JP2003243903A - Phase shifter rotary mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a phase shifter rotary mechanism capable of reducing intermodulation distortion. <P>SOLUTION: This invention provides the phase shifter rotary mechanism capable of setting a phase shift amount of a rotary phase shifter by rotation of a motor. The phase shifter rotary mechanism includes a gear 28 coupled to a rotary shaft C1 of the rotary phase shifter, a feed member (engagement projection 26) turned by rotation of the motor and coupled to teeth of the gear 28 to feed the gear 28 by one tooth each, and a latchet claw (pin 27). At least either of a pair of moving contact members selected by the gear 28, the feed member and the latchet claw is made of a resin. Configuring at least either of a pair of the moving contact members in contact with each other with the resin, can reduce intermodulation distortion caused by improper contact between metals. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation mechanism of a phase shifter that sets a main beam direction by adjusting a phase difference between antenna elements. In particular, it relates to a phase shifter rotating mechanism capable of reducing intermodulation distortion.

[0002]

2. Description of the Related Art In general, an array antenna 1 used in a mobile communication base has a plurality of antenna elements 2 as shown in FIG. By adjusting the phase difference between the antenna elements 2 using the phase shifter 3, the angle θ ₁ or θ ₂ with respect to the horizontal direction of the main beam radiating the radio wave most strongly by the antenna is changed to set the communication area. , Suppress interference between base stations.

As a rotating mechanism used here, Japanese Patent Laid-Open No. 2001-2
JP-A-84902 and JP-A-2001-284903 disclose a phase shifter rotating mechanism that can accurately set the rotation angle even if the rotation accuracy of the motor is low with a simple configuration. This rotating mechanism includes a gear connected to the rotating shaft of the rotary type phase shifter, and a feed member for rotating with the rotation of the motor and feeding the gears one by one by engaging the teeth of the gear. , With ratchet pawls for holding the rotation angle of the gear. When the motor is rotated to rotate the feed member, the gear teeth can be advanced in a fixed direction. At this time, the ratchet pawl for holding the rotation angle of the gear can stop the gear at a predetermined rotation angle even if the rotation amount of the motor is not accurate.

[0004]

However, the above-mentioned phase shifter rotating mechanism has the following problems.

If the materials of the parts are not properly selected, intermodulation distortion will occur. This is because a metal part is usually used for the movable part, but if metal-to-metal contact is incomplete, intermodulation distortion occurs.

When using two phase shifters, two rotating mechanisms are also required. When operating the two phase shifters in synchronization, it is conceivable to use a connecting plate for transmitting the rotation of one phase shifter to the other phase shifter. At that time, two rotation mechanisms are required to accurately stop each phase shifter at a desired rotation angle.

Therefore, a main object of the present invention is to provide a phase shifter rotating mechanism capable of reducing intermodulation distortion.

Another object of the present invention is to provide a phase shifter rotating mechanism capable of accurately interlocking a plurality of phase shifters with one rotating mechanism.

[0009]

The present invention achieves the above object by resinizing at least one side of a movable contact member.

That is, the phase shifter rotating mechanism of the present invention is a phase shifter rotating mechanism capable of setting the amount of phase shift of the rotary type phase shifter by rotating the motor. A gear connected to the shaft, a feed member that rotates with the rotation of the motor, and feeds one or more gears by engaging the teeth of the gear, and to maintain the rotation angle of the gear. With ratchet claws. At least one of the pair of movable contact members selected from the gear, the feed member and the ratchet pawl is made of resin.

By constituting at least one of a pair of movable contact members, which are members of the phase shifter rotating mechanism, contacting each other with resin, intermodulation distortion caused by incomplete contact between metals is reduced. can do.

The movable contact member made of this resin can be expected to reduce the intermodulation distortion even if it is one of the gear, the feed member and the ratchet pawl. All three members may be made of resin. Since the gear contacts both the feed member and the ratchet pawl, it is preferable that the gear is made of resin. If the gear is made of resin, the feeding member and the ratchet pawl may be made of metal. That is, one of the pair of movable contact members may be made of resin and the other may be made of metal.

In addition, when a rotation transmission mechanism for transmitting the rotation of the motor to the feed member is provided, it is also preferable that at least one of the pair of movable contact members in the rotation transmission mechanism is made of resin. For example, when a rotation transmission mechanism including a motor gear mounted on a rotation shaft of a motor and a driven gear that meshes with the motor gear is provided and a feed member is provided on the rotation shaft of the driven gear, the motor gear is made of resin. It can be mentioned. Further, the bearing that rotatably supports the gear may be made of resin.

The resin constituting the movable contact member is preferably one having excellent heat resistance, abrasion resistance and dimensional stability. For example, polyacetal can be mentioned.

It is also possible to control the rotation of a plurality of phase shifters by using the above rotation mechanism. That is, a first phase shifter having the above rotation mechanism, a second phase shifter having a rotation shaft but not having a drive source for the rotation shaft, and a second rotation operation of the rotation shaft of the first phase shifter. And a connecting plate for transmitting to the rotation axis of the phase shifter.

According to this structure, the two phase shifters can be accurately controlled by one rotating mechanism, and the number of parts and the cost can be reduced.

In particular, since the second phase shifter, which is the driven side phase shifter, does not require a drive source such as a motor, a gear, a feed member, and a ratchet mechanism, the drive load is reduced, and the movable contact portion has a resin component. Is easier to use. Also, the motor output can be reduced.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. (Overall Structure) FIG. 1 is a circuit diagram of an array antenna incorporating a phase shifter. This array antenna is a polarization diversity array antenna in which a + 45 ° polarized antenna element 8a and a −45 ° polarized antenna element 8b are vertically arranged. Three pairs of antenna elements 8a and 8b that follow vertically constitute one power feeding unit,
An array antenna is composed of five power supply units. These power supply units are represented by reference numerals 2a to 2e. The array antenna also includes phase shifters 3a and 3b with variable phase shift angles.

The feed signal to this array antenna is +45
The polarized wave is supplied from the fixed phase shifter 6a and the -45 polarized wave is supplied from the fixed phase shifter 6b. The input signals are distributed by the distributors 7a and 7b, respectively, and one of the distributed signals is directly supplied to the power supply unit 2c. The other is a phase shifter
The phase difference is given by 3a and 3b, and the feeding units 2a and 2a,
Power is supplied to 2b, 2c, 2d and 2e. The phase shifters 3a and 3b (collectively referred to as 3) have the same structure and are connected to each other by connecting rods (described later) so that the rotations are interlocked. Here, the phase shifter 3a is a first phase shifter, and the phase shifter 3b is a second phase shifter.

(Structure of Phase Shifter) FIG. 2 is an exploded perspective view of a main part of the phase shifter 3. The phase shifter 3 is provided on a fixed ground plate (not shown) made of metal (copper, aluminum, etc.), and is rotationally coupled to an insulating substrate 17 into which an arc-shaped strip conductor 15 and a cylindrical center conductor 16 are fitted. Rotating rod 12 supporting the conductor 13
And an insulating film 14 made of an insulating material such as polytetrafluoroethylene. An adhesive is applied to the insulating film 14.

In FIG. 2, the insulating film 14 is a disc-shaped sheet that covers the entire strip conductor 15, but the insulating film 14 is shaped so as to match the surface of the center conductor 16 and the surface of the strip conductor 15 and is provided with an adhesive agent. May be applied and attached, or an adhesive may be applied and attached on the surface of the rotary coupling conductor 13.

Rotating holes 16a, 14a and 12a are provided at the centers of the central conductor 16, the insulating film 14 and the rotating rod 12, respectively. The rotary rod 12 is rotationally driven around the rotary hole 12a in synchronization with the rotation of the rotary shaft C (C1 or C2 described later). The rotation drive is performed by the following rotation mechanism.

(Rotation Mechanism) FIG. 3 is a plan view of a phase shifter rotation mechanism including a phase shifter, and FIG. 4 is a sectional view taken along line XX of FIG.
The phase shifter rotating mechanism has four rotating shafts A, B, C1 and D provided on the entire mounting plate 33 so as not to move vertically. The rotating shafts A to D are all made of metal.

The rotary shaft A is the rotary shaft of the electric motor 21, and is equipped with a resin motor gear 22.

The rotating shaft B is equipped with a driven gear 23 made of metal which meshes with the motor gear 22. The driven gear 23 and the motor gear 22 constitute a rotation transmission mechanism that transmits the rotation of the motor 21 to the feeding member described below. On the rotating shaft B, a metal engaging protrusion 26 is formed as a feeding member for feeding a gear 28 partially formed with teeth. The rotating shaft B is rotatably supported by the entire mounting plate 33 via a resin bearing 41. Further, the rotating shaft B is equipped with a measuring gear (not shown). The rotation of this measuring gear is
It is detected electrically, magnetically or optically by a detector (not shown).

