Antenna device

Abstract

An antenna device (101) is provided with: a ground conductor (12); a patch conductor (13) disposed so as to face the ground conductor (12); a monopole conductor (14) passing through a through-hole (15) of the patch conductor (13); a feeding point (21) capable of feeding power to the patch conductor (13); a feeding point (22) capable of feeding power to the monopole conductor (14); a distribution synthesizer (31) for distributing a supplied signal to the feeding point (21) and the feeding point (22); and a phase shifter (32) for controlling a phase difference between a first radio signal to the feeding point (21) distributed by the distribution synthesizer (31) and a second radio signal to the feeding point (22) distributed by the distribution synthesizer (31).

Description

Antenna device

[0001] The present disclosure relates to an antenna device.

[0002] Patent Document 1 discloses an antenna device capable of electrically switching the directivity of the antenna. The antenna device disclosed in Patent Document 1 includes a feed element disposed substantially perpendicular to a dielectric substrate and a plurality of parasitic elements disposed on the dielectric substrate. The antenna device disclosed in Patent Document 1 can switch the directivity of the antenna by changing the capacitance of a variable capacitance element loaded on the parasitic element.

[0003] Patent No. 4173453

[0004] The antenna device disclosed in Patent Document 1 switches the directivity of the antenna by changing the capacitance of the variable capacitance element. In doing so, the coupling between the feed element and the parasitic element changes, which changes the impedance at the feed point and increases the loss due to impedance mismatch.

[0005] The present disclosure has been made to solve the above-mentioned problems, and provides an antenna device that can electrically switch the antenna directivity without causing an increase in loss due to impedance mismatch that accompanies switching of antenna operation.

[0006] The antenna device according to the present disclosure includes a ground conductor, a patch conductor arranged to face the ground conductor, a monopole conductor passing through a through hole of the patch conductor, a first feed point capable of feeding power to the patch conductor, a second feed point capable of feeding power to the monopole conductor, a divider that divides a supplied signal to the first feed point and the second feed point, and a phase shifter that controls the phase difference between a first radio signal distributed by the divider to the first feed point and a second radio signal distributed by the divider to the second feed point.

[0007] According to the present disclosure, the directivity of an antenna can be electrically switched without increasing loss due to impedance mismatch that accompanies switching of the antenna operation.

[0008] 11 is a perspective view of the appearance of an antenna device according to a first embodiment. FIG. 12 is a cross-sectional view taken along the arrows II-II of FIG. 1 . FIG. 13 is a feed configuration included in the antenna device according to the first embodiment. FIG. 14 is a result of simulating the radiation characteristics of the antenna device according to the first embodiment, showing a radiation pattern in the XY plane for linear polarization. FIG. 15 is a cross-sectional view of the appearance of an antenna device according to a second embodiment, showing antenna coupling between a patch conductor viewed from a first feed point and a monopole conductor viewed from a second feed point, when a matching circuit is inserted between the second feed point and the corresponding feed line. FIG. 16 is a perspective view of the appearance of an antenna device according to a second embodiment. FIG. 17 is a cross-sectional view taken along the arrows VII-VII of FIG. 6 . FIG. 18 is a feed configuration included in the antenna device according to the second embodiment. FIG. 19 is a first specific example of a switch configuration. FIG. 20 is a second specific example of a switch configuration. FIG. 21 is a third specific example of a switch configuration. FIG. 19 is a perspective view of the appearance of an antenna device according to a third embodiment. FIG. 11 is a cross-sectional view taken along the arrows XII-XII of FIG. 11 . FIG. 22 is a result of simulating the radiation characteristics of the antenna device according to the third embodiment, showing a radiation pattern in the XY plane for linear polarization. FIG. 19 is a perspective view of the appearance of another antenna device according to the third embodiment. FIG. 23 is a feed configuration included in another antenna device according to the third embodiment. 1 is a plan view of an antenna device according to a fourth embodiment; FIG. 2 is a power supply configuration of the antenna device according to the fourth embodiment; FIG. 3 is a result of simulating the radiation characteristics of the antenna device according to the fourth embodiment, showing a radiation pattern of linearly polarized waves in the XY plane.

[0009] In order to explain the present disclosure in more detail, embodiments of the present disclosure will be described below with reference to the accompanying drawings.

[0010] First Embodiment An antenna device 101 according to a first embodiment will be described with reference to FIGS.

