Antenna device

Abstract

This antenna device is provided with: a bottomed cylindrical resin body (11) having an opening at one end; a circuit board (2) to which the resin body (11) is mounted such that the opening of the resin body (11) is covered, which has a through-hole (2a) penetrating from an inner surface to an outer surface, and on which a power supply line (26) is formed on the outer surface; a power supply element (12a) comprising an antenna pattern formed on an inner wall surface of the resin body (11); and a power supply terminal (12b) formed at one end of the antenna pattern, penetrating through the through-hole (2a) of the circuit board (2), and electrically connected to the other end of a power supply line (24) having one end formed on the outer surface of the circuit board (2).

Description

Antenna device

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

[0002] Known antenna devices used in communications, radar, positioning, etc. include antenna devices in which an antenna element is electrically connected to a feeder line having a feed point formed on the surface of a circuit board. Patent Document 1 (JP-A-2005-102523) also discloses a mobile phone in which a wiring area for an antenna pattern is formed by printing and plating on the inner wall surface of an outer cover.

[0003] JP 2009-188755 A

[0004] In an antenna device in which an antenna element is electrically connected to a feed line having a feed point formed on the surface of a circuit board, it is desirable to prevent the antenna element from being damaged by external disturbances such as wind, rain, or sunlight.

[0005] The present disclosure has been made in consideration of the above-mentioned points, and aims to obtain an antenna device that suppresses degradation of the performance of the antenna element by preventing the antenna element from being damaged due to the influence of external disturbances.

[0006] The antenna device according to the present disclosure comprises a cylindrical resin body having an opening at one end and a bottom; a circuit board to which the resin body is attached with the opening of the resin body covered, having a through hole that penetrates from the inner surface to the outer surface, and having a feed line formed on its outer surface; a feed element consisting of an antenna pattern formed on the inner wall surface of the resin body; and a feed terminal formed at one end of the antenna pattern, passing through the through hole of the circuit board, and having one end electrically connected to the other end of the feed line formed on the outer surface of the circuit board.

[0007] According to the present disclosure, an antenna pattern constituting an antenna element is formed on the inner wall surface of a resin body, and a power supply terminal formed at one end of the antenna pattern constituting the antenna element is passed through a through hole in a circuit board and electrically connected to a power supply line, thereby preventing damage to the antenna element due to external disturbances from the resin body and facilitating electrical connection between the antenna element and the power supply line.

[0008] FIG. 1 is a perspective view showing an antenna device according to a first embodiment, with the resin body shown transparent to show the antenna element. FIG. 2 is a perspective view showing a state before a housing antenna is assembled to a circuit board in the antenna device according to the first embodiment. FIG. 3 is an inner surface view showing the circuit board in the antenna device according to the first embodiment. FIG. 4 is an outer surface view showing the circuit board in the antenna device according to the first embodiment. FIG. 5 is an enlarged cross-sectional view of a main part, schematically showing a fitting portion between a resin cover and a circuit board in the antenna device according to the first embodiment. FIG. 6 is a perspective view of the antenna device according to the first embodiment, seen from the bottom side. FIG. 7 is a perspective view of the antenna device according to the second embodiment, with the resin body shown transparent to show the antenna element. FIG. 8 is an inner surface view showing the circuit board in the antenna device according to the second embodiment. FIG. 9 is an outer surface view showing the circuit board in the antenna device according to the second embodiment. FIG. 10 is a perspective view of the antenna device according to the second embodiment, seen from the bottom side. FIG. 11 is a perspective view of the antenna device according to the third embodiment, with the resin body shown transparent to show the antenna element. FIG. 12 is an inner surface view showing the circuit board in the antenna device according to the third embodiment. FIG. 13 is an outer surface view showing the circuit board in the antenna device according to the third embodiment. FIG. 14 is a perspective view of the antenna device according to the third embodiment, seen from the bottom side. FIG. 10 is a schematic diagram showing the layout of a circuit mounted on a circuit board in an antenna device according to embodiment 3. FIG. 11 is a perspective view showing an antenna device according to embodiment 4, with a resin body being transparently shown to show the antenna element. FIG. 12 is a developed view for explaining a pair of antenna elements and a parasitic antenna element in the antenna device according to embodiment 4. FIG. 13 is a perspective view showing an antenna device according to embodiment 5, with a resin body being transparently shown to show the antenna element and the shielding case being transparently shown. FIG. 14 is an exploded perspective view showing the antenna housing, circuit board, and shielding case in the antenna device according to embodiment 5.

[0009] Embodiment 1 An antenna device according to embodiment 1 will be described with reference to Figures 1 to 6. The antenna device according to embodiment 1 is an antenna device used in communications, radar, 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 the first embodiment 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 cylindrical with a bottom, and has a flange 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 thermosetting material may also be used in consideration of heat resistance. In the first embodiment, the shape of the resin body 11 is a quadrangular prism with a rectangular cross section, but it may also be cylindrical, spherical, or streamlined.

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

[0013] In the first embodiment, the feed 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, the other end of which is 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 11 from the antenna main portion toward the opening 11a of the resin body 11 to the feed terminal 12b. The antenna main portion is formed along the four sides of the inner surface of the bottom wall. The extension portion is formed in the center of the inner surface of the one side wall.

[0014] In the first embodiment, the feed element 12a has a shape obtained by bending a monopole antenna. The total length from the feed terminal 12b of the feed element 12a to the open end of the feed element 12a is 1 / 4 wavelength of the wavelength corresponding to the resonant frequency. The length of 1 / 4 wavelength here refers to a length including an allowable range ±α for the 1 / 4 wavelength of the resonant frequency. Note that the shape of the feed element 12a is not limited to 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.

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

[0016] Since the feed element 12a is formed in close contact with the inner wall surface of the resin body 11, there is no gap between the feed element 12a and the inner wall surface of the resin body 11, and the size of the feed element 12a can be maximized relative to the resin body 11, improving its performance as an antenna element. Furthermore, since the feed element 12a and the resin body 11 can be handled as an integrated unit as the housing antenna 1, the assembly and handling are easy.

[0017] The resin body 11 is attached to the circuit board 2 with the opening 11a of the resin body 11 covered by the inner surface (front surface) of the circuit board 2. The circuit board 2 has a through hole 2a that penetrates from the inner surface to the outer surface (back surface). A feed terminal 12b of the antenna element 12 is fitted into the through hole 2a formed in the circuit board 2. By fitting the feed terminal 12b into the through hole 2a, it plays a role in determining the position of the feed element 12a of the antenna element 12 relative to the circuit board 2.

[0018] The circuit board 2 has 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, i.e., electrically insulated from, a land 22a formed around the through hole 2a. The first ground conductor 22 is grounded.

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

[0020] A first ground conductor 22 formed on the front surface of the insulating substrate 21 and a second ground conductor 23 formed on the back surface of the insulating substrate 21 are electrically connected by a large number of through holes Th1. In Figures 3 and 4, to avoid cluttering the figures, a plurality of through holes Th1 are shown around the first ground conductor 22 and the second ground conductor 23, but a suitable number of through holes Th1 are also formed inside the first ground conductor 22 and the second ground conductor 23 so as to avoid the locations of circuit components and circuit patterns (not shown).

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

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

[0023] As shown in Figure 6, the power supply terminal 12b of the antenna element 12 is fitted into the through hole 2a formed in the circuit board 2, and then the end of the power supply terminal 12b is connected by solder to the land 23a formed on the back surface of the insulating substrate 21, 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 having the power supply element 12a formed on the inner wall surface of the resin body 11, the flange portion 11b of the resin body 11 is attached to the circuit board 2, and the power supply terminal 12b is inserted into the through hole 2a formed in the circuit board 2 and attached thereto. After that, the power supply terminal 12b is soldered to the land 23a and electrically connected to the power supply line 24. This not only simplifies assembly, but also reduces loss due to the electrical connection between the power supply element 12a and the power supply line 24, improving durability.

