JP5987740B2 - Phase shift circuit and antenna device - Google Patents

Description

  The present invention relates to a phase shift circuit, and more particularly to a phase shift circuit suitable for application to a base station antenna as an example of an antenna device.

  An example of a conventional phase shift circuit used for a base station antenna is described in Patent Document 1 and Patent Document 2.

  The phase shift circuit described in Patent Document 1 includes a signal line, a ground conductor provided opposite to the signal line, and a vertical line to the longitudinal direction of the signal line between the signal line and the ground conductor. And a dielectric plate inserted from the direction. In the phase shift circuit described in Patent Document 1, the overlapping area between the dielectric plate and the signal line changes according to the insertion length of the dielectric plate, thereby controlling the phase of the signal output from the signal line. Is done.

  Patent Document 2 describes a phase shift circuit having substantially the same configuration as the phase shift circuit described in Patent Document 1. However, in the phase shift circuit described in Patent Document 2, the characteristic impedance of the signal line is changed by inserting the dielectric plate. In other words, the phase shift circuit described in Patent Document 2 also incorporates a circuit for matching impedance.

Japanese Patent No. 4745213 US Pat. No. 5,943,030

  In the phase shift circuits described in Patent Documents 1 and 2, a dielectric plate is inserted from a direction perpendicular to the longitudinal direction of the signal line. In such a configuration, the dielectric plate itself needs to have a dimension for matching the characteristic impedance, and the length of the dielectric plate in the extending direction of the signal line becomes long. For this reason, the size of the dielectric plate is increased, and the size of the phase shift circuit is increased. As a result, the size of the base station antenna tends to increase.

  When the size of the base station antenna increases, the following problems occur. For example, the wind pressure load received by the base station antenna increases. Moreover, since the steel tower on which the antenna for the base station is installed is enlarged, the site for installing the steel tower becomes wide and it is difficult to secure the site.

  An object of the present invention is to reduce the size of the phase shift circuit as much as possible.

The present invention was devised to achieve the above object, and according to one embodiment, is a phase shift circuit that changes the phase of a signal, and is a first dielectric and a second dielectric that face each other. And the first moving member and the second moving member facing each other, between the first dielectric and the second dielectric, and between the first moving member and the second moving member. A first conductor, wherein the first dielectric is disposed to face the first main surface of the first conductor, and the second dielectric is the first conductor of the first conductor. The first moving member is arranged to face the first side surface of the first conductor, and the second moving member is arranged to face the second main surface opposite to the main surface. are disposed to face the second side surface opposite to the first side surface of said first conductor, said first dielectric and before The second dielectric is configured to move in a direction crossing the extending Mashimashi direction of the first conductor, the first moving member and the second moving member are the same as the direction extending in the first conductor The second dielectric member moves in the same direction as the first dielectric member as the first dielectric member moves, and the second moving member moves to the first moving member. Moves in the same direction as the first moving member .

  The present invention can reduce the size of the phase shift circuit as much as possible.

It is the schematic which shows an example of a structure of the antenna for base stations which concerns on one embodiment of this invention. It is a perspective view which shows an example of the structure of the phase shift circuit applied to the antenna for base stations of FIG. It is a top view which shows an example of the structure of the phase shift circuit applied to the antenna for base stations of FIG. 4A and 4B are cross-sectional views taken along the line x-x ′ and the line y-y ′ in FIG. 3. FIGS. 2A to 4C are explanatory views showing an example of movement between the first and second dielectric plates and the first and second movable lines in the simulation based on the structure of the phase shift circuit of FIGS. It is. In the simulation result of FIG. 5, it is explanatory drawing which shows an example (1st example of conditions) of the relationship between a frequency and VSWR. In the simulation result of FIG. 5, it is explanatory drawing which shows an example (1st condition example) of the relationship between a frequency and a phase. In the simulation result of FIG. 5, it is explanatory drawing which shows an example (2nd condition example) of the relationship between a frequency and VSWR. In the simulation result of FIG. 5, it is explanatory drawing which shows an example (2nd condition example) of the relationship between a frequency and a phase.

  In the following embodiments, when it is necessary for the sake of convenience, the description will be divided into a plurality of embodiments or sections. However, unless otherwise specified, they are not irrelevant and one is the other. There are some or all of the modifications, details, supplementary explanations, and the like. Further, in the following embodiments, when referring to the number of elements (including the number, numerical value, quantity, range, etc.), especially when clearly indicated and when clearly limited to a specific number in principle, etc. Except, it is not limited to the specific number, and may be more or less than the specific number.

  Further, in the following embodiments, the constituent elements (including element steps and the like) are not necessarily indispensable unless otherwise specified and apparently essential in principle. Needless to say. Similarly, in the following embodiments, when referring to the shapes, positional relationships, etc. of the components, etc., the shapes are substantially the same unless otherwise specified, or otherwise apparent in principle. And the like are included. The same applies to the above numerical values and ranges.

[Outline of the embodiment]
First, an outline of the embodiment will be described. In the outline of the present embodiment, as an example, the corresponding components and reference numerals of the embodiment will be added and described.

  The phase shift circuit according to the present embodiment changes the phase of the input signal. The phase shift circuit according to the present embodiment includes a signal line 11 as a first conductor, a first dielectric plate 12 and a second dielectric plate 13 as a first dielectric and a second dielectric, and a first movement. It has the 1st movable track | line 14 and the 2nd movable track | line 15 as a member and a 2nd moving member.