[0011] First, the configuration of the antenna device 101 according to the first embodiment will be described with reference to Fig. 1 to Fig. 3. Fig. 1 is an external perspective view of the antenna device 101 according to the first embodiment. Fig. 2 is a cross-sectional view taken along the line II-II in Fig. 1. Fig. 3 shows a power supply configuration provided in the antenna device 101 according to the first embodiment.

[0012] As shown in Fig. 1, the coordinate system of the antenna device 101 according to the first embodiment is a coordinate system with three orthogonal axes. The Z-axis direction is the thickness direction of the antenna device 101. The X-axis direction and the Y-axis direction are perpendicular to each other. The X-axis direction and the Y-axis direction form a horizontal plane perpendicular to the Z-axis direction. The rotation angle around the Z-axis in the XY plane is defined as φ, and the rotation angle around the Y-axis in the ZX plane is defined as θ.

[0013] As shown in FIGS. 1 and 2, the antenna device 101 according to the first embodiment includes, for example, an element section 10 and a feeding section 30.

[0014] The element section 10 includes a dielectric substrate 11 , a ground conductor 12 , a patch conductor 13 , and a monopole conductor 14 .

[0015] The dielectric substrate 11 is an insulating substrate made of a dielectric material such as ceramics or glass. The ground conductor 12 is a conductive plate provided on one surface of the dielectric substrate 11.

[0016] The patch conductor 13 is a square conductor plate provided on the other surface of the dielectric substrate 11. The other surface is the surface located opposite to the one surface in the thickness direction of the dielectric substrate 11. The one surface and the other surface are parallel to each other. Here, if the wavelength of the radio waves transmitted and received by the antenna device 101 is λ, then, for example, the electrical length of one side of the patch conductor 13 is λ / 2 or less. The patch conductor 13 also has a through hole 15. The through hole 15 is a hole that penetrates approximately the center of the patch conductor 13 in its thickness direction.

[0017] The monopole conductor 14 is a conductor having an electrical length of approximately λ / 4. The monopole conductor 14 is arranged so as to be approximately perpendicular to one surface and the other surface of the dielectric substrate 11. The axial direction of the monopole conductor 14 approximately coincides with the Z-axis direction. The monopole conductor 14 is arranged so as to protrude upward from one surface of the dielectric substrate 11. At this time, the monopole conductor 14 passes through the through hole 15 of the patch conductor 13. The monopole conductor 14 is not in contact with the through hole 15 and is not electrically short-circuited with the patch conductor 13. The monopole conductor 14 does not protrude from the other surface of the dielectric substrate 11.

[0018] The feed point 21 is a first feed point. The feed point 21 is a portion where power is fed to the patch conductor 13. The feed point 21 is provided between the lower end of the conductor 51a and the ground conductor 12. The conductor 51a is provided inside the dielectric substrate 11. The feed line 51b is provided from one surface side of the dielectric substrate 11 to the outside thereof. The feed point 21 is electrically connected to the patch conductor 13 via the conductor 51a. The feed point 21 is also electrically connected to the terminal 41 of the feed section 30 via the feed line 51b.

[0019] The feed point 22 is a second feed point. The feed point 22 is a portion where power is fed to the monopole conductor 14. The feed point 22 is provided between the lower end of the monopole conductor 14 and the ground conductor 12. The feed line 52b is provided on one surface of the dielectric substrate 11 to the outside thereof. The feed point 22 is electrically connected to the lower end of the monopole conductor 14. The feed point 22 is also electrically connected to the terminal 42 of the feed unit 30 via the feed line 52b.

[0020] As shown in FIG. 3, the power supply section 30 includes a divider / synthesizer 31, a phase shifter 32, and terminals 40, 41, and .

[0021] When the distributor / synthesizer 31 functions as a distributor, it distributes a radio signal input via the terminal 40 into two radio signals at a preset distribution ratio.

[0022] Specifically, the first radio signal after distribution is fed to the feed point 21 via the terminal 41 and the feed line 51b. Next, the first radio signal fed to the feed point 21 is fed to the patch conductor 13 via the conductor 51a. Then, the first radio signal fed to the patch conductor 13 is radiated from the patch conductor 13 as a radio wave.

[0023] On the other hand, the second radio signal after division is fed to the feed point 22 via the phase shifter 32, the terminal 42, and the feed line 52b. Next, the second radio signal fed to the feed point 22 is fed to the lower end of the monopole conductor 14. Then, the second radio signal fed to the lower end of the monopole conductor 14 is radiated as a radio wave from the monopole conductor 14.

