Antenna device

Abstract

The antenna device includes: a resin body (11) having a bottomed cylindrical shape with an opening at one end; a circuit board (2) with a through hole (2a) that penetrates from the inner surface to the outer surface, where the opening of the resin body (11) is covered and the resin body (11) is mounted, and a power supply line (26) is formed on the outer surface; a feeding element (12a) composed of an antenna pattern formed on the inner wall surface of the resin body (11); and a feeding terminal (12b) formed at one end of the antenna pattern, passing through the through hole (2a) of the circuit board (2), and having one end electrically connected to the other end of a power supply line (24) formed on the outer surface of the circuit board (2).

Description

Technical Field

[0001] The present disclosure relates to an antenna device formed on the surface of a circuit board, in which one end of an antenna element is formed at the other end of a power supply line having a power supply point at one end.

Background Art

[0002] As an antenna device used in communication, radar, positioning, etc., an antenna device is known in which an antenna element is electrically connected to a power supply line having a power supply point formed on the surface of a circuit board. Further, in the case of a mobile phone, Patent Document 1 shows a mobile phone in which a wiring area of an antenna pattern formed by printing and plating is formed on the inner wall surface of an outer cover.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In an antenna device in which an antenna element is electrically connected to a power supply line having a power supply point formed on the surface of a circuit board, it is desired to prevent the antenna element from being damaged by the influence of wind, rain or sunlight disturbance.

[0005] The present disclosure has been made in view of the above points, and an object thereof is to obtain an antenna device in which a decrease in the performance of an antenna element is suppressed by preventing the antenna element from being damaged by the influence of disturbance.

Means for Solving the Problems

[0006] The antenna device according to the present disclosure includes a bottomed cylindrical resin body having an opening at one end, a circuit board having a power supply terminal through hole that penetrates from the inner surface to the outer surface and is covered with the opening of the resin body and on which a power supply line is formed on the outer surface, a power supply element composed of an antenna pattern formed on the inner wall surface of the resin body, and one end of the antenna pattern in the shape of formed into a power supply terminal that penetrates the power supply terminal through hole of the circuit board and is electrically connected to the other end of the power supply line formed on the outer surface of the circuit board. , the cross-sectional shape of the resin body is rectangular, and the power supply element includes an antenna main portion formed along four sides of the inner surface of the bottom wall constituting the inner wall surface of the resin body, with the other end being an open end, and an extension portion formed on the inner surface of one side wall constituting the inner wall surface of the resin body from the antenna main portion toward the power supply terminal and toward the opening of the resin body .

Advantages of the Invention

[0007] According to the present disclosure, an antenna pattern constituting an antenna element is formed on the inner wall surface of the resin body, and one end of the antenna pattern constituting the antenna element in the shape of formed into a power supply terminal is passed through the through hole of the circuit board and electrically connected to the power supply line, the cross-sectional shape of the resin body is rectangular, and the power supply element includes an antenna main portion formed along four sides of the inner surface of the bottom wall constituting the inner wall surface of the resin body, with the other end being an open end, and an extension portion formed on the inner surface of one side wall constituting the inner wall surface of the resin body from the antenna main portion toward the power supply terminal and toward the opening of the resin body so that the resin body can prevent damage to the antenna element due to external disturbances, and the electrical connection between the antenna element and the power supply line can be facilitated. there is no gap between the power supply element and the inner wall surface of the resin body, the size of the power supply element can be maximized with respect to the resin body, and the performance as an antenna element can be improved Moreover, set it has good standing property and handleability.

Brief Description of the Drawings

[0008]

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Modes for Carrying Out the Invention

[0009] Embodiment 1. The antenna device according to Embodiment 1 will be described with reference to FIGS. 1 to 6. The antenna device according to Embodiment 1 is an antenna device used in communication, radar, or positioning, etc. The antenna device according to Embodiment 1 is used as a transmitting antenna or a receiving antenna.

[0010] The antenna device according to Embodiment 1 includes a housing antenna 1 and a circuit board 2. The housing antenna 1 includes a resin body 11 and an antenna element 12. The housing antenna 1 functions as an antenna. The resin body 11 functions as a resin cover (radome) that protects the antenna element 12.

[0011] The resin body 11 has an opening 11a at one end, is a bottomed cylindrical shape, and has a flange portion 11b extending outward from the outer periphery of the opening 11a. The material of the resin body 11 is a thermoplastic resin that is easy to process. A material having thermosetting properties may also be used in consideration of heat resistance. In Embodiment 1, the shape of the resin body 11 is a cylindrical shape of a quadrangular prism with a rectangular cross section, but it may also be a cylindrical shape, a spherical shape, or a streamline shape.

[0012] The antenna element 12 has a feeding element 12a formed of an antenna pattern and a feeding terminal 12b formed at one end as the feeding element 12a. The other end of the antenna pattern formed as the feeding element 12a is an open end, and the antenna pattern is formed on the inner wall surface of the resin body 11.

[0013] In Embodiment 1, the feeding element 12a has an antenna main portion formed on the inner surface of the bottom wall constituting the inner wall surface of the resin body 11 with the other end being an open end, and an extending portion formed on the inner surface of one side wall constituting the inner wall surface of the resin body 11 from the antenna main portion toward the opening 11a of the resin body 11 to the feeding terminal 12b. The antenna main portion is formed along the four sides of the inner surface of the bottom wall. The extension part is formed at the center of the inner surface of one side wall.

[0014] In Embodiment 1, the power supply element 12a has a shape obtained by bending a monopole antenna. The total length from the power supply terminal 12b to the open end of the power supply element 12a in the power supply element 12a is 1 / 4 wavelength of the wavelength corresponding to the resonance frequency. The length of 1 / 4 wavelength mentioned here refers to a length including an allowable range of ±α with respect to 1 / 4 wavelength with respect to the resonance frequency. Note that the power supply element 12a is not limited to the shape obtained by bending a monopole antenna, and may be an inverted-F antenna, a folded monopole antenna, or an antenna branched into a T shape.

[0015] The housing antenna 1 in which the power supply element 12a is formed on the inner wall surface of the resin body 11 is manufactured by MID (Molded Interconnect Devices, molded circuit components) or molding by a 3D printer.

[0016] Since the power supply element 12a is formed in close contact with the inner wall surface of the resin body 11, there is no gap between the power supply element 12a and the inner wall surface of the resin body 11, the size of the power supply element 12a can be maximized with respect to the resin body 11, and the performance as an antenna element can be improved. In addition, since the power supply element 12a and the resin body 11 can be integrated and handled as the housing antenna 1, the assemblability and handleability are good.

[0017] The opening 11a of the resin body 11 is covered by the inner surface (surface) of the circuit board 2, and the resin body 11 is mounted on the circuit board 2. The circuit board 2 has a through hole 2a penetrating from the inner surface to the outer surface (back surface). The power supply terminal 12b in the antenna element 12 is fitted into the through hole 2a formed in the circuit board 2. By fitting the power supply terminal 12b into the through hole 2a, the power supply terminal 12b plays a role of determining the position of the power supply element 12a in the antenna element 12 with respect to the circuit board 2.

[0018] The circuit board 2 includes an insulating substrate 21, a first ground conductor 22, a second ground conductor 23, and a power supply line 24. As shown in FIG. 3, the first ground conductor 22 is a conductive layer formed on the surface of the insulating substrate 21, separated from, that is, electrically insulated from, the land 22a formed around the through hole 2a. The first ground conductor 22 is grounded.

[0019] As shown in FIG. 4, the second ground conductor 23 is a conductive layer formed on the back surface of the insulating substrate 21, separated from, that is, electrically insulated from, the land 23a formed around the through hole 2a and the power supply line 24 extending from the land 23a and having a power supply point 25 at one end. The second ground conductor 23 is grounded. The power supply point 25 is not formed as a physical component but is a portion that excites a high-frequency signal.

[0020] The first ground conductor 22 formed on the surface of the insulating substrate 21 and the second ground conductor 23 formed on the back surface of the insulating substrate 21 are electrically connected by a plurality of through holes Th1. In FIGS. 3 and 4, to avoid complication of the figures, a plurality of through holes Th1 are shown around the first ground conductor 22 and the second ground conductor 23. However, a plurality of through holes Th1 are appropriately formed inside the first ground conductor 22 and the second ground conductor 23 so as to avoid the positions of circuit components and circuit patterns (not shown).

[0021] The land 22a, which is a conductive layer formed on the surface of the insulating substrate 21, and the land 23a, which is a conductive layer formed on the back surface of the insulating substrate 21, are electrically connected by a plurality of through holes Th2 formed around the through hole 2a.

[0022] A plurality of through holes Th3 for electrically connecting the first ground conductor 22 and the second ground conductor 23 are formed around the power supply line 24 and the land 22a in the first ground conductor 22 and the second ground conductor 23. The power supply line 24 is a grounded coplanar line. Note that other transmission lines such as a microstrip line may be used as the power supply line 24.

