JPH046902A - Polarizer - Google Patents

Abstract

PURPOSE:To improve the magnetic efficiency of a magnetic field generated by a coil current by arranging a magnetic body to the intermediate part of the outer circumference of the coil in a polarizer arranging the coil around the waveguide to which a ferrimagnetic body is inserted. CONSTITUTION:A coil 21 is wound around a coil bobbin 22 so that the direction of magnetic field by a coil current is coincident in the lengthwise direction of a ferrimagnetic body 1. A waveguide 3 is inserted in the inner diameter part of the coil bobbin 22. A magnetic body 6 is arranged in the middle at the outer circumference of the coil 2. Thus, the magnetic body 6 acts like a yoke to the magnetic field caused by a current flowing to the coil 21. Thus, the magnetic efficiency is improved. Since the magnetic body 6 is arranged in the middle of the outer circumference of the coil 21, the presence of the magnetic body 6 does not give effect on the structure and shape or the like of the waveguide 3. A structure suitable for improving the impedance matching and the efficiency is adopted for the waveguide 3.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a polarization device in which a coil is arranged around a waveguide into which a ferrimagnetic material is inserted. By arranging the coil, magnetic efficiency against the coil current magnetic field is high, and insertion loss can be kept low.
Furthermore, it is possible to provide a polarization device that is easy to assemble and has a structure that does not interfere with coil winding.

<Prior Art> This type of polarization device is mainly used in satellite communication (CS) receiving systems. Satellite broadcasting (BS) systems use circularly polarized waves, but CS systems use circularly polarized waves.
Since linearly polarized waves are used, a polarization device for linearly polarized waves may be incorporated into the receiving system. One type of polarization device has a structure in which a coil is placed around a waveguide into which a ferrimagnetic material is inserted, and the magnetic field created by the coil current causes Faraday rotation in the electric field applied to the ferrimagnetic material. and get the output. As a prior art document, there is Japanese Utility Model Application Publication No. 1-95814, in which a coil is arranged around a waveguide constructed by inserting ferrite, and the magnetic field generated when the coil conducts is applied to the ferrite to change the polarization plane of the radio wave. A structure for switching is disclosed. FIG. 11 is a cross-sectional view of a conventional polarization device known from the above-mentioned public literature.
1 is a ferrite, 2 is a coil, 3 is a waveguide, 4.5 is a matching element, and 61.62 is a magnetic washer serving as a yoke.

The magnetic washers 61 and 62 are provided as a means to improve magnetic efficiency against the magnetic field created by the current flowing through the coil 21, and sleeves (611, 612) extending in directions facing each other are provided at both ends of the coil 2. 621,6
22) and has a double cylindrical shape. These magnetic washers 61 , 62 are arranged such that the outer sleeves 611 , 621 face each other on both ends of the coil 21 .

<Problems to be Solved by the Invention> However, the above-mentioned conventional technology has the following problems.

(A) Since the magnetic washers 61 and 62 have double cylindrical sleeves (611, 612) and (621, 622), their shape is complicated and the combined structure with the waveguide 3 is complicated. It gets complicated. These lead to high product costs.

(B) When the polarization device is connected to another waveguide, the contact surface with the other waveguide is the outer surface of the magnetic washer 61 or 62. Therefore, the current flows through the other waveguide-magnetic washer 6
1 or 62 through a path between the outer surface and the inner surface of the waveguide 3. Here, the magnetic washers 61 and 62 are made of a magnetic material, and have a high specific resistance value due to material purchasing considerations. Therefore, insertion loss increases and efficiency decreases.

(C) Since the magnetic washers 61 and 62 have sleeves 611 and 621 extending in directions facing each other, in any combination of the coils 21, an assembly structure is formed in which the sleeves 611 and 621 cover the ends of the coils. Therefore, the magnetic washers 61 and 620 and the sleeves 611 and 621 become obstacles when winding the coil 21. This drawback becomes more noticeable as the length of the sleeves 611, 621 is increased in order to improve the function as a yoke.

(D) By shortening the sleeves 611 and 621, the problems encountered when winding the coil can be solved to some extent, but this increases the distance between the sleeves where no magnetic material is present, and the function as a yoke deteriorates.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and provide a polarization device that is easy to assemble and has a structure that has high magnetic efficiency with respect to the coil current magnetic field, low insertion loss, and does not interfere with coil winding. It is to provide.

Means for solving the above-mentioned i! In order to solve this problem, the present invention provides a polarization device in which a coil is arranged around a waveguide into which a ferrimagnetic material is inserted, and the magnetic material is arranged in the middle part of the outer periphery of the coil. do.

