Cavity type phase shifter, antenna device and phase shifter installation method

Abstract

The invention discloses a cavity type phase shifter, an antenna device and a phase shifter installation method. The cavity type phase shifter comprises a shell with a plurality of cavities formed side by side, flanges divide the corresponding cavities into two spaces which are communicated left and right, a phase shifting assembly is installed in one space, a pull rod is installed in the other space in a sliding mode, and moving media are installed on the pull rod in the length direction at intervals; the phase shifting assembly comprises an upper-layer medium, a metal transmission line and a lower-layer medium which are installed into a whole, a containing groove is formed in the top face of the lower-layer medium, the metal transmission line is assembled in the containing groove, and the upper-layer medium is installed on the lower-layer medium located at an opening of the containing groove or above the containing groove; the metal transmission line positioned outside the accommodating groove forms a phase shifting section; the phase shifting section crosses the convex edge and is assembled in the mobile medium; according to the utility model, reliable installation of the metal transmission line is realized, installation and use planeness of the metal transmission line is greatly guaranteed, the metal transmission line can be effectively kept in the middle of the phase shift assembly, stability of electrical performance of the antenna is guaranteed, simplification is facilitated, and actual assembly operation is facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of mobile communication antennas, and in particular to a cavity-type phase shifter, an antenna device and a phase shifter installation method. Background Art

[0002] With the rapid development of the mobile communications industry, people's requirements for mobile networks have gradually increased. In the current environment where 3G, 4G and 5G networks coexist, the number of base stations has increased significantly, and the number of antennas has continued to increase, resulting in increased power consumption and operating costs of base stations. This requires base station antennas to take a green design route to reduce antenna losses and improve antenna performance; that is, under the same coverage range, the base station transmission power needs to be reduced; or under the same power, the coverage range needs to be improved.

[0003] In the prior art, the reflector and the phase shifter are relatively independent parts or components, and the two are usually connected and fixed by metal or non-metallic connectors. The phase shifter usually uses a metal transmission line, which is fixed in the cavity through a filler. The metal transmission line and the filler are separately installed in the cavity. During operation, it is difficult to ensure the relative fixed position of the strip line in the cavity; moreover, due to the shape characteristics of the metal transmission line itself, its flatness is easily affected during assembly, and even deformation occurs.

[0004] In addition, the phase shifter in the prior art usually includes metal transmission lines, fillers, mobile media, positioning pins and other components, which are numerous in number and have complex assembly procedures. It is difficult to install them step by step and reliably in the cavity. At the same time, the antenna assembly process has high requirements and the antenna timeliness is poor. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a cavity-type phase shifter, an antenna device and a phase shifter installation method with a reasonable structure, thereby greatly ensuring the installation and use flatness of the metal transmission line, and being able to effectively maintain the middle position of the phase shift component, thereby ensuring the stability of the antenna's electrical performance, and helping to simplify and facilitate the actual assembly operation.

[0006] The technical solution adopted by the present invention is as follows:

[0007] A cavity-type phase shifter comprises a flat shell, the top surface of the shell forms a reflector, a plurality of cavities are formed in parallel along the width direction on the shell below the reflector, the inner bottom surface of each cavity extends upward to form a convex ridge, and the convex ridge divides the corresponding cavity into two spaces communicating with each other on the left and right; a phase shifting assembly is installed in one space of the cavity, a pull rod is slidably installed in the other space of the cavity, and a moving medium is installed on the pull rod at intervals along the length direction;

[0008] The structure of the phase shifting assembly is as follows: it includes an upper dielectric layer, a metal transmission line, and a lower dielectric layer installed as one body, the top surface of the lower dielectric layer is provided with a receiving groove, the metal transmission line is installed inside the receiving groove, and the upper dielectric layer is installed on the lower dielectric layer located at the opening of the receiving groove or above the upper portion;

[0009] The metal transmission line located outside the accommodating groove constitutes a phase shifting section, and the phase shifting section is mounted in the mobile medium over the convex ridge.

[0010] As a further improvement of the above technical solution:

[0011] A groove is provided along the middle of the side of the moving medium facing the phase shifting section, and the phase shifting section is fitted in the groove; convex columns are extended at intervals along the length direction on the side of the moving medium facing the pull rod, and a hole is provided on the pull rod to fit with the convex columns.

[0012] The depth of the accommodating groove is adapted to the height of the metal transmission line, and the upper medium is installed flat on the top surface of the lower medium; the upper medium is installed on the top surface of the lower medium via a fixing structure, and the fixing structure includes but is not limited to hot melt adhesive, glue, double-sided tape, and pins.

[0013] The depth of the accommodating groove is greater than the height of the metal transmission line. The upper dielectric layer includes multiple dielectric segments that are shaped like the metal transmission line. Each dielectric segment is fitted to a corresponding position of the accommodating groove above the metal transmission line. Each dielectric segment is interference fitted with the accommodating groove.

[0014] The lower medium is a monolithic structure, or,

[0015] The lower layer medium is composed of two layers of dielectric sheets, the dielectric sheet located at the upper layer is provided with a receiving groove, and the dielectric sheet located at the lower layer is a flat plate structure, and the upper and lower dielectric sheets are assembled and fixed between them.

[0016] A plurality of protrusions are extended upward from the inner bottom surface of the accommodating groove, and positioning holes corresponding to the protrusions are opened on the metal transmission line.

[0017] The metal transmission line is provided with a feeding joint, and a feeding hole is provided on the feeding joint; a notch is provided on the lower medium or the lower medium and the upper medium at the feeding joint, and the feeding joint is exposed through the notch.

[0018] The accommodating groove is a discontinuous multi-stage structure. The accommodating groove is processed according to the shape of the metal transmission line, and the gap between the metal transmission line and the accommodating groove is fitted; the accommodating groove is formed by stamping cutting or hot-melt cutting.

[0019] An antenna device comprises the cavity-type phase shifter described in any one of the above.

[0020] A method for installing the cavity-type phase shifter comprises the following steps:

[0021] Place the surface of the lower dielectric layer with the accommodating groove upwards, lay the metal transmission line flat in the accommodating groove, and place the phase shifting section of the metal transmission line outside the lower dielectric layer;

[0022] The upper dielectric layer is installed and fixed on the lower dielectric layer above the metal transmission line, so that the metal transmission line is stably maintained between the upper dielectric layer and the lower dielectric layer, thereby forming a phase shifting component;

[0023] The phase shifting assembly is mounted on one side of the convex ridge in the housing cavity along the length direction, and the phase shifting section is located above the convex ridge;

[0024] The moving medium is installed on the pull rod, and the moving medium is fitted to the other side of the convex ridge in the cavity through the pull rod, so that the phase shifting section is accommodated in the middle groove of the moving medium.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The present invention provides a receiving groove for assembling the metal transmission line on the lower dielectric layer of the phase shifting component, thereby not only realizing reliable installation of the metal transmission line, greatly ensuring the flatness of the metal transmission line during installation and use, and being able to effectively maintain the metal transmission line in the middle of the phase shifting component, thus ensuring the stability of the antenna electrical performance, but also helping to simplify and facilitate the actual assembly operation;

[0027] The present invention also includes the following advantages:

[0028] The top surface of the shell is used as a reflector, and the lower part of the shell forms multiple cavities for installing phase shifting components, thereby effectively integrating the phase shifter and the reflector, effectively reducing the number of parts, greatly facilitating the assembly of the phase shifter and the antenna device as a whole, helping to reduce production costs, and also helping to realize a phase shifter in the form of a low-loss metal strip line transmission structure, reducing network losses, improving antenna radiation efficiency, and improving structural consistency and electrical performance stability;

[0029] The upper medium, the metal transmission line and the lower medium can be conveniently installed as a whole, and then installed in the shell as a whole, which is convenient for actual assembly operation and effectively reduces the number of parts during assembly, facilitating mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the structure of the present invention.

[0031] Figure 2 for Figure 1 A partial enlarged view of point A in the middle.

[0032] Figure 3 It is a schematic structural diagram of the housing of the present invention.

[0033] Figure 4It is a schematic diagram of the assembly of the mobile medium and the pull rod of the present invention.

[0034] Figure 5 It is a schematic diagram of the structure of the mobile medium of the present invention.

[0035] Figure 6 It is a schematic diagram of the assembly of the pull rod, the moving medium and the phase shifting component of the present invention.

[0036] Figure 7 for Figure 6 A partial enlarged view of point B in the middle.

[0037] Figure 8 It is a schematic structural diagram of the first embodiment of the phase shifting component of the present invention.

[0038] Fig. 9 for Figure 8 A partial enlarged view of point C in the middle.

[0039] Fig.10 for Figure 8 A partial enlarged view of point D in the middle.

[0040] Fig.11 FIG. 1 is a schematic structural diagram of a second embodiment of a phase shifting component of the present invention.

[0041] Fig.12 for Fig.11 A partial enlarged view of point E in the middle.

[0042] Among them: 1. Shell; 2. Moving medium; 3. Pull rod; 4. Upper medium; 5. Metal transmission line; 6. Lower medium; 10. Phase shifting component;

[0043] 11. cavity; 12. convex ridge;

[0044] 21. groove; 22. convex column;

[0045] 40. medium segment; 41. notch 1;

[0046] 51. Phase shifting section; 52. Positioning hole; 53. Feeding hole; 54. Feeding connector;

[0047] 61. Accommodating groove; 62. Protrusion; 63. Recess II. DETAILED DESCRIPTION

[0048] The specific implementation of the present invention will be described below in conjunction with the accompanying drawings.

[0049] like Figure 1 , Figure 2 and Figure 3As shown, a cavity-type phase shifter of the present embodiment comprises a shell 1 with a flat structure, the top surface of the shell 1 constitutes a reflector, a plurality of cavities 11 are formed in parallel along the width direction on the shell 1 below the reflector, the bottom surface of each cavity 11 extends upward to form a ridge 12, and the ridge 12 divides the corresponding cavity 11 into two spaces communicating with each other on the left and right; a phase shifting assembly 10 is installed in one space of the cavity 11, a pull rod 3 is slidably installed in the other space of the cavity 11, and a moving medium 2 is installed on the pull rod 3 at intervals along the length direction.

[0050] In this embodiment, the top surface of the shell 1 is used as a reflector, and the lower part of the shell 1 constitutes a plurality of cavities 11 for installing the phase shifting assembly 10, thereby effectively integrating the phase shifter and the reflector, effectively reducing the number of components, greatly facilitating the assembly of the phase shifter and the antenna device as a whole, helping to reduce production costs, and also helping to realize a phase shifter in the form of a low-loss metal strip line transmission structure, reducing network losses, improving antenna radiation efficiency, and enhancing structural consistency and electrical performance stability.

[0051] In this embodiment, Figure 1 , Figure 2 and Figure 3 The front of the reflector shown in the figure has 5 rows of longitudinal vertical plates which are integrated with the reflector. The vertical plates are the radiation boundaries of each column of antennas, which effectively reduces the number of parts, greatly facilitates the assembly of the entire antenna, helps to reduce production costs, and improves structural consistency and electrical performance stability.

[0052] The structure of the phase shifting assembly 10 is as follows: it includes an upper dielectric layer 4, a metal transmission line 5, and a lower dielectric layer 6 installed as a whole. A receiving groove 61 is opened on the top surface of the lower dielectric layer 6. The metal transmission line 5 is installed inside the receiving groove 61. The upper dielectric layer 4 is installed on the lower dielectric layer 6 located at the opening of the receiving groove 61 or above.

[0053] By opening a receiving groove 61 for accommodating the metal transmission line 5 on the lower dielectric layer 6 of the phase shifting component 10, not only the metal transmission line 5 can be reliably installed, the flatness of the metal transmission line 5 during installation and use is greatly guaranteed, and the metal transmission line 5 can be effectively kept in the middle of the phase shifting component 10.

[0054] In this embodiment, the upper medium 4, the metal transmission line 5, and the lower medium 6 can be conveniently installed as a whole, and then installed in the shell 1 as a whole, which is convenient for actual assembly operations and effectively reduces the number of parts during assembly, facilitating mass production.

[0055] The metal transmission line 5 located outside the accommodating groove 61 forms a phase shifting section 51 , and the phase shifting section 51 is installed in the moving medium 2 beyond the convex ridge 12 .

[0056] The pull rod 3 is pulled by an external power to drive the moving medium 2 to move, so that the area covered by the moving medium 2 on the phase shifting section 51 of the metal transmission line 5 changes, generating a phase difference of the electromagnetic wave of the metal transmission line 5 relative to that in the air, thereby achieving phase shift.