[0025] Since the electrical connection between the antenna element 12 and the power supply line 24 is made by soldering within a narrow area between the end of the power supply terminal 12b and the land 23a, no large amount of 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 feed point 25, the input signal is transmitted through feed line 24 and then transmitted to feed element 12a via feed terminal 12b.

[0027] When an input signal is transmitted to the feed element 12a, a resonance phenomenon occurs during transmission through the feed element 12a, causing electromagnetic waves corresponding to the high-frequency signal of the input signal to be radiated into space from the feed element 12a. That is, when the input signal transmits through the feed element 12a, an electromagnetic wave corresponding to the magnitude of the current generated by the resonance phenomenon is radiated into space from the feed element 12a. Because the total length from the feed terminal 12b of the feed element 12a to the open end of the feed element 12a is ¼ of the wavelength corresponding to the resonant frequency, electromagnetic waves are efficiently radiated into space from the feed element 12a.

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

[0029] In the antenna device of embodiment 1, a housing antenna 1 is formed by forming a power supply element 12a consisting of an antenna pattern on the inner wall surface of a resin body 11. Therefore, the resin body 11 that protects the antenna element 12 including the power supply element 12a itself has the function of an antenna, so there is no gap between the power supply element 12a and the inner wall surface of the resin body 11, and the size of the power supply element 12a can be maximized relative to the resin body 11, thereby improving its performance as an antenna element.

[0030] Furthermore, the antenna device according to embodiment 1 is configured such that 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 power supply terminal 12b and the through hole 2a enable the resin body 11 to be positioned relative to the circuit board 2, improving the attachability of the antenna device, reducing loss due to the electrical connection between the power supply element 12a and the power supply line 24, and improving durability.

[0031] Furthermore, since the electrical connection between the antenna element 12 and the power supply line 24 is made by soldering within a narrow area between the end of the power supply terminal 12b and the land 23a, no large amount of 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.

[0032] Embodiment 2 An antenna device according to embodiment 2 will be described using Figures 7 to 10. The antenna device according to embodiment 2 differs from the antenna device according to embodiment 1 in that it further includes a parasitic antenna element 13, but is otherwise the same. Therefore, the following description will focus on the parasitic antenna element 13. In Figures 7 to 10, the same reference numerals as those in Figures 1 to 6 indicate the same or corresponding parts.

[0033] The antenna device according to the second embodiment 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 parasitic antenna element 13. The parasitic antenna element 13 is electromagnetically coupled to the antenna element 12, thereby achieving multi-band operation, broadband operation, and improved antenna efficiency.

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

[0035] In the second embodiment, parasitic element 13a has a main antenna portion formed on the inner surface of the bottom wall that constitutes the inner wall surface of resin body 11, the other end of which is an open end, and an extension portion formed on the inner surface of one side wall that constitutes the inner wall surface of resin body 11, extending from the main antenna portion to parasitic terminal 13b toward opening 11a of resin body 11. The main antenna portion of parasitic element 13a is arranged inside and parallel to the portion of feed element 12a that is located on the open end side of the main antenna portion, and the extension portion of parasitic element 13a is arranged parallel to the extension portion of feed element 12a.

[0036] In the second embodiment, the parasitic element 13a has a shape obtained by bending a monopole antenna. The total length from the parasitic terminal 13b of the parasitic element 13a to the open end of the parasitic element 13a is ¼ wavelength of the wavelength corresponding to a frequency f2 (≠ f1), which is different from the resonant frequency f1 for the feed element 12a. The parasitic element 13a resonates at the frequency f2.

[0037] The length of the quarter wavelength corresponding to frequency f2 here refers to a length including an allowable range ±β for the quarter wavelength of frequency f2, which is the resonant frequency for parasitic element 13a. Note that parasitic element 13a is not limited to a 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.

[0038] The housing antenna 1A, in which the feed element 12a and the parasitic element 13a are formed on the inner wall surface of the resin body 11, is produced by molding using an MID or 3D printer. Because the feed element 12a and the parasitic element 13a are formed in close contact with the inner wall surface of the resin body 11, there is no gap between the feed element 12a or the parasitic element 13a and the inner wall surface of the resin body 11, which allows the size of the feed element 12a and the parasitic element 13a to be maximized relative to the resin body 11, improving performance as an antenna element. Furthermore, because the feed element 12a and the parasitic element 13a and the resin body 11 can be handled as an integrated unit as the housing antenna 1, assembly and handling are easy.

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

[0040] The circuit board 2A has a parasitic terminal through-hole 2b that penetrates from the inner surface to the outer surface. A parasitic terminal 13b of the parasitic antenna element 13 is fitted into the parasitic terminal through-hole 2b formed in the circuit board 2A. By fitting the parasitic terminal 13b into the parasitic terminal through-hole 2b, the parasitic terminal 13b plays a role in determining the position of the parasitic element 13a of the parasitic antenna element 13 relative to the circuit board 2.

[0041] A plurality of through holes Th4 are formed around the through holes 2b for the non-powered terminals formed in the circuit board 2A in the first ground conductor 22 and the second ground conductor 23, electrically connecting the first ground conductor 22 and the second ground conductor 23.

[0042] As shown in Figure 10, the feed terminal 12b of the antenna element 12 is fitted into the feed terminal through hole 2a formed in the circuit board 2, and the parasitic terminal 13b of the parasitic antenna element 13 is fitted into the parasitic terminal through hole 2b formed in the circuit board 2, and then an end of the feed terminal 12b is connected by solder to a land 23a formed on the back surface of the insulating substrate 21, so that the feed terminal 12b is electrically connected to the other end of the feed line 24, and an end of the parasitic terminal 13b is connected by solder to a second ground conductor 23 formed on the back surface of the insulating substrate 21, so that the parasitic terminal 13b is electrically connected to the second ground conductor 23.

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

[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 feed point 25, the input signal is transmitted through feed line 24 and then transmitted to feed element 12a via feed terminal 12b.

[0045] When an input signal is transmitted to the feed element 12a, a resonance phenomenon occurs during transmission through the feed element 12a, causing electromagnetic waves corresponding to the high-frequency signal of the input signal to be radiated into space from the feed element 12a. That is, when the input signal transmits through the feed element 12a, an electromagnetic wave corresponding to the magnitude of the current generated by the resonance phenomenon is radiated into space from the feed element 12a. Because the total length from the feed terminal 12b of the feed element 12a to the open end of the feed element 12a is ¼ of the wavelength corresponding to the resonant frequency, electromagnetic waves are efficiently radiated into space from the feed element 12a.

[0046] On the other hand, a current flows through parasitic element 13a due to electromagnetic coupling with fed element 12a. That is, parasitic element 13a resonates because its wavelength is a quarter of the wavelength corresponding to frequency f2, which is the resonant frequency of parasitic element 13a.

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

[0048] On the other hand, a current flows through parasitic element 13a due to electromagnetic coupling with fed element 12a. That is, parasitic element 13a resonates because its wavelength is a quarter of the wavelength corresponding to frequency f2, which is the resonant frequency of parasitic element 13a.

[0049] The antenna device according to the second embodiment has the same effects as the antenna device according to the first embodiment, and in addition, since it includes the parasitic antenna element 13, it can achieve multi-band and wideband operation.

