation conductor 543 and the radiation conductor 547 can be reduced.
The wireless communication module 1 includes an antenna 11, an RF module 12, and a circuit board 14. The circuit board 14 has a ground conductor 13A and a printed circuit board 13B.
The antenna 11 includes the antenna 10 illustrated in
The antenna 11 is located on the circuit board 14 as illustrated in
The antenna 11 is not limited to the one having both the first feeder line 51 and the second feeder line 52. The antenna 11 may have one feeder line of the first feeder line 51 and the second feeder line 52. When the antenna 11 has one feeder line of the first feeder line 51 and the second feeder line 52, the configuration of the circuit board 14 can be appropriately changed according to the configuration of the antenna 11 having one feeder line. For example, the RF module 12 may have only one connection terminal. For example, the circuit board 14 may have one conductive wire configured to connect the connection terminal of the RF module 12 and the feeder line of the antenna 11.
The ground conductor 13A may include a conductive material. The ground conductor 13A can extend in the XY plane.
The antenna 11 may be integrated with the circuit board 14. In the configuration in which the antenna 11 and the circuit board 14 are integrated, the ground conductor 60 of the antenna 11 may be integrated with the ground conductor 13A of the circuit board 14.
The RF module 12 is configured to control power fed to the antenna 11. The RF module 12 is configured to modulate a baseband signal and supply the modulated baseband signal to the antenna 11. The RF module 12 is configured to modulate an electrical signal received by the antenna 11 into the baseband signal.
The wireless communication module 1 can efficiently radiate electromagnetic waves by including the antenna 11.
The wireless communication device 2 can be located on a board 3. A material of the board 3 may be any material. As illustrated in
The sensor 15 may include, for example, a speed sensor, a vibration sensor, an acceleration sensor, a gyro sensor, a rotation angle sensor, an angular velocity sensor, a geomagnetic sensor, a magnet sensor, a temperature sensor, a humidity sensor, an atmospheric pressure sensor, an optical sensor, an illuminance sensor, a UV sensor, a gas sensor, a gas concentration sensor, an atmosphere sensor, a level sensor, an odor sensor, a pressure sensor, an air pressure sensor, a contact sensor, a wind power sensor, an infrared sensor, a human sensor, a displacement sensor, an image sensor, a weight sensor, a smoke sensor, a liquid leakage sensor, a vital sensor, a battery remaining amount sensor, an ultrasonic sensor, or a global positioning system (GPS) signal receiving device, or the like.
The battery 16 is configured to supply power to the wireless communication module 1. The battery 16 may be configured to supply the power to at least one of the sensor 15, the memory 17, and the controller 18. The battery 16 may include at least one of a primary battery and a secondary battery. A negative electrode of the battery 16 is configured to be electrically connected to the ground terminal of the circuit board 14 illustrated in
The memory 17 can include, for example, a semiconductor memory or the like. The memory 17 may be configured to function as a work memory of the controller 18. The memory 17 can be included in the controller 18. The memory 17 stores a program that describes processing contents for implementing each function of the wireless communication device 2, information used for processing in the wireless communication device 2, and the like.
The controller 18 can include, for example, a processor. The controller 18 may include one or more processors. The processor may include a general-purpose processor that loads a specific program and executes a specific function, and a dedicated processor that is specialized for specific processing. The dedicated processor may include an application specific IC. The application specific IC is also called an application specific integrated circuit (ASIC). The processor may include a programmable logic device. The programmable logic device is also called a programmable logic device (PLD). The PLD may include a field-programmable gate array (FPGA). The controller 18 may be either a system-on-a-chip (SoC) in which one or a plurality of processors cooperate, and a system in a package (SiP). The controller 18 may store various kinds of information, a program for operating each component of the wireless communication device 2, or the like in the memory 17.
The controller 18 is configured to generate a transmission signal transmitted from the wireless communication device 2. The controller 18 may be configured to acquire measurement data from, for example, the sensor 15. The controller 18 may be configured to generate a transmission signal according to the measurement data. The controller 18 can be configured to transmit a baseband signal to the RF module 12 of the wireless communication module 1.
The housing 19 illustrated in
The first housing 19A illustrated in
The second housing 19B illustrated in
The conductor member 19C illustrated in
The configuration according to the present disclosure is not limited to the embodiments described above, and various modifications or changes can be made. For example, the functions and the like included in each component can be rearranged so as not to logically contradict each other, and a plurality of components can be combined into one or divided.
For example, in the above-described embodiments as illustrated in
For example, the second coupler 73 may be located on the positive direction side of the Z axis as compared to the first radiation conductor 41 and the second radiation conductor 42.
The diagrams illustrating the configuration according to the present disclosure are schematic. The dimensional ratios and the like on the drawings do not always match the actual ones.
In the present disclosure, the terms “first”, “second”, “third” and so on are examples of identifiers meant to distinguish the configurations from each other. In the present disclosure, regarding the configurations distinguished by the terms “first” and “second”, the respective identifying numbers can be reciprocally exchanged. For example, regarding a first frequency and a second frequency, the identifiers “first” and “second” can be reciprocally exchanged. The exchange of identifiers is performed simultaneously. Even after exchanging the identifiers, the configurations remain distinguished from each other. Identifiers may be removed. The configurations from which the identifiers are removed are still distinguishable by the reference numerals. In the present disclosure, the terms “first”, “second”, and so on of the identifiers should not be used in the interpretation of the order of the configurations, or should not be used as the basis for having identifiers with low numbers, or should not be used as the basis for having identifies with high numbers.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2018-206002 | Oct 2018 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2019/042058 | 10/25/2019 | WO |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2020/090691 | 5/7/2020 | WO | A |
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| Number | Date | Country | |
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| 20210399435 A1 | Dec 2021 | US |