  The first dielectric plate 12 and the second dielectric plate 13 are opposed to each other, and the signal line 11 is disposed between the first dielectric plate 12 and the second dielectric plate 13. Here, the signal line 11 in the present embodiment has a rectangular cross section. That is, the signal line 11 has two main surfaces. Therefore, one of the first dielectric plate 12 and the second dielectric plate 13 facing each other across the signal line 11 faces one main surface of the signal line 11, and the first dielectric plate 12 and the second dielectric plate The other side of the plate 13 faces the other main surface of the signal line 11. Therefore, in the following description, of the two main surfaces of the signal line 11, the main surface that the first dielectric plate 12 faces is called “first main surface”, and the main surface that the second dielectric plate 13 faces. Is called the “second main surface”. In other words, the dielectric plate facing the first main surface of the signal line 11 is the first dielectric plate 12, and the dielectric plate facing the second main surface of the signal line 11 is the second dielectric plate 13. is there.

  The first movable line 14 and the second movable line 15 face each other, and the signal line 11 is disposed between the first movable line 14 and the second movable line 15. As described above, since the signal line 11 in the present embodiment has a rectangular cross section, the signal line 11 includes two side surfaces. Therefore, one of the first movable line 14 and the second movable line 15 facing each other across the signal line 11 faces one side surface of the signal line 11, and the other of the first movable line 14 and the second movable line 15 is , Opposite to the other side surface of the signal line 11. Therefore, in the following description, of the two side surfaces of the signal line 11, the side surface to which the first movable line 14 faces is referred to as the “first side surface”, and the side surface to which the second movable line 15 faces is the “second side surface”. Call it. In other words, the movable line facing the first side surface of the signal line 11 is the first movable line 14, and the movable line facing the second side surface of the signal line 11 is the second movable line 15.

  The first dielectric plate 12 and the second dielectric plate 13 are movable in a direction intersecting with the extending direction of the signal line 11, and the first movable line 14 and the second movable line 15 are The signal line 11 can move in the same direction as the extending direction. In the movement of the first dielectric plate 12 and the second dielectric plate 13 and the first movable line 14 and the second movable line 15, the signal lines 11 of the first dielectric plate 12 and the second dielectric plate 13 The movement in the direction intersecting the extending direction and the movement of the first movable line 14 and the second movable line 15 in the same direction as the extending direction of the signal line 11 are synchronized.

  The phase shift circuit according to the present embodiment is a phase shift circuit suitable for application to a base station antenna as an example of an antenna device.

  The details of the embodiment will be described below with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.

[One Embodiment]
One embodiment will be described with reference to FIGS. In the present embodiment, a base station antenna and a phase shift circuit applied to this base station antenna will be described as an example.

<Configuration of base station antenna>
First, the configuration of the base station antenna according to the present embodiment will be described using FIG. FIG. 1 is a schematic diagram showing an example of the configuration of this base station antenna.

  As shown in FIG. 1, the base station antenna includes an input terminal (not shown) to which a high frequency signal output from a high frequency circuit (not shown) and the like, and a plurality of phase shift circuits 1a to 1f (collectively “ And a plurality of antenna elements 2a to 2h (also collectively referred to as “antenna element 2”). FIG. 1 shows six phase shift circuits 1 and eight antenna elements 2 as an example, but the number of phase shift circuits 1 and antenna elements 2 is limited to the number shown. is not.

  The input terminals of the second phase shift circuit 1b and the third phase shift circuit 1c are connected to the input terminals of the base station antenna shown in FIG. That is, the second phase shift circuit 1b and the third phase shift circuit 1c are connected in parallel to the input terminal. Furthermore, the input side of the first phase shift circuit 1a and the fifth phase shift circuit 1e is connected in parallel to the output side of the second phase shift circuit 1b. The input side of the fourth phase shift circuit 1d and the sixth phase shift circuit 1f is connected in parallel to the output side of the third phase shift circuit 1c. The first antenna element 2a and the second antenna element 2b are connected in parallel to the output side of the first phase shift circuit 1a. A third antenna element 2c and a fourth antenna element 2d are connected in parallel to the output side of the fifth phase shift circuit 1e. A fifth antenna element 2e and a sixth antenna element 2f are connected in parallel to the output side of the sixth phase shift circuit 1f. A seventh antenna element 2g and an eighth antenna element 2h are connected in parallel to the output side of the fourth phase shift circuit 1d.

  The phase shift circuit 1 and the antenna element 2 as described above are housed in an antenna body having a cylindrical shape, for example. In this case, the eight antenna elements 2 are arranged along the longitudinal direction of the antenna body having a cylindrical shape, and the corresponding phase shift circuit 1 is connected to each of the arranged antenna elements 2. Each phase shift circuit 1 changes the phase of the input high-frequency signal and outputs the high-frequency signal whose phase has been changed to the corresponding antenna element 2. Thus, a base station antenna having a predetermined directivity is realized.

  For example, the first, second, and fifth phase shift circuits 1a, 1b, and 1e connected to the first to fourth antenna elements 2a to 2d disposed above the antenna body having a cylindrical shape are input. The phase of the high-frequency signal is advanced, and the high-frequency signal whose phase is advanced is output to the first to fourth antenna elements 2a to 2d. On the other hand, the third, fourth, and sixth phase shift circuits 1c, 1d, and 1f connected to the fifth to eighth antenna elements 2e to 2h arranged below the antenna body are used for the input high-frequency signal. The phase is delayed, and the phase-delayed high-frequency signal is output to the fifth to eighth antenna elements 2e to 2h. Thereby, a desired beam tilt angle (directivity) can be realized. In general, a base station antenna is installed at a high place, and a mobile phone or the like existing below is a communication target. Therefore, the base station antenna has a characteristic of tilting a beam downward from a horizontal plane.