Effect> The magnetic body placed in the middle of the outer periphery of the coil acts as a yoke for the magnetic field created by the coil current. Therefore, magnetic efficiency is improved.

Since the magnetic material is placed in the middle of the outer periphery of the coil, the presence of the magnetic material does not affect the structure, shape, etc. of the waveguide. The waveguide can be of any suitable structure to reduce insertion loss and improve efficiency.

Furthermore, since the magnetic material is attached to the outer periphery of the coil after it has been wound, it does not interfere with the coil winding work.

In addition, since a magnetic material is placed in the middle of the outer circumference of the coil,
Magnetic efficiency can be improved or adjusted by increasing or decreasing the width of the magnetic body.

<Example> FIG. 1 is a perspective view of a polarization device according to the present invention, and FIG. 2 is a front sectional view thereof. In the figure, 1 is a ferrimagnetic material, 21 is a coil, 22 is a coil bobbin around which the coil 21 is wound, 3 is a waveguide, 4.5 is a matching element, 6 is a magnetic material,
7 is a dielectric layer.

The ferrimagnetic material 1 is composed of an oxide magnetic material having a ferrite or garnet structure, for example, YIG. Its cross-sectional shape may be circular, square, or rectangular.

The coil 21 is wound around the coil bobbin 22 so that the direction of the magnetic field due to the coil current matches the length direction of the ferrimagnetic body 1. A waveguide 3 is inserted into the inner diameter portion of the coil bobbin 22 . Coil bobbin 22
When the waveguide 3 has flanges 31 and 32, it is constructed as a combination of a plurality of pieces divided along the axis.

The waveguide 3 is made of a non-magnetic conductive metal material such as aluminum, and coaxially surrounds the ferrimagnetic material 1.

The matching element 4.5 is made of a ceramic dielectric material or the like, and is connected to both end surfaces of the ferrimagnetic material 1 in the axial direction. As a connection method, means such as adhesion can be used. Matching element 4.
5, matching element 4 corresponds to the antenna input side, matching element 5 corresponds to the output side, and other waveguides (not shown) are connected to each.

The magnetic body 6 is arranged at an intermediate portion of the outer periphery of the coil 2 . Therefore, the magnetic body 6 serves as a yoke for the magnetic field created by the current flowing through the coil 21. Therefore, magnetic efficiency is improved.

Moreover, since the magnetic body 6 is arranged in the middle of the outer circumference of the coil 21, the presence of the magnetic body 6 does not affect the structure, shape, etc. of the waveguide 3.

The waveguide 3 can be of any suitable structure to improve impedance matching and efficiency. For example, as shown in the figure, the flanges 31 and 32 provided at both ends of the waveguide 3 are led out to both end faces in the axial direction, and when connecting with another waveguide (not shown), conductive Waveguide 3 made of good aluminum etc.
The end surfaces of the collar portions 31 and 32 of are used as contact surfaces with other waveguides,
Insertion loss can be reduced and efficiency can be improved.

Moreover, since the magnetic body 6 is attached to the outer periphery of the coil 21 after it is wound, it does not become an obstacle to the coil winding work.

The width W2 of the magnetic body 6 can be increased or decreased within the axial length W1 of the coil 21. This allows the magnetic efficiency to be improved and adjusted. The magnetic material 6 is basically:
It can be made of almost any magnetic material such as a metal magnetic material, a composite magnetic material, a metal oxide magnetic material, or a dust magnetic material. It is preferable that these magnetic materials be made into a tape and wound around the outer periphery of the coil 21 in a ring shape. A typical example of the tape-shaped magnetic material constituting the magnetic material 6 is an amorphous alloy.

The dielectric layer 7 is provided so as to surround the outer peripheral surface of the ferrimagnetic material 1 . The apparent dielectric constant of the waveguide 3 as a whole is adjusted to a predetermined value that is a combination of the dielectric constant of the ferrimagnetic material 1 and the dielectric constant of the dielectric layer 7. Thereby, the dielectric constant of the waveguide as a whole is adjusted to a value necessary for impedance matching with other waveguides connected to the input/output side. The dielectric layer 7 may be provided by being divided into a plurality of parts in the length direction of the ferrimagnetic material 1, may be provided with minute holes, or may be a laminate of a plurality of layers having different dielectric constants. Furthermore, a tape having a predetermined dielectric constant may be wound around the ferrimagnetic material 1.

