JP2508379B2 - Magnetostatic wave device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetostatic wave device, and more particularly to a magnetostatic wave device capable of changing frequency characteristics by changing the magnitude of a magnetic field applied to a ferrimagnetic substrate. .

(Prior Art) Conventionally, there has been a magnetostatic wave device that applies a magnetic field to a ferrimagnetic substrate with a permanent magnet and an electromagnet. In order to change the frequency characteristic of this magnetostatic wave device, the magnitude of the magnetic field applied to the ferrimagnetic substrate was changed by changing the current flowing through the electromagnet.

Further, conventionally, there has been a magnetostatic wave device provided with an adjusting screw for adjusting the magnitude of the magnetic field applied to the ferrimagnetic substrate. To change the frequency characteristics of this magnetostatic wave device,
For example, by moving the adjusting screw with a motor,
The magnitude of the magnetic field applied to the ferrimagnetic substrate was changed.

(Problems to be Solved by the Invention) However, in a magnetostatic wave device that uses both a permanent magnet and an electromagnet, a constant amount of current is passed through the electromagnet, resulting in high power consumption. Further, in this magnetostatic wave device, it is necessary to increase the size of the electromagnet for changing the frequency characteristic, so that the size also increases.

Further, in the magnetostatic wave device that moves the adjusting screw to change the frequency characteristic, the adjusting screw is moved by the motor, so that it takes time to change the frequency characteristic.

Therefore, a main object of the present invention is to provide a magnetostatic wave device that can be miniaturized, consumes less power, and can change frequency characteristics in a short time.

(Means for Solving the Problem) The present invention is directed to a ferrimagnetic base, a frame that constitutes at least a part of a magnetic circuit for applying a magnetic field to the ferrimagnetic base, and a magnetic member provided so as to be contactable with the frame. A body plate, an electromagnet provided near the magnetic body plate for displacing the magnetic body plate, and for holding the magnetic body plate in a state of being in contact with the frame body and a state of being separated from the frame body, respectively. And a magnetic member plate is displaced by an electromagnet so that the magnetic member plate contacts the frame member or is separated from the frame member by an electromagnet, thereby gradually changing the magnetic resistance of the magnetic circuit.
It is a magnetostatic wave device.

(Operation) The electromagnet displaces the magnetic plate so that it contacts the frame or separates from the frame. Further, the magnetic plate is held by the holding means in the state of being in contact with the frame and in the state of being separated from the frame.

When the magnetic plate comes into contact with the frame, the magnetic resistance of the magnetic circuit for applying the magnetic field to the ferrimagnetic base becomes small, and the magnitude of the magnetic field applied to the ferrimagnetic base becomes large.

On the contrary, if the magnetic plate is separated from the frame, the magnetic resistance of the magnetic circuit for applying the magnetic field to the ferrimagnetic base increases and the magnitude of the magnetic field applied to the ferrimagnetic base decreases.

Since the magnitude of the magnetic field applied to the ferrimagnetic substrate can be changed in this manner, the frequency characteristic of the magnetostatic wave device can be changed.

Further, since the electromagnet is used for displacing the magnetic plate, it can be made smaller than the electromagnet which directly applies a magnetic field to the ferrimagnetic substrate in the conventional example. Therefore, the magnetostatic wave device can be downsized.

Further, when changing the magnitude of the magnetic field applied to the ferrimagnetic substrate, the magnetic material plate is held by the holding means in the state of being in contact with the frame body and in the state of being separated from the frame body. It suffices to apply a current to the electromagnet only when the plate is displaced, and it is not necessary to apply a constant current. Therefore, power consumption is reduced.

Further, in order to change the magnitude of the magnetic field applied to the ferrimagnetic base, it is only necessary to displace the magnetic plate with the electromagnet, so that the magnitude of the magnetic field applied to the ferrimagnetic base can be changed in a short time. Therefore, the frequency characteristics of the magnetostatic wave device can be changed in a short time.

(Effect of the Invention) According to the present invention, miniaturization is possible, power consumption is small, and frequency characteristics can be changed in a short time.
A magnetostatic wave device is obtained.

The above-mentioned objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of the embodiments with reference to the drawings.

(Embodiment) FIG. 1 is an illustrative view showing one embodiment of the present invention. The magnetostatic wave device 10 includes a box-shaped outer frame body 12, for example. Also,
A partition plate 14 having, for example, a rectangular plate shape is fixed to a substantially central portion in the vertical direction inside the outer frame 12. The outer frame body 12 and the partition frame body 14 are integrally formed of, for example, a magnetic material.

A magnetic circuit 16 is formed on the partition frame body 14 and its lower part, and another magnetic circuit 18 magnetically affecting the magnetic circuit 16 is formed on the partition frame body 14 and its upper part.

Further, a YIG element 20 as a ferrimagnetic base is supported by a support plate 22 in the middle of the magnetic circuit 16 in the vertical direction. In this case, the support plate 22 is fixed to the outer frame body 12, and the YIG element 20 is fixed to the support plate 22.

Further, in the magnetic circuit 16, a permanent magnet 24a for applying a magnetic field to the YIG element 20 is fixed on the YIG element 20. The permanent magnet 24a is fixed to the lower surface of the partition frame body 14. Further, a permanent magnet 24b for applying a magnetic field to the YIG element 20 is also fixed below the YIG element 20 in the magnetic circuit 16. The permanent magnet 24b is fixed to the bottom wall of the outer frame body 12.

On the other hand, in another magnetic circuit 18, a permanent magnet 26 is provided in the outer frame body 12.
It is fixed to the center of the upper wall. Further, a holding member 28 made of a magnetic material is fixed to the upper wall of the outer frame 12 so as to cover the permanent magnet 26. At the center of the holding member 28, a holding piece 28a having a V-shaped cross-section at its tip is formed so as to extend vertically downward. Also, the holding piece 28a
Are formed with a predetermined distance from the partition frame body 14.

Further, a first electromagnet 30 and a second electromagnet 32 are formed on the lower surface of the holding member 28 with the holding piece 28a interposed therebetween.

The vertical length of the first electromagnet 30 is formed to be substantially the same as the vertical length of the holding piece 28a. The vertical length of the second electromagnet 32 is shorter than the vertical length of the holding piece 28a.

On the other hand, the middle portion of the magnetic plate 34 made of a magnetic material is held by the attraction force of the permanent magnet 26 at the tip of the holding piece 28a. In this case, the magnetic plate 34 can be held in two states.

That is, in the first state, one end of the magnetic plate 34 is in contact with the upper surface of the partition frame 14, and the other end is the second end.
It can be held by the holding piece 28a while being in contact with the lower end of the electromagnet 32. In the second state, one end of the magnetic plate 34 contacts the lower end of the first electromagnet 30, and the other end of the magnetic plate 34 is placed on the holding piece 28a at a distance from the lower end of the second electromagnet 32. Can be retained.

In this magnetostatic wave device 10, when the magnetic plate 34 is in contact with the partition frame 14, the magnetic resistance of the magnetic circuit 18 is small and the YI
The magnetic field applied to the G element 20 is large.

Then, in this state, when a current is passed through the first electromagnet 30 in one direction so that a magnetic field is generated in the same direction as the magnetic field of the permanent magnet 26, one end of the magnetic plate 34 is the first electromagnet.
As it is attracted to 30, and does not come into contact with the partition frame 14 as shown by the chain double-dashed line, the magnetic resistance of the magnetic circuit 18 increases and the magnetic field applied to the YIG element 20 decreases. After that, even if the current flowing through the first electromagnet 30 is cut off, the magnetic plate 34 is held by the holding piece 28a in that state by the attractive force of the permanent magnet 26. In addition, this magnetic plate 34
May be rotatably supported at the tip of the holding piece 28a by, for example, a pin.