<Structure of phase shift circuit>
Next, the structure of the phase shift circuit 1 (1a to 1f) shown in FIG. 1 will be described with reference to FIGS. FIG. 2 is a perspective view showing an example of the structure of the phase shift circuit 1. FIG. 3 is a plan view showing an example of the structure of the phase shift circuit 1. 4A and 4B are cross-sectional views taken along line xx ′ and line yy ′ in FIG.

  The phase shift circuit 1 according to the present embodiment is a phase shift circuit that can output by changing the phase of an input signal. As shown in FIGS. 2, 3, and 4, the phase shift circuit 1 includes a signal line 11, a first dielectric plate 12 and a second dielectric plate 13, a first movable line 14, and a second movable line 15. And a first ground plate 16 and a second ground plate 17. The first dielectric plate 12 is disposed to face the first main surface of the signal line 11, and the second dielectric plate 13 is disposed to face the second main surface of the signal line 11. In the following description, the first main surface of the signal line 11 is sometimes referred to as “front surface”, and the second main surface is referred to as “back surface”. However, such a distinction is merely a distinction for convenience of explanation. The first dielectric plate 12 and the second dielectric plate 13 are integrally movable in a direction that intersects the direction in which the signal line 11 extends (for example, the vertical direction in the present embodiment). The first movable line 14 is disposed to face the first side surface of the signal line 11, and the second movable line 15 is disposed to face the second side surface of the signal line 11. The first movable line 14 and the second movable line 15 are synchronized with the movement of the first dielectric plate 12 and the second dielectric plate 13 in the same direction as the direction in which the signal line 11 extends (for example, in the present embodiment). It can move integrally in the horizontal direction). The first ground plate 16 is disposed on the opposite side of the signal line 11 with the first dielectric plate 12 interposed therebetween, and the second ground plate 17 is disposed on the opposite side of the signal line 11 with the second dielectric plate 13 interposed therebetween. Has been. That is, the signal line 11, the first dielectric plate 12 and the second dielectric plate 13, the first movable line 14, and the second movable line 15 are disposed between the opposing first ground plate 16 and second ground plate 17. Has been placed. 2 and 3 show a state where the first ground plate 16 and the second ground plate 17 are removed. In FIG. 3, the second dielectric plate 13 is hidden behind the first dielectric plate 12 and cannot be seen, but the reference numerals of the components of the second dielectric plate 13 are also shown in parentheses. .

  As shown mainly in FIG. 3, the signal line 11 includes a signal input end 11 a disposed on one end side in the longitudinal direction of the phase shift circuit 1 and a signal output end disposed on the other end side in the longitudinal direction of the phase shift circuit 1. 11b, and a line connecting the signal input end 11a and the signal output end 11b. That is, the signal line 11 has a linear line structure connected from the signal input end 11a to the signal output end 11b.

  The first dielectric plate 12 and the second dielectric plate 13 sandwich the signal line 11 from the front surface and the back surface. Further, the first dielectric plate 12 and the second dielectric plate 13 are arranged closer to the signal input end 11 a of the signal line 11 with respect to the first movable line 14 and the second movable line 15. That is, the first dielectric plate 12 is disposed on the surface side of the signal line 11 and on the side closer to the signal input end 11 a of the signal line 11 so as to face the signal line 11. Further, the second dielectric plate 13 is disposed on the back side of the signal line 11 and on the side closer to the signal input end 11 a of the signal line 11 so as to face the signal line 11.

  The first dielectric plate 12 and the second dielectric plate 13 are movable in the direction perpendicular to the direction in which the signal line 11 extends. That is, the first dielectric plate 12 and the second dielectric plate 13 are movable in a direction perpendicular to a straight line connecting the signal input end 11a and the signal output end 11b of the signal line 11. In this case, the first dielectric plate 12 and the second dielectric plate 13 are configured to move in the same direction in synchronization with each other via the mover 18. Hereinafter, the second dielectric plate 13 as well as the first dielectric plate 12 will be described in the same manner mainly using FIG. 3.

  The first dielectric plate 12 and the second dielectric plate 13 have, for example, a triangular shape or a substantially triangular shape in plan view. Specifically, the first dielectric plate 12 and the second dielectric plate 13 are made of a plate-like body having an isosceles triangle shape, and a vertex facing the bottom is arranged in the direction of the signal line 11. The isosceles triangle includes not only an isosceles triangle but also a shape approximately similar to an isosceles triangle.

  Then, the first and second dielectric plates 12 and 13 are moved in a direction perpendicular to the direction in which the signal line 11 extends. That is, the first and second dielectric plates 12 and 13 having the shape of an isosceles triangle are moved in a direction connecting the intermediate portion of the base and the apex facing the base. Thereby, the line length between the first and second dielectric plates 12 and 13 and the first and second movable lines 14 and 15 can be adjusted.

For example, as shown in FIG. 3, in the signal line 11, the line length from the position of the first and second dielectric plates 12, 13 to the position of the first and second movable lines 14, 15 is the first frequency f. It is adjusted to the length of lambda _1/4 with respect to the first wavelength lambda ₁ in _1. The length of the lambda _1/4 is the length at the center line of the width of the signal line 11, also the length referenced to the position of the equilateral isosceles triangle of the first and second dielectric plates 12 and 13 That's it.

  The first and second dielectric plates 12 and 13 are arranged as follows with respect to the signal line 11. With respect to the direction in which the signal line 11 extends, the two equilateral sides of the isosceles triangles of the first and second dielectric plates 12 and 13 each have a first angle of 65 degrees or less. Note that 65 degrees includes an angle close to approximately 65 degrees in addition to 65 degrees, and may be an angle equal to or less than a right angle in the present embodiment.

  As described above, the first dielectric plate 12 and the second dielectric plate 13 move in synchronization with each other in the same direction, and the first and second movable lines 14 and 15 also have the first and second movable lines 14 and 15. The plate-like bodies move in synchronization with each other so that the line length between the second dielectric plates 12 and 13 and the first and second movable lines 14 and 15 is adjusted.

  The first movable line 14 and the second movable line 15 sandwich the signal line 11 from both side surfaces. The first movable line 14 and the second movable line 15 are disposed closer to the signal output end 11 b of the signal line 11 with respect to the first dielectric plate 12 and the second dielectric plate 13. That is, the first movable line 14 is opposed to the signal line 11 on one side surface side of both side surfaces in the width direction of the signal line 11 and closer to the signal output end 11b of the signal line 11. Is arranged. In addition, the second movable line 15 is opposed to the signal line 11 on the other side surface side of both side surfaces in the width direction of the signal line 11 and closer to the signal output end 11 b of the signal line 11. Has been placed.

  The first movable line 14 and the second movable line 15 are movable in the horizontal direction with respect to the direction in which the signal line 11 extends. That is, the first movable line 14 and the second movable line 15 are movable in the horizontal direction with respect to a straight line connecting the signal input end 11a and the signal output end 11b. In this case, the first movable line 14 and the second movable line 15 are configured to move in the same direction in synchronization with each other via the connecting member.

  In FIG. 3, the first movable line 14 and the second movable line 15 have, for example, a square shape or a substantially square shape in plan view. Specifically, the first movable line 14 and the second movable line 15 are formed of a rectangular plate-like body, and one side surface of each of the first and second movable lines 14 and 15 is each of the signal lines 11. It is arranged in a direction facing the side surface. In addition, a rectangle includes not only a rectangle but also a shape that is approximately a rectangle.

  Then, the first and second movable lines 14 and 15 are moved in the horizontal direction with respect to the direction in which the signal line 11 extends. That is, the first and second movable lines 14 and 15 having a rectangular shape are moved in the long side direction of the rectangle. Thereby, as described above, the line length between the first and second dielectric plates 12 and 13 and the first and second movable lines 14 and 15 can be adjusted.

  In the phase shift circuit 1 configured as described above, the first and second dielectric plates 12 and 13 and the first and second movable lines 14 and 15 are synchronized so as to satisfy desired phase characteristics. The first and second dielectric plates 12 and 13 are moved in the direction perpendicular to the direction in which the signal line 11 extends, and the first and second movable lines 14 and 15 are signaled so that the reflection characteristics are good at a specific frequency. It is moved in the horizontal direction with respect to the direction in which the track 11 extends. Thus, the line length between the first and second dielectric plates 12 and 13 and the first and second movable lines 14 and 15 is adjusted, and the phase of the signal input from the signal input end 11a is controlled. . That is, a signal whose phase is advanced or a signal whose phase is delayed with respect to the signal input to the signal input end 11a of the signal line 11 is output from the signal output end 11b.

  The first and second dielectric plates 12 and 13 and the first and second movable lines 14 and 15 shown in FIG. 3 are the first and second dielectric plates 12 and 13 and the first and second movable lines. 14 and 15 in the middle of the movable range (also shown in FIG. 5A). If this intermediate position is used as a reference (referred to herein as an initial phase), the first and second dielectric plates 12 and 13 move to the movable range end in the upward direction in FIG. 3, and the first and second movable plates are movable. When the lines 14 and 15 move to the end of the movable range in the left direction in FIG. 3, the phase becomes minimum (referred to as -phase here) (shown in FIG. 5B). On the contrary, the first and second dielectric plates 12 and 13 move to the end of the movable range in the lower direction of FIG. 3, and the first and second movable lines 14 and 15 are movable in the right direction of FIG. When moving to the end of the range, the phase becomes maximum (referred to as + phase here) (shown in FIG. 5C).

  The phase shift circuit 1 shown in FIGS. 2 and 3 has a cross-sectional structure as shown in FIG. 4, for example. 4A is a cross-sectional view of the phase shift circuit 1 cut along the xx ′ cut line in FIG. 3, and FIG. 4B is a cross section cut along the yy ′ cut line in FIG. The cross section of the phase circuit 1 is shown. 4A shows a cross section of the first and second dielectric plates 12 and 13 cut, and FIG. 4B shows a cross section of the first and second movable lines 14 and 15 cut. Is shown.

  The cross section obtained by cutting the first and second dielectric plates 12 and 13 is a portion where the signal line 11 and the first and second dielectric plates 12 and 13 overlap. As shown in FIG. The signal line 11 is sandwiched between the first dielectric plate 12 and the second dielectric plate 13 on the front and back surfaces. Further, the first and second dielectric plates 12 and 13 are sandwiched between the first ground plate 16 and the second ground plate 17 on the side opposite to the signal line 11.

  Moreover, the cross section which cut | disconnected the part of the 1st and 2nd movable lines 14 and 15 is a part with which the signal line 11 and the 1st and 2nd movable lines 14 and 15 overlap, and as shown in FIG.4 (b). The signal line 11 is sandwiched between the first movable line 14 and the second movable line 15 on both sides. Further, the signal line 11 and the first and second movable lines 14 and 15 are sandwiched between the first ground plate 16 and the second ground plate 17 on the front surface side and the back surface side.

  That is, as shown in FIG. 4, in the phase shift circuit 1, the first and second dielectric plates 12 and 13 are arranged so as to sandwich the signal line 11 from the front surface and the back surface, respectively. The first and second movable lines 14 and 15 are disposed so as to be sandwiched between the first and second dielectric plates 12 and 13, and the first and second ground plates 16 and 13 are disposed on the opposite side of the first and second dielectric plates 12 and 13 from the signal line 11. 17 has a structure in which each is arranged.

  In the structure of the phase shift circuit 1 as described above, the first and second dielectric plates 12, 13 and the first and second movable lines 14, 15 are synchronized with each other, As a mechanism for moving 13 in the direction perpendicular to the direction in which the signal line 11 extends and moving the first and second movable lines 14 and 15 in the horizontal direction with respect to the direction in which the signal line 11 extends, Although not limited, for example, a mechanism as shown in FIGS.

  In the mechanism as shown in FIGS. 2 to 4, the first dielectric plate 12 and the second dielectric plate 13 are coupled to the mover 18 at the end portions on the bottom sides of the first dielectric plate 12 and the second dielectric plate 13. A screw member 19 such as a screw rod is fitted, and the screw member 19 is rotated by a motor or the like. Accordingly, the first and second dielectric plates 12 and 13 can be moved in conjunction with the movement of the mover 18.

  Specifically, the coupling between the first and second dielectric plates 12 and 13 and the mover 18 is in the direction of 45 degrees to approximately 45 degrees with respect to the extending direction of the signal line 11 formed in the mover 18. The protrusions 12a and 13a of the coupling member that couples the first dielectric plate 12 and the second dielectric plate 13 are movable along the formed apertures 18a and 18b. Furthermore, the mover 18 is movably fitted to the screw member 19. Accordingly, the screw member 19 is rotated by a motor or the like to move the mover 18 in the right direction or the left direction, and the first and second dielectric plates are moved in accordance with the movement of the mover 18 in the right direction or the left direction. 12 and 13 are structured to move upward or downward.

  On the other hand, the first movable line 14 and the second movable line 15 are coupled to each other at a part thereof, and a screw member 20 such as a screw rod is fitted to the coupling portion, and the screw member 20 is connected to the first movable line 14. And it rotates with a motor etc. similarly to the 2nd dielectric plates 12 and 13. FIG. Accordingly, the first and second movable lines 14 and 15 can be moved in synchronization with the first and second dielectric plates 12 and 13.

  In addition, the motor which rotates the screw member 19 and the screw member 20 illustrated here may rotate both using one motor, or it is also possible to use a different motor. It is also possible to change the rotation ratio of the screw members 19 and 20 using a gear mechanism or the like.

  In FIG. 3, a screw member 19 that moves the first and second dielectric plates 12 and 13 and a screw member 20 that moves the first and second movable lines 14 and 15 are rotated clockwise (in the direction of the arrow in FIG. 3). ), The mover 18 moves to the right, the first and second dielectric plates 12, 13 move upward, and the first and second movable lines 14, 15 move to the left. Moving. Conversely, the screw member 19 that moves the first and second dielectric plates 12 and 13 and the screw member 20 that moves the first and second movable lines 14 and 15 are rotated counterclockwise (as indicated by arrows in FIG. 3). When rotating in the opposite direction), the mover 18 moves to the left, the first and second dielectric plates 12, 13 move downward, and the first and second movable lines 14, 15 move to the right. Move in the direction.

  In other words, for example, in the movement direction of the first and second dielectric plates 12 and 13, the upward direction is the direction of the vertex facing the bottom sides of the first and second dielectric plates 12 and 13. Yes, the downward direction is the opposite direction. In the moving direction of the first and second movable lines 14 and 15, the right direction is the direction of the signal output end 11b of the signal line 11, and the left direction is the opposite direction to the direction of the signal input end 11a. .

  Further, in the structure of the phase shift circuit 1 as described above, each component is not limited to this, but is composed of, for example, the following materials. The signal line 11 is made of a conductor, and is made of a metal material such as copper, for example. The 1st and 2nd dielectric plates 12 and 13 consist of dielectrics, for example, are comprised from resin materials, such as glass epoxy. The 1st and 2nd movable lines 14 and 15 consist of dielectrics, for example, are constituted from resin materials, such as glass epoxy. The first and second ground plates 16 and 17 are made of a conductor, and are made of a metal material such as copper, for example.

<Results of phase-shift circuit simulation>
Next, the simulation by the structure of the phase shift circuit 1 (1a-1f) shown in FIGS. 2-4 is demonstrated using FIGS. FIG. 5 is an explanatory diagram showing an example of movement between the first and second dielectric plates 12 and 13 and the first and second movable lines 14 and 15 in the simulation based on the structure of the phase shift circuit 1. 6 and 7 are explanatory diagrams showing an example (first condition example) of the relationship between the frequency and the VSWR and the relationship between the frequency and the phase in the simulation result. FIG. 8 and FIG. 9 are explanatory diagrams showing an example of the relationship between the frequency and the VSWR and the relationship between the frequency and the phase (second condition example) in the simulation result.

  In the simulation based on the structure of the phase shift circuit 1, the first and second dielectric plates 12, 13 are synchronized with the first and second dielectric plates 12, 13 and the first and second movable lines 14, 15. The first and second dielectric plates are moved in a direction perpendicular to the direction in which the signal line 11 extends, and the first and second movable lines 14 and 15 are moved in the horizontal direction in the direction in which the signal line 11 extends. This can be done by adjusting the line length between the lines 12 and 13 and the first and second movable lines 14 and 15.

  As shown in FIG. 5, the simulation measured the case shown in (a), the case shown in (b), and the case shown in (c). (A) is a case where the position of the 1st and 2nd dielectric plates 12 and 13 and the position of the 1st and 2nd movable lines 14 and 15 are the initial phase in the intermediate position of a movable range. (B) shows that the first and second dielectric plates 12 and 13 are moved to the end of the movable range in the upward direction in FIG. 5, and the first and second movable lines 14 and 15 are moved in the left direction in FIG. This is the case of -phase depending on the position moved to the end of the movable range. (C) moves the first and second dielectric plates 12 and 13 to the end of the movable range in the downward direction in FIG. 5, and moves the first and second movable lines 14 and 15 to the right in FIG. This is the case of + phase depending on the position moved to the end of the movable range.

  In this simulation, the signal line 11, the first and second dielectric plates 12 and 13, the first and second movable lines 14 and 15, and the first and second ground plates 16 and 17 that constitute the phase shift circuit 1. Each was formed under the following conditions. The distance between the first ground plate 16 and the second ground plate 17 was 5 mm. The thickness of the signal line 11 was 1 mm. The thickness of the first and second dielectric plates 12 and 13 was 2 mm. The thickness of the first and second movable lines 14 and 15 was 1 mm. The width of the signal line 11 was 2.1 mm.

  Further, the first and second movable lines 14 and 15 are determined so that the width thereof is the same as the characteristic impedance of the insertion portions of the first and second dielectric plates 12 and 13, and the length is the first. It is determined based on the sizes of the second dielectric plates 12 and 13. Here, the first condition example when the length of the first and second movable lines 14 and 15 is 4 mm and the width is 6 mm, and the length of the first and second movable lines 14 and 15 is 5 mm and the width The simulation result with the 2nd example of a case where is 6 mm is shown.

  The widths of the first and second movable lines 14 and 15 are the lengths from the end surface of the first movable line 14 opposite to the signal line 11 to the end surface of the second movable line 15 opposite to the signal line 11. It is. The lengths of the first and second movable lines 14 and 15 are the lengths of the first and second movable lines 14 and 15 in the extending direction of the signal line 11.

<< First Condition Example >>
Under the simulation conditions as described above, the relationship between the frequency and the VSWR was as shown in FIG. FIG. 6 shows a first condition example (when the length of the first and second movable lines 14 and 15 is 4 mm and the width is 6 mm). In FIG. 6, the horizontal axis represents frequency [MHz], and the vertical axis represents VSWR (Voltage Standing Wave Ratio). The frequency was simulated in the range of 1500 MHz to 2500 MHz.

  In the case of the initial phase, the frequency is 1500 MHz and the VSWR is 1.36. As the frequency increases to 1700 MHz and 1900 MHz, the VSWR decreases to 1.27 and 1.14. The frequency is 2100 MHz and the VSWR is 1. It decreased to 02. When the frequency increased to 2300 MHz, VSWR increased to 1.18, and when the frequency further increased to 2500 MHz, VSWR increased to 1.42.

  In the case of phase, the frequency is 1500 MHz and the VSWR is 1.43. As the frequency increases to 1700 MHz and 1900 MHz, the VSWR decreases to 1.32 and 1.19, the frequency is 2100 MHz and the VSWR is 1. Decreased to 13. When the frequency increased to 2300 MHz, VSWR increased to 1.26, and when the frequency further increased to 2500 MHz, VSWR increased to 1.50.

  In the case of + phase, the frequency is 1500 MHz and the VSWR is 1.34. As the frequency increases to 1700 MHz and 1900 MHz, the VSWR decreases to 1.27 and 1.17, the frequency is 2100 MHz and the VSWR is 1.. Decreased to 12. When the frequency increased to 2300 MHz, VSWR increased to 1.20, and when the frequency further increased to 2500 MHz, VSWR increased to 1.40.

  As described above, the relationship between the frequency and the VSWR is substantially V-shaped in the initial phase, in the case of the -phase, and in the case of the + phase, the frequency is 2100 MHz, and the VSWR is minimized. The resonance frequency was reached. In the frequency band of 1500 MHz to 2500 MHz, VSWR was 1.50 or less.

  As described above, in the simulation result shown in FIG. 6, the relationship between the frequency and the VSWR has a resonance point at 2100 MHz in the frequency band of 1500 MHz to 2500 MHz. Thereby, it turned out that it is the phase shift circuit 1 which has a resonance point with the frequency of 2100 MHz. In addition, at this resonance point, VSWR was 1.02 (in the case of the initial phase), and it was found that the phase shift circuit 1 was good in terms of impedance matching.

  At this resonance point, the influence of the reflected wave on the traveling wave of the signal input from the signal input end 11a and output from the signal output end 11b is minimized. For example, in FIG. 3, the positions of the first and second movable lines 14 and 15 overlapping the signal line 11 serve as reflection points of the reflected wave with respect to the traveling wave. The frequency of this resonance point becomes the operating frequency of the phase shift circuit 1.

In this case, as shown in FIG. 3, in the signal line 11, the line length from the position of the first and second dielectric plates 12, 13 to the position of the first and second movable lines 14, 15 is 2100 MHz. the length of lambda _1/4 with respect to the first wavelength lambda ₁ of the first frequency _{f 1.}

  Further, the relationship between the frequency and the phase is as shown in FIG. FIG. 7 shows the same first condition example as FIG. In FIG. 7, the horizontal axis indicates the frequency [MHz], and the vertical axis indicates the phase [deg]. The frequency was simulated in the range of 2000 MHz to 2200 MHz.

  In the case of the initial phase, it was −150 deg at 2045 MHz and −170 deg at 2125 MHz. -In the case of phase, it was -150 deg at 2035 MHz and -170 deg at 2125 MHz. In the case of + phase, −150 deg at 2060 MHz and −170 deg at 2140 MHz.

  As described above, in the case of the initial phase, in the case of -phase and in the case of + phase, the relationship between the frequency and the phase decreases in the frequency band around 2050 MHz to 2150 MHz as the frequency increases. It turns out that it changes linearly in the direction.

  Further, in the relationship between the frequency and the phase, as shown in FIG. 7, for example, when the frequency is 2100 MHz, the initial phase is −163 deg, the −phase is −167 deg, and the + phase is Was -161 deg. The phase difference between the -phase case and the + phase case with respect to the initial phase case is -4 deg and +2 deg, respectively, and the frequency is constant in the range from 2050 MHz to 2150 MHz.

  As described above, in the simulation result shown in FIG. 7, the relationship between the frequency and the phase is advanced by 4 deg in the case of −phase and 2 deg in the case of + phase with respect to the initial phase. It was found that the phase shift circuit 1 has the characteristic of delaying the phase.

<< Second Condition Example >>
In the second condition example (when the lengths of the first and second movable lines 14 and 15 are 5 mm and the width is 6 mm), the relationship between the frequency and the VSWR is shown in FIG. 8, and the relationship between the frequency and the phase is shown in FIG. The result was as follows.

  As shown in FIG. 8, in the case of the initial phase, the frequency is 1500 MHz and the VSWR is 1.50. As the frequency increases to 1700 MHz and 1900 MHz, the VSWR decreases to 1.37 and 1.20. However, at 2100 MHz, the VSWR decreased to 1.05. When the frequency increased to 2300 MHz, VSWR increased to 1.23, and when the frequency further increased to 2400 MHz, VSWR increased to 1.38.

  In the case of phase, the VSWR was 1.47 at a frequency of 1700 MHz, the VSWR decreased to 1.30 as the frequency increased to 1900 MHz, and the VSWR decreased to 1.20 at a frequency of 2100 MHz. When the frequency increased to 2300 MHz, VSWR increased to 1.34, and when the frequency further increased to 2400 MHz, VSWR increased to 1.50.

  In the case of + phase, the frequency is 1500 MHz and the VSWR is 1.45. As the frequency increases to 1700 MHz and 1900 MHz, the VSWR decreases to 1.34 and 1.20. The frequency is 2100 MHz and the VSWR is 1.. Decreased to 12. When the frequency increased to 2300 MHz, VSWR increased to 1.25, and when the frequency increased further to 2400 MHz, VSWR increased to 1.37.

  As described above, the relationship between the frequency and the VSWR is substantially V-shaped in the initial phase, in the case of the -phase, and in the case of the + phase, the frequency is 2100 MHz, and the VSWR is minimized. The resonance frequency was reached. Further, in the frequency band of 1700 MHz to 2400 MHz, VSWR was 1.50 or less.

  As described above, in the simulation result shown in FIG. 8, the relationship between the frequency and the VSWR has a resonance point at 2100 MHz in the frequency band of 1500 MHz to 2500 MHz. Thereby, it turned out that it is the phase shift circuit 1 which has a resonance point with the frequency of 2100 MHz. Further, at this resonance point, VSWR was 1.05 (in the case of the initial phase), and it was found that the phase shift circuit 1 was good in terms of impedance matching.

  Further, the relationship between the frequency and the phase is as shown in FIG. As shown in FIG. 9, in the case of the initial phase, −160 deg at 2070 MHz and −180 deg at 2140 MHz. In the case of -phase, it was -160 deg at 2055 MHz and -180 deg at 2140 MHz. In the case of the + phase, −160 deg at 2083 MHz and −180 deg at 2155 MHz.

  As described above, in the case of the initial phase, in the case of -phase and in the case of + phase, the relationship between the frequency and the phase decreases in the frequency band around 2050 MHz to 2150 MHz as the frequency increases. It turns out that it changes linearly in the direction.

  Furthermore, in the relationship between the frequency and the phase, as shown in FIG. 9, for example, when the frequency is 2100 MHz, the initial phase is −168 deg, the negative phase is −173 deg, and the positive phase. Was -165 deg. The phase difference between the -phase case and the + phase case with respect to the initial phase case is -5 deg and +2 deg, respectively, and the frequency is constant in the range from around 2050 MHz to around 2150 MHz.

  As described above, in the simulation result shown in FIG. 9, the relationship between the frequency and the phase is advanced by 5 deg in the case of −phase and 2 deg in the case of + phase with respect to the initial phase. It was found that the phase shift circuit 1 has the characteristic of delaying the phase.