[0057] In this embodiment, the housing 1 can be made of an aluminum profile that is formed by pultrusion, which has high precision and good consistency, effectively ensuring the structural performance of the integral housing 1 and facilitating subsequent automated assembly line processing.

[0058] like Figure 4 , Figure 5 , Figure 6 and Figure 7 As shown, a groove 21 is provided along the middle of the side of the moving medium 2 facing the phase shifter 51, and the phase shifter 51 is fitted in the groove 21; protrusions 22 are extended at intervals along the length direction on the side of the moving medium 2 facing the pull rod 3, and a hole is provided on the pull rod 3 to fit with the protrusion 22.

[0059] In this embodiment, the mobile medium 2 can be formed by an integrated injection molding process to effectively ensure structural and dimensional consistency.

[0060] In this embodiment, the movable medium 2 is quickly and reliably installed on the pull rod 3 through the assembly of the protruding column 22 and the hole, and the movable medium 2 can be driven to move synchronously through the movement of the pull rod 3 .

[0061] Embodiment 1:

[0062] like Figure 8 , Fig. 9 and Fig.10 As shown, the depth of the accommodating groove 61 is adapted to the height of the metal transmission line 5, and the upper dielectric layer 4 is installed flat on the top surface of the lower dielectric layer 6; thus, the metal transmission line 5 can be reliably and fixedly installed in the accommodating groove 61 by matching the installation of the upper dielectric layer 4.

[0063] The upper medium 4 is installed on the top surface of the lower medium 6 via a fixing structure, and the fixing structure includes but is not limited to hot melt adhesive, glue, double-sided tape, and pins, so as to achieve the fixation of the upper medium 4 on the top surface of the lower medium 6. The upper medium 4, the metal transmission line 5, and the lower medium 6 constitute a whole that can be pre-assembled.

[0064] Embodiment 2:

[0065] like Fig.11 and Fig.12 As shown, the depth of the accommodating groove 61 is greater than the height of the metal transmission line 5, and the upper dielectric 4 includes a plurality of dielectric segments 40 that are shaped like the metal transmission line 5, and each dielectric segment 40 is fitted to a corresponding position of the accommodating groove 61 above the metal transmission line 5; each dielectric segment 40 is interference fit with the accommodating groove 61.

[0066] In this embodiment, the upper dielectric layer 4 can be assembled at the lower dielectric layer 6 receiving groove 61 to realize reliable and fixed installation of the metal transmission line 5 in the receiving groove 61; and, by setting the upper dielectric layer 4 as a multi-segment structure that matches the shape of the metal transmission line 5, it is possible to effectively ensure that the metal transmission line 5 in the receiving groove 61 is limited and positioned by the upper dielectric layer 4, and effectively ensure that each dielectric segment 40 in the upper dielectric layer 4 is reliably, stably and fixedly installed on the lower dielectric layer 6.

[0067] In one embodiment, for example Figure 8 , Fig. 9 and Fig.10 In the middle, the lower medium 6 is an integral structure.

[0068] In another embodiment, such as Fig.11 and Fig.12 The lower dielectric layer 6 is composed of two dielectric sheets, the dielectric sheet at the upper layer is provided with a receiving groove 61, and the dielectric sheet at the lower layer is a flat plate structure, and the two dielectric sheets are assembled and fixed.

[0069] In actual operation, the upper and lower dielectric sheets can be fixed together by hot melt adhesive, glue, etc.

[0070] A plurality of protrusions 62 extend upward from the inner bottom surface of the accommodating groove 61, and positioning holes 52 corresponding to the protrusions 62 are opened on the metal transmission line 5 to realize the positioning of the metal transmission line 5 when it is installed in the accommodating groove 61, effectively ensuring the installation position of the metal transmission line 5 relative to the lower layer medium 6.

[0071] A feeding connector 54 is provided on the metal transmission line 5, and a feeding hole 53 is opened on the feeding connector 54; a recess is opened on the lower layer medium 6 or the lower layer medium 6 and the upper layer medium 4 located at the feeding connector 54, and the feeding connector 54 is exposed through the recess, and the feeding connector 54 can be connected to the external antenna radiation unit for feeding through the recess.