[0050] Third Embodiment An antenna device according to a third embodiment will be described with reference to Figs. 11 to 15. The antenna device according to the third embodiment has a pair of antenna elements 12 and a parasitic antenna element 13, whereas the antenna device according to the second embodiment has a plurality of pairs of antenna elements 12, four pairs in this example. １ ~12 ４ and the parasitic antenna element 13 １ ~13 ４ The difference is that it has the above, but the other points are the same.

[0051] Therefore, four pairs of first antenna elements 12 １ to the fourth antenna element 12 ４ and the first parasitic antenna element 13 １ to the fourth parasitic antenna element 13 ４ 11 to 15, the same reference numerals as those in FIGS. 7 to 10 designate the same or corresponding parts.

[0052] The antenna device according to the third embodiment includes a housing antenna 1B and a circuit board 2B. The housing antenna 1B includes a resin body 11 and four pairs of first antenna elements 12. １ to the fourth antenna element 12 ４ and the first parasitic antenna element 13 １ to the fourth parasitic antenna element 13 ４ The first antenna element 12 of the pair １ to the fourth antenna element 12 ４ and the first parasitic antenna element 13 １ to the fourth parasitic antenna element 13 ４ are electromagnetically coupled in pairs.

[0053] Paired first antenna element 12 １ to the fourth antenna element 12 ４ and the first parasitic antenna element 13 １ to the fourth parasitic antenna element 13 ４are formed on the inner wall surface of the resin body 11 with 90-degree rotational symmetry. Therefore, to avoid complexity in the explanation, when there is no need to distinguish between them, the pair of antenna element 12 and parasitic antenna element 13 will be explained as representatives. Subscripts will also be omitted.

[0054] The antenna element 12 has a feed element 12a formed of an antenna pattern and a feed terminal 12b formed at one end of the feed element 12a. The other end of the antenna pattern formed as the feed 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 that constitutes the inner wall surface of the resin body 11, the other end of which is an open end, and an extension portion formed on the inner surface of one side wall that constitutes the inner wall surface of the resin body 11 from the antenna main portion to the power supply terminal 12b toward the opening 11a of the resin body 11.

[0056] The extension of the feed element 12a is formed linearly along one side of the inner surface of one side wall. The main antenna portion of the feed element 12a is formed along three sides of the inner surface of the bottom wall, excluding the top side of the side wall opposite the side wall on which the extension is formed. The main antenna portion of the feed element 12a is Z-shaped.

[0057] In the third embodiment, the feed element 12a has a shape obtained by bending a monopole antenna. The total length from the feed terminal 12b of the feed element 12a to the open end of the feed element 12a is ¼ of the wavelength corresponding to the resonant frequency f1. Note that the shape of the feed element 12a is not limited to a shape obtained by bending a monopole antenna, and it may also be an inverted-F antenna.

[0058] The parasitic antenna element 13 has a parasitic element 13a formed of an antenna pattern and a parasitic terminal 13b formed at one end of the parasitic element 13a. The other end of the antenna pattern formed as the parasitic 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 parasitic element 13a has an antenna main part formed on the inner surface of the bottom wall that constitutes the inner wall surface of the resin body 11, the other end of which is an open end, and an extension part formed on the inner surface of one side wall that constitutes the inner wall surface of the resin body 11 from the antenna main part toward the opening 11a of the resin body 11 to the parasitic terminal 13b.

[0060] The extending portion of the parasitic element 13a is arranged parallel to the extending portion of the feed element 12a on the other side of one side wall relative to the extending portion of the feed element 12a. The main antenna portion of the parasitic element 13a is arranged parallel to the portion of the main antenna portion of the feed element 12a located on the open end side, between the main antenna portion of the feed element 12a and the upper edge of the one side wall on which the extending portion is formed. The main antenna portion of the parasitic element 13a is L-shaped. However, the main antenna portion of the parasitic element 13a may also be Z-shaped.

[0061] In the third embodiment, the parasitic element 13a has a shape obtained by bending a monopole antenna. The total length from the parasitic terminal 13b of the parasitic element 13a to the open end of the parasitic element 13a is ¼ wavelength of the wavelength corresponding to a frequency f2 (≠ f1), which is different from the resonant frequency f1 for the feed element 12a. The parasitic element 13a resonates at frequency f2. Note that the shape of the parasitic element 13a is not limited to a shape obtained by bending a monopole antenna, and it may also be an inverted-F antenna.

[0062] Paired first antenna element 12 １ to the fourth antenna element 12 ４ and the first parasitic antenna element 13 １ to the fourth parasitic antenna element 13 ４ The first antenna element 12 is disposed on the inner wall surface of the resin body 11 in pairs, each corresponding to one of the four side walls of the resin body 11. １ to the fourth antenna element 12 ４ The feed element 12a in each １ ~12a ４ and the first parasitic antenna element 13 １ to the fourth parasitic antenna element 13 ４ The parasitic element 13a in each １ ~13a ４The housing antenna 1B on which the above-mentioned is formed is produced by molding using an MID or 3D printer.

[0063] Feed element 12a １ ~12a ４ and the parasitic element 13a １ ~13a ４ is formed in close contact with the inner wall surface of the resin body 11, １ ~12a ４ and the parasitic element 13a １ ~13a ４ There is no gap between the power supply element 12a and the inner wall surface of the resin body 11. １ ~12a ４ and the parasitic element 13a １ ~13a ４ The size of the feeding element 12a can be maximized relative to the resin body 11, and the performance as an antenna element can be improved. １ ~12a ４ and the parasitic element 13a １ ~13a ４ and the resin body 11 can be handled as an integrated unit as the housing antenna 1, and therefore assembly and handling are easy.

[0064] The circuit board 2B has a first power supply terminal through hole 2a for a power supply terminal, which penetrates from the inner surface to the outer surface (rear surface). １ to the fourth power supply terminal through hole 2a ４ The first power supply terminal through hole 2a formed in the circuit board 2B １ The first antenna element 12 １ Power supply terminal 12b １ The power supply terminal 12b is fitted to the １ is the first power supply terminal through hole 2a １ By fitting the first antenna element 12 to the circuit board 2B, １ The feed element 12a in １ It plays a role in determining the position of the

[0065] A second power supply terminal through hole 2a formed in the circuit board 2B ２ the second antenna element 12 ２ Power supply terminal 12b ２ The power supply terminal 12b is fitted to the２ is the second power supply terminal through hole 2a ２ By fitting the second antenna element 12 to the circuit board 2B, ２ The feed element 12a in ２ It plays a role in determining the position of the

[0066] A third power supply terminal through hole 2a formed in the circuit board 2B ３ the third antenna element 12 ３ Power supply terminal 12b ３ The power supply terminal 12b is fitted to the ３ is the third power supply terminal through hole 2a ３ By fitting the third antenna element 12 to the circuit board 2B, ３ The feed element 12a in ３ It plays a role in determining the position of the

[0067] A fourth power supply terminal through hole 2a formed in the circuit board 2B ４ the fourth antenna element 12 ４ Power supply terminal 12b ４ The power supply terminal 12b is fitted to the ４ is the fourth power supply terminal through hole 2a ４ By fitting the fourth antenna element 12 to the circuit board 2B, ４ The feed element 12a in ４ It plays a role in determining the position of the

[0068] The circuit board 2B has a first through hole 2b for a parasitic terminal that penetrates from the inner surface to the outer surface (rear surface). １ through the fourth parasitic terminal through hole 2b ４ The first parasitic terminal through hole 2b １ through the fourth parasitic terminal through hole 2b ４ are the first power supply terminal through holes 2a １ to the fourth power supply terminal through hole 2a ４ The pair of first power supply terminal through holes 2a １ to the fourth power supply terminal through hole 2a ４ and the first parasitic terminal through hole 2b １ through the fourth parasitic terminal through hole 2b ４are arranged parallel to each other along the four sides of the circuit board 2B.

[0069] A first through hole 2b for a parasitic terminal formed in the circuit board 2B １ the first parasitic antenna element 13 １ Unpowered terminal 13b in １ The non-powered terminal 13b is fitted. １ is the first parasitic terminal through hole 2b １ By fitting the first parasitic antenna element 13 to the circuit board 2B, １ Parasitic element 13a in １ It plays a role in determining the position of the

[0070] A second through hole 2b for a parasitic terminal formed in the circuit board 2B ２ the second parasitic antenna element 13 ２ Unpowered terminal 13b in ２ The non-powered terminal 13b is fitted. ２ is the second parasitic terminal through hole 2b ２ By fitting the second parasitic antenna element 13 to the circuit board 2B, ２ Parasitic element 13a in ２ It plays a role in determining the position of the

[0071] A third through hole 2b for a parasitic terminal formed in the circuit board 2B ３ the third parasitic antenna element 13 ３ Unpowered terminal 13b in ３ The non-powered terminal 13b is fitted. ３ is the third parasitic terminal through hole 2b ３ By fitting the third parasitic antenna element 13 to the circuit board 2B, ３ Parasitic element 13a in ３ It plays a role in determining the position of the

[0072] A fourth through hole 2b for a parasitic terminal formed in the circuit board 2B ４ the fourth parasitic antenna element 13 ４ Unpowered terminal 13b in ４ The non-powered terminal 13b is fitted. ４ is the fourth through hole 2b for the parasitic terminal ４By fitting the fourth parasitic antenna element 13 to the circuit board 2B, ４ Parasitic element 13a in ４ It plays a role in determining the position of the

[0073] Pair of first power supply terminal through holes 2a １ to the fourth power supply terminal through hole 2a ４ and the first parasitic terminal through hole 2b １ through the fourth parasitic terminal through hole 2b ４ are formed on the circuit board 2B with 90-degree rotational symmetry. Therefore, to avoid complexity in the explanation, when there is no need to distinguish between them, the pair of power supply terminal through-holes 2a and unpowered terminal through-holes 2b will be explained as representatives. 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, and a first power supply line 24. １ to the fourth feeder line 24 ４ The antenna 10 has a power supply section 26 and an interface circuit 27. The interface circuit 27 functions as a power supply circuit for high frequency signals, and has a 180-degree hybrid 27a, a first 90-degree hybrid 27b, and a second 90-degree hybrid 27c.

[0075] 12, the first ground conductor 22 is a conductive layer formed on the surface of the insulating substrate 21, separated from the land 22a formed around the power supply terminal through hole 2a, i.e., electrically insulated from it. The first ground conductor 22 is grounded.

[0076] 13, the second ground conductor 23 is a conductive layer formed on the back surface of the insulating substrate 21, separated from the land 23a formed around the through hole 2a and the feed line 24 extending from the land 23a and having a feed point 25 at one end, i.e., electrically insulated from the land 23a. The feed point 25 is not formed as a physical component, but is a part that excites a high-frequency signal. The second ground conductor 23 is grounded.

[0077] The second ground conductor 23 is connected to a transmission line electrically connecting the power supply portion 26 and the 180-degree hybrid 27a, a transmission line electrically connecting the 180-degree hybrid 27a and the first 90-degree hybrid 27b and the second 90-degree hybrid 27c, and a transmission line electrically connected to the first 90-degree hybrid 27b and the first power supply point 25. １ and the fourth feed point 25 ４ and a second 90-degree hybrid 27c, and a second feed point 25 ２ and the third feed point 25 ３ The transmission lines that carry them are also formed separately and electrically insulated.

[0078] A first ground conductor 22 formed on the surface of the insulating substrate 21 and a second ground conductor 23 formed on the back surface of the insulating substrate 21 are electrically connected by a large number of through holes Th1. A land 22a, which is a conductive layer formed on the surface of the insulating substrate 21, and a 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 electrically connecting the first ground conductor 22 and the second ground conductor 23 are formed around the feeder line 24 and the land 22a and the land 23a in the first ground conductor 22 and the second ground conductor 23. A plurality of through holes Th4 electrically connecting the first ground conductor 22 and the second ground conductor 23 are formed around the non-power-fed terminal through hole 2b in the first ground conductor 22 and the second ground conductor 23.

[0080] As shown in FIG. 14, the first antenna element 12 １ to the fourth antenna element 12 ４ The power supply terminal 12b １ ~12b ４ The power supply terminal through holes 2a are formed in the circuit board 2. １ ~2a ４ The first parasitic antenna element 13 １ to the fourth parasitic antenna element 13 ４ The parasitic terminal 13b in each １ ~13b４ The through hole 2b for the non-power-supply terminal is formed in the circuit board 2. １ ~2b ４ The connector is fitted to the connector.

[0081] After mating, the power supply terminal 12b １ ~12b ４ The ends of the respective electrodes are connected to corresponding lands 23a formed on the back surface of the insulating substrate 21. １ ~23a ４ and the power supply terminal 12b is connected by soldering. １ ~12b ４ Each corresponds to a feeder line 24 １ ~24 ４ The other end of the non-powered terminal 13b is electrically connected to the １ ~13b ４ Each end is connected by soldering to a second ground conductor 23 formed on the back surface of the insulating substrate 21, and the non-powered terminal 13b １ ~13b ４ is electrically connected to the second ground conductor 23.

[0082] Therefore, the feed element 12a １ ~12a ４ and power supply line 24 １ ~24 ４ This reduces the loss due to the electrical connection with the non-powered terminal 13b, improving durability. １ ~13b ４ This reduces the loss due to the electrical connection between the first ground conductor 21 and the second ground conductor 23, thereby improving durability.

[0083] When the antenna device according to the third embodiment is used as a transmitting antenna, the interface circuit 27 divides the high-frequency signal input to the power supply unit 26, which changes in the range from 0 to 360 degrees, into four high-frequency signals each having a phase difference of 90 degrees, and outputs the divided high-frequency signals to the first power supply line 24. １ to the fourth feeder line 24 ４ via the first power supply terminal 12b １ to the fourth power supply terminal 12b ４ It functions as a distribution circuit that supplies each of them.

[0084] For example, if the phase of the high frequency signal input to the power supply unit 26 is 0 degrees, the interface circuit 27 divides the input signal, which is a high frequency signal with a phase difference of 0 degrees, 90 degrees, 180 degrees, and 270 degrees, into high frequency signals and outputs them to the first power supply line 24. １ to the fourth feeder line 24 ４ via the first power supply terminal 12b １ to the fourth power supply terminal 12b ４ That is, the interface circuit 27 divides the high frequency signal input to the power supply unit 26 into four high frequency signals each having a phase difference of 90 degrees, and outputs the four high frequency signals to the first power supply terminal 12b. １ to the fourth power supply terminal 12b ４ The first power supply line 24 electrically connected to each other １ to the fourth feeder line 24 ４ Output to each one.

[0085] When the antenna device according to the third embodiment is used as a receiving antenna, the interface circuit 27 is １ to the fourth power supply terminal 12b ４ The first power supply line 24 １ to the fourth feeder line 24 ４ The four high-frequency signals, each having a phase difference of 90 degrees, are combined and output to the power supply unit 26.

[0086] The following mainly describes the case where the antenna device according to the third embodiment is used as a transmitting antenna, since the operation of the interface circuit 27 is reversible between when the device is used as a transmitting antenna and when it 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 make up the interface circuit 27 are mounted on the outer surface of the circuit board 2 while being electrically insulated from the second ground conductor 23.

[0087] 15, a high-frequency signal from power supply 26 is input to 180-degree hybrid 27a, which splits the input high-frequency signal into two high-frequency signals with a phase difference of 180 degrees and outputs them.

[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, which then distributes the input high-frequency signal into two high-frequency signals with a phase difference of 90 degrees and outputs them.

[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 fed to the first feed line 24. １ The other high-frequency signal distributed from the first 90-degree hybrid 27b, for example, a high-frequency signal that is 90 degrees ahead of the high-frequency signal input to the first 90-degree hybrid 27b, is transmitted to the second feed line 24. ２ That is, the first power supply line 24 １ and the second power supply line 24 ２ There is a 90 degree phase difference between the high frequency signals transmitted to the

[0090] The other high-frequency signal distributed from the 180-degree hybrid 27a, for example, a high-frequency signal whose phase is advanced by 180 degrees relative to the high-frequency signal input to the 180-degree hybrid 27a, is input to the second 90-degree hybrid 27c, which then distributes the input high-frequency signal into two high-frequency signals with a phase difference of 90 degrees and outputs them.

[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 fed to the third feed line 24. ３ The third power supply line 24 ３ The high frequency signal transmitted to the 180-degree hybrid 27a has a phase difference of 180 degrees with respect to the high frequency signal input to the 180-degree hybrid 27b.

[0092] The other high frequency signal distributed from the second 90-degree hybrid 27c, for example, a high frequency signal that is 90 degrees ahead of the high frequency signal input to the second 90-degree hybrid 27c, is fed to the fourth feed line 24. ４ The fourth power supply line 24 ４ The high frequency signal transmitted to the 180-degree hybrid 27a has a phase difference of 270 degrees with respect to the high frequency signal input to the 180-degree hybrid 27b.

[0093] Therefore, the first feed line 24 １ The first power supply terminal 12b connected to １ A high frequency signal in phase with the high frequency signal from the power supply section 26 is transmitted to the second power supply line 24. ２ The second power supply terminal 12b connected to ２ A high frequency signal having a phase difference of 90 degrees with respect to the high frequency signal from the power supply 26 is transmitted through the third power supply line 24. ３ The third power supply terminal 12b connected to ３ A high frequency signal having a phase difference of 180 degrees with respect to the high frequency signal from the power supply 26 is transmitted through the fourth power supply line 24. ４ The fourth power supply terminal 12b connected to ４ A high frequency signal having a phase difference of 270 degrees with respect to the high frequency signal from the power supply 26 is supplied from the power supply 26 via the interface circuit 27 .

[0094] Next, a description will be given of the operation when the antenna device according to embodiment 3 is used as a transmitting antenna. When an input signal, which is a high-frequency signal, is supplied to power feeder 26 and the high-frequency signal from power feeder 26 is input to 180-degree hybrid 27a, 180-degree hybrid 27a outputs a high-frequency signal having the same phase as the input high-frequency signal to first 90-degree hybrid 27b, and outputs a high-frequency signal whose phase is 180 degrees ahead of the input high-frequency signal to second 90-degree hybrid 27c.

[0095] The first 90-degree hybrid 27b transmits 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 24. １ and outputs a high frequency signal having a phase lead of 90 degrees relative to the high frequency signal from the power supply 26 to the second power supply line 24. ２The second 90-degree hybrid 27c outputs a high-frequency signal, the phase of which is advanced by 180 degrees relative to the high-frequency signal from the power supply unit 26 of the 180-degree hybrid 27a, to the third power supply line 24. ３ and outputs a high frequency signal having a phase lead of 270 degrees relative to the high frequency signal from the power supply unit 26 from the 180-degree hybrid 27 a to the fourth power supply line 24 . ４ Output to.

[0096] That is, the first feed line 24 １ to the fourth feeder line 24 ４ The high frequency signals with a phase lead of 90 degrees are supplied from the interface circuit 27 in this order. １ to the fourth feeder line 24 ４ and the first power supply terminal 12b １ to the fourth power supply terminal 12b ４ , the first antenna element 12 of the pair is １ to the fourth antenna element 12 ４ and the first parasitic antenna element 13 １ to the fourth parasitic antenna element 13 ４ are the first antenna elements 12 as explained in the second embodiment. １ to the fourth antenna element 12 ４ The feed element 12a in each １ ~12a ４ Due to the resonance phenomenon that occurs when the electromagnetic wave corresponding to the high frequency signal propagates through the power supply element 12a, １ ~12a ４ Each one radiates into space.

[0097] In this case, the feed element 12a １ ~12a ４ Since the high frequency phases of the signals transmitted through each lead by 90 degrees in sequence, a right-handed circularly polarized wave (RHCP) is emitted from the circuit board 2B in the direction of the resin body 11.

[0098] The first 90-degree hybrid 27b and the second 90-degree hybrid 27c are connected to the first feed line 24. １ to the fourth feeder line 24 ４ In other words, the phase of the high frequency signal output from the first 90-degree hybrid 27b to the first feed line 24 １ A high frequency signal having a phase lead of 90 degrees with respect to the second power supply line 24 ２ The second 90-degree hybrid 27c outputs a high-frequency signal having the same phase as the high-frequency signal from the power supply 26 to the third power supply line 24. ３ A high frequency signal having a phase lead of 270 degrees relative to the high frequency signal from the power supply 26 is transmitted to the fourth power supply line 24. ４ By outputting a high-frequency signal whose phase is 180 degrees ahead of the high-frequency signal from the power supply 26, a left-handed circularly polarized wave (LHCP) can be radiated from the circuit board 2B in the direction of looking at the resin body 11.

[0099] When the antenna device according to the third embodiment 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 have the following configuration.

[0100] The first 90-degree hybrid 27b is connected to the first power supply terminal 12b. １ to the first power supply line 24 １ and the first feed line 24 １ The second power supply terminal 12b is advanced by 90 degrees relative to the high frequency signal from ２ to the second power supply line 24 ２ The first 90-degree hybrid 27b is connected to the first power supply terminal 12b. １ to the first power supply line 24 １ and the second power supply terminal 12b ２ to the second power supply line 24 ２ The high frequency signals are combined and output to the 180-degree hybrid 27a.

[0101] The first feed line 24 is connected to the second 90-degree hybrid 27c.１ The third power supply terminal 12b is 180 degrees ahead of the high frequency signal from ３ to the third power supply line 24 ３ and the first feed line 24 １ The fourth power supply terminal 12b is advanced by 270 degrees relative to the high frequency signal from ４ to the fourth feeder line 24 ４ The second 90-degree hybrid 27c is connected to the third power supply terminal 12b. ３ to the third power supply line 24 ３ and the fourth power supply terminal 12b ４ to the fourth feeder line 24 ４ The high frequency signals are combined and output to the 180-degree hybrid 27a.

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

[0103] 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, electrically insulated from the first ground conductor 22. In this case, the electrical connection between the power supply unit 26 and the 180-degree hybrid 27a, the first 90-degree hybrid 27b and the second 90-degree hybrid 27c, and the first power supply line 24 are １ to the fourth feeder line 24 ４ Electrical connection between them can be achieved by forming through holes in the circuit board 2B for interlayer connection.

[0104] The antenna device according to the third embodiment has the same effects as the antenna device according to the second embodiment, and in addition, the antenna device according to the third embodiment has a plurality of pairs of antenna elements 12 １ ~12 ４ and the parasitic antenna element 13 １ ~13 ４ Therefore, it can accommodate both right-handed and left-handed circularly polarized waves.

[0105] Fourth Embodiment An antenna device according to a fourth embodiment will be described with reference to Fig. 16 and Fig. 17. The antenna device according to the third embodiment has an antenna element 12 １ ~12 ４ The feed element 12a in １ ~12a ４ and the parasitic antenna element 13 １ ~13 ４ Parasitic element 13a in １ ~13a ４ Each antenna is a monopole antenna.

[0106] In contrast, the antenna device according to the fourth embodiment has antenna element 12 １ ~12 ４ The feed element 12a in １ ~12a ４ and the parasitic antenna element 13 １ ~13 ４ Parasitic element 13a in １ ~13a ４ It differs from the antenna device according to the third embodiment in that it has an antenna pattern in which each element is bent in a spiral shape, but in other respects it is the same as the antenna device according to the third embodiment.

[0107] Therefore, the first antenna element 12 １ to the fourth antenna element 12 ４ The feed element 12a in １ ~12a ４ and the first parasitic antenna element 13 １ to the fourth parasitic antenna element 13 ４ Parasitic element 13a in １ ~13a ４ 16 and 17, the same reference numerals as those in FIGS. 11 to 15 designate the same or corresponding parts.

[0108] Four pairs of first antenna elements 12 １ to the fourth antenna element 12 ４ and the first parasitic antenna element 13 １ to the fourth parasitic antenna element 13 ４are formed in pairs at the four corners of the inner wall of the resin body 11, as shown in FIG. １ to the fourth antenna element 12 ４ and the first parasitic antenna element 13 １ to the fourth parasitic antenna element 13 ４ are formed on the inner wall surface of the resin body 11 with 90-degree rotational symmetry, as in the third embodiment.

[0109] Therefore, a pair of antenna elements 12 and a parasitic antenna element 13 will be described representatively using the developed view shown in Fig. 17. In the developed view of Fig. 17, line X-X indicates the upper edge of the inner surface of the side wall of the resin body 11, and line Y-Y indicates the side edge of the inner surface of the side wall of the resin body 11. That is, the upper side of line X-X in Fig. 17 is the inner surface of the bottom wall of the resin body 11, and the lower side in Fig. 17 is the inner surface of one side wall of the resin body 11. Line Y-Y indicates the side edges of two adjacent, continuous side walls of the resin body 11, and the left side of line Y-Y in Fig. 17 is the inner surface of one of the two side walls of the resin body 11, and the right side in Fig. 17 is the inner surface of the other of the two side walls of the resin body 11.

[0110] In order to simplify the explanation, the subscripts will be omitted. In FIG. 16, the first antenna element 12 １ and the first parasitic antenna element 13 １ The subscript 1 is used for the second antenna element 12 ２ and the second parasitic antenna element 13 ２ The subscript 2 is used for the third antenna element 12 ３ and the third parasitic antenna element 13 ３ The subscript 3 is used for the fourth antenna element 12 ４ and the fourth parasitic antenna element 13 ４ The subscript 4 is added to the

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

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

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

[0114] The third conductor surface 123 extends from the branch point BP1 in the other direction perpendicular to the first conductor surface 121, then extends in a rectangular shape bent in a spiral shape, and the other end is an open end. The third conductor 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 the one side wall of the resin body 11.

[0115] The total length from the feed terminal 12b of the feed element 12a to the open end of the second conductor surface 122 is ¼ of the wavelength corresponding to the resonant frequency f1. The ¼ wavelength length here refers to a length that includes an allowable range ±α for the ¼ wavelength for the resonant frequency.

[0116] The total length from the open end of the second conductor surface 122 to the open end of the third conductor surface 123 is ½ of the wavelength corresponding to the resonant frequency f1. The ½ wavelength length here refers to a length that includes an allowable range ±α1 for the ½ wavelength for the resonant frequency.

[0117] The parasitic antenna element 13 has a parasitic element 13a formed of an antenna pattern and a parasitic terminal 13b formed at one end of the parasitic element 13a. The parasitic element 13a has a first conductor surface 131, a second conductor surface 132, and a third conductor surface 133.

[0118] First conductor surface 131 extends from parasitic terminal 13b toward the inner surface of the bottom wall of resin body 11, parallel to the lateral edges of the inner surfaces of the side walls of resin body 11, and parallel to first conductor surface 121 of feed element 12a in a straight line toward the center of one side wall to branch point BP2. First conductor surface 131 is formed on the inner surface of one side wall and the inner surface of the bottom wall of resin body 11. The length of first conductor surface 131 is shorter than the length of first conductor surface 121 of feed element 12a.

[0119] The power supply 12a branches into a second conductor surface 132 and a third conductor surface 133 in opposite directions, perpendicular to the first conductor surface 131, at a branch point BP2. The second conductor surface 132 extends in one direction from the branch point BP2 perpendicular to the first conductor surface 131, parallel to the second conductor surface 122 of the power supply element 12a, and in an L-shape on one side wall of the inner surface of the bottom wall of the resin body 11, with the other end being an open end. The second conductor surface 132 is formed on the inner surface of the bottom wall of the resin body 11 from the branch point BP2 to the open end of the second conductor surface 132. The length of the second conductor surface 132 is shorter than the length of the second conductor surface 122 of the power supply element 12a.

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

[0121] The total length from parasitic terminal 13b of parasitic element 13a to the open end of second conductor surface 132 is a quarter wavelength of the wavelength corresponding to frequency f2 (≠ f1), which is different from the resonant frequency f1 of parasitic element 12a. In this example, f2 > f1. The length of the quarter wavelength corresponding to frequency f2 here refers to a length that includes an allowable range ±β for the quarter wavelength of frequency f2, which is the resonant frequency of parasitic element 13a.

[0122] The total length from the open end of second conductor surface 132 to the open end of third conductor surface 133 is ½ of the wavelength corresponding to resonant frequency f2. Here, the length of ½ of the wavelength corresponding to frequency f2 refers to a length that includes an allowable range ±β1 for ½ of the wavelength for frequency f2, which is the resonant frequency for parasitic element 13a.

[0123] In this way, the antenna element 12 １ ~12 ４ The feed element 12a in １ ~12a ４ and the parasitic antenna element 13 １ ~13 ４ Parasitic element 13a in １ ~13a ４ Since the antenna patterns (third conductor surface 123, third conductor surface 133) each bent in a spiral shape are added, the feed element 12a １ ~12a ４ In addition to the function as a monopole antenna for a frequency band including the resonant frequency f1 for the frequency band, the antenna also functions as a dipole antenna.

[0124] Paired first antenna element 12 １ to the fourth antenna element 12 ４ and the first parasitic antenna element 13 １ to the fourth parasitic antenna element 13 ４ The first antenna elements 12 are arranged in pairs at four corners of the resin body 11. １ to the fourth antenna element 12 ４ The feed element 12a in each １ ~12a ４ and the first parasitic antenna element 13 １ to the fourth parasitic antenna element 13 ４ The parasitic element 13a in each １ ~13a ４ The housing antenna 1B on which the above-mentioned is formed is produced by molding using an MID or 3D printer.

[0125] Feed element 12a １ ~12a ４and the parasitic element 13a １ ~13a ４ is formed in close contact with the inner wall surface of the resin body 11, １ ~12a ４ and the parasitic element 13a １ ~13a ４ There is no gap between the power supply element 12a and the inner wall surface of the resin body 11. １ ~12a ４ and the parasitic element 13a １ ~13a ４ The size of the feeding element 12a can be maximized relative to the resin body 11, and the performance as an antenna element can be improved. １ ~12a ４ and the parasitic element 13a １ ~13a ４ and the resin body 11 can be handled as an integrated unit as the housing antenna 1, and therefore assembly and handling are easy.