The matching element 4.5 is composed of a ceramic dielectric material having a dielectric constant of about 5 to 10, and the ferrimagnetic material 1 is made of a ceramic material having a dielectric constant of 1.
When ferrite of about 5 is used, the dielectric layer 7 is preferably made of Teflon. The dielectric constant of Teflon is 2
The apparent dielectric constant of the waveguide as a whole including the ferrimagnetic material 1 and the dielectric layer 7 can be lowered to achieve impedance matching.

FIG. 3 is a perspective view illustrating the operation of the polarization device described above. In the figures, the same reference numerals as in FIGS. 1 and 2 indicate the same components. (2) is the current flowing through the coil 21, and Hl is the DC magnetic field generated by the coil current I. , 1lii field H, is directed from the input side to the output side of the ferrimagnetic material 1. E is a linearly polarized wave component in the y-axis direction that is manually applied to the matching element 4.

When the coil current 11 is flowing through the coil 21, the linearly polarized wave component Ey in the y-axis direction passes through the ferrimagnetic material 1 disposed inside the waveguide 3 (see FIGS. 1 and 2). In the meantime, the linearly polarized waves Eyl and 1 rotated by an angle θ according to Faraday rotation under the influence of the magnetic field H3 caused by the coil current are input to the matching element 5 and output.

When the current l is not flowing through the coil 21, the linearly polarized wave component E is input to the matching element 5 as a linearly polarized wave Ey2 in substantially the same direction as the linearly polarized wave component Ey, without undergoing Faraday rotation. and output. Therefore, by switching the current 11 flowing through the coil 21, the input linearly polarized wave component E can be switched between the linearly polarized wave Ey1 and the linearly polarized wave Ey2. The direction of Faraday rotation can be reversed by reversing the direction of the magnetic field H.

Further, the rotation angle θ is controlled by the magnitude of the magnetic field H1, the length of the ferrimagnetic body 1, and the like.

Next, regarding other embodiments of the polarization device according to the present invention, the fourth embodiment will be explained.
This will be explained with reference to FIGS. In either embodiment, effects equal to or greater than those of the embodiments shown in FIGS. 1 and 2 can be obtained.

Figure 4 is an exploded perspective view, and Figure 5 is a cross-sectional view.
81 and 82 indicate magnetic pieces. Magnetic piece 81.8
2 uses the same magnetic material as the magnetic body 6 to form the opening 81.
It is formed into a washer shape with a diameter of 1.821. The waveguide 3 and the coil bobbin 22 each have flanges (31, 32) and (221, 222) that protrude in the radial direction at both ends in the axial direction, and the magnetic pieces 81 and 82 are attached to the flanges 31- 22
It is arranged between the gap 91.92 generated between 1.32 and 222. The arrow alba2 in Fig. 4 indicates the magnetic piece 81.8.
2 shows the insertion direction.

In this embodiment, a magnetic circuit including the magnetic body 81, the magnetic body 6, and the magnetic body 82 is configured for the magnetic field caused by iti flowing through the coil 2, so that the magnetic efficiency is further improved.

In the embodiment shown in FIG. 6, the collar portion 221 of the coil bobbin 22.
222 with an annular spacing 91.92;
Magnetic material pieces 81 and 82 are mounted inside 92. The coil bobbin 22 can be made of an electrically insulating material such as plastic or a non-magnetic conductive material such as aluminum. When the coil bobbin 22 is made of a non-magnetic conductive material, the coil bobbin 22 is integrated with the waveguide 3, and the end surfaces of the flanges 221 and 222 of the coil bobbin 22 are used as contact surfaces with other waveguides to reduce insertion loss. efficiency can be improved. In this case, it is desirable that the coil winding area of the coil bobbin 22 be insulated.

FIG. 7 is an exploded perspective view of another embodiment, and FIG. 8 is a sectional view thereof. 81 to 84 are magnetic pieces. These are the collar portions 221 and 222 of the coil bobbin 22.
It is installed within the interval 91.92 provided in the table. The spacing 91.92 can also be realized by a structure as shown in FIGS. 4 and 5. In FIG. 7, 811 to 841
indicates each opening provided in the magnetic pieces 81 to 84, and arrows a1 to a4 indicate the insertion direction of the magnetic pieces 81 to 84. In this embodiment, a substantially circular yoke is formed by the magnetic pieces 81 to 84 at both ends in the axial direction, so that the magnetic efficiency is further improved. In this embodiment as well, the coil bobbin 22 can be made of a non-magnetic conductive material such as aluminum, and is integrated with the waveguide 3 so that the end surfaces of the flanges 221 and 222 of the coil bobbin 22 are the contact surfaces with other waveguides. As a result, insertion loss can be reduced and efficiency can be improved.