[0023] As shown in FIG. 6, after the power supply terminal 12b in the antenna element 12 is fitted into the through hole 2a formed in the circuit board 2, the end of the power supply terminal 12b is connected to the land 23a formed on the back surface of the insulating substrate 21 by soldering, and the power supply terminal 12b is electrically connected to the other end of the power supply line 24.

[0024] In the housing antenna 1 in which the power supply element 12a is formed on the inner wall surface of the resin body 11, after the flange portion 11b of the resin body 11 is mounted on the circuit board 2 and the power supply terminal 12b is passed through the through hole 2a formed in the circuit board 2, the power supply terminal 12b is soldered to the land 23a and electrically connected to the power supply line 24. Therefore, the assemblability is easy, the loss due to the electrical connection between the power supply element 12a and the power supply line 24 can be reduced, and the durability is improved.

[0025] Since the electrical connection between the antenna element 12 and the power supply line 24 is a connection by soldering in a narrow range between the end of the power supply terminal 12b and the land 23a, no large heat is applied to the resin body 11, and a thermoplastic resin that is easy to process can be used as the resin body 11.

[0026] Next, the operation of the antenna device according to Embodiment 1 will be described. The operation when the antenna device according to Embodiment 1 is used as a transmitting antenna will be described. When an input signal, which is a high-frequency signal, is excited at the feeding point 25, the input signal is transmitted through the feeding line 24 and transmitted to the feeding element 12a via the feeding terminal 12b.

[0027] The input signal transmitted to the feeding element 12a is radiated into space from the feeding element 12a as an electromagnetic wave corresponding to the high-frequency signal that is the input signal due to the resonance phenomenon that occurs when the input signal is transmitted through the feeding element 12a. That is, an electromagnetic wave corresponding to the magnitude of the current generated by the resonance phenomenon when the input signal is transmitted through the feeding element 12a is radiated into space from the feeding element 12a. Since the total length from the power supply terminal 12b to the open end of the power supply element 12a in the power supply element 12a is 1 / 4 of the wavelength corresponding to the resonance frequency, electromagnetic waves are efficiently radiated from the power supply element 12a into space.

[0028] When the antenna device according to Embodiment 1 is used as a receiving antenna, the power supply element 12a receives a transmission wave, which is an electromagnetic wave transmitted from another antenna device. The power supply element 12a that has received the transmission wave transmits it as a high-frequency signal corresponding to the received transmission wave to the power supply terminal 12b. The high-frequency signal transmitted to the power supply terminal 12b is transmitted through the power supply line 24, excited at the power supply point 25, and output as a high-frequency signal.

[0029] In the antenna device according to Embodiment 1, since the power supply element 12a formed of an antenna pattern is formed on the inner wall surface of the resin body 11 to constitute the housing antenna 1, the resin body 11 itself that protects the antenna element 12 including the power supply element 12a has the function of an antenna. Therefore, there is no gap between the power supply element 12a and the inner wall surface of the resin body 11, the size of the power supply element 12a can be maximized with respect to the resin body 11, and the performance as an antenna element can be improved.

[0030] Furthermore, in the antenna device according to Embodiment 1, the power supply terminal 12b formed at one end of the power supply element 12a passes through the through hole 2a formed in the circuit board 2 and is electrically connected to the power supply line 24 formed on the outer surface of the circuit board 2. Therefore, the resin body 11 can be positioned with respect to the circuit board 2 by the power supply terminal 12b and the through hole 2a, the mountability as an antenna device is improved, the loss due to the electrical connection between the power supply element 12a and the power supply line 24 can be reduced, and the durability is improved.

[0031] Moreover, since the electrical connection between the antenna element 12 and the power supply line 24 is a connection by soldering in a narrow range between the end of the power supply terminal 12b and the land 23a, a large amount of heat is not applied to the resin body 11, and a thermoplastic resin that is easy to process can be used as the resin body 11.

[0032] Embodiment 2 The antenna device according to Embodiment 2 will be described with reference to FIGS. 7 to 10. The antenna device according to Embodiment 2 is different from the antenna device according to Embodiment 1 in that it further includes a wireless power feeding antenna element 13, and the other points are the same. Therefore, the following description will focus on the wireless power feeding antenna element 13. In FIGS. 7 to 10, the same reference numerals as those in FIGS. 1 to 6 denote the same or corresponding parts.

[0033] The antenna device according to Embodiment 2 includes a housing antenna 1A and a circuit board 2A. The housing antenna 1A includes a resin body 11, an antenna element 12, and a wireless power feeding antenna element 13. The wireless power feeding antenna element 13 is electromagnetically coupled to the antenna element 12 to achieve multi-band operation, wide-band operation, and improved antenna efficiency.

[0034] The wireless power feeding antenna element 13 has a wireless power feeding element 13a formed of an antenna pattern and a wireless power feeding terminal 13b formed at one end as the wireless power feeding element 13a. The other end of the antenna pattern formed as the wireless power feeding element 13a is an open end, and the antenna pattern is formed on the inner wall surface of the resin body 11.

[0035] In Embodiment 2, the wireless power feeding element 13a has an antenna main portion formed on the inner surface of the bottom wall constituting the inner wall surface of the resin body 11 with the other end being an open end, and an extending portion formed on the inner surface of one side wall constituting the inner wall surface of the resin body 11 from the antenna main portion toward the opening 11a of the resin body 11 to the wireless power feeding terminal 13b. The antenna main portion of the wireless power feeding element 13a is arranged inside in parallel with the portion located on the open end side of the antenna main portion of the feeding element 12a, and the extending portion of the wireless power feeding element 13a is arranged in parallel with the extending portion of the feeding element 12a.

[0036] In Embodiment 2, the wireless power feeding element 13a has a shape obtained by bending a monopole antenna. The overall length from the wireless power supply terminal 13b to the open end of the wireless power supply element 13a in the wireless power supply element 13a is 1 / 4 wavelength of the wavelength corresponding to a frequency f2 (≠f1) different from the resonance frequency f1 with respect to the power supply element 12a. The wireless power supply element 13a resonates at the frequency f2.

[0037] The length of 1 / 4 wavelength of the wavelength corresponding to the frequency f2 referred to here means a length including an allowable range of ±β with respect to 1 / 4 wavelength of the frequency f2 which is the resonance frequency with respect to the wireless power supply element 13a. Note that the wireless power supply element 13a is not limited to the shape of a bent monopole antenna, and it may also be an inverted F antenna, a folded monopole antenna, or an antenna branched into a T shape.

[0038] The housing antenna 1A in which the power supply element 12a and the wireless power supply element 13a are formed on the inner wall surface of the resin body 11 is manufactured by molding using MID or a 3D printer. Since the power supply element 12a and the wireless power supply element 13a are formed in close contact with the inner wall surface of the resin body 11, there is no gap between the power supply element 12a and the wireless power supply element 13a and the inner wall surface of the resin body 11, the sizes of the power supply element 12a and the wireless power supply element 13a can be maximized with respect to the resin body 11, and the performance as an antenna element can be improved. In addition, since the power supply element 12a and the wireless power supply element 13a and the resin body 11 can be integrated and handled as the housing antenna 1, the assemblability and handleability are good.

[0039] The circuit board 2A has an insulating substrate 21, a first ground conductor 22, a second ground conductor 23, and a power supply line 24. The circuit board 2A has a power supply terminal through hole 2a penetrating from the inner surface to the outer surface. The power supply terminal 12b in the antenna element 12 is fitted into the power supply terminal through hole 2a formed in the circuit board 2A. By fitting the power supply terminal 12b into the power supply terminal through hole 2a, the power supply terminal 12b of the antenna element 12 with respect to the circuit board 2 plays a role of determining the position of the power supply element 12a.

[0040] The circuit board 2A has a through-hole 2b for a wireless power supply terminal that penetrates from the inner surface to the outer surface. The wireless power supply terminal 13b of the wireless power supply antenna element 13 fits into the through-hole 2b for a wireless power supply terminal formed in the circuit board 2A. By fitting the wireless power supply terminal 13b into the through-hole 2b for a wireless power supply terminal, the wireless power supply terminal 13b of the wireless power supply antenna element 13 plays a role in determining the position of the wireless power supply element 13a with respect to the circuit board 2.

[0041] A plurality of through-holes Th4 that electrically connect the first ground conductor 22 and the second ground conductor 23 are formed around the through-hole 2b for a wireless power supply terminal formed in the circuit board 2A of the first ground conductor 22 and the second ground conductor 23.

[0042] As shown in FIG. 10, after the power supply terminal 12b of the antenna element 12 is fitted into the through-hole 2a for a power supply terminal formed in the circuit board 2 and the wireless power supply terminal 13b of the wireless power supply antenna element 13 is fitted into the through-hole 2b for a wireless power supply terminal formed in the circuit board 2, the end of the power supply terminal 12b is connected by soldering to the land 23a formed on the back surface of the insulating substrate 21. The power supply terminal 12b is electrically connected to the other end of the power supply line 24. The end of the wireless power supply terminal 13b is connected by soldering to the second ground conductor 23 formed on the back surface of the insulating substrate 21, and the wireless power supply terminal 13b is electrically connected to the second ground conductor 23.

