Patent Application
20240258703
This application is based upon and claims benefit of priority from Japanese Patent Application No. 2023-011974, filed on Jan. 30, 2023, the entire contents of which are incorporated herein by reference.
The present invention relates to a metal plate antenna and an antenna device.
In recent years, various types of antennas have been developed. For example, Satoshi Honda and three others disclose a disc monopole antenna arranged on a substrate.
The antenna as disclosed by Satoshi Honda and three others has a problem of impedance matching. Furthermore, a devise for stably arranging the antenna as disclosed by Satoshi Honda and three others on the substrate is demanded.
The present invention has been made in light of the above problem, and an object of the present invention is to provide a metal plate antenna that achieves both of impedance matching and stable arrangement of the metal plate antenna on a substrate.
To solve the above described problem, according to an aspect of the present invention, there is provided a metal plate antenna arranged on a substrate, the metal plate antenna comprising: a parallel part arranged in substantially parallel to the substrate; a power feeding point contact part extended from the parallel part substantially perpendicularly to the parallel part, and provided in contact with a power feeding point with a metal foil pattern formed on the substrate and interposed therebetween; and a leg part formed separately from the power feeding point contact part, and extended from the parallel part substantially perpendicularly to the parallel part, wherein a contact area of the metal foil pattern and the power feeding point is narrower than a contact area of the metal foil pattern and the power feeding point contact part.
To solve the above described problem, according to another aspect of the present invention, there is provided an antenna device comprising: a substrate; and a metal plate antenna arranged on a substrate, wherein the metal plate antenna includes: a parallel part arranged in substantially parallel to the substrate; a power feeding point contact part extended from the parallel part substantially perpendicularly to the parallel part, and provided in contact with a power feeding point with a metal foil pattern formed on the substrate and interposed therebetween; and a leg part formed separately from the power feeding point contact part, and extended from the parallel part substantially perpendicularly to the parallel part, and a contact area of the metal foil pattern and the power feeding point is narrower than a contact area of the metal foil pattern and the power feeding point contact part.
As described above, the present invention can provide a metal plate antenna that achieves both of impedance matching and stable arrangement of the metal plate antenna on a substrate.
Hereinafter, referring to the appended drawings, preferred embodiments of the present invention will be described in detail. It should be noted that, in this specification and the appended drawings, structural elements that have substantially the same function and structure are denoted with the same reference numerals, and repeated explanation thereof is omitted.
Furthermore, the same types of a plurality of existing components will be distinguished and described by assigning alphabets to ends of reference numerals in this description and the drawings in some cases. On the other hand, in a case where the same types of the plurality of existing components do not need to be distinguished, the above alphabets will be omitted, and common description will be made on all of the same types of the plurality of existing components in some cases.
To describe the advantage of the metal plate antenna included in an antenna device 10 according to the embodiment of the present invention, a metal plate antenna 910 included in a device for comparison 90 will be described first with reference to
The metal plate antenna 910 includes a parallel part 912 arranged in substantially parallel to the substrate 950, a power feeding point contact part 914 extended from the parallel part 912 substantially perpendicularly to the parallel part 912, and provided in contact with a power feeding point 970 arranged on the substrate 950, and a leg part 916 formed separately from the power feeding point contact part 914, extended from the parallel part 912 substantially perpendicularly to the parallel part 912, and provided in contact with a GND 960 formed on the substrate 950.
The metal plate antenna 910 is a transmission line antenna that operates as a one-wavelength (2) loop antenna using a mirror image formed using the GND 960 as a mirror surface.
Furthermore, the metal plate antenna 910 may be formed by press-machining one metal plate.
The power feeding point contact part 914 included in the metal plate antenna 910 may be formed such that the width of the lower end that is in contact with the power feeding point 970 is shorter than the width of the upper end as illustrated in
According to the above shape, an effect of making it easier to perform impedance matching is expected.
However, in a case where the width of the lower end of the power feeding point contact part 914 that is in contact with the power feeding point 970 is made shorter (e.g., one mm or less), a precise press-machining technology is required.
Furthermore, in a case where the width of the lower end of the power feeding point contact part 914 that is in contact with the power feeding point 970 is made shorter, the metal plate antenna 910 may have difficulty in standing by itself on the substrate 950.
The metal plate antenna according to the embodiment of the present invention has been conceived focusing on the above point, and achieves both of impedance matching and stable arrangement of the metal plate antenna on the substrate.
Hence, the metal plate antenna included in the antenna device 10 according to the present embodiment has a characteristic shape described later.
Hereinafter, the shape examples of the metal plate antenna according to the present embodiment will be described in detail with reference to each of
As illustrated in
The transmission line antenna 110 according to the present embodiment includes a parallel part 112 arranged in substantially parallel to a substrate 150, a power feeding point contact part 114 extended from the parallel part 112 substantially perpendicularly to the parallel part 112, and provided in contact with a power feeding point 170 (indicated by diagonal lines) arranged on the substrate 150 with a metal foil pattern 180 (indicated by a lattice pattern) formed on the substrate 150 and interposed therebetween, and a leg part 116 formed separately from the power feeding point contact part 114, extended from the parallel part 112 substantially perpendicularly to the parallel part 112, and provided in contact with a GND 160 (indicated by a dot pattern) formed on the substrate 150.
Here, one of features of the antenna device 10 illustrated in
According to the above feature, it is possible to more easily perform impedance matching similar to the device for comparison 90 illustrated in
Furthermore, formation of the metal foil pattern 180 on the substrate 150 is easy and accurate compared to the above-described press-machining, so that the antenna device 10 according to the present embodiment provides an advantageous effect compared to the device for comparison 90.
Furthermore, in a case where the metal foil pattern 180 is formed as in the above feature, it is not necessary to machine the width of the lower end of the power feeding point contact part 114 short, so that it is possible to increase the contact area of the power feeding point contact part 114 and the substrate 150, and more stably arrange the metal plate antenna on the substrate 150.
Note that the metal foil pattern 180 may be formed using, for example, a copper foil.
In a case where the antenna device 10 includes the transmission line antenna 110, the transmission line antenna 110 is formed such that an antenna length defined by the lengths of the parallel part 112, the power feeding point contact part 114, and the leg part 116 is approximately ½ of the wavelength of a wireless signal that conforms to specific wireless communication standards.
In this regard, the metal plate antenna according to the present embodiment is not limited to the transmission line antenna illustrated in
For example, the metal plate antenna according to the present embodiment may be an inverted L antenna 120 illustrated in
The inverted L antenna 120 illustrated in
A contact portion of the leg part 126 and the substrate 150 is electrically insulated as illustrated in
According to the above configuration, it is possible to achieve both of impedance matching and stable arrangement on the substrate.
In a case where the antenna device 10 includes the inverted L antenna 120, the inverted L antenna 120 is formed such that an antenna length defined by the lengths of the parallel part 122, the power feeding point contact part 124, and the leg part 126 is approximately ¼ of the wavelength of a wireless signal that conforms to the specific communication standards.
Furthermore, for example, the metal plate antenna according to the present embodiment may be an inverted F antenna 130 illustrated in
The inverted F antenna 130 illustrated in
According to the above configuration, it is possible to achieve both of impedance matching and stable arrangement on the substrate.
In a case where the antenna device 10 includes the inverted F antenna 130, the inverted F antenna 130 is formed such that an antenna length defined by the lengths of the parallel part 132, the power feeding point contact part 134, and the leg part 136 is approximately ¼ of the wavelength of a wireless signal that conforms to the specific communication standards.
Furthermore, for example, the metal plate antenna according to the present embodiment may be a branched power feeding transmission line antenna 140 illustrated in
The branched power feeding transmission line antenna 140 illustrated in
According to the above configuration, it is possible to achieve both of impedance matching and stable arrangement on the substrate.
In a case where the antenna device 10 includes the branched power feeding transmission line antenna 140, the branched power feeding transmission line antenna 140 is formed such that an antenna length defined by the lengths of the parallel part 142, the power feeding point contact part 144, and the leg parts 146 is approximately ½ of the wavelength of a wireless signal that conforms to the specific communication standards.
The shape examples of the metal plate antenna according to the present embodiment have been described above. In this regard, the shape of each metal plate antenna described with reference to each of
The antenna length defined by the lengths of the parallel part, the power feeding point contact part, and the leg part may be determined based on the wavelength of a wireless signal that conforms to the specific communication standards for the metal plate antenna according to the present embodiment to transmit and receive the wireless signal that conforms to the specific communication standards.