[0072] exist Figure 8 , Fig. 9 and Fig.10 In the illustrated embodiment, a notch 41 may be provided on the upper dielectric layer 4 located above the feeding connector 54, and a notch 63 may be provided on the lower dielectric layer 6 located below the feeding connector 54, so that the feeding connector 54 of the metal transmission line 5 is exposed through the provision of the notch 41 and the notch 63.

[0073] exist Fig.11 and Fig.12In the illustrated embodiment, a second notch 63 penetrating in the thickness direction may be provided on the lower dielectric layer 6, the second notch 63 being connected to the accommodating groove 61, and the dielectric segment 40 is not mounted at the second notch 63, so that the feed connector 54 of the metal transmission line 5 is exposed.

[0074] In one embodiment, the accommodating groove 61 is a discontinuous multi-stage structure. The accommodating groove 61 is processed according to the shape of the metal transmission line 5, and the gap between the metal transmission line 5 and the accommodating groove 61 is fitted; the accommodating groove 61 is formed by stamping or hot-melt cutting.

[0075] For example, for the lower layer medium 6 of the integral structure, the upper receiving groove 61 can be formed by hot-melt cutting and grooving. Of course, in actual use, other existing forming methods can also be used.

[0076] For the lower layer medium 6 composed of the upper and lower layers of medium sheets, the upper layer medium 4 can be formed by punching and cutting, or by hot-melt cutting, or by other existing forming means.

[0077] The metal transmission line 5 is an integral or spliced ​​structure.

[0078] In this embodiment, the metal transmission line 5 can be formed in a conventional manner, such as by stamping or laser cutting.

[0079] The antenna device of this embodiment includes any one of the above-mentioned cavity-type phase shifters, and the phase shift component 10 is connected to the antenna radiation unit via a feeding cable or a probe.

[0080] The installation method of the cavity-type phase shifter of this embodiment includes the following steps:

[0081] Step 1: Place the lower dielectric layer 6 with the receiving groove 61 facing upwards, lay the metal transmission line 5 flatly in the receiving groove 61, and place the phase shifting section 51 of the metal transmission line 5 outside the lower dielectric layer 6;

[0082] Step 2: The upper dielectric layer 4 is mounted and fixed on the lower dielectric layer 6 above the metal transmission line 5, so that the metal transmission line 5 is stably located between the upper dielectric layer 4 and the lower dielectric layer 6, forming a phase shifting component 10;

[0083] Step 3: assemble the phase shifting assembly 10 along the length direction to one side of the convex ridge 12 in the cavity 11 of the housing 1 , with the phase shifting section 51 located above the convex ridge 12 ;

[0084] Step 4: Install the moving medium 2 on the pull rod 3 , and fit the moving medium 2 to the other side of the ridge 12 in the cavity 11 through the pull rod 3 , so that the phase shifting section 51 is accommodated in the middle groove 21 of the moving medium 2 .

[0085] In this embodiment, the metal transmission line 5, the upper dielectric 4, and the lower dielectric 6 can be first installed to form the phase shift assembly 10, and then the phase shift assembly 10 can be installed as a whole into the cavity 11 of the housing 1, which is convenient for actual assembly operations.

[0086] The present invention greatly ensures the installation and use flatness of the metal transmission line, can effectively maintain the central position of the phase shift component, ensures the stability of the antenna electrical performance, and helps to simplify and facilitate the actual assembly operation.

[0087] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0088] The above description is an explanation of the present invention, not a limitation of the present invention. The scope of the present invention is defined in the claims. Any form of modification may be made within the scope of protection of the present invention.

Claims

1. A cavity-type phase shifter, characterized in that: The invention comprises a shell (1) of a flat structure, wherein the top surface of the shell (1) forms a reflector, and a plurality of cavities (11) are formed in parallel along the width direction on the shell (1) located below the reflector, and the bottom surface of each cavity (11) extends upward to form a convex ridge (12), and the convex ridge (12) divides the corresponding cavity (11) into two spaces that are connected to each other on the left and right; a phase shifting component (10) is installed in one space of the cavity (11), and a pull rod (3) is slidably installed in the other space of the cavity (11), and a moving medium (2) is installed on the pull rod (3) at intervals along the length direction; The structure of the phase shifting assembly (10) is as follows: it comprises an upper layer medium (4), a metal transmission line (5), and a lower layer medium (6) which are installed as one body; a receiving groove (61) is provided on the top surface of the lower layer medium (6); the metal transmission line (5) is installed inside the receiving groove (61); and the upper layer medium (4) is installed on the lower layer medium (6) located at the opening of the receiving groove (61) or above the upper layer medium (6); The metal transmission line (5) located outside the accommodating groove (61) forms a phase shifting section (51), and the phase shifting section (51) goes over the convex ridge (12) and is installed in the moving medium (2).