[0043] Therefore, the loss due to the electrical connection between the power supply element 12a and the power supply line 24 can be reduced, the durability is improved, the loss due to the electrical connection between the wireless power supply terminal 13b and the second ground conductor 23 can be reduced, and the durability is improved.

[0044] Next, the operation of the antenna device according to Embodiment 2 will be described. The operation when the antenna device according to Embodiment 2 is used as a transmitting antenna will be described. When an input signal, which is a high-frequency signal, is excited at the power supply point 25, the input signal is transmitted through the power supply line 24 and transmitted to the power supply element 12a via the power supply terminal 12b.

[0045] The input signal transmitted to the power supply element 12a causes an electromagnetic wave corresponding to the high-frequency signal, which is the input signal, to be radiated into space from the power supply element 12a due to the resonance phenomenon that occurs when the input signal is transmitted through the power supply element 12a. That is, an electromagnetic wave corresponding to the magnitude of the current generated by the resonance phenomenon when the input signal is transmitted through the power supply element 12a is radiated into space from the power supply element 12a. Since the total length from the power supply terminal 12b to the open end of the power supply element 12a in the power supply element 12a is 1 / 4 of the wavelength corresponding to the resonance frequency, electromagnetic waves are efficiently radiated into space from the power supply element 12a.

[0046] On the other hand, in the non-powered element 13a, a current flows due to electromagnetic coupling with the power supply element 12a. That is, the non-powered element 13a generates resonance that occurs when it becomes 1 / 4 of the wavelength corresponding to the frequency f2, which is the resonance frequency of the non-powered element 13a.

[0047] When the antenna device according to Embodiment 2 is used as a receiving antenna, the power supply element 12a receives the transmitted wave, which is an electromagnetic wave transmitted from another antenna device. The power supply element 12a that has received the transmitted wave transmits it as a high-frequency signal corresponding to the received transmitted wave to the power supply terminal 12b. The high-frequency signal transmitted to the power supply terminal 12b is transmitted through the power supply line 24 and excited at the power supply point 25, and then output as a high-frequency signal.

[0048] On the other hand, in the non-powered element 13a, a current flows due to electromagnetic coupling with the power supply element 12a. That is, the non-powered element 13a generates resonance that occurs when it becomes 1 / 4 of the wavelength corresponding to the frequency f2, which is the resonance frequency of the non-powered element 13a.

[0049] The antenna device according to Embodiment 2 has the same effects as the antenna device according to Embodiment 1, and since it includes the non-powered antenna element 13, it can achieve multi-band and wide-band characteristics.

[0050] Embodiment 3. The antenna device according to Embodiment 3 will be described with reference to FIGS. 11 to 15. The antenna device according to Embodiment 3 is different from the antenna device according to Embodiment 2 in that the antenna device according to Embodiment 2 includes a pair of antenna elements 12 and a non-powered antenna element 13, while this example includes a plurality of pairs, in this case four pairs, of antenna elements 121 to 124 and non-powered antenna elements 131 to 134, and the other points are the same.

[0051] Therefore, the following description will be centered around the four pairs of first antenna elements 121 to 124 and fourth antenna elements 124 and the first non-powered antenna elements 131 to 134 and fourth non-powered antenna elements 134. In FIGS. 11 to 15, the same reference numerals as those given in FIGS. 7 to 10 denote the same or corresponding parts.

[0052] The antenna device according to Embodiment 3 includes a housing antenna 1B and a circuit board 2B. The housing antenna 1B includes a resin body 11, four pairs of first antenna elements 121 to 124, and first non-powered antenna elements 131 to 134 and fourth non-powered antenna elements 134. The paired first antenna elements 121 to 124 and fourth antenna elements 124 and the first non-powered antenna elements 131 to 134 and fourth non-powered antenna elements 134 are electromagnetically coupled for each pair.

[0053] The paired first antenna elements 121 to 124 and fourth antenna elements 124 and the first non-powered antenna elements 131 to 134 and fourth non-powered antenna elements 134 are formed on the inner wall surface of the resin body 11 with 90-degree rotational symmetry. Therefore, in order to avoid complexity in the description, when there is no need to distinguish and describe, the pair of antenna elements 12 and the non-powered antenna element 13 will be described representatively. The subscripts will also be omitted.

[0054] The antenna element 12 has a feeding element 12a made of an antenna pattern and a feeding terminal 12b formed at one end as the feeding element 12a. The other end of the antenna pattern formed as the power supply element 12a is an open end, and the antenna pattern is formed on the inner wall surface of the resin body 11.

[0055] In Embodiment 3, the power supply element 12a has an antenna main portion formed on the inner surface of the bottom wall constituting the inner wall surface of the resin body 11, with the other end being an open end, and an extending portion formed on the inner surface of one side wall constituting the inner wall surface of the resin body 11 from the antenna main portion toward the power supply terminal 12b along the opening 11a of the resin body 11.

[0056] The extending portion of the power supply element 12a is linearly formed along one side of the inner surface of one side wall. The antenna main portion of the power supply element 12a is formed along three sides of the inner surface of the bottom wall, excluding the upper side of the side wall opposite to the side wall on which the extending portion is formed. The antenna main portion of the power supply element 12a is in a Z shape.

[0057] In Embodiment 3, the power supply element 12a has a shape obtained by bending a monopole antenna. The total length from the power supply terminal 12b to the open end of the power supply element 12a in the power supply element 12a is 1 / 4 wavelength of the wavelength corresponding to the resonance frequency f1. Note that the power supply element 12a is not limited to the shape obtained by bending a monopole antenna, and an inverted F antenna may also be used.

[0058] The non-powered antenna element 13 has a non-powered element 13a composed of an antenna pattern and a non-powered terminal 13b formed at one end as the non-powered element 13a. The other end of the antenna pattern formed as the non-powered element 13a is an open end, and the antenna pattern is formed on the inner wall surface of the resin body 11.

[0059] In Embodiment 3, the non-powered element 13a has an antenna main portion formed on the inner surface of the bottom wall constituting the inner wall surface of the resin body 11, with the other end being an open end, and an extending portion formed on the inner surface of one side wall constituting the inner wall surface of the resin body 11 from the antenna main portion toward the non-powered terminal 13b along the opening 11a of the resin body 11.

[0060] The extending portion of the non-powered element 13a is arranged parallel to the extending portion of the feeding element 12a on the other side of one side wall with respect to the extending portion of the feeding element 12a. The main antenna portion of the non-powered element 13a is arranged between the upper side of the side wall where the main antenna portion and the extending portion of the feeding element 12a are formed, parallel to the portion located on the open end side of the main antenna portion of the feeding element 12a. The main antenna portion of the non-powered element 13a is L-shaped. Note that the main antenna portion of the non-powered element 13a may be Z-shaped.

[0061] In Embodiment 3, the non-powered element 13a has a shape obtained by bending a monopole antenna. The total length from the non-powered terminal 13b to the open end of the non-powered element 13a in the non-powered element 13a is 1 / 4 wavelength corresponding to a frequency f2 (≠f1) different from the resonance frequency f1 with respect to the feeding element 12a. The non-powered element 13a resonates at the frequency f2. Note that the non-powered element 13a is not limited to the shape obtained by bending a monopole antenna, and an inverted F antenna may also be used.

[0062] Each of the paired first antenna element 121 to fourth antenna element 124 and the first non-powered antenna element 131 to fourth non-powered antenna element 134 is arranged corresponding to each of the four side walls of the resin body 11 for each pair. The housing antenna 1B in which the feeding elements 12a1 to 12a4 in each of the first antenna element 121 to fourth antenna element 124 and the non-powered elements 13a1 to 13a4 in each of the first non-powered antenna element 131 to fourth non-powered antenna element 134 are formed on the inner wall surface of the resin body 11 is manufactured by molding using an MID or a 3D printer.

[0063] Since the power supply elements 12a1 to 12a4 and the non-power supply elements 13a1 to 13a4 are formed in close contact with the inner wall surface of the resin body 11, there is no gap between the power supply elements 12a1 to 12a4 and the non-power supply elements 13a1 to 13a4 and the inner wall surface of the resin body 11. The sizes of the power supply elements 12a1 to 12a4 and the non-power supply elements 13a1 to 13a4 can be maximized with respect to the resin body 11, and the performance as an antenna element can be improved. In addition, since the power supply elements 12a1 to 12a4 and the non-power supply elements 13a1 to 13a4 and the resin body 11 can be integrated and handled as the housing antenna 1, the assemblability and handleability are good.

[0064] The circuit board 2B has a first power supply terminal through hole 2a1 to a fourth power supply terminal through hole 2a4 for power supply terminals penetrating from the inner surface to the outer surface (back surface). The power supply terminal 12b1 in the first antenna element 121 fits into the first power supply terminal through hole 2a1 formed in the circuit board 2B. By fitting the power supply terminal 12b1 into the first power supply terminal through hole 2a1, the power supply terminal 12b1 serves to determine the position of the power supply element 12a1 in the first antenna element 121 with respect to the circuit board 2B.