[0024] The phase shifter 32 imparts a predetermined phase difference between the two radio signals respectively fed to the patch conductor 13 and the monopole conductor 14. In the antenna device 101 according to the first embodiment, the phase shifter 32 sets the phase difference between the two radio signals respectively fed to the patch conductor 13 and the monopole conductor 14 to 0 degrees or 180 degrees. That is, the phase shifter 32 can switch the phase difference between 0 degrees and 180 degrees. Note that although the phase shifter 32 is connected between the distributor / combiner 31 and the terminal 42, it may also be connected between the distributor / combiner 31 and the terminal 41.

[0025] Next, the operation of the antenna device 101 according to the first embodiment will be described with reference to FIGS.

[0026] Fig. 4 shows the radiation pattern of linearly polarized wave Eθ in the XY plane, which is a result of simulating the radiation characteristics of the antenna device 101 according to embodiment 1. The solid line shown in Fig. 4 indicates the linearly polarized wave Eθ when the phase difference between the two radio signals fed to the patch conductor 13 and the monopole conductor 14 is 0 degrees. The dashed line shown in Fig. 4 indicates the linearly polarized wave Eθ when the phase difference between the two radio signals fed to the patch conductor 13 and the monopole conductor 14 is 180 degrees.

[0027] 4, for the linearly polarized wave Eθ indicated by the solid line, the directional gain in the +X-axis direction (φ0 degrees) is greater than the directional gain in the −X-axis direction (φ180 degrees), the difference being approximately 24 dB. Therefore, by exciting the patch conductor 13 and the monopole conductor 14 in phase, the antenna device 101 according to the first embodiment can radiate a beam in the +X-axis direction, which is the desired direction, within the horizontal plane (within the XY plane), while suppressing radiation of the beam in the −X-axis direction, which is the opposite direction to the desired direction.

[0028] Furthermore, for linearly polarized wave Eθ indicated by the dashed line, the directional gain in the -X-axis direction (φ180 degrees) is larger than the directional gain in the +X-axis direction (φ0 degrees), the difference being approximately 50 dB. Therefore, the antenna device 101 according to the first embodiment can invert both the beam direction and the null direction by approximately 180 degrees with respect to the radiation pattern of linearly polarized wave Eθ indicated by the solid line. Therefore, the antenna directivity can be switched by electrically switching the excitation phase difference using the phase shifter 32.

[0029] Fig. 5 shows the inter-antenna coupling between the patch conductor 13 as viewed from the feed point 21 and the monopole conductor 14 as viewed from the feed point 22 when a matching circuit (not shown) is inserted between the feed point 22 and the feed line 52b. The vertical axis of Fig. 5 represents the magnitude of the inter-antenna coupling. The horizontal axis of Fig. 5 represents the normalized frequency obtained by normalizing the frequency f of the intended frequency band with the center frequency f0.

[0030] 5, the inter-antenna coupling is −20 dB or less when the normalized frequency is near 1, and it can be said that the antenna coupling between the patch conductor 13 and the monopole conductor 14 is small. The reason why the inter-antenna coupling is small in this way is that the monopole conductor 14 is placed near the center of the patch conductor 13, where the electric field generated between the patch conductor 13 and the ground conductor 12 is small. If the feeding section 30 is designed so that the input impedance of the patch conductor 13 is matched with the impedance of the feed line 51 b and so that the input impedance of the monopole conductor 14 is matched with the impedance of the feed line 52 b, the impedance matching can be maintained even when the phase shifter 32 switches the phase difference.

[0031] As described above, the antenna device 101 according to the first embodiment can electrically switch the antenna directivity without increasing loss due to impedance mismatch caused by switching the antenna operation. Furthermore, the antenna device 101 can switch the directivity of radio waves having linear polarization perpendicular to one surface and the other surface of the dielectric substrate 11 between two directions. Furthermore, the antenna device 101 has a patch conductor 13 formed in a rectangular shape with an electrical length of one side of λ / 2 or less, thereby achieving switching of the antenna directivity while achieving miniaturization. Furthermore, the antenna device 101 has the ground conductor 12 disposed on one surface of the dielectric substrate 11, which is the lower surface, so that the dielectric substrate 11 can be installed on or in close proximity to a metal housing.

[0032] Second Embodiment An antenna device 102 according to a second embodiment will be described with reference to Fig. 6 to Fig. 11. Note that components having the same functions as those described in the first embodiment above are denoted by the same reference numerals, and descriptions thereof will be omitted.

[0033] First, the configuration of the antenna device 102 according to the second embodiment will be described with reference to Fig. 6 to Fig. 8. Fig. 6 is an external perspective view of the antenna device 102 according to the second embodiment. Fig. 7 is a cross-sectional view taken along the line VII-VII in Fig. 6. Fig. 8 shows the power supply configuration of the antenna device 102 according to the second embodiment.

[0034] The antenna device 101 according to embodiment 1 shown in Figures 1 and 2 has one feed point 21 connected to the patch conductor 13, whereas the antenna device 102 according to embodiment 2 shown in Figures 6 and 7 has two feed points 21, 23 connected to the patch conductor 13.

[0035] 6 and 7 , the feed point 23 is a first feed point. The feed point 23 is a portion where power is fed to the patch conductor 13. The feed point 23 is provided between the lower end of the conductor 53a and the ground conductor 12. The conductor 53a is provided inside the dielectric substrate 11. The feed line 53b is provided from one surface side of the dielectric substrate 11 to the outside thereof. The feed point 23 is electrically connected to the patch conductor 13 via the conductor 53a. The feed point 23 is also electrically connected to the terminal 43 of the feed section 30 via the feed line 53b.

[0036] Here, the connection point of the patch conductor 13 with the conductor 51a and the connection point of the patch conductor 13 with the conductor 53a are located at positions separated by a rotation angle of 180 degrees from each other around the axis C of the patch conductor 13. This axis C extends in the Z-axis direction and coincides with the central axis of the monopole conductor 14, for example.

[0037] As shown in FIG. 8, the power supply unit 30 includes a distributor / synthesizer 31, a switch 33, and terminals 40, 41, 42, and 43.

[0038] One end of the distributor / synthesizer 31 is connected to the terminal 40, while the other end of the distributor / synthesizer 31 is connected to the switch 33 and the terminal 42. When the distributor / synthesizer 31 functions as a distributor, it distributes a radio signal input via the terminal 40 into two radio signals at a preset distribution ratio.

[0039] The switch 33 is a feed point selection unit. The switch 33 is connected between the other end of the distributor / synthesizer 31 and terminals 41 and 43. The switch 33 can be electrically connected to either terminal 41 or terminal 43 by its switch function. In this case, the transmission line connecting the switch 33 to the feed point 21 via terminal 41 and the transmission line connecting the switch 33 to the feed point 23 via terminal 43 have the same electrical length. Therefore, the switch 33 supplies the first wireless signal distributed from the distributor / synthesizer 31 to the electrically connected terminal 41 or terminal 43 in the same phase.

[0040] Next, a specific example of the configuration of the switch 33 will be described with reference to FIGS.

[0041] 9 shows a first specific configuration example of the switch 33 for matching the input impedance of the patch conductor 13 with the input impedance of the transmission line extending from the connection point between the patch conductor 13 and the conductor 51 a or the conductor 53 a to the terminal 41 or the terminal 43. The switch 33 shown in FIG. 9 includes, for example, a DPDT switch 34 and a resistor 35.

[0042] The DPDT switch 34 has terminals 34a, 34b, 34c, 34d, 34e, and 34f. The DPDT switch 34 can select one of two states: a state in which the terminals 34a and 34c are electrically connected to the terminals 34b and 34e, and a state in which the terminals 34a and 34d are electrically connected to the terminals 34b and 34f. In other words, the DPDT switch 34 can switch the electrical connection state between these two states. The terminals 34c and 34f are always electrically connected to the terminal 41. The terminals 34d and 34e are always electrically connected to the terminal 43.

[0043] One end of resistor 35 is connected to terminal 34b. The other end of resistor 35 is connected to ground point 35a. Resistor 35 is designed to have a resistance value that results in a reflectionless termination when resistor 35 is connected to either feed point 21 or feed point 23. Therefore, resistor 35 can satisfy impedance matching for terminal 41 or 43, whichever is not electrically connected to terminal 31a of distributor / combiner 31, of terminal 41 or 43.

[0044] 10 shows a second specific configuration example of the switch 33 for matching the input impedance of the patch conductor 13 with the input impedance of the transmission line extending from the connection point between the patch conductor 13 and the conductor 51 a or the conductor 53 a to the terminal 41 or the terminal 43. The switch 33 shown in FIG. 10 includes, for example, a DPDT switch 34 and a transmission line 80.

[0045] The length of the transmission line 80 is designed so that the electrical length from the connection point between the patch conductor 13 and the conductor 51a or the conductor 53a to the ground point 35a is λ / 4. Therefore, in the antenna device 102 according to the second embodiment, the conductor 51a or the conductor 53a that is not electrically connected via the terminal 31a and the DPDT switch 34 can be regarded as an open end when viewed from the patch conductor 13. As a result, the radio signal supplied from the conductor 51a or the conductor 53a is totally reflected at the connection point between the conductor 51a or the conductor 53a and the patch conductor 13.

[0046] 11 shows a third specific configuration example of the switch 33 for matching the input impedance of the patch conductor 13 with the input impedance of the transmission line extending from the connection point between the patch conductor 13 and the conductor 51 a or the conductor 53 a to the terminal 41 or the terminal 43. The switch 33 shown in FIG. 11 includes, for example, an SPST switch 36, a transmission line 37, and a transmission line 38.

[0047] The SPST switch 36 has terminals 36 a, 36 b, and 36 c. The SPST switch 36 can select either a state in which the terminals 36 a and 36 b are electrically connected, or a state in which the terminals 36 a and 36 c are electrically connected. In other words, the SPST switch 36 can switch the electrical connection state between the two states.

[0048] The transmission line 37 is connected between the terminal 36c and the terminal 41. The transmission line 38 is connected between the terminal 36b and the terminal 43. The length of the transmission line 37 is designed so that the electrical length from the terminal 36c to the connection point where the conductor 51a is connected to the patch conductor 13 is λ / 2. The transmission line 38 is designed so that the electrical length from the terminal 36b to the connection point where the conductor 53a is connected to the patch conductor 13 is λ / 2.

[0049] Therefore, in the antenna device 102 according to the second embodiment, the conductor 51a or the conductor 53a that is not electrically connected via the terminal 31a and the SPST switch 36 can be regarded as an open end when viewed from the patch conductor 13. As a result, the radio signal supplied from the conductor 51a or the conductor 53a is totally reflected at the connection point between the conductor 51a or the conductor 53a and the patch conductor 13.

[0050] Therefore, the electrical length of the transmission line connecting the switch 33 to the feed point 21 via the terminal 41 is equal to that of the transmission line connecting the switch 33 to the feed point 23 via the terminal 43. The phases of the radio signal fed to the patch conductor 13 via the feed point 21 and the radio signal fed to the patch conductor 13 via the feed point 23 are equal to each other. Furthermore, the feed points 21 and 23 are located at positions separated by a rotation angle of 180 degrees with the axis C of the patch conductor 13 as the center of rotation, and therefore the radiation patterns when power is fed to each of them are reversed by 180 degrees.

[0051] As described above, the antenna device 102 according to the first embodiment can electrically switch the antenna directivity without increasing the loss due to impedance mismatch that accompanies switching of the antenna operation. Furthermore, the antenna device 102 can switch the directivity of radio waves having linear polarization perpendicular to one surface and the other surface of the dielectric substrate 11 between two directions.

[0052] Third Embodiment Antenna devices 103 and 103A according to a third embodiment will be described with reference to Fig. 12 to Fig. 16. Note that components having the same functions as those described in the first and second embodiments are given the same reference numerals, and descriptions thereof will be omitted.

[0053] First, the configuration of the antenna device 103 according to the third embodiment will be described with reference to Fig. 12 and Fig. 13. Fig. 12 is a perspective view of the appearance of the antenna device 103 according to the third embodiment. Fig. 13 is a cross-sectional view taken along the line XIII-XIII in Fig. 12.

[0054] In the antenna device 102 according to the second embodiment shown in FIG. 6, the two feed points 21 and 23 are arranged at positions that are 180 degrees apart in rotational angle with the axis C of the patch conductor 13 as the center of rotation, whereas in the antenna device 103 according to the third embodiment shown in FIG. 12, the two feed points 21 and 24 are arranged at positions that are 90 degrees apart in rotational angle with the axis C of the patch conductor 13 as the center of rotation.

[0055] 12 and 13 , the feed point 24 is a first feed point. The feed point 24 is a portion where power is fed to the patch conductor 13. The feed point 24 is provided between the lower end of the conductor 54a and the ground conductor 12. The conductor 54a is provided inside the dielectric substrate 11. The feed line 54b is provided from one surface side of the dielectric substrate 11 to the outside thereof. The feed point 24 is electrically connected to the patch conductor 13 via the conductor 54a. The feed point 24 is also electrically connected to the terminal 44 of the feed section 30 via the feed line 54b.

[0056] Here, the connection point of the patch conductor 13 with the conductor 51a and the connection point of the patch conductor 13 with the conductor 54a are positioned at positions that are 90 degrees apart in rotation with the axis C of the patch conductor 13 as the center of rotation.

[0057] The terminal 44 is provided in place of the terminal 43 of the switch 33 shown in FIG.

[0058] Fig. 14 shows the radiation pattern of linearly polarized wave Eθ in the XY plane, which is a result of simulating the radiation characteristics of the antenna device 103 according to embodiment 3. The solid line in Fig. 14 indicates the linearly polarized wave Eθ when the phase difference between the two radio signals fed to the patch conductor 13 and the monopole conductor 14 is 0 degree. The dashed line in Fig. 14 indicates the linearly polarized wave Eθ when the phase difference between the two radio signals fed to the patch conductor 13 and the monopole conductor 14 is 180 degrees.

[0059] 14, for the linearly polarized wave Eθ indicated by the solid line, the directional gain in the +Y-axis direction (φ90 degrees) is larger than the directional gain in the −Y-axis direction (φ−90 degrees), the difference being approximately 25 dB. Therefore, by exciting the patch conductor 13 and the monopole conductor 14 in phase, the antenna device 103 according to the third embodiment can radiate a beam in the +Y-axis direction, which is the desired direction, within the horizontal plane (within the XY plane), while suppressing radiation of the beam in the −Y-axis direction, which is the opposite direction to the desired direction.

[0060] Furthermore, for linearly polarized wave Eθ indicated by the dashed line, the directional gain in the -Y-axis direction (φ-90 degrees) is larger than the directional gain in the +Y-axis direction (φ90 degrees), the difference being approximately 60 dB. Therefore, antenna device 101 according to embodiment 3 can invert both the beam direction and null direction by approximately 180 degrees with respect to the radiation pattern of linearly polarized wave Eθ indicated by the solid line. Therefore, the antenna directivity can be switched by electrically switching the excitation phase difference using switch 33.

[0061] Therefore, when the switch 33 is connected to the terminal 44 and power is fed to the patch conductor 13 via the feed point 24, the antenna device 103 according to the third embodiment can radiate beams in the ±Y-axis directions. When the switch 33 is connected to the terminal 41 and power is fed to the patch conductor 13 via the feed point 21, the antenna device 103 according to the third embodiment can radiate beams in the ±X-axis directions.

[0062] As described above, the antenna device 103 according to the third embodiment can switch the directivity of radio waves having linear polarization perpendicular to one surface and the other surface of the dielectric substrate 11 between four directions.

[0063] In the antenna device 103 according to the third embodiment described above, the two feed points 21 and 24 are arranged at positions that are 90 degrees apart in rotational angle with the axis C of the patch conductor 13 as the center of rotation, but the four first feed points may also be arranged at positions that are 90 degrees apart in rotational angle with the axis C of the patch conductor 13 as the center of rotation.

[0064] Fig. 15 is a perspective view of the appearance of another antenna device 103A according to embodiment 3. Fig. 16 shows a power supply configuration provided in another antenna device 103A according to embodiment 3.

[0065] As shown in FIG. 15 , in another antenna device 103A according to the third embodiment, the conductors 51 a, 53 a, 54 a, and 55 a connected to four first feed points are arranged at positions spaced apart by a rotation angle of 90 degrees with the axis C of the patch conductor 13 as the center of rotation.

[0066] 16 , the switch 33 can be electrically connected to one of the terminal 41 corresponding to the conductor 51 a, the terminal 43 corresponding to the conductor 53 a, the terminal 44 corresponding to the conductor 54 a, and the terminal 45 corresponding to the conductor 55 a. Therefore, the first radio signal distributed by the distributor / synthesizer 31 is supplied to one of the four feed points.

[0067] The element section 10 has the same structure at 90-degree rotation angle intervals with the axis C of the patch conductor 13 as the center of rotation. When the switch 33 is used to switch between four feed points connected to the patch conductor 13, a radiation pattern that is point-symmetric with respect to the axis C is obtained for each of the four identical structures.

[0068] As described above, the antenna device 103A according to the third embodiment can switch the directivity of radio waves having linear polarization perpendicular to one surface and the other surface of the dielectric substrate 11 between four directions.

[0069] Fourth Embodiment An antenna device 104 according to a fourth embodiment will be described with reference to Figures 17 to 19. Note that components having the same functions as those described in the first to third embodiments above will be assigned the same reference numerals, and descriptions thereof will be omitted.