<Effect of one embodiment>
According to the phase shift circuit 1 (1a to 1f) applied to the base station antenna according to the present embodiment described above, the signal line 11, the first dielectric plate 12 and the second dielectric plate 13, The first movable line 14 and the second movable line 15 are included. The first dielectric plate 12 and the second dielectric plate 13 are opposed to each other, and the signal line 11 is disposed between the first dielectric plate 12 and the second dielectric plate 13. The first movable line 14 and the second movable line 15 face each other, and the signal line 11 is disposed between the first movable line 14 and the second movable line 15. Then, the movement of the first dielectric plate 12 and the second dielectric plate 13 in the direction intersecting the extending direction of the signal line 11 and the signals of the first movable line 14 and the second movable line 15 The movement in the same direction as the direction in which the line 11 extends is synchronized. Accordingly, the first and second movable lines 14 and 15 are moved in the horizontal direction with respect to the signal line 11 in synchronization with the first and second dielectric plates 12 and 13 moving in the vertical direction with respect to the signal line 11. By moving, the length of the signal line 11 in the extending direction can be shortened, so that the size of the phase shift circuit 1 can be made as small as possible. As a result, the size of the base station antenna can also be reduced. Further, according to the result of the simulation, it is possible to realize a wider reflection characteristic than in the conventional configuration.

  Furthermore, according to the present embodiment, the following effects can be obtained.

(1) In the signal line 11, the line length from the position of the first and second dielectric plates 12 and 13 to the position of the first and second movable lines 14 and 15 is the first wavelength λ at the first frequency f ₁ . it can be the length of lambda _1/4 with respect to _1. As a result, _one line length having an impedance matching line length of λ 1/4 is formed, and the phase shift circuit 1 having one resonance point can be realized. Further, the reflection characteristic can be widened.

(2) In the first and second movable lines 14 and 15, the width can be determined to be the same as the characteristic impedance of the insertion portion of the first and second dielectric plates 12 and 13. That is, since the portions of the first and second movable lines 14 and 15 are mismatched lines, the distance from the insertion portion of the first and second dielectric plates 12 and 13 is set to λ ₁ / Impedance matching can be achieved by leaving about 4 spaces.

  (3) In the first and second movable lines 14 and 15, the length can be determined based on the sizes of the first and second dielectric plates 12 and 13. In this way, by determining the lengths of the first and second movable lines 14 and 15 based on the sizes of the first and second dielectric plates 12 and 13, the desired phase characteristics are satisfied, and reflection is performed at a specific frequency. The phase shift circuit 1 with good characteristics can be realized.

<Modification of one embodiment>
Regarding the phase shift circuit 1 (1a to 1f) applied to the above-described base station antenna according to the present embodiment, the following modifications may be considered.

  (1) In FIG. 2 and the like, the first and second dielectric plates 12 and 13 are illustrated as having an isosceles triangle shape. However, the present invention is not limited to this. For example, all triangles including triangles, right triangles, etc. It can be applied to other shapes. Even in the case of such a phase shift circuit, the same effect as that of the above-described embodiment can be obtained.

  (2) In FIG. 2 and the like, the first and second movable lines 14 and 15 are illustrated as examples having a rectangular shape. However, the present invention is not limited to this example. Applicable. In this case, the widths of the first and second movable lines are determined so as to be the same as the characteristic impedances of the insertion portions of the first and second dielectric plates, and the lengths of the first and second movable lines are determined. It is necessary to make a decision based on the size of the body plate. Even in the case of such a phase shift circuit, the same effect as that of the above-described embodiment can be obtained.

  (3) Although the 1st and 2nd movable track | line 14 and 15 demonstrated the example comprised from resin materials, such as glass epoxy, not only this but the dielectric material comprised from another resin material, for example, Furthermore, It can also be applied to conductors such as metals. In this case, the widths of the first and second movable lines are determined so as to be the same as the characteristic impedances of the insertion portions of the first and second dielectric plates, and the lengths of the first and second movable lines are determined. It is necessary to make a decision based on the size of the body plate. Even in the case of such a phase shift circuit, the same effect as that of the above-described embodiment can be obtained.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the embodiment, and various modifications can be made without departing from the scope of the invention. Needless to say.

1a to 1f Phase shift circuit 2a to 2h Antenna element 11 Signal line (first conductor)
11a Signal input end 11b Signal output end 12 First dielectric plate (first dielectric)
13 Second dielectric plate (second dielectric)
12a, 13a Protrusion 14 First movable line (first moving member)
15 Second movable track (second moving member)
16 First ground plate (second conductor)
17 Second ground plate (third conductor)
18 Mover 18a, 18b Opening part 19, 20 Screw member

Claims (4)

A phase shift circuit that changes the phase of a signal,
Opposing first and second dielectrics;
Opposing first and second moving members;
A first conductor disposed between the first dielectric and the second dielectric and between the first moving member and the second moving member;
Have
The first dielectric is disposed to face the first main surface of the first conductor,
The second dielectric is disposed to face the second main surface opposite to the first main surface of the first conductor,
The first moving member is disposed to face the first side surface of the first conductor,
The second moving member is disposed to face a second side surface opposite to the first side surface of the first conductor,
The first dielectric and the second dielectric, the while moving in a direction crossing the extending Mashimashi direction of the first conductor, the first moving member and the second moving member, said first conductor Move in the same direction as
The second dielectric moves in the same direction as the first dielectric as the first dielectric moves, and the second moving member moves as the first moving member moves. A phase shift circuit that moves in the same direction as the first moving member . The phase shift circuit according to claim 1 ,
The line length of the first conductor from the position of the first dielectric and the second dielectric to the position of the first moving member and the second moving member is the first wavelength λ _{1 at} the first frequency f ₁ . of lambda _1/4 with respect to the length, the phase shift circuit. The phase shift circuit according to claim 1 or 2 ,
A phase shift circuit further comprising a second conductor and a third conductor of a ground plate arranged to face the surfaces of the first dielectric and the second dielectric opposite to the first conductor, respectively. An antenna device comprising the phase shift circuit according to any one of claims 1 to 3 .

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