[0065] The power supply terminal 12b2 in the second antenna element 122 fits into the second power supply terminal through hole 2a2 formed in the circuit board 2B. By fitting the power supply terminal 12b2 into the second power supply terminal through hole 2a2, the power supply terminal 12b2 serves to determine the position of the power supply element 12a2 in the second antenna element 122 with respect to the circuit board 2B.

[0066] The power supply terminal 12b3 in the third antenna element 123 fits into the third power supply terminal through hole 2a3 formed in the circuit board 2B. By fitting the power supply terminal 12b3 into the third power supply terminal through hole 2a3, the power supply terminal 12b3 serves to determine the position of the power supply element 12a3 in the third antenna element 123 with respect to the circuit board 2B.

[0067] The power supply terminal 12b4 in the fourth antenna element 124 fits into the fourth power supply terminal through-hole 2a4 formed in the circuit board 2B. By fitting the power supply terminal 12b4 into the fourth power supply terminal through-hole 2a4, the power supply element 12a4 in the fourth antenna element 124 with respect to the circuit board 2B plays a role in determining the position.

[0068] The circuit board 2B has a first non-powered terminal through-hole 2b1 to a fourth non-powered terminal through-hole 2b4 that penetrate from the inner surface to the outer surface (back surface). The first non-powered terminal through-hole 2b1 to the fourth non-powered terminal through-hole 2b4 respectively form a pair with the first power supply terminal through-hole 2a1 to the fourth power supply terminal through-hole 2a4. The paired first power supply terminal through-hole 2a1 to the fourth power supply terminal through-hole 2a4 and the first non-powered terminal through-hole 2b1 to the fourth non-powered terminal through-hole 2b4 are respectively arranged in parallel along each side of the four sides of the circuit board 2B.

[0069] The non-powered terminal 13b1 in the first non-powered antenna element 131 fits into the first non-powered terminal through-hole 2b1 formed in the circuit board 2B. By fitting the non-powered terminal 13b1 into the first non-powered terminal through-hole 2b1, the non-powered element 13a1 in the first non-powered antenna element 131 with respect to the circuit board 2B plays a role in determining the position.

[0070] The non-powered terminal 13b2 in the second non-powered antenna element 132 fits into the second non-powered terminal through-hole 2b2 formed in the circuit board 2B. By fitting the non-powered terminal 13b2 into the second non-powered terminal through-hole 2b2, the non-powered element 13a2 in the second non-powered antenna element 132 with respect to the circuit board 2B plays a role in determining the position.

[0071] The non-powered terminal 13b3 in the third non-powered antenna element 133 fits into the third non-powered terminal through-hole 2b3 formed in the circuit board 2B. The non-powered terminal 13b3 fits into the third non-powered terminal through-hole 2b3, thereby playing a role in determining the position of the non-powered element 13a3 in the third non-powered antenna element 133 with respect to the circuit board 2B.

[0072] The non-powered terminal 13b4 of the fourth non-powered antenna element 134 fits into the fourth non-powered terminal through-hole 2b4 formed in the circuit board 2B. The non-powered terminal 13b4 fits into the fourth non-powered terminal through-hole 2b4, thereby playing a role in determining the position of the non-powered element 13a4 in the fourth non-powered antenna element 134 with respect to the circuit board 2B.

[0073] The first to fourth power supply terminal through-holes 2a1 to 2a4 and the first to fourth non-powered terminal through-holes 2b1 to 2b4 that form a pair are formed on the circuit board 2B in a 90-degree rotational symmetry. Therefore, to avoid complexity in the description, when there is no need to explain them separately, the pair of power supply terminal through-holes 2a and non-powered terminal through-holes 2b will be described representatively. The subscripts will also be omitted.

[0074] The circuit board 2B includes an insulating substrate 21, a first ground conductor 22, a second ground conductor 23, first to fourth power supply lines 241 to 244, a power supply unit 26, and an interface circuit 27. The interface circuit 27 functions as a high-frequency signal power supply circuit and includes a 180-degree hybrid 27a, a first 90-degree hybrid 27b, and a second 90-degree hybrid 27c.

[0075] As shown in FIG. 12, the first ground conductor 22 is formed as a conductive layer on the surface of the insulating substrate 21, separated from, that is, electrically insulated from, the land 22a formed around the power supply terminal through-hole 2a. The first ground conductor 22 is grounded.

[0076] As shown in FIG. 13, the second ground conductor 23 is a conductive layer formed on the back surface of the insulating substrate 21, separated from, that is, electrically insulated from, the power supply line 24 having a power supply point 25 at one end, which extends from the land 23a formed around the through hole 2a. The power supply point 25 is not formed as a physical component but is a portion that excites a high-frequency signal. The second ground conductor 23 is grounded.

[0077] The second ground conductor 23 is also formed separately and electrically insulated from the transmission line that electrically connects the power supply unit 26 and the 180-degree hybrid 27a shown in FIG. 15, the transmission lines that electrically connect the 180-degree hybrid 27a to the first 90-degree hybrid 27b and the second 90-degree hybrid 27c respectively, the transmission line electrically connected to the first 90-degree hybrid 27b and having the first power supply point 251 and the fourth power supply point 254 respectively, and the transmission line electrically connected to the second 90-degree hybrid 27c and having the second power supply point 252 and the third power supply point 253 respectively.

[0078] The first ground conductor 22 formed on the surface of the insulating substrate 21 and the second ground conductor 23 formed on the back surface of the insulating substrate 21 are electrically connected by a number of through holes Th1. The land 22a, which is a conductive layer formed on the surface of the insulating substrate 21, and the land 23a, which is a conductive layer formed on the back surface of the insulating substrate 21, are electrically connected by a plurality of through holes Th2 formed around the through hole 2a.

[0079] A plurality of through holes Th3 are formed around the power supply line 24 and the lands 22a and 23a in the first ground conductor 22 and the second ground conductor 23 to electrically connect the first ground conductor 22 and the second ground conductor 23. A plurality of through holes Th4 are formed around the through hole 2b for the non-powered terminal in the first ground conductor 22 and the second ground conductor 23 to electrically connect the first ground conductor 22 and the second ground conductor 23.

[0080] As shown in FIG. 14, each of the power supply terminals 12b1 to 12b4 in each of the first to fourth antenna elements 121 to 124 is fitted into the corresponding power supply terminal through-holes 2a1 to 2a4 formed in the circuit board 2, and each of the non-powered terminals 13b1 to 13b4 in each of the first to fourth non-powered antenna elements 131 to 134 is fitted into the non-powered terminal through-holes 2b1 to 2b4 formed in the circuit board 2.

[0081] After being fitted, the ends of each of the power supply terminals 12b1 to 12b4 are connected by soldering to the corresponding lands 23a1 to 23a4 formed on the back surface of the insulating substrate 21, and each of the power supply terminals 12b1 to 12b4 is electrically connected to the other ends of the corresponding power supply lines 241 to 244. Also, the ends of each of the non-powered terminals 13b1 to 13b4 are connected by soldering to the second ground conductor 23 formed on the back surface of the insulating substrate 21, and the non-powered terminals 13b1 to 13b4 are electrically connected to the second ground conductor 23.

[0082] Therefore, the loss due to the electrical connection between the power supply elements 12a1 to 12a4 and the power supply lines 241 to 244 can be reduced, the durability is improved, the loss due to the electrical connection between the non-powered terminals 13b1 to 13b4 and the second ground conductor 23 can be reduced, and the durability is improved.

[0083] When the antenna device according to Embodiment 3 is used as a transmitting antenna, the interface circuit 27 functions as a distribution circuit that distributes a high-frequency signal that changes in the range of 0 degrees to 360 degrees input to the power supply unit 26 to four high-frequency signals with a phase difference advancing by 90 degrees each, and supplies them to each of the first to fourth power supply terminals 12b1 to 12b4 through each of the first to fourth power supply lines 241 to 244.

[0084] For example, when the phase of the high-frequency signal input to the power supply unit 26 is 0 degrees, the interface circuit 27 functions as a distribution circuit that distributes an input signal composed of a high-frequency signal with a phase of 0 degrees input to the power supply unit 26 into high-frequency signals with phase differences of 0 degrees, 90 degrees, 180 degrees, and 270 degrees, and supplies them to the first power supply terminal 12b1 to the fourth power supply terminal 12b4 via the first power supply line 241 to the fourth power supply line 244, respectively. That is, the interface circuit 27 distributes the high-frequency signal input to the power supply unit 26 into four high-frequency signals with a phase progression of 90 degrees each, and outputs them to the first power supply line 241 to the fourth power supply line 244, to which the first power supply terminal 12b1 to the fourth power supply terminal 12b4 are electrically connected, respectively.

[0085] In addition, when the antenna device according to Embodiment 3 is used as a receiving antenna, the interface circuit 27 functions as a combining circuit that combines four high-frequency signals with a phase progression of 90 degrees each, which are output from the first power supply terminal 12b1 to the fourth power supply terminal 12b4 and transmitted through the first power supply line 241 to the fourth power supply line 244, and outputs the combined signal to the power supply unit 26.