[0070] Fig. 17 is a plan view of the antenna device 104 according to the fourth embodiment. Fig. 18 shows a power supply configuration provided in the antenna device 104 according to the fourth embodiment.

[0071] The antenna device 103 according to the third embodiment shown in FIG. 12 is capable of switching the directivity of radio waves having linear polarization perpendicular to one surface and the other surface of the dielectric substrate 11, whereas the antenna device 104 according to the fourth embodiment shown in FIG. 17 is capable of switching the directivity of radio waves having linear polarization parallel to one surface and the other surface of the dielectric substrate 11.

[0072] The antenna device 104 according to the fourth embodiment includes a plurality of linear conductive elements 60 to 67 and a plurality of switch elements 70 to 77 .

[0073] The linear conductive elements 60 to 67 are arranged so as to surround the periphery of the patch conductor 13. The linear conductive elements 60 to 63 are formed in a straight line, and the linear conductive elements 64 to 67 are formed in an L-shape. The linear conductive elements 60 to 67 are arranged on the same plane (for example, on the XY plane) so that they form a square ring as a whole. The switch elements 70 to 77 are arranged between adjacent linear conductive elements 60 to 67, and open and close the electrical connection between the adjacent linear conductive elements 60 to 67.

[0074] 18, the power supply unit 30 includes a distributor / synthesizer 31 and switches 33 and 39. The switch 39 is connected between the other end of the distributor / synthesizer 31 and a terminal 42, and switches the electrical connection therebetween.

[0075] When power is not supplied to the monopole conductor 14, the terminal of the switch 39 connected to the other end of the divider / synthesizer 31 is terminated by an impedance-matching resistor, as in Fig. 9. Also, as in Fig. 10, the electrical length of the transmission line between the switch 39 and the divider / synthesizer 31 may be λ / 2. In this case, in the antenna apparatus 104 according to the fourth embodiment, the switch 39 becomes an open end when viewed from the connection point between the switch 39 and the divider / synthesizer 31, and the signal from the divider / synthesizer 31 is totally reflected.

[0076] Next, the operation of the antenna device 104 according to the fourth embodiment will be described with reference to FIG.

[0077] When radio waves having linear polarization parallel to one surface or the other surface of the dielectric substrate 11 resonate the patch conductor 13 via the feed point 24, the antenna device 104 according to the fourth embodiment radiates a beam strongly in the ±X-axis directions. Also, when radio waves having linear polarization parallel to one surface or the other surface of the dielectric substrate 11 resonate the patch conductor 13 via the feed point 21, the antenna device 104 according to the fourth embodiment radiates a beam strongly in the ±Y-axis directions. Such radio wave directivity is controlled in accordance with the operating principle of the Yagi-Uda antenna.

[0078] For example, the electrical length of the linear conductive elements 60 to 63 can be designed to be shorter than λ / 2. Therefore, when the linear conductive elements 60 to 63 are opened together with the switch elements 70 to 77 connected to both ends of the linear conductive elements 60 to 63, they function as directors with respect to the patch conductor 13. Furthermore, the antenna device 104 according to the fourth embodiment can be designed so that the electrical length of the multiple linear conductive elements 60 to 67 connected in series is longer than λ / 2 by closing the switch elements 70 to 77. Therefore, the multiple linear conductive elements 60 to 67 connected in series function as reflectors with respect to the patch conductor 13.

[0079] Therefore, the antenna device 104 according to the fourth embodiment can determine whether the linear conductive elements 60 to 67 operate as directors or reflectors by opening or closing the switch 39. Therefore, the antenna device 104 according to the fourth embodiment can control the directivity of radio waves having linear polarization parallel to one surface or the other surface of the dielectric substrate 11 by the operating principle of the Yagi-Uda antenna.

[0080] 19 shows the radiation pattern of linearly polarized wave Eφ in the XY plane, which is a result of simulating the radiation characteristics of antenna device 104 according to embodiment 4. Fig. 19 shows the case where power is fed to patch conductor 13 via feed point 24, switch elements 70 and 71 are open, and the other switch elements 72 to 77 are closed.

[0081] 19, for linearly polarized wave Eφ, the directional gain in the +X-axis direction (φ0 degrees) is greater than the directional gain in the −X-axis direction (φ180 degrees), the difference being approximately 22 dB. Therefore, the antenna device 104 according to the fourth embodiment operates the linear conductor element 60 as a director and the other linear conductor elements 61 to 67 as reflectors, thereby being able to radiate a beam in the +X-axis direction, which is the desired direction, within the horizontal plane (within the XY plane), while suppressing radiation of the beam in the −X-axis direction, which is the opposite direction to the desired direction.