[0126] The circuit board 2B has a first power supply terminal through hole 2a, similar to the circuit board 2B in the antenna device according to the third embodiment. １ to the fourth power supply terminal through hole 2a ４ and the first parasitic terminal through hole 2b １ through the fourth parasitic terminal through hole 2b ４ , an insulating substrate 21, a first ground conductor 22, a second ground conductor 23, and a first power supply line 24. １ to the fourth feeder line 24 ４ The power supply unit 26 and the interface circuit 27 are also included.

[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 the third embodiment, and the first antenna element 12 １ to the fourth antenna element 12 ４ and the first parasitic antenna element 13 １ to the fourth parasitic antenna element 13 ４ Since the positions where the components are formed are slightly different from those in the antenna device according to the third embodiment, the positions where the components are formed and mounted on the circuit board 2B are only slightly different, and are essentially the same.

[0128] In short, in the antenna device according to the fourth embodiment, the first power supply terminal through hole 2a １ to the fourth power supply terminal through hole 2a ４ and the first parasitic terminal through hole 2b １ through the fourth parasitic terminal through hole 2b ４ , and the first feed line 24 １ to the fourth feeder line 24 ４ and the first feeding point 25 １ to the fourth feeding point 25 ４ are formed on the circuit board 2B with 90-degree rotational symmetry. Therefore, a description of the circuit board 2B will be omitted.

[0129] The antenna device according to the fourth embodiment includes an antenna element 12 １ ~12 ４ and the parasitic antenna element 13 １ ~13 ４ Each of them is a feed element 12a １ ~12a ４ The antenna functions as a monopole antenna for a frequency band including the resonant frequency f1 for the first feeding point 25 and also functions as a dipole antenna. １ to the fourth feeding point 25 ４ The current excited in each can be reduced, and the current flowing through the first ground conductor 22 and the second ground conductor 23 can be reduced while maintaining impedance matching.

[0130] As a result, it is possible to suppress the cross polarization component (LHCP) in the direction toward the rear of the antenna device, that is, in the direction from the inner surface toward the outer surface of the circuit board 2B. If the cross polarization component can be suppressed, the antenna device will not receive multipath waves incident from the rear of the antenna device, and therefore, when used as a receiving antenna, for example, the antenna device according to the fourth embodiment is effective for GNSS (Global Navigation Satellite System) applications.

[0131] The antenna device according to the fourth embodiment has the same effects as the antenna device according to the third embodiment, and also has the effect of adding the function of a dipole antenna to the function of a monopole antenna.

[0132] Fifth Embodiment An antenna device according to a fifth embodiment will be described with reference to Figures 18 and 19. The antenna device according to the fifth embodiment differs from the antenna device according to the fourth embodiment in that a shielding case 3 is added, but is otherwise the same as the antenna device according to the fourth embodiment. Therefore, the following description will focus on the shielding case 3. In Figures 18 and 19, the same reference numerals as those in Figures 16 and 17 indicate 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 the fourth embodiment. The difference is that the housing antenna 1B has drilled through holes 11c for screws at the four corners of the flange portion 11b of the resin body 11. １ ~11c ４ is formed.

[0134] The circuit board 2B is substantially the same as the circuit board 2B in the antenna device according to the fourth embodiment. The difference is that the circuit board 2B has screw through holes 2c, which are drilled holes, at the four corners of the insulating substrate 21, the first ground conductor 22, and the second ground conductor 23. １ ~2c ４ is formed.

[0135] The shield case 3 is attached to the outer surface of the circuit board 2B and shields the outer surface of the circuit board 2B, that is, it covers the interface circuit 27 that handles high frequency signals mounted on the outer surface of the circuit board 2B, shielding the interface circuit 27 from external noise and the like. The shield case 3 is made of metal and has a frame 31 and a bottom 32. The outer shape of the shield case 3 is rectangular. Screw holes 31c are provided at the four corners of the frame 31 of the shield case 3. １ ~31c ４ is formed

[0136] Corresponding screw through hole 11c １ ~11c ４ Respective center lines and screw through holes 2c １ ~2c ４ Respective center lines and screw holes 31c １ ~31c ４ The centerlines of each screw are aligned.１ ~4 ４ Each of them is connected to the screw through hole 11c １ ~11c ４ From the top of each screw through hole 11c １ ~11c ４ and screw through hole 2c １ ~2c ４ Each of them is penetrated, and a screw hole 31c １ ~31c ４ By fastening each of them with a screw, the housing antenna 1B is attached to the shield case 3 with the circuit board 2B sandwiched between them. １ ~4 ４ It may be plastic, but is preferably metal.

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

[0138] The housing antenna 1B, the circuit board 2B, and the shield case 3 are assembled as follows. １ ~12 ４ Power supply terminal 12b １ ~12b ４ The power supply terminal through hole 2a formed in the circuit board 2B １ ~2a ４ and the parasitic antenna element 13 １ ~13 ４ Unpowered terminal 13b in １ ~13b ４ The through-hole 2b for the non-power-supply terminal formed in the circuit board 2B １ ~2b ４ The housing antenna 1B and the circuit board 2B are positioned.

[0139] The mated power supply terminal 12b １ ~12b ４is soldered to the power supply line 24 １ ~24 ４ The non-powered terminal 13b is electrically connected to and fitted with the １ ~13b ４ is soldered to be electrically connected to second ground conductor 23. The outer conductor of a radio frequency (RF) coaxial cable inserted through a cable insertion hole (not shown) formed in frame 31 or bottom 32 of shielding case 3 is electrically connected to second ground conductor 23, and the core wire is electrically connected to power supply part 26.

[0140] In this state, screw 4 １ ~4 ４ through the screw hole 11c １ ~11c ４ and screw through hole 2c １ ~2c ４ and the screw hole 31c １ ~31c ４ By fastening the housing antenna 1B, the circuit board 2B and the shield case 3 together with screws, the assembly of the housing antenna 1B, the circuit board 2B and the shield case 3 is completed.

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

[0142] Furthermore, the antenna device according to embodiment 5 is easy to assemble the housing antenna 1B, the circuit board 2B, and the shielding case 3. Note that the shielding case 3 shown in embodiment 5 may be attached to the outer surface of the circuit board 2B of the antenna device according to embodiment 4.

[0143] It should be noted that the embodiments may be freely combined, any of the components of the embodiments may be modified, or any of the components of the embodiments may be omitted.

[0144] The antenna device of the present disclosure is suitable for use in communications, radar, positioning, or the like.

[0145] 1A Housing antenna, 11 Resin body, 11a Opening, 12, 12 １ ~12 ４ Antenna elements, 12a, 12a １ ~12a ４ Antenna pattern (feed element), 12b, 12b １ ~12b ４ Power supply terminal, 121 first conductor surface, 122 second conductor surface, 123 third conductor surface, 13, 13 １ ~13 ４ Parasitic antenna elements 13a, 13a １ ~13a ４ Parasitic elements, 13b, 13b １ ~13b ４ Non-powered terminal, 131 first conductor surface, 132 second conductor surface, 133 third conductor surface, 2 circuit board, 2a through hole, 2a １ ~2a ４ Power supply terminal through hole, 2b １ ~2b ４ Through hole for parasitic terminal, 21 insulator, 22 first ground conductor, 23 second ground conductor, 24, 24 １ ~24 ４ Power supply line, 25, 25 １ ~25 ４ Feed point, 26 feed section, 27 interface circuit, 27a 180-degree hybrid, 27b first 90-degree hybrid, 27c second 90-degree hybrid, 3 shielding case.