[0086] Since the operation of the interface circuit 27 is reversible when the antenna device according to Embodiment 3 is used as a transmitting antenna and when it is used as a receiving antenna, the case of using it as a transmitting antenna will be mainly described. The 180-degree hybrid 27a, the first 90-degree hybrid 27b, and the second 90-degree hybrid 27c that constitute the interface circuit 27 are mounted on the outer surface of the circuit board 2 in electrical insulation from the second ground conductor 23.

[0087] As shown in FIG. 15, the high-frequency signal from the power supply unit 26 is input to the 180-degree hybrid 27a. The 180-degree hybrid 27a distributes and outputs the input high-frequency signal into two high-frequency signals with a phase difference of 180 degrees.

[0088] One of the high-frequency signals distributed from the 180-degree hybrid 27a, for example, a high-frequency signal having the same phase as the high-frequency signal input to the 180-degree hybrid 27a, is input to the first 90-degree hybrid 27b, and the input high-frequency signal is distributed into two high-frequency signals having a phase difference of 90 degrees and output.

[0089] One of the high-frequency signals distributed from the first 90-degree hybrid 27b, for example, a high-frequency signal having the same phase as the high-frequency signal input to the first 90-degree hybrid 27b, is transmitted to the first power supply line 241. The other high-frequency signal distributed from the first 90-degree hybrid 27b, for example, a high-frequency signal advanced by 90 degrees with respect to the high-frequency signal input to the first 90-degree hybrid 27b, is transmitted to the second power supply line 242. That is, there is a 90-degree phase difference between the high-frequency signal transmitted to the first power supply line 241 and the high-frequency signal transmitted to the second power supply line 242.

[0090] The other high-frequency signal distributed from the 180-degree hybrid 27a, for example, a high-frequency signal advanced by 180 degrees with respect to the high-frequency signal input to the 180-degree hybrid 27a, is input to the second 90-degree hybrid 27c, and the input high-frequency signal is distributed into two high-frequency signals having a phase difference of 90 degrees and output.

[0091] One of the high-frequency signals distributed from the second 90-degree hybrid 27c, for example, a high-frequency signal having the same phase as the high-frequency signal input to the second 90-degree hybrid 27c, is transmitted to the third power supply line 243. The high-frequency signal transmitted to the third power supply line 243 becomes a high-frequency signal having a 180-degree phase difference with respect to the high-frequency signal input to the 180-degree hybrid 27a.

[0092] The other high-frequency signal distributed from the second 90-degree hybrid 27c, for example, a high-frequency signal advanced by 90 degrees with respect to the high-frequency signal input to the second 90-degree hybrid 27c, is transmitted to the fourth power supply line 244. The high-frequency signal transmitted to the fourth power supply line 244 becomes a high-frequency signal having a phase difference of 270 degrees with respect to the high-frequency signal input to the 180-degree hybrid 27a.

[0093] Therefore, a high-frequency signal in phase with the high-frequency signal from the power supply unit 26 is supplied to the first power supply terminal 12b1 connected to the first power supply line 241, a high-frequency signal having a phase difference of 90 degrees with respect to the high-frequency signal from the power supply unit 26 is supplied to the second power supply terminal 12b2 connected to the second power supply line 242, a high-frequency signal having a phase difference of 180 degrees with respect to the high-frequency signal from the power supply unit 26 is supplied to the third power supply terminal 12b3 connected to the third power supply line 243, and a high-frequency signal having a phase difference of 270 degrees with respect to the high-frequency signal from the power supply unit 26 is supplied to the fourth power supply terminal 12b4 connected to the fourth power supply line 244, and these are supplied from the power supply unit 26 via the interface circuit 27.

[0094] Next, the operation when the antenna device according to Embodiment 3 is used as a transmitting antenna will be described. When an input signal, which is a high-frequency signal, is supplied to the power supply unit 26 and the high-frequency signal from the power supply unit 26 is input to the 180-degree hybrid 27a, the 180-degree hybrid 27a outputs a high-frequency signal having the same phase as the input high-frequency signal to the first 90-degree hybrid 27b, and outputs a high-frequency signal having a phase advanced by 180 degrees with respect to the input high-frequency signal to the second 90-degree hybrid 27c.

[0095] The first 90-degree hybrid 27b outputs a high-frequency signal having the same phase as the high-frequency signal from the power supply unit 26 from the 180-degree hybrid 27a to the first power supply line 241, and outputs a high-frequency signal having a phase advanced by 90 degrees with respect to the high-frequency signal from the power supply unit 26 to the second power supply line 242. The second 90-degree hybrid 27c outputs a high-frequency signal having a phase advanced by 180 degrees with respect to the high-frequency signal from the power supply unit 26 from the 180-degree hybrid 27a to the third power supply line 243, and outputs a high-frequency signal having a phase advanced by 270 degrees with respect to the high-frequency signal from the power supply unit 26 from the 180-degree hybrid 27a to the fourth power supply line 244.

[0096] That is, high-frequency signals with phases advancing by 90 degrees in sequence from the first power supply line 241 to the fourth power supply line 244 are provided by the interface circuit 27. When high-frequency signals with phases advancing by 90 degrees are provided from the first power supply line 241 to the fourth power supply line 244 and are respectively supplied to the first power supply terminal 12b1 to the fourth power supply terminal 12b4, the paired first antenna element 121 to the fourth antenna element 124 and the first parasitic antenna element 131 to the fourth parasitic antenna element 134, similar to the description in Embodiment 2, due to the resonance phenomenon occurring when passing through the power supply elements 12a1 to 12a4 respectively in the first antenna element 121 to the fourth antenna element 124, electromagnetic waves corresponding to the high-frequency signals are radiated into space from the power supply elements 12a1 to 12a4 respectively.

[0097] In this case, since the high-frequency phases of the signals passing through the power supply elements 12a1 to 12a4 advance by 90 degrees in sequence, a right-handed circularly polarized wave (RHCP) is radiated in the direction of looking at the resin body 11 from the circuit board 2B.

[0098] Note that by reversing the phases of the high-frequency signals output from the first 90-degree hybrid 27b and the second 90-degree hybrid 27c respectively to the first power supply line 241 to the fourth power supply line 244, that is, outputting a high-frequency signal with a phase advanced by 90 degrees from the first 90-degree hybrid 27b to the first power supply line 241 to the second power supply line 242 with the same phase as the high-frequency signal from the power supply unit 26, and outputting a high-frequency signal with a phase advanced by 270 degrees from the second 90-degree hybrid 27c to the third power supply line 243 with respect to the high-frequency signal from the power supply unit 26, and a high-frequency signal with a phase advanced by 180 degrees from the fourth power supply line 244 with respect to the high-frequency signal from the power supply unit 26, a left-handed circularly polarized wave (LHCP) can be radiated in the direction of looking at the resin body 11 from the circuit board 2B.

[0099] When the antenna device according to Embodiment 3 is used as a receiving antenna, the 180-degree hybrid 27a, the first 90-degree hybrid 27b, and the second 90-degree hybrid 27c that constitute the interface circuit 27 are configured as follows.

[0100] A high-frequency signal from the first power supply terminal 12b1 via the first power supply line 241 and a high-frequency signal from the second power supply terminal 12b2 via the second power supply line 242 that is 90 degrees advanced with respect to the high-frequency signal from the first power supply line 241 are input to the first 90-degree hybrid 27b. The first 90-degree hybrid 27b combines the high-frequency signal from the first power supply terminal 12b1 via the first power supply line 241 and the high-frequency signal from the second power supply terminal 12b2 via the second power supply line 242 and outputs the combined signal to the 180-degree hybrid 27a.

[0101] A high-frequency signal from the third power supply terminal 12b3 via the third power supply line 243 that is 180 degrees advanced with respect to the high-frequency signal from the first power supply line 241 and a high-frequency signal from the fourth power supply terminal 12b4 via the fourth power supply line 244 that is 270 degrees advanced with respect to the high-frequency signal from the first power supply line 241 are input to the second 90-degree hybrid 27c. The second 90-degree hybrid 27c combines the high-frequency signal from the third power supply terminal 12b3 via the third power supply line 243 and the high-frequency signal from the fourth power supply terminal 12b4 via the fourth power supply line 244 and outputs the combined signal to the 180-degree hybrid 27a.

[0102] The high-frequency signal from the first 90-degree hybrid 27b and the high-frequency signal from the second 90-degree hybrid 27c are input to the 180-degree hybrid 27a. The 180-degree hybrid 27a combines the high-frequency signal from the first 90-degree hybrid 27b and the high-frequency signal from the second 90-degree hybrid 27c and outputs the combined signal to the power supply unit 26.

[0103] Note that the 180-degree hybrid 27a, the first 90-degree hybrid 27b, and the second 90-degree hybrid 27c that constitute the interface circuit 27 may be mounted on the inner surface of the circuit board 2 in electrical insulation from the first ground conductor 22. In this case, for the electrical connection between the power supply unit 26 and the 180-degree hybrid 27a, and for the electrical connection between each of the first 90-degree hybrid 27b and the second 90-degree hybrid 27c and each of the first power supply line 241 to the fourth power supply line 244, through holes may be formed in the circuit board 2B for interlayer connection.

[0104] The antenna device according to Embodiment 3 has the same effects as the antenna device according to Embodiment 2, and further includes a plurality of pairs of antenna elements 121 to 124 and non-powered antenna elements 131 to 134, so it can support right-handed circular polarization and left-handed circular polarization.

[0105] Embodiment 4. The antenna device according to Embodiment 4 will be described with reference to FIGS. 16 and 17. In the antenna device according to Embodiment 3, each of the feeding elements 12a1 to 12a4 in the antenna elements 121 to 124 and each of the non-powered elements 13a1 to 13a4 in the non-powered antenna elements 131 to 134 are used as monopole antennas.

[0106] In contrast, the antenna device according to Embodiment 4 is different from the antenna device according to Embodiment 3 in that an antenna pattern in which each of the feeding elements 12a1 to 12a4 in the antenna elements 121 to 124 and each of the non-powered elements 13a1 to 13a4 in the non-powered antenna elements 131 to 134 are spirally bent is added, and is the same as the antenna device according to Embodiment 3 in other respects.

[0107] Therefore, the feeding elements 12a1 to 12a4 in the first antenna element 121 to the fourth antenna element 124 and the non-powered elements 13a1 to 13a4 in the first non-powered antenna element 131 to the fourth non-powered antenna element 134 will be described below. In FIGS. 16 and 17, the same reference numerals as those given to FIGS. 11 to 15 denote the same or corresponding parts.

[0108] The four pairs of first antenna elements 121 to 124 and first to fourth passive antenna elements 131 to 134 are formed at the four corners of the inner wall of the resin body 11, respectively, for each pair, as shown in FIG. 16. The pairs of first antenna elements 121 to 124 and first to fourth passive antenna elements 131 to 134 are formed on the inner wall surface of the resin body 11 with 90-degree rotational symmetry, similar to Embodiment 3.

[0109] Therefore, one pair of antenna elements 12 and passive antenna elements 13 will be representatively described using the developed view shown in FIG. 17. In the developed view of FIG. 17, the X-X line indicates the upper side of the inner surface of the side wall in the resin body 11, and the Y-Y line indicates the side of the inner surface of the side wall in the resin body 11. That is, the upper side shown in FIG. 17 of the X-X line is the inner surface of the bottom wall in the resin body 11, and the lower side shown in FIG. 17 is the inner surface of one side wall in the resin body 11. Also, the Y-Y line indicates the side with respect to two adjacent and continuous side walls in the resin body 11. The left side shown in FIG. 17 of the Y-Y line is the inner surface of one side wall of the two side walls in the resin body 11, and the right side shown in FIG. 17 is the inner surface of the other side wall of the two side walls in the resin body 11.

[0110] To avoid complexity in the description, the subscripts will be omitted in the description. In FIG. 16, for the first antenna element 121 and the first passive antenna element 131, subscript 1 is added; for the second antenna element 122 and the second passive antenna element 132, subscript 2 is added; for the third antenna element 123 and the third passive antenna element 133, subscript 3 is added; and for the fourth antenna element 124 and the fourth passive antenna element 134, subscript 4 is added.

[0111] The antenna element 12 has a power supply element 12a formed of an antenna pattern and a power supply terminal 12b formed at one end as the power supply element 12a. The power supply element 12a has a first conductive surface 121, a second conductive surface 122, and a third conductive surface 123.

[0112] The first conductive surface 121 extends linearly from the power supply terminal 12b parallel to the side of the inner surface of the side wall in the resin body 11 toward the inner surface of the bottom wall in the resin body 11 to a branch point BP1. The first conductive surface 121 is formed on the inner surface of one side wall and the inner surface of the bottom wall in the resin body 11.

[0113] At the branch point BP1, the first conductive surface 121 branches into the second conductive surface 122 and the third conductive surface 123 in opposite directions perpendicular to each other. The second conductive surface 122 extends from the branch point BP1 in one direction perpendicular to the first conductive surface 121 parallel to the upper side of the inner surface of one side wall in the resin body 11, then extends in an L shape bent 90 degrees inward, and the other end is an open end. The second conductive surface 122 is formed on the inner surface of the bottom wall in the resin body 11 from the branch point BP1 to the open end of the second conductive surface 122.

[0114] The third conductive surface 123 extends from the branch point BP1 in the other direction perpendicular to the first conductive surface 121, then extends in a shape of a rectangle and spirally bent, and the other end is an open end. The third conductive surface 123 is formed on the inner surface of the bottom wall, the inner surface of the other side wall, and the inner surface of one side wall in the resin body 11.

[0115] The total length from the power supply terminal 12b in the power supply element 12a to the open end of the second conductive surface 122 is 1 / 4 wavelength of the wavelength corresponding to the resonance frequency f1. The length of 1 / 4 wavelength mentioned here refers to a length including an allowable range of ±α with respect to 1 / 4 wavelength with respect to the resonance frequency.

[0116] The total length from the open end of the second conductive surface 122 to the open end of the third conductive surface 123 is half the wavelength corresponding to the resonance frequency f1. The length of the half wavelength mentioned here refers to a length including an allowable range of ±α1 with respect to the half wavelength corresponding to the resonance frequency.

[0117] The non-powered antenna element 13 has a non-powered element 13a composed of an antenna pattern and a non-powered terminal 13b formed at one end as the non-powered element 13a. The non-powered element 13a has a first conductive surface 131, a second conductive surface 132, and a third conductive surface 133.

[0118] The first conductive surface 131 extends linearly from the non-powered terminal 13b parallel to the side of the inner surface of the side wall in the resin body 11 toward the inner surface of the bottom wall in the resin body 11, parallel to the first conductive surface 121 in the feeding element 12a, and extends to the branching point BP2 at the center side of one side wall. The first conductive surface 131 is formed on the inner surface of one side wall and the inner surface of the bottom wall in the resin body 11. The length of the first conductive surface 131 is shorter than the length of the first conductive surface 121 in the feeding element 12a.

[0119] Branched into the second conductive surface 132 and the third conductive surface 133 in opposite directions perpendicular to the first conductive surface 131 with the branching point BP2 as the boundary. The second conductive surface 132 is perpendicular to the first conductive surface 131 in one direction from the branching point BP2, extends in an L shape to the inner surface of the bottom wall in the resin body 11 on one side wall parallel to the second conductive surface 122 in the feeding element 12a, and the other end is an open end. The second conductive surface 132 is formed on the inner surface of the bottom wall in the resin body 11 from the branching point BP2 to the open end of the second conductive surface 132. The length of the second conductive surface 132 is shorter than the length of the second conductive surface 122 in the feeding element 12a.

[0120] The third conductive surface 133 extends perpendicular to the first conductive surface 131 in the other direction from the branching point BP2, and then extends in a shape that is rectangular and spirally bent, and the other end is an open end. The third conductive surface 133 is formed on the inner surface of the bottom wall and the inner surface of one side wall in the resin body 11. The third conductive surface 133 is formed between the first conductive surface 131 and the first conductive surface 121 in the power feeding element 12a. The length of the third conductive surface 133 is shorter than the length of the third conductive surface 123 in the power feeding element 12a.

[0121] The total length from the non-power feeding terminal 13b in the non-power feeding element 13a to the open end of the second conductive surface 132 is 1 / 4 wavelength of the wavelength corresponding to a frequency f2 (≠f1) different from the resonance frequency f1 for the power feeding element 12a. In this example, f2 > f1. The length of 1 / 4 wavelength of the wavelength corresponding to the frequency f2 referred to here means a length including an allowable range ±β with respect to 1 / 4 wavelength of the frequency f2 which is the resonance frequency for the non-power feeding element 13a.

[0122] The total length from the open end of the second conductive surface 132 to the open end of the third conductive surface 133 is 1 / 2 wavelength of the wavelength corresponding to the resonance frequency f2. The length of 1 / 2 wavelength of the wavelength corresponding to the frequency f2 referred to here means a length including an allowable range ±β1 with respect to 1 / 2 wavelength of the frequency f2 which is the resonance frequency for the non-power feeding element 13a.

[0123] In this way, since an antenna pattern (the third conductive surface 123, the third conductive surface 133) in which each of the power feeding elements 12a1 to 12a4 in the antenna elements 121 to 124 and each of the non-power feeding elements 13a1 to 13a4 in the non-power feeding antenna elements 131 to 134 are spirally bent is added, a function as a dipole antenna is added to the function as a monopole antenna for a frequency band including the resonance frequency f1 for the power feeding elements 12a1 to 12a4.

[0124] Each of the paired first antenna element 121 to the fourth antenna element 124 and the first non-power feeding antenna element 131 to the fourth non-power feeding antenna element 134 is arranged corresponding to each of the four corners of the resin body 11 for each pair. The housing antenna 1B, on the inner wall surface of the resin body 11, has power supply elements 12a1 to 12a4 for each of the first antenna element 121 to the fourth antenna element 124 and non-powered elements 13a1 to 13a4 for each of the first non-powered antenna element 131 to the fourth non-powered antenna element 134, and is manufactured by molding using MID or a 3D printer.

