JPH01311601A - Switch for plane of polarization - Google Patents

Abstract

PURPOSE:To reduce power consumption and the generation of heat by providing a magnetic core part outside a waveguide, forming closed loop structure in which a ferrite bar part positioning inside the waveguide is connected continuously to the magnetic core part, and winding a core across the waveguide. CONSTITUTION:The ferrite bar part 14 is arranged in the waveguide 12 with high conductivity such as aluminum, etc., and the coil 20 is wound in the periphery of the waveguide 12 on which the ferrite bar part 14 is positioned. And the magnetic core part 22 is provided outside the waveguide 12, and the closed loop structure is constituted by connecting the ferrite bar part 14 to the magnetic core part 22 continuously. Therefore, since a magnetic hysteresis curve can be formed in upright shape without generating a diamagnetic field, it is not required to supply a current only by supplying a coil current at the time of switching a plane of polarization, and even when the current is required, only a few amount of current is required. In such a way, it is possible to realize power saving, and to reduce the generation of the heat.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a polarization plane switching device that utilizes the Faraday effect of ferrite, and more specifically, the present invention relates to a polarization plane switching device that utilizes the Faraday effect of ferrite, and more specifically, a closed loop is formed by a ferrite rod portion located inside a waveguide and an outer magnetic core portion, and a polarization plane is formed by winding a coil around the closed loop. This relates to a wavefront switching device. [Prior art] A polarization plane switch uses the Faraday effect of ferrite to rotate the plane of polarization of electromagnetic waves traveling in direct yI polarization.
It is in i position. This type of device is used, for example, to pass only the received waves of a desired channel among the received waves collected by a parabolic antenna (the plane of polarization is tilted 90 degrees for each channel) as part of a satellite broadcast receiving system. It is used for such things. The conventional polarization plane cutter has a structure in which a ferrite rod is inserted into a waveguide and a coil is attached to the outside of the waveguide, and a predetermined magnetic field is applied to the ferrite rod by continuing to flow a constant current through the coil. The plane of polarization of the electromagnetic waves applied and traveling is rotated. The plane of polarization is switched by continuing to supply current in the opposite direction. [Problems to be Solved by the Invention] As described above, the conventional device has a structure in which a coil is wound around the outside of a ferrite rod, so it has an open magnetic path configuration, and therefore a demagnetizing field is generated inside the ferrite rod. Since this demagnetizing field reduces the internal magnetic field, it is necessary to constantly supply a fairly large coil current during use to keep the magnetic field applied to the ferrite rod at a predetermined value. For these reasons, conventional devices have the drawback of being difficult to save power and generating a lot of heat. It is an object of the present invention to provide a polarization plane switching device using the Faraday effect that eliminates the drawbacks of the prior art as described above, consumes less power (and does not cause problems with heat generation). Means for Solving] The present invention, which can achieve the above objects, applies a magnetic field to a ferrite rod placed in a waveguide, and utilizes the Faraday effect to rotate the polarization plane of advancing electromagnetic waves. In the switching device, a magnetic core is provided outside the waveguide, and the ferrite rod portion located inside the waveguide and the magnetic core continuously form a closed loop structure, and a coil is wound around the polarization plane switching device. Here, the magnetic core located outside the waveguide has, for example, a U-shape, and is configured to be continuous with the side surfaces of both ends of the ferrite rod inside the waveguide.U-shaped magnetic core The and ferrite rod portions may be separate members and bonded together using an adhesive or the like, or they may be integrally molded and sintered. If they are combined as separate members, the 1sin ratio μ of each may be the same. Select a material that has a high JLT resistance (lithium-based ferrite, etc., which is suitable for microwave use) for the ferrite rod part.

[Effect] In the present invention, since the ferrite rod portion located inside the waveguide and the magnetic core portion provided outside the waveguide continuously form a closed loop structure, no demagnetizing field is generated. Therefore, B-I! The curve (magnetic hysteresis curve) has a vertical shape, and if you use its squareness to flow current only when switching the plane of polarization, the residual magnetization will then obtain the desired Faraday rotation, which can be used to supply power during normal operation. becomes unnecessary. Furthermore, even if the fine adjustment of the polarization plane rotation angle is taken into consideration, only a very small amount of current is required during normal operation. 【Example】

FIG. 1 is a sectional view showing an embodiment of a polarization plane switching device according to the present invention. This polarization switcher is attached to a receiving parabolic antenna, etc. in a satellite broadcast receiving system.
It rotates the plane of polarization of traveling electromagnetic waves using the Faraday effect. The polarization plane switching device IO has a ferrite rod part 14 placed inside a waveguide 12 made of aluminum or the like with high conductivity, and a ceramic material with a dielectric constant of several to ten tens for impedance matching etc. is placed at both ends of the ferrite rod part 14. Input converter 16 made of dielectric and output change! Negative device! 8 and attach the ferrite rod part 14.
It has a structure in which a coil 20 is wound around a waveguide 12 in which a waveguide 12 is located. Here, the feature of the present invention is that a magnetic core portion 22 is provided on the outside of the waveguide 12.
, and the ferrite rod portion 12 and the magnetic core portion 22 are configured to continuously form a closed loop structure. The input side of the waveguide 12 has a horn 24 facing the antenna direction.
is attached, and the output side of the waveguide 12 is connected to a low noise amplifier. Note that a resistor 26 is inserted into the output converter 18 to absorb unnecessary electromagnetic waves. The ferrite rod portion 14 is made of lithium-based ferrite or the like, which has high resistance and is suitable for microwave use. Magnetic core part 22
may be the same lithium-based ferrite or may be made of different materials. When using different materials, select materials with approximately the same i3 magnetic coefficient μ. In the case of the lithium-based ferrite material tq for microwaves, if it has a closed loop structure, the B-H curve will be as shown in FIG. 2, and will have a square, upright shape. On the other hand, if the conventional structure is a simple rod-shaped open loop structure, the B-H curve will be considerably inclined as shown in FIG. 2B. In the present invention, for example, if a magnetic flux density of Ba is required to obtain a predetermined Faraday effect, what happens if a current is first applied and a magnetic field of -HHa is applied? i
Similarly, if a magnetic flux density of Bb is required, then a coil current is supplied in the opposite direction to apply a magnetic field of only Hb, and then the coil current can be zero. In other words, even if the required magnetic flux density is Ba or Bb, the magnetic field supplied from the outside may be zero, and if the necessary current is supplied only during switching, there is no need to supply any current thereafter. On the other hand, in the prior art as shown in FIG. 2B, Ba
If such a magnetic flux density is required, a magnetic field of Hc must be applied, and therefore a coil current must be continuously supplied. Conversely, if a magnetic flux density of nb is required, the magnetic field 1
(In order to apply d, it is necessary to constantly supply a corresponding coil current in the opposite direction. In other words, in principle, in the present invention, it is only necessary to flow current only when switching the polarization plane, and the magnetic field to be supplied is Since the magnetic flux density may be small, it is possible to save power and reduce coil turn failure.Also, in the present invention, even if the required magnetic flux density is slightly different from Ba or nb, only by passing a small current, those ml can be reduced. !It is possible to perform adjustment. FIG. 3 is a sectional view showing another embodiment of the present invention, and FIG.
The figure is a perspective view thereof. Since the basic configuration is the same as that shown in FIG. 1, corresponding parts are given the same reference numerals and explanations thereof will be omitted. Since the ferrite rod portion 14 located inside the waveguide 12 and the magnetic core portion 22 located outside form a closed loop configuration, the coil 20 may be wound anywhere. A coil 20 is wound around the . FIG. 5 is a more detailed enlarged view of the ferrite rod-shaped portion 14 and the U-shaped magnetic core portion 22 in the present invention. The ferrite rod portion 14 and the U-shaped magnetic core portion 22 are separately molded and sintered, and if necessary, a coil is mounted in a predetermined position using a bobbin, and then a coil is attached to both end sides of the ferrite rod portion 14. The tips of the lever-shaped magnetic core portions 22 are assembled and tightly fixed with adhesive. In this case, different materials may be used for the ferrite rod portion 14 and the U-shaped magnetic core portion 22, and in that case, it is desirable to use materials having approximately the same i3'&11 ratio. Another example is a configuration in which the □ elite rod portion 14 and the U-shaped magnetic core portion 22 are integrally molded and sintered. In that case, assembly will be easier if the coil is wound by making the part circular and fitting the split bobbin, and then winding the coil while rotating the bobbin. In addition to the above-mentioned lithium-based ferrite, usable ferrite materials include nickel-zinc-based ferrite materials. [Effects of the Invention] As described above, the present invention provides a closed loop structure in which a magnetic core portion is provided on the outside of a waveguide, a ferrite rod portion located inside the waveguide and the magnetic core portion are continuous, and a coil is wound around it. Because of this configuration, no demagnetizing field is generated and the I3-II curve has a vertical shape, so if the coil current is supplied only when switching the polarization plane, there is no need to supply current afterwards. However, only a small amount is required, and it is possible to save power and reduce heat generation. Furthermore, even when switching the plane of polarization, a smaller current is required than in the prior art because the I3-H curve stands. Furthermore, by continuing to supply a small amount of current, it is possible to finely adjust the polarization switching angle. ! Even a single device can be used in a wide area where the polarization plane switching angle is slightly different.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an embodiment of the polarization plane cutter IIA device according to the present invention, FIG. 2A is an illustration of the 13-H curve thereof, and FIG. 2B is an explanation of the 3-11 curve of the prior art. 3 are sectional views showing other embodiments of the polarization plane switching device according to the present invention,
FIG. 4 is a perspective view thereof, and FIG. 5 is a perspective view showing an example of a ferrite rod portion and a magnetic core portion used in the present invention. 10...Polarization plane switcher, 12...Waveguide, 14...
- Ferrite rod part, 20... Coil, 22... U-shaped magnetic core part. Patent distributor Fuji Electrochemical Co., Ltd. Agent Shigeru Mi 1 Figure 1 Figure 2 A B

Claims (3)

[Claims] 1. A magnetic field is applied to the ferrite rod placed inside the waveguide,
In a polarization plane switching device that uses the Faraday effect to rotate the polarization plane of advancing electromagnetic waves, a magnetic core is provided outside the waveguide, and a ferrite rod portion located inside the waveguide and the magnetic core are connected to each other. A polarization switcher in which a coil is wound around a continuous closed-loop structure. 2. 2. The polarization plane switching device according to claim 1, wherein the magnetic core located outside the waveguide has a U-shape and is connected to both end side surfaces of a separate ferrite rod portion. 3. 2. The polarization plane switching device according to claim 1, wherein the ferrite rod portion located within the waveguide and the U-shaped magnetic core portion located outside the waveguide are integrally molded.