The rotary shaft C1 works in conjunction with the rotary rod 12 described above, and is a resin gear having teeth formed only on a part of its outer circumference.
I am wearing 28. The rotary shaft C1 is attached to the whole mounting plate 33
On the other hand, it is rotatably supported via a bearing 42 made of resin. Further, a measurement gear (not shown) is attached to the rotary shaft C1. By a transmission gear (not shown) that meshes with the measurement gear and a detector (not shown) that works with the transmission gear,
The rotation angle of the rotation shaft C1 can be detected by detecting the rotation angle of the transmission gear.

An L-shaped metal fitting 25 is attached to the rotary shaft D. One end of the L-shaped metal fitting 25 is provided with a pin 27 that is elastically moved by the teeth of the gear 28. Since the pin 27 is elastically engaged with the tooth of the gear 28 as a ratchet pawl, the gear 28 can push the pin 27 away and rotate one tooth at a time. The other end of the L-shaped metal fitting 25 is pulled in the direction of arrow E in FIG. 3 by a tension spring 24 mounted between the L-shaped metal fitting 25 and the fixed shaft 34. Therefore, the pin 27 is always urged in the direction to bite into the teeth of the gear 28.

(Operation of Rotation Mechanism) When the electric motor 21 is rotated to rotate the rotating shaft B about one rotation in the clockwise direction in FIG. 3, the engaging protrusion 26 formed on the rotating shaft B causes the engagement protrusion 26 of the gear 28 to rotate. Move the teeth counterclockwise. At this time, as described above, since the elastically moving pin 27 is inserted in the tooth of the gear 28, the gear 28 can push the pin 27 away and rotate one tooth counterclockwise.

When the rotating shaft B is rotated counterclockwise about one turn in FIG. 3, the engaging projection 26 formed on the rotating shaft B advances the teeth of the gear 28 clockwise. Also at this time, as described above, the gear 28 can push the pin 27 away and rotate one tooth clockwise.

The engaging protrusion 26 has one tooth of the gear 28,
It suffices to proceed clockwise or counterclockwise, and even if the engagement protrusion 26 further rotates, it does not contribute to the rotation of the gear 28 unless the rotation angle reaches the angle for advancing the next tooth. Therefore, the accuracy of the rotation angle of the engagement protrusion 26, that is, the rotation axis B is not as strict as in the case where the rotational movement by the motor is changed to the linear movement by using the cam.

In a series of these rotating operations, the motor gear 22 and the driven gear 23, the rotating shaft B and the bearing 41, the feeding member (engaging protrusion 26) and the gear 28, the gear 28 and the ratchet pawl (pin 2).
7) By configuring one of the movable contact members of the rotary shaft C1 and the bearing 42 with resin, it is possible to suppress intermodulation distortion caused by incomplete contact between metals. This intermodulation distortion suppressing effect can also be obtained by forming the rotating shaft C2 and the bearing of the second phase shifter, which will be described later, and the connecting rod 50 and one of the rotating shafts F1 and F2 from resin.

In such a rotating mechanism, the rotating shaft
A pressure contact member 4a is interposed at the lower end of C1. This pressure contact member 4a
Pushes the rotating rod 12 shown in FIG. 2 downward. for that reason,
The electrostatic coupling between the rotary coupling conductor 13 formed on the lower surface of the rotating rod 12, the central conductor 16 and the arc-shaped strip conductor 15 is maintained, and an electrically stable phase shift characteristic can be realized.
Specific examples of the pressure contact member 4a include the configurations disclosed in JP 2001-284902 A and JP 2001-284903 A.

(Interlocking of first and second phase shifters) First phase shifter 3a
Is the rotation axis C1 driven by the motor 21 driven by the rotation mechanism described above.
Is rotated, and the rotary rod 12 is rotated accordingly. On the other hand, as shown in FIGS. 3 and 4, the second phase shifter 3b itself does not have a drive source such as a motor and is rotated in association with the rotation of the first phase shifter 3a.

The second phase shifter 3b is a rotary shaft from the first phase shifter 3a.
A, motor 21, motor gear 22, driven gear 23, rotary shaft B, feed member (engaging protrusion 26), gear 28, rotary shaft D, L-shaped metal fitting 25
The tension spring 24 is removed. This phase shifter 3b has a rotation axis C2. The rotary rod 12 shown in FIG. 2 is rotated in association with the rotation of the rotary shaft C2, and the rotary coupling conductor 13 is electrostatically coupled to the central conductor 16 and the arc-shaped strip conductor 15 by the action of the pressure contact member 4b. The point to keep is the first phase shifter 3a
Is the same as.