[0125] Since the power supply elements 12a1 to 12a4 and the non-powered elements 13a1 to 13a4 are formed in close contact with the inner wall surface of the resin body 11, there is no gap between the power supply elements 12a1 to 12a4 and the non-powered elements 13a1 to 13a4 and the inner wall surface of the resin body 11. The sizes of the power supply elements 12a1 to 12a4 and the non-powered elements 13a1 to 13a4 can be maximized with respect to the resin body 11, and the performance as antenna elements can be improved. Also, since the power supply elements 12a1 to 12a4 and the non-powered elements 13a1 to 13a4 and the resin body 11 can be integrated and handled as the housing antenna 1, the assemblability and handleability are good.

[0126] The circuit board 2B, similar to the circuit board 2B in the antenna device according to Embodiment 3, has first power supply terminal through holes 2a1 to 2a4 to fourth power supply terminal through holes 2a4 and first non-powered terminal through holes 2b1 to 2b4 to fourth non-powered terminal through holes 2b4, and has an insulating substrate 21, a first ground conductor 22, a second ground conductor 23, first power supply lines 241 to 244 to fourth power supply lines 244, a power supply unit 26, and an interface circuit 27.

[0127] That is, the components of the circuit board 2B are the same as the components of the circuit board 2B in the antenna device according to Embodiment 3. Only the formation positions and mounting positions of the components of the circuit board 2B are slightly different because the positions where the first antenna element 121 to the fourth antenna element 124 and the first non-powered antenna element 131 to the fourth non-powered antenna element 134 are formed are slightly different from the positions formed in the antenna device according to Embodiment 3, and they are substantially the same.

[0128] In short, also in the antenna device according to Embodiment 4, the first power supply terminal through hole 2a1 to the fourth power supply terminal through hole 2a4, the first non-powered terminal through hole 2b1 to the fourth non-powered terminal through hole 2b4, and the first power supply line 241 to the fourth power supply line 244 and the first power supply point 251 to the fourth power supply point 254 are formed on the circuit board 2B with 90-degree rotational symmetry. Therefore, the description of the circuit board 2B is omitted.

[0129] In the antenna device according to Embodiment 4, each of the antenna elements 121 to 124 and each of the non-powered antenna elements 131 to 134 function as a monopole antenna with respect to a frequency band including the resonance frequency f1 with respect to the power supply elements 12a1 to 12a4, and also function as a dipole antenna. Therefore, the current excited at each of the first power supply point 251 to the fourth power supply point 254 can be reduced, and while impedance matching is achieved, the current flowing through the first ground conductor 22 and the second ground conductor 23 can be reduced.

[0130] As a result, the cross-polarization component (LHCP) in the back direction of the antenna device, that is, the direction from the inner surface to the outer surface of the circuit board 2B, can be suppressed. Since the cross-polarization component can be suppressed and the multipath wave incident from the back direction of the antenna device is not received, for example, when used as a receiving antenna, the antenna device according to Embodiment 4 is effective for GNSS (Global Navigation Satellite System) applications.

[0131] The antenna device according to Embodiment 4 has the same effects as the antenna device according to Embodiment 3, and in addition, the effect of adding the function of a dipole antenna to the function of a monopole antenna can be obtained.

[0132] Embodiment 5. The antenna device according to Embodiment 5 will be described with reference to FIGS. 18 and 19. The antenna device according to Embodiment 5 is different from the antenna device according to Embodiment 4 in that a shield case 3 is added, and is the same as the antenna device according to Embodiment 4 in other respects. Therefore, the following description will focus on the shield case 3. In FIGS. 18 and 19, the same reference numerals as those in FIGS. 16 and 17 denote the same or corresponding parts.

[0133] The housing antenna 1B is substantially the same as the housing antenna 1B in the antenna device according to Embodiment 4. The difference is that in the housing antenna 1B, screw through-holes 11c1 to 11c4, which are drill holes, are formed at the four corners of the flange portion 11b of the resin body 11.

[0134] The circuit board 2B is substantially the same as the circuit board 2B in the antenna device according to Embodiment 4. The difference is that in the circuit board 2B, screw through-holes 2c1 to 2c4, which are drill holes, are formed at the four corners of the insulating substrate 21, the first ground conductor 22, and the second ground conductor 23, respectively.

[0135] The shield case 3 is mounted on the outer surface of the circuit board 2B to shield the outer surface of the circuit board 2B, that is, to cover the interface circuit 27 that handles the high-frequency signals mounted on the outer surface of the circuit board 2, so as to shield the interface circuit 27 from external noise and the like. The shield case 3 is made of metal and has a frame portion 31 and a bottom portion 32. The outer shape of the shield case 3 is rectangular. Screw holes 31c1 to 31c4 are formed at the four corners of the frame portion 31 of the shield case 3.

[0136] The center lines of the screw through-holes 11c1 to 11c4, the center lines of the screw through-holes 2c1 to 2c4, and the center lines of the screw holes 31c1 to 31c4 that correspond to each other coincide. Each of the screws 41 to 44 is passed through each of the screw through-holes 11c1 to 11c4 and the screw through-holes 2c1 to 2c4 from above each of the screw through-holes 11c1 to 11c4, and screwed into each of the screw holes 31c1 to 31c4, so that the housing antenna 1B is attached to the shield case 3 so as to sandwich the circuit board 2B. The screws 41 to 44 may be made of plastic, but metal is preferred.

[0137] Since the upper surface of the frame portion 31 of the shield case 3 is in close contact with the second ground conductor 23 of the circuit board 2B when the shield case 3 is attached to the outer surface of the circuit board 2B, the shield case 3 is grounded through the second ground conductor 23. Since the space formed by the second ground conductor 23 and the shield case 3 is shielded by the second ground conductor 23 and the shield case 3, the interface circuit 27 mounted on the outer surface of the circuit board 2 is protected from external noise and the like.

[0138] The assembly of the housing antenna 1B, the circuit board 2B, and the shield case 3 is performed as follows. The power supply terminals 12b1 to 12b4 of the antenna elements 121 to 124 in the housing antenna 1B are fitted into the power supply terminal through-holes 2a1 to 2a4 formed in the circuit board 2B, and the non-powered terminals 13b1 to 13b4 of the non-powered antenna elements 131 to 134 are fitted into the non-powered terminal through-holes 2b1 to 2b4 formed in the circuit board 2B. The housing antenna 1B and the circuit board 2B are positioned.

[0139] The fitted power supply terminals 12b1 to 12b4 are soldered to be electrically connected to the power supply lines 241 to 244, and the fitted non-powered terminals 13b1 to 13b4 are soldered to be electrically connected to the second ground conductor 23. The outer conductor of the high-frequency (RF) coaxial cable inserted through the cable insertion hole (not shown) formed in the frame portion 31 or the bottom portion 32 of the shield case 3 is electrically connected to the second ground conductor 23, and the core wire is electrically connected to the power supply portion 26.

[0140] In this state, the screws 41 to 44 are passed through the screw through holes 11c1 to 11c4 and the screw through holes 2c1 to 2c4, and screwed into the screw holes 31c1 to 31c4, thereby completing the assembly of the housing antenna 1B, the circuit board 2B, and the shield case 3.

[0141] The antenna device according to Embodiment 5 has the same effects as the antenna device according to Embodiment 4. In addition, since the shield case 3 mounted on the outer surface of the circuit board 2B is provided, the outer surface of the circuit board 2B can be shielded. In particular, the interface circuit 27 that handles high-frequency signals mounted on the outer surface of the circuit board 2 can be protected from external noise and the like.

[0142] Also, the antenna device according to Embodiment 5 is easy to assemble the housing antenna 1B, the circuit board 2B, and the shield case 3. Note that the shield case 3 shown in Embodiment 5 may be mounted on the outer surface of the circuit board 2B of the antenna device according to Embodiment 4.

[0143] Note that free combinations of each embodiment, modifications of any component of each embodiment, or omissions of any component of each embodiment are possible.

Industrial Applicability

[0144] The antenna device of the present disclosure is suitable for an antenna device used in communication, radar, or positioning.

Explanation of Signs

[0145] 1A housing antenna, 11 resin body, 11a opening, 12, 121 to 124 antenna elements, 12a, 12a1 to 12a4 antenna patterns (feeding elements), 12b, 12b1 to 12b4 feeding terminals, 121 first conductive surface, 122 second conductive surface, 123 third conductive surface, 13, 131 to 134 non-fed antenna elements, 13a, 13a1 to 13a4 non-fed elements, 13b, 13b1 to 13b4 non-fed terminals, 131 first conductive surface, 132 second conductive surface, 133 third conductive surface, 2 circuit board, 2a through hole, 2a1 to 2a4 through holes for feeding terminals, 2b1 to 2b4 through holes for non-fed terminals, 21 insulator, 22 first ground conductor, 23 second ground conductor, 24, 241 to 244 feeding lines, 25, 251 to 254 feeding points, 26 feeding section, 27 interface circuit, 27a 180-degree hybrid, 27b first 90-degree hybrid, 27c second 90-degree hybrid, 3 shield case.