An example of the above specific communication standards includes Ultra-Wide Band (UWB) wireless communication.
Furthermore, the leg part included in the metal plate antenna according to the present embodiment may contact the metal foil pattern 180 arranged on the substrate 150.
When the leg part 116 is in more contact with the metal foil pattern 180, an effect of making it easier to adjust impedance matching is expected.
Note that, although
The metal plate antenna according to the present embodiment has been basically described above. Next, the modified examples of the metal plate antenna according to the present embodiment will be described.
Note that, although description on the following modified examples will adopt the transmission line antenna 110 as a main example, the inverted L antenna 120, the inverted F antenna 130, and the branched power feeding transmission line antenna 140 can be also modified likewise.
First, a modified example of the leg part included in the metal plate antenna will be described.
In this regard, the shape of the leg part 116 according to the present embodiment is not limited to this example.
As illustrated at the upper part in
Furthermore, as illustrated at the middle part in
In this case, it is easy to form a fillet at a time of fixing using a conductive adhesive such as a solder, and, moreover, it is easy to check the formed fillet.
On the other hand, the leg part 116 according to the present embodiment may not have the bending structure as illustrated at the lower part in
Even in this case, the transmission line antenna 110 can stand by itself on the substrate 150 by being fixed using a conductive adhesive such as a solder.
Furthermore, the transmission line antenna 110 may include opening parts 210 in the vicinity just above the contact portion of the leg part 116 and the substrate 150.
The transmission line antenna 110 is formed using a metal material, and therefore has high thermal conductivity. Hence, when fixing is performed using a conductive adhesive such as a solder, heat tends to escape upward.
However, in a case where the opening parts 210 are formed in the vicinity just above the contact portion of the leg part 116 and the substrate 150 as illustrated in
Next, a modified example where an antenna length is secured will be described.
To secure the antenna length of interest, the metal plate antenna according to the present embodiment may have a structure such as slits 220 for causing a current to detour.
As illustrated in
In a case where the transmission line antenna 110 includes the slits 220 as illustrated in
Note that, although
The slits 220 according to the present embodiment may be formed in opposing two directions as illustrated at, for example, the upper part and the lower part in
Furthermore, structures that are formed in the metal plate antenna and cause a current to detour are not limited to the slits 220. The structures may be the opening parts 210.
As illustrated in
In a case where the transmission line antenna 110 includes the opening parts 210 as illustrated in
The slits 220 and the opening parts 210 that are the structures for causing a current to detour have been described above. Formation patterns of the slits 220 and the opening parts 210 may be designed as appropriate according to an antenna length of interest, the size of the metal plate antenna, and the like.
Next, a modified example in a case where the metal plate antenna according to the present embodiment includes stabs 240 will be described.
As illustrated in
As illustrated at the upper part in
The stabs 240 formed as described above can cause a current to further flow in the direction perpendicular to the direction that connects the power feeding point contact part 114 and the leg part 116, and consequently can cause the transmission line antenna 110 to function as a circularly polarized antenna.
Alternatively, as illustrated at the lower part in
Furthermore, the stab 240 may be bent at, for example, a portion indicated by a two-dot-dash line in
The stabs 240 according to the present embodiment can efficiently adjust a polarized wave and the antenna length.
Next, a mold structure according to the present embodiment will be described.
As illustrated at the upper part in
Alternatively, as illustrated at the lower part in
This mold structure that uses the insulation material 250 can effectively prevent change of the shape of the metal plate antenna.
Next, a modified example of the metal plate according to the present embodiment will be described.
The case where the metal plate antenna according to the present embodiment is formed by one metal plate has been mainly described above.
On the other hand, the metal plate antenna according to the present embodiment may be formed by a plurality of metal plates.
As illustrated in
Note that, for example, the insulation material 250 may be filled in the region between the metal plate 110A and the metal plate 110B as illustrated in
In this case, it is possible to more stably keep the shape (structure) of the transmission line antenna 110.
Heretofore, preferred embodiments of the present invention have been described in detail with reference to the appended drawings, but the present invention is not limited thereto. It is obvious that a person skilled in the art can arrive at various alterations and modifications within the scope of the technical ideas defined in the claims, and it should be naturally understood that such alterations and modifications are also encompassed by the technical scope of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2023-011974 | Jan 2023 | JP | national |