Both of these phase shifters 3a and 3b are composed of respective pressure contact members 4a,
The rotating shafts F1 and F2 provided on the upper surface of 4b are linked by connecting rods 50. The motor in this connection structure
When 21 is driven, the rotation axis C1 of the first phase shifter is rotated.
At that time, the pressure contact member 4a of the first phase shifter 3a is also rotated. Further, by the action of the connecting rod 50, the pressure contact member 4b of the second phase shifter 3b is also rotated in synchronization, and the rotation shaft C2 is also rotated. Therefore, one rotating mechanism can rotate the two phase shifters 3a and 3b.

(Other Design Modifications) The present invention is not limited to the above embodiments, and various modifications can be made within the scope of the present invention.

An engaging projection 2 for sending the gear 28 to the rotating shaft B
Multiple 6 may be formed. For example, a pair of engagement protrusions are provided at opposite positions on the outer circumference of the rotation axis B. This axis of rotation
When B is rotated about half a turn, the one engagement protrusion formed on the rotation axis B advances the teeth of the gear 28 by one tooth. When the rotating shaft B is further rotated about half a turn, the other engaging protrusion advances the tooth of the gear 28 by another tooth. Therefore, the gear 28 advances by two teeth while the rotating shaft B makes one rotation.

Further, although two phase shifters 3 of the above-mentioned specific example are prepared for use in the diversity array antenna, it is needless to say that when the phase shifter 3 is used in a non-diversity array antenna, only one is required. Absent.

[0039]

As described above, according to the phase shifter rotating mechanism of the present invention, intermodulation distortion can be reduced by forming at least one of the movable contact members with resin.

Further, by connecting the two phase shifters by the connecting member, it is possible to operate the two phase shifters with one rotating mechanism.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an array antenna incorporating a phase shifter.

FIG. 2 is an exploded perspective view of a main part of a phase shifter 3.

FIG. 3 is a plan view of a phase shifter rotating mechanism.

4 is a sectional view taken along line XX of FIG.

FIG. 5 is an explanatory diagram showing a state where radio waves are radiated from the array antenna in the main beam direction.

[Explanation of symbols]

A, B, C1, C2, D rotation axis F1, F2 rotation axis 1 array antenna 2a, 2b, 2c, 2d, 2e power supply unit 3, 3a, 3b Phase shifter 4a, 4b Pressure contact member 6a, 6b Fixed phase shifter 7a, 7b distributor 8a, 8b antenna element 12 rotating rod 13 Rotating coupling conductor 14 Insulation film 15 strip conductor 16 center conductor 17 Insulation board 21 electric motor 22 Motor gear 23 Driven gear 24 tension spring 25 L-shaped bracket 26 Engagement protrusion 27 pin 28 gears 33 Overall mounting plate 34 fixed axis 41, 42, 43 bearings 50 connecting rod

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Claims (5)

[Claims] 1. A phase shifter rotating mechanism capable of setting a phase shift amount of a rotary type phase shifter by rotating a motor, comprising: a gear connected to a rotary shaft of the rotary type phase shifter; The motor is rotated with the rotation of the motor, and is provided with a feed member for feeding the gear by one tooth or more by being fitted into the teeth of the gear, and a ratchet pawl for holding the rotation angle of the gear, the gear, A phase shifter rotating mechanism, wherein at least one of a pair of movable contact members selected from a feed member and a ratchet pawl is made of resin. 2. A rotation transmission mechanism for transmitting the rotation of a motor to the feed member, wherein at least one of a pair of movable contact members in the rotation transmission mechanism is made of resin. The phase shifter rotating mechanism described in. 3. The phase shifter rotating mechanism according to claim 1, wherein the bearing of the rotating shaft is made of resin. 4. A first phase shifter having the rotating mechanism according to claim 1, a second phase shifter having a rotating shaft, and a second shifting operation of the rotating shaft of the first phase shifter. A phase shifter rotating mechanism, comprising: a connecting member that transmits the rotation shaft of the phaser. 5. The phase shifter rotating mechanism according to claim 1, wherein one of the pair of movable contact members is made of resin and the other is made of metal.