Claims

1. A cylindrical resin body having an opening at one end and a bottom; a circuit board on which the resin body is attached by covering the opening of the resin body, the circuit board having a through hole for a power supply terminal penetrating from an inner surface to an outer surface, and a power supply line formed on an outer surface; A power supply element including an antenna pattern formed on an inner wall surface of the resin body; a power supply terminal formed at one end of the antenna pattern, passing through a power supply terminal through hole of the circuit board, and having one end electrically connected to the other end of a power supply line formed on the outer surface of the circuit board; Equipped with The cross-sectional shape of the resin body is rectangular, the power supply element has an antenna main part formed along four sides of an inner surface of a bottom wall constituting an inner wall surface of the resin body, the other end of which is an open end, and an extension part formed on an inner surface of one side wall constituting the inner wall surface of the resin body from the antenna main part toward the opening of the resin body to the power supply terminal, Antenna device.

2. 2. The antenna device according to claim 1, wherein a total length from the feed terminal of the feed element to the open end of the feed element is 1 / 4 of a wavelength corresponding to a resonant frequency.

3. The antenna device according to claim 1 , wherein the resin body is made of a thermoplastic resin.

4. The feeding element is a first conductor surface extending linearly from the power supply terminal to a branch point; a second conductor surface extending linearly from a branch point perpendicular to the first conductor surface, the second conductor surface being an open end at the other end; a third conductor surface having an open end at the other end, extending from a branch point in a direction opposite to the second conductor surface and having a shape bent in a spiral shape; 2. The antenna device according to claim 1, further comprising:

5. a total length from the power supply terminal to an open end of the second conductor surface of the power supply element is a quarter wavelength of a wavelength corresponding to a resonant frequency, a total length from the open end of the second conductor surface to the open end of the third conductor surface is ½ of a wavelength corresponding to a resonant frequency; 5. The antenna device according to claim 4.

6. A cylindrical resin body having an opening at one end and a bottom; a circuit board on which the resin body is attached by covering the opening of the resin body, the circuit board having a through hole for a power supply terminal penetrating from an inner surface to an outer surface, and a power supply line formed on an outer surface; A power supply element including an antenna pattern formed on an inner wall surface of the resin body; a power supply terminal formed at one end of the antenna pattern, passing through a power supply terminal through hole of the circuit board, and having one end electrically connected to the other end of a power supply line formed on the outer surface of the circuit board; Equipped with the circuit board has a through hole for a parasitic terminal that penetrates from an inner surface to an outer surface, a parasitic element formed on an inner wall surface of the resin body; a parasitic terminal formed at one end of the parasitic element, passing through a parasitic terminal through hole of the circuit board, and having one end electrically connected to a ground conductor formed on an outer surface of the circuit board; An antenna device comprising:

7. the circuit board has a through hole for a parasitic terminal that penetrates from an inner surface to an outer surface, a parasitic element formed on an inner wall surface of the resin body; a parasitic terminal formed at one end of the parasitic element, passing through a parasitic terminal through hole of the circuit board, and having one end electrically connected to a ground conductor formed on an outer surface of the circuit board; The antenna device according to claim 1 , further comprising:

8. 8. The antenna device according to claim 7, wherein a total length from the parasitic terminal to the open end of the parasitic element is ¼ wavelength of a wavelength corresponding to a frequency different from a resonant frequency for the feed element.

9. The parasitic element is a first conductor surface extending linearly from the parasitic terminal to a branch point; a second conductor surface extending linearly from a branch point perpendicular to the first conductor surface, the second conductor surface being an open end at the other end; a third conductor surface having an open end at the other end, extending from a branch point in a direction opposite to the second conductor surface and having a shape bent in a spiral shape; 8. The antenna arrangement according to claim 7, comprising:

10. 10. The antenna device according to claim 9, wherein, in the parasitic terminal, a total length from the parasitic terminal to the open end of the second conductor surface in the parasitic element is ¼ wavelength of a wavelength corresponding to a frequency different from a resonant frequency for the feed element, and a total length from the open end of the second conductor surface to the open end of the third conductor surface is ½ wavelength of a wavelength corresponding to the frequency different from the resonant frequency for the feed element.

11. A cylindrical resin body having an opening at one end and a bottom; A plurality of feeding elements each having an antenna pattern formed on an inner wall surface of the resin body; a plurality of power supply terminals each formed at one end of each of the plurality of power supply elements; a plurality of parasitic elements each of which is an antenna pattern formed on an inner wall surface of the resin body and which are paired with the plurality of feed elements; a plurality of parasitic terminals each formed at one end of each of the plurality of parasitic elements; a circuit board on which the resin body is attached with an opening portion thereof covered, the circuit board having a plurality of power supply terminal through holes each penetrating from an inner surface to an outer surface and through which each of the plurality of power supply terminals passes, a plurality of power supply lines each electrically connected to each of the plurality of power supply terminals that pass through each of the plurality of power supply terminal through holes, a plurality of parasitic terminal through holes each penetrating from the inner surface to the outer surface and through which each of the plurality of parasitic terminals passes, and a ground conductor to which the plurality of parasitic terminals that pass through each of the plurality of parasitic terminal through holes are electrically connected; An antenna device comprising:

12. the plurality is four, i.e., first through fourth; an interface circuit is mounted on the circuit board, the interface circuit being electrically connected to a first power supply terminal to a fourth power supply terminal to which the first power supply line to the fourth power supply line are connected, and the interface circuit is connected to a power supply unit; 12. The antenna device according to claim 11.

13. each of the plurality of feeding elements has a first conductor surface extending linearly from the corresponding feeding terminal to a branch point, a second conductor surface having the other end as an open end and extending linearly from the branch point perpendicular to the first conductor surface, and a third conductor surface having the other end as an open end, extending from the branch point in a direction opposite to the second conductor surface and having a shape bent in a spiral shape; Each of the plurality of parasitic elements has a first conductor surface extending linearly from the corresponding parasitic terminal to a branch point, a second conductor surface having the other end as an open end and extending linearly from the branch point perpendicular to the first conductor surface, and a third conductor surface having the other end as an open end, extending from the branch point in a direction opposite to the second conductor surface, and having a shape bent in a spiral shape.

13. An antenna device according to claim 12.

14. In each of the plurality of feeding elements, a total length from the feeding terminal of the feeding element to an open end of the second conductor surface is ¼ wavelength of a wavelength corresponding to a resonance frequency, and a total length from the open end of the second conductor surface to the open end of the third conductor surface is ½ wavelength of a wavelength corresponding to a resonance frequency, In each of the plurality of parasitic elements, a total length from the parasitic terminal of the parasitic element to the open end of the second conductor surface is ¼ wavelength of a wavelength corresponding to a frequency different from a resonant frequency for the parasitic element, and a total length from the open end of the second conductor surface to the open end of the third conductor surface is ½ wavelength of a wavelength corresponding to the frequency different from a resonant frequency for the parasitic element.

14. An antenna device according to claim 13.

15. The interface circuit includes: a 180-degree hybrid that receives a high-frequency signal from the power supply unit, divides the signal into two high-frequency signals having a phase difference of 180 degrees, and outputs the two high-frequency signals; a first 90-degree hybrid that receives a radio frequency signal having the same phase as a radio frequency signal input from the 180-degree hybrid to the 180-degree hybrid, outputs a radio frequency signal having the same phase as the input radio frequency signal to the first power supply terminal, and outputs a radio frequency signal having a phase leading by 90 degrees with respect to the input signal to the fourth power supply terminal; a second 90-degree hybrid that receives a high-frequency signal having a phase lead of 180 degrees from the high-frequency signal input to the 180-degree hybrid from the 180-degree hybrid, outputs a high-frequency signal having the same phase as the input high-frequency signal to the second power supply terminal, and outputs a high-frequency signal having a phase lead of 90 degrees from the input signal to the third power supply terminal. The antenna device according to any one of claims 12 to 14.

16. The interface circuit includes: a first 90-degree hybrid that receives a high-frequency signal from the first power supply terminal and a high-frequency signal from the fourth power supply terminal that is advanced by 90 degrees with respect to the high-frequency signal from the first power supply terminal, combines the two high-frequency signals, and outputs the combined signal; a second 90-degree hybrid that receives a high-frequency signal from the second power supply terminal that is 180 degrees ahead of the high-frequency signal from the first power supply terminal and a high-frequency signal from the third power supply terminal that is 270 degrees ahead of the high-frequency signal from the first power supply terminal, combines the two high-frequency signals, and outputs the combined signal; a 180-degree hybrid that receives the high-frequency signal from the first 90-degree hybrid and the high-frequency signal from the second 90-degree hybrid, combines the two high-frequency signals, and outputs the combined signal to the power supply unit; The antenna device according to any one of claims 12 to 14.

17. 15. The antenna device according to claim 12, further comprising a shield case attached to an outer surface of the circuit board and covering the interface circuit.

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