FIG. 9 shows a cross-sectional view of yet another embodiment.

In this embodiment, the collar portion 221.22 of the coil bobbin 21
An insulating washer 10.11 is arranged on the inner surface side of 2, and the distance 9 between the insulating washer 10.11 and the flange 221.222 is
A magnetic piece 81.82 is placed within 1.92. In this embodiment as well, the coil bobbin 22 can be made of a conductive material such as aluminum, so that the coil bobbin 22 is integrated with the waveguide 3, and the end faces of the flanges 221 and 222 of the coil bobbin 22 are separated from other waveguides. The contact surface can be used to reduce insertion loss and improve efficiency.

FIG. 10 shows a sectional view of yet another embodiment. The feature of this embodiment is that the structure of the matching element 5 on the output side is
One or more resistance layers 53 are provided inside the dielectrics 51 and 52 made of ceramic. The resistive layer 53 passes polarized waves perpendicular to the plane and absorbs polarized waves parallel to the plane.

Preferably, the resistive layer 53 is provided integrally within the dielectric 51,52. As a means for forming the resistance layer 53, printing, coating, baking, vapor deposition, sputtering, etc. can be employed. - For legalization, techniques known for other ceramic electronic components such as multilayer ceramic capacitors can also be used. For example, after applying a resistive layer to one dielectric, another dielectric is laminated, or a ceramic dielectric paste and a resistive paste are alternately laminated and sintered.

In the case of this embodiment, the same effects as those explained in FIGS. 1 to 9 can of course be obtained, but the resistive layer 53 absorbs unnecessary polarized waves and extracts only necessary polarized waves. A polarization device is obtained.

Although not shown, it goes without saying that there are many combinations of the above embodiments.

<Effects of the Invention> As described above, the polarization device according to the present invention provides the following effects.

(a) A polarization device in which a coil is placed around a waveguide into which a ferrimagnetic material is inserted, and the magnetic material is placed in the middle of the outer circumference of the coil, improving magnetic efficiency against the magnetic field created by the coil current. It is possible to provide a polarization device with

(b) Since the magnetic material is placed in the middle of the outer periphery of the coil, a waveguide with a structure suitable for reducing insertion loss and improving efficiency despite the presence of the magnetic material can be created. It is possible to provide a polarization device comprising:

(c) Since the magnetic material is placed in the middle of the outer periphery of the coil, it is possible to provide a polarization device that can improve magnetic efficiency without causing trouble in the coil winding operation.

(d) Since the magnetic material is placed in the middle part of the outer periphery of the coil,
A polarization device that can improve or adjust magnetic efficiency can be provided.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view of a polarization device according to the present invention, Fig. 2 is a sectional view thereof, Fig. 3 is a perspective view illustrating the operation of the polarization device, and Fig. 4 is an exploded view of another embodiment. 5 is a sectional view thereof, FIG. 6 is a sectional view of yet another embodiment, FIG. 7 is an exploded perspective view of still another embodiment, and FIG. 8 is a sectional view thereof, 's9 The figure is a cross-sectional view of yet another embodiment, FIG. 10 is a cross-sectional view of still another embodiment, and FIG. 11 is a cross-sectional view of a conventional polarization device. 1... Ferrimagnetic material 2... Coil 3... Waveguide 6... Magnetic material Figure 1 Figure 2 Figure Figure Figure

Claims (5)

[Claims] (1) A polarization device comprising a coil arranged around a waveguide into which a ferrimagnetic material is inserted, the polarization device characterized in that a magnetic material is arranged at an intermediate portion of the outer periphery of the coil. (2) Claim 1, wherein the magnetic body is arranged so as to cover the outer peripheral surface of the coil in a ring shape.
The polarization device described in . (3) The polarization device according to claim 2, wherein the magnetic body is configured by winding a tape-shaped magnetic body around the outer periphery of the coil. (4) The magnetic material is a metal magnetic material, a composite magnetic material,
4. The polarization device according to claim 1, wherein the polarization device is made of either a metal oxide magnetic material or a powder magnetic material. (5) At least one of the waveguide or the bobbin of the coil has a radially protruding flange at both ends in the axial direction, and a magnetic piece is arranged along the surface of the flange. The polarization device according to claim 1, 2, 3, or 4, characterized in that: