JPH03181201A - Polarization device - Google Patents

Abstract

PURPOSE:To easily attain the matching of impedance to another waveguide connected to the input/output side by providing a dielectric layer enclosing the outer circumferential surface of a ferrimagnetic substance. CONSTITUTION:A dielectric layer 6 is provided so as to enclose the outer circumferential surface of a ferrimagnetic substance 1. Therefore the overall apparent dielectric constant of a waveguide 3 is controlled to a prescribed level, i.e., the synthetic value of the dielectric constants of the ferrimagnetic substance 1 and the layer 6 respectively. Then the overall dielectric constant of the waveguide 3 is controlled to a level necessary for matching of impedance to another waveguide connected to the input/output side. Thus it is possible to easily attain the matching of impedance to another waveguide connected to the input/output side by the dielectric constant synthesizing function of the added layer 6 together with dielectric constants of the substance 1 and the matching elements 4 and 5 kept as they are.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a polarization device, and by arranging a dielectric layer so as to surround the outer peripheral surface of a ferrimagnetic material, other polarization devices connected to the input/output side This allows easy impedance matching between the waveguide and the waveguide.

<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. Matching elements are connected to both ends of the ferrite.

<Problems to be Solved by the Invention> This type of polarization device is connected to both ends of the ferrite because it is necessary to achieve impedance matching with other waveguides connected to its input and output sides. The matching element cannot have an arbitrary dielectric constant, and a predetermined dielectric constant is selected within a dielectric constant range of about 5 to 10. On the other hand, ferrite has a dielectric constant of about 15.

As mentioned above, in order to ensure impedance matching with other waveguides connected to the input and output sides, the permittivity that the matching element can take is limited, and the permittivity of ferrite is, for example, The dielectric constant is a fixed value such as 15, and impedance matching may not be achieved depending on the dielectric constant selected in this way, and there is no adjustment means for such a case.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a polarization device that solves the above-mentioned conventional problems and allows easy impedance matching with other waveguides connected to the input and output sides. It is in.

Means for Solving the Problems> In order to solve the above problems, the present invention provides a polarization device in which a coil is arranged around a waveguide into which a ferrimagnetic material is inserted, the outer peripheral surface of the ferrimagnetic material being It is characterized in that a dielectric layer is provided so as to surround it.

Since the dielectric layer is provided so as to wrap around the outer peripheral surface of the ferrimagnetic material, the apparent dielectric constant of the entire waveguide in the polarization device is the same as the dielectric constant of the ferrimagnetic material. It is adjusted to a predetermined value that is a combination of the dielectric constant of the layer and the dielectric constant of the layer. With this combined dielectric constant, 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 and output sides. Therefore, impedance matching can be easily achieved by the dielectric constant composition effect of the added dielectric layer while leaving the dielectric constants of the ferrimagnetic material and the matching element unchanged.

<Example> FIG. 1 is a front sectional view of a polarization device according to the present invention, and FIG. 2 is a sectional view taken along line A and -A in FIG. 1. In the figure, 1 is a ferrimagnetic material, 2 is a coil, 3 is a waveguide, 4.
5 is a matching element, 6 is a dielectric layer, and 7 and 8 are yokes.

The ferrimagnetic material 1 is composed of an oxide tn material having a ferrite or garnet structure, such as YIG.

Its cross-sectional shape may be circular, square, or rectangular.

The coil 2 is wound around the ferrimagnetic material 1 such that the direction of the magnetic field due to the coil current matches the length direction of the ferrimagnetic material 1.

The waveguide 3 is made of a non-magnetic conductive metal material such as aluminum, and coaxially surrounds the ferrimagnetic material 1. In the embodiment, the waveguide 3 also serves as a bobbin around which the coil 2 is wound.

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 dielectric layer 6 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 6. Based on this, 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 6 may be 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.

In the embodiment, the dielectric layer 6 is arranged so as to fill the annular space created between the ferrimagnetic material 1 and the waveguide 3. Such an arrangement can be easily realized by constructing the dielectric layer 6 with a resin sleeve, attaching this to the outer periphery of the ferrimagnetic material 1, and then inserting it into the inside of the waveguide 3. becomes easier.

Furthermore, when the dielectric layer 6 is made of resin and arranged to fill the annular space between the ferrimagnetic material 1 and the waveguide 3, variations in the dimensions of the ferrimagnetic material 1 and the waveguide 3 can be prevented. It is absorbed by the dielectric layer 6, prevents an air gap from forming between the ferrimagnetic material 1 and the waveguide 3, and changes the composite permittivity without being affected by the permittivity due to the air gap.
It can be set to a predetermined value determined by the dielectric constant of the dielectric layer 6 and the dielectric constant of the ferrimagnetic material 1.

The matching element 4.5 is made of ceramic 'I' with a dielectric constant of about 5 to 10.
When the ferrite is composed of a NN material and the ferrimagnetic material 1 has a dielectric constant of about 15, the dielectric layer 6
is preferably made of Teflon. The dielectric constant of Teflon is about 2, and the apparent dielectric constant of the entire waveguide including the ferrimagnetic material 1 and the dielectric layer 6 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. I+ is a current flowing through the coil 2, and Hl is a DC magnetic field generated by the coil current 11. The magnetic field H1 is directed from the input side to the output side of the ferrimagnetic body 1. E is a linearly polarized wave component in the y-axis direction input to the matching element 4.

When a coil current I is flowing through the coil 2, the linearly polarized wave component E in the y-axis direction is caused by the ferrimagnetic material 1 disposed inside the waveguide 3 (see Figs. 1 and 2). While passing through
Under the influence of the magnetic field H1 caused by the coil current 11, a straight line rotated by an angle θ according to Faraday rotation (as a polarized wave Eyl) is input to the matching element 5 and output.

When the current I+ is not flowing through the coil 2, 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 E, without undergoing Faraday rotation. and output. Therefore, by switching the current 11 flowing through the coil 2, it is possible to switch the manually input linearly polarized wave component E between the linearly polarized wave Ey+ and the linearly polarized wave Ey2. The direction of Faraday rotation can be reversed by reversing the direction of the magnetic field H1. Further, the rotation angle θ is controlled by the magnitude of the magnetic field H3, the length of the ferrimagnetic body 1, and the like.

FIG. 4 shows a sectional view of another embodiment of the polarization device according to the present invention. A feature of this embodiment is that the structure of the matching element 5 on the output side has one or more resistance layers 53 inside a dielectric material 51, 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. The resistance layer 53 can be formed by printing, coating, baking, vapor deposition, sputtering, or the like. For integration, 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 the embodiment shown in FIG. 4, the same effects as those explained in FIGS. 1 to 3 can be obtained, but the resistance layer 53
Thus, a polarization device that absorbs unnecessary polarized waves and extracts only necessary polarized waves can be obtained.

<Effects of the Invention> As described above, in the polarization device according to the present invention, since the dielectric layer is provided so as to wrap around the outer peripheral surface of the ferrimagnetic material, the dielectric constants of the ferrimagnetic material and the matching element remain unchanged. This is a polarization device that adjusts the apparent dielectric constant of the waveguide as a whole while leaving the waveguide as a whole, making it easy to match the impedance with other waveguides connected to the input and output sides. can be provided.

[Brief explanation of drawings]

Fig. 1 is a front sectional view of the polarization device according to the present invention, Fig. 2 is a sectional view taken along the edge line of Fig. 1, Fig. 3 is a perspective view explaining the action of the polarization device, and Fig. 4 is FIG. 6 is a cross-sectional view of another embodiment. l... Ferrimagnetic material 2... Coil 3... Waveguide 4.5... Matching element 6... Dielectric layer Fig.

Claims (3)

[Claims] (1) A polarization device in which a coil is arranged around a waveguide into which a ferrimagnetic material is inserted, characterized in that a dielectric layer is provided so as to surround the outer peripheral surface of the ferrimagnetic material. wave device. (2) The polarized structure according to claim 1, wherein the dielectric layer is arranged to fill a space between an inner circumferential surface of the waveguide and an outer circumferential surface of the ferrimagnetic material. wave device. (3) The polarization device according to claim 1 or 2, wherein the dielectric layer is a sleeve.