2. A cavity-type phase shifter according to claim 1, characterized in that: A groove (21) is provided along the middle of the side of the moving medium (2) facing the phase shifting section (51), and the phase shifting section (51) is fitted in the groove (21); a convex column (22) is extended at intervals along the length direction on the side of the moving medium (2) facing the pull rod (3), and a hole is provided on the pull rod (3) to fit with the convex column (22).

3. The cavity-type phase shifter according to claim 1, characterized in that: The depth of the accommodating groove (61) is adapted to the height of the metal transmission line (5), and the upper medium (4) is installed flat on the top surface of the lower medium (6); the upper medium (4) is installed on the top surface of the lower medium (6) via a fixing structure, and the fixing structure includes but is not limited to hot melt adhesive, glue, double-sided tape, and pins.

4. The cavity-type phase shifter according to claim 1, characterized in that: The depth of the accommodating groove (61) is greater than the height of the metal transmission line (5); the upper dielectric (4) includes a plurality of dielectric segments (40) that are shaped like the metal transmission line (5); each dielectric segment (40) is fitted to a corresponding position of the accommodating groove (61) above the metal transmission line (5); and each dielectric segment (40) is interference fit with the accommodating groove (61).

5. The cavity-type phase shifter according to claim 1, characterized in that: The lower layer medium (6) is an integral structure, or, The lower layer medium (6) is composed of two layers of dielectric sheets, the dielectric sheet located at the upper layer is provided with a receiving groove (61) through it, and the dielectric sheet located at the lower layer is a flat plate structure, and the upper and lower dielectric sheets are assembled and fixed between them.

6. The cavity-type phase shifter according to claim 1, characterized in that: A plurality of protrusions (62) extend upward from the inner bottom surface of the accommodating groove (61), and positioning holes (52) corresponding to the protrusions (62) are provided on the metal transmission line (5).

7. The cavity-type phase shifter according to claim 1, characterized in that: The metal transmission line (5) is provided with a feeding connector (54), and a feeding hole (53) is provided on the feeding connector (54); a notch is provided on the lower layer medium (6) located at the feeding connector (54) or the lower layer medium (6) and the upper layer medium (4), and the feeding connector (54) is exposed through the notch.

8. The cavity-type phase shifter according to claim 1, characterized in that: The accommodating groove (61) is a discontinuous multi-stage structure. The accommodating groove (61) is processed according to the shape of the metal transmission line (5). The gap between the metal transmission line (5) and the accommodating groove (61) is fitted. The accommodating groove (61) is formed by stamping or hot-melt cutting.

9. An antenna device, characterized in that: A cavity-type phase shifter comprising any one of claims 1 to 8.

10. A method for installing the cavity-type phase shifter according to claim 1, characterized in that: The steps include: The surface of the lower dielectric (6) with the receiving groove (61) is facing upwards, and the metal transmission line (5) is laid flat and installed in the receiving groove (61), and the phase shift section (51) of the metal transmission line (5) is located outside the lower dielectric (6); the upper dielectric (4) is installed and fixed on the lower dielectric (6) above the metal transmission line (5), so that the metal transmission line (5) is stably maintained between the upper dielectric (4) and the lower dielectric (6), thereby forming a phase shift assembly (10); The phase shifting assembly (10) is mounted on one side of a convex ridge (12) in a cavity (11) of a housing (1) along a length direction, with the phase shifting section (51) being located above the convex ridge (12); The moving medium (2) is mounted on the pull rod (3), and the moving medium (2) is fitted to the other side of the convex ridge (12) in the cavity (11) via the pull rod (3), so that the phase shifting section (51) is accommodated in the middle groove (21) of the moving medium (2).

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