[0082] Furthermore, when power is fed to the patch conductor 13 via the feed point 24, the switch elements 74 and 75 are opened, and the other switch elements 70 to 73 to 76 and 77 are closed, the linear conductive element 62 operates as a director, and the other linear conductive elements 60, 61, 63 to 67 operate as reflectors. Therefore, the antenna device 104 according to the fourth embodiment can radiate a beam in the desired direction, the −X-axis direction, within the horizontal plane (within the XY plane).

[0083] Furthermore, by feeding the patch conductor 13 via the feeding point 21 and making either one of the linear conductor elements 61, 63 operate as a director, the antenna device 104 according to embodiment 4 can radiate a beam in the desired direction, that is, the ±Y axis direction, within the horizontal plane (within the XY plane).

[0084] As described above, the antenna device 104 according to the fourth embodiment can switch the directivity of radio waves having linear polarization parallel to one surface and the other surface of the dielectric substrate 11 between four directions.

[0085] However, in the above-described first to fourth embodiments, the shape of the patch conductor 13 is not limited to a square, and may be a rectangle, a circle, or the like. Also, a notch may be formed in the patch conductor 13, or a short-circuit plate may be disposed at the tip of the patch conductor 13. This allows the patch conductor 13 to be miniaturized. The monopole conductor 14 may be an antenna of another shape, such as a capacity-loaded monopole antenna or a helical antenna. This allows the monopole conductor 14 to be low-profile.

[0086] Furthermore, although the ground conductor 12 is disposed on one surface of the dielectric substrate 11 and the patch conductor 13 is disposed on the other surface, the ground conductor 12 and the patch conductor 13 may be disposed on different dielectric substrates. The ground conductor 12 and the patch conductor 13 may be formed of sheet metal or the like instead of being formed as a copper foil pattern on the dielectric substrate 11. The linear conductive elements 60 to 67 may be disposed on a different plane from the patch conductor 13.

[0087] It should be noted that within the scope of the present disclosure, the embodiments may be freely combined, or any component in each embodiment may be modified, or any component in each embodiment may be omitted.

[0088] The antenna device according to the present disclosure can electrically switch the antenna directionality by controlling the phase difference between the radio signals to each feed point without increasing the loss due to impedance mismatch that accompanies switching the antenna operation, and is therefore suitable for use in antenna devices, etc.

[0089] 101, 102, 103, 103A, 104 Antenna device, 10 Element section, 11 Dielectric substrate, 12 Ground conductor, 13 Patch conductor, 14 Monopole conductor, 15 Through hole, 21, 22, 23, 24 Feeding point, 30 Feeding section, 31 Divider / combiner, 31a Terminal, 32 Phase shifter, 33 Switch, 34 DPDT switch, 34a to 34f Terminal, 35 Resistor, 35a Grounding point, 36 STSP switch, 36a to 36c Terminal, 37, 38 Transmission line, 39 Switch, 40 to 45 Terminal, 51a, 53a, 54a, 55a Conductor, 51b, 52b, 53b, 54b Feeding line, 60 to 67 Linear conductor element, 70 to 77 Switch element, 80 Transmission line, C axis.

Claims

1. Ground conductor and, A patch conductor is arranged opposite the ground conductor, A monopole conductor passing through the through-hole of the patch conductor, A first power supply point capable of supplying power to the patch conductor, A second power supply point capable of supplying power to the aforementioned monopole conductor, A distributor that distributes the supplied signal to the first power supply point and the second power supply point, A phase shifter that controls the phase difference between the first radio signal distributed to the first power supply point by the distributor and the second radio signal distributed to the second power supply point by the distributor, and a plurality of switch elements that open and close electrical connections, The patch conductor is surrounded by a plurality of linear conductor elements connected in series via the switch element. An antenna device characterized by the following features.

2. Multiple first power supply points are provided, The system includes a power supply point selection unit that supplies the first wireless signal to a first power supply point selected from among a plurality of first power supply points. The antenna device according to claim 1, characterized in that it is a feature of the present invention.

3. The plurality of first power supply points are provided around the axis of the monopole conductor. The antenna device according to claim 2, characterized by the features described above.

4. The dielectric substrate comprises one surface on which the ground conductor is provided and the other surface on which the patch conductor is provided. The antenna device according to any one of claims 1 to 3.