Then, when a current is passed through the second electromagnet 32 in one direction so that a magnetic field is generated in the same direction as the magnetic field of the permanent magnet 26, the other end of the magnetic plate 34 is attracted to the second electromagnet 32. The one end of the magnetic plate 34 separates from the first electromagnet 30 and comes into contact with the partition frame 14 again. After that, even if the current passed through the second electromagnet 32 is cut off, the magnetic plate 34
The attraction force of the permanent magnet 26 holds the holding piece 28a in that state.

When a current is applied to the first electromagnet 30 in the opposite direction, a magnetic field is generated in the first electromagnet 30 in the direction opposite to the direction of the magnetic field of the permanent magnet 26, so that one end of the magnetic plate 34 is the first electromagnet. The magnetic resistance of the magnetic circuit 18 decreases away from 30. Also, the second
When a current is passed in the opposite direction to the electromagnet 32, a magnetic field is generated in the second electromagnet 32 in the direction opposite to the direction of the magnetic field of the permanent magnet 26.
The other end of the magnetic plate 34 separates from the second electromagnet 32, and the magnetic resistance of the magnetic circuit 18 increases.

Therefore, in this magnetostatic wave device 10, the first electromagnet 30
By displacing the magnetic plate 34 with the second electromagnet 32, the magnitude of the magnetic field applied to the YIG element 20 can be changed stepwise. Therefore, the frequency characteristics of the magnetostatic wave device 10 can be changed stepwise.

If the coils of the first electromagnet 30 and the second electromagnet 32 are wound in reverse, the displacement direction of the magnetic plate 34 with respect to the direction of the current flowing through the electromagnets 30 and 32 is also reversed.

Further, the first electromagnet 30 and the second electromagnet 30 of the magnetostatic wave device 10
Since the electromagnet 32 is used for displacing the magnetic plate 34, it can be downsized compared to an electromagnet that applies a magnetic field to the ferrimagnetic base. Therefore, the magnetostatic wave device 10 can be downsized.

Further, in this magnetostatic wave device 10, when the magnetic plate 34 is displaced, a current may be passed through the first electromagnet 30 or the second electromagnet 32, and it is not necessary to pass a current through these electromagnets. Consumption is low.

Further, when changing the frequency characteristic of the magnetostatic wave device 10, the first electromagnet 30 or the second electromagnet 32 is used to change the magnetic material plate.
Since it is only necessary to displace 34, the frequency characteristic can be changed in a short time.

In the above-described embodiment, the magnetic material plate and the electromagnet for displacing the magnetic material plate are provided in one set so that the frequency characteristic can be changed in two steps. It is also possible to provide two or more sets of electromagnets and the like so that the frequency characteristics can be changed in multiple stages.

[Brief description of drawings]

The drawing is an illustrative view showing one embodiment of the present invention. In the figure, 10 is a magnetostatic wave device, 12 is an outer frame, 14 is a partition frame, 16 is a magnetic circuit, 18 is another magnetic circuit, 20 is a YIG element, 24a, 24b and 26 are permanent magnets, 28 is a holding element. A member, 30 is a first electromagnet, 32 is a second electromagnet, and 34 is a magnetic plate.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Fumio Kanaya 2 26-10 Tenjin, Nagaokakyo City, Kyoto Prefecture Murata Manufacturing Co., Ltd. Murata Manufacturing Co., Ltd.

Claims (1)

(57) [Claims] 1. A ferrimagnetic base, a frame forming at least a part of a magnetic circuit for applying a magnetic field to the ferrimagnetic base, a magnetic plate provided in contact with the frame, and a magnetic plate of the magnetic plate. Electromagnets provided in the vicinity for displacing the magnetic plate, and holding means for holding the magnetic plate in the respective states of being in contact with the frame and being separated from the frame are provided. Included, by displacing the magnetic plate so that the magnetic plate comes into contact with or separate from the frame by the electromagnet, the magnetic resistance of the magnetic circuit is changed stepwise, Magnetic wave device.