Claims

1. An antenna device comprising: a cylindrical resin body having an opening at one end and a bottom; a circuit board to which the resin body is attached with the opening of the resin body covered, the circuit board having a through hole that passes through from the inner surface to the outer surface and a feed line formed on the outer surface; a feed element consisting of an antenna pattern formed on the inner wall surface of the resin body; and a feed terminal formed at one end of the antenna pattern, passing through the through hole of the circuit board, and having one end electrically connected to the other end of the feed line formed on the outer surface of the circuit board.

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

3. The antenna device according to claim 1 or 2, wherein the resin body is made of a thermoplastic resin.

4. An antenna device according to any one of claims 1 to 3, wherein the resin body has a rectangular cross-sectional shape, and the feeding element has an antenna main part formed along the four sides of the inner surface of a bottom wall that constitutes the inner wall surface of the resin body, the other end of which is an open end, and an extension part formed on the inner surface of one side wall that constitutes the inner wall surface of the resin body, extending from the antenna main part toward the opening of the resin body to the feeding terminal.

5. An antenna device as claimed in any one of claims 1 to 4, wherein the feed element has: a first conductor surface extending linearly from the feed terminal to a branch point; a second conductor surface having the other end open and extending linearly from the branch point perpendicular to the first conductor surface; and a third conductor surface having the other end open and extending from the branch point in the opposite direction to the second conductor surface and having a spirally bent shape.

6. The antenna device according to claim 5, wherein the total length from the feed terminal of the feed element to the open end of the second conductor surface is 1 / 4 of the wavelength corresponding to the resonant frequency, and the total length from the open end of the second conductor surface to the open end of the third conductor surface is 1 / 2 of the wavelength corresponding to the resonant frequency.

7. An antenna device as claimed in any one of claims 1 to 6, wherein the circuit board has a second through-hole that penetrates from the inner surface to the outer surface, and comprises: a parasitic element formed on the inner wall surface of the resin body; and a parasitic terminal formed at one end of the parasitic element, which penetrates the second through-hole of the circuit board, and whose one end is electrically connected to a ground conductor formed on the outer surface of the circuit board.

8. An antenna device according to claim 7, wherein the total length from the unfed terminal of the unfed element to the open end of the unfed element is 1 / 4 wavelength of the wavelength corresponding to a frequency different from the resonant frequency for the fed element.

9. An antenna device as described in claim 7 or claim 8, wherein the parasitic element has: a first conductor surface extending linearly from the parasitic terminal to a branch point; a second conductor surface having the other end open and extending linearly from the branch point perpendicular to the first conductor surface; and a third conductor surface having the other end open and extending from the branch point in the opposite direction to the second conductor surface and having a spirally bent shape.

10. The antenna device according to claim 9, wherein, in the parasitic terminal, the total length from the parasitic terminal of the parasitic element to the open end of the second conductor surface is 1 / 4 wavelength of a wavelength corresponding to a frequency different from the resonant frequency for the feed element, and the total length from the open end of the second conductor surface to the open end of the third conductor surface is 1 / 2 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 feed elements each consisting of an antenna pattern formed on the inner wall surface of the resin body, a plurality of feed terminals each formed at one end of the plurality of feed elements, a plurality of parasitic elements each consisting of an antenna pattern formed on the inner wall surface of the resin body and paired with a plurality of feed elements, a plurality of parasitic terminals each formed at one end of the plurality of parasitic elements, a circuit board to which the resin body is attached with the opening of the resin body covered, the circuit board having a plurality of feed terminal through holes each passing from the inner surface to the outer surface and through which each of the plurality of feed terminals passes, a plurality of feed lines each passing through each of the plurality of feed terminals and being electrically connected to each of the plurality of feed terminals that pass through each of the plurality of feed terminal through holes, a plurality of parasitic terminal through holes each passing from the inner surface to the outer surface and through which each of the plurality of parasitic terminals passes, and ground conductors 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 antenna device according to claim 11, wherein the plurality of power supply terminals are four, i.e., first to fourth power supply terminals, and an interface circuit is mounted on the circuit board and is electrically connected to the first to fourth power supply terminals, to which the first to fourth power supply lines are connected, respectively, and is connected to the power supply section.

13. The antenna apparatus according to claim 12, wherein each of the plurality of feed elements has a first conductor surface extending linearly from a corresponding feed terminal to a branch point, a second conductor surface having an open end at the other end and extending linearly from the branch point perpendicular to the first conductor surface, and a third conductor surface having an open end at the other end, extending from the branch point in a direction opposite to the second conductor surface and having a spirally bent shape; and wherein each of the plurality of parasitic elements has a first conductor surface extending linearly from a corresponding parasitic terminal to a branch point, a second conductor surface having an open end at the other end and extending linearly from the branch point perpendicular to the first conductor surface, and a third conductor surface having an open end at the other end, extending from the branch point in a direction opposite to the second conductor surface and having a spirally bent shape.

14. The antenna device according to claim 13, wherein, in each of the plurality of feed elements, the total length from the feed terminal of the feed element to the open end of the second conductor surface is 1 / 4 of the wavelength corresponding to the resonant frequency, and the total length from the open end of the second conductor surface to the open end of the third conductor surface is 1 / 2 of the wavelength corresponding to the resonant frequency; and, in each of the plurality of parasitic elements, the total length from the parasitic terminal of the parasitic element to the open end of the second conductor surface is 1 / 4 of the wavelength corresponding to a frequency different from the resonant frequency for the feed element, and the total length from the open end of the second conductor surface to the open end of the third conductor surface is 1 / 2 of the wavelength corresponding to the frequency different from the resonant frequency for the feed element.

15. The antenna device according to any one of claims 12 to 14, wherein the interface circuit comprises: a 180-degree hybrid that receives as input 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 divided signals; a first 90-degree hybrid that receives as input a high-frequency signal from the 180-degree hybrid that has the same phase as the high-frequency signal input to the 180-degree hybrid, outputs a high-frequency signal that has the same phase as the input high-frequency signal to the first power supply terminal, and outputs a high-frequency signal that is 90 degrees phase-advanced relative to the input signal to the fourth power supply terminal; and a second 90-degree hybrid that receives as input a high-frequency signal that has a phase advancing 180 degrees relative to the high-frequency signal input from the 180-degree hybrid, outputs a high-frequency signal that is the same phase as the input high-frequency signal to the second power supply terminal, and outputs a high-frequency signal that is 90 degrees phase-advanced relative to the input signal to the third power supply terminal.

16. The antenna device according to any one of claims 12 to 14, wherein the interface circuit comprises: a first 90-degree hybrid that receives as input a high-frequency signal from the first feed terminal and a high-frequency signal from the fourth feed terminal that is 90 degrees ahead of the high-frequency signal from the first feed terminal, and combines and outputs the two high-frequency signals; a second 90-degree hybrid that receives as input a high-frequency signal from the second feed terminal that is 180 degrees ahead of the high-frequency signal from the first feed terminal, and a high-frequency signal from the third feed terminal that is 270 degrees ahead of the high-frequency signal from the first feed terminal, and combines and outputs the two high-frequency signals; and a 180-degree hybrid that receives as input a high-frequency signal from the first 90-degree hybrid and a high-frequency signal from the second 90-degree hybrid, and combines and outputs the two high-frequency signals to the feed section.

17. The antenna device according to any one of claims 12 to 16, further comprising a shield case attached to the outer surface of the circuit board and covering the interface circuit.

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