JPS6314483Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field of the Invention The present invention relates to a microwave circuit, and particularly to a microstrip line circulator that utilizes the characteristics of ferrite in a high frequency electromagnetic field such as a microwave.

Technical background of the invention In recent years, as high-frequency electromagnetic fields such as microwaves have been used in a wide variety of fields, there has been an increasing demand for smaller and lighter components used in microwave circuits. For this reason, microwave circuits are also becoming integrated circuits. Similarly, the integration of circulators has progressed, and microstripline circulators have been put into practical use. An example of this is shown in FIG. In this figure, a
1 is a plan view of the microstripline circulator, and b is a front view of a. In FIGS. 1a and 1b, a resonator conductor 3 forming a transmission path of a circulator is provided at the center of the upper surface of a cylindrical ferrite 1, and line conductors 4a to 4c extend radially from this resonator conductor 3. There is. Above the resonator conductor 4, a cylindrical magnet 51 having an appropriate diameter is further provided.

On the other hand, a ground conductor 2 is provided on the lower surface of the ferrite 1.
is provided over the entire surface, and the magnet 51
A magnet 6 is provided facing the. Note that this magnet 6 does not necessarily need to be provided, and the magnet 51
Even if it is alone, it has sufficient characteristics as a circulator. In addition, the magnet 51 is
When using a magnet 52 made of a conductive material such as alnico or rare earth, the forward loss as a circulator increases, so as shown in FIG. An insulating plate 7 is interposed between the two.

The magnet 51 needs to form a sufficient magnetic field to exhibit the effect of the ferrite 1, and its diameter should be approximately the same as that of the resonator conductor 3, or the diameter of the magnet 51 should be approximately the same as that of the resonator conductor 3, or the diameter of the magnet 51 should be the same as that of the resonator conductor 3, or the diameter of the magnet 51 should be the same as that of the resonator conductor 3. The diameter is set larger than the diameter of the resonator conductor 3 due to the need to uniformly magnetize the ferrite. In addition, in order to improve compatibility with other circuits, it is necessary to widen the band of the circulator, and for this purpose, the diameter of the magnet 51 is made extremely large, and the ferrite 1
The magnetization region of the resonator conductor 3 may be about 1.4 to 2.1 times the size of the resonator conductor 3.

Problems with the Background Art By the way, in general, in a structure such as a microstrip line, electromagnetic waves leak into the surrounding free space, and similarly in a microstrip line circulator, the line conductor 4
Electromagnetic waves leak from a to 4c or the resonator conductor 3 into free space. However, since microstripline circulators are generally shielded by a shield plate, these leaked electromagnetic waves are reflected by the shield plate and then emitted.
It is easy to combine with nearby dielectric or metal conductors, especially the magnet 51 mentioned above, and form an electric field component perpendicular to the transmission direction of the leaked electromagnetic waves, so the forward or reverse loss of the circulator and the impedance at the coupling terminal of each line are reduced. This will have a negative impact on consistency, etc.

In order to reduce such inconveniences, the shape of the magnets 51 or 52 may be made smaller and the height may be lowered, but on the other hand, it is difficult to obtain a sufficient magnetic field for the ferrite 1 to exhibit the desired effect. Furthermore, the operating band of the circulator must become narrower.

Purpose of the invention This invention was made in view of the above points,
It is an object of the present invention to provide a microstripline circulator that can reduce the adverse effects of leaked electromagnetic waves while maintaining its function as a circulator and a sufficient operating band.

Summary of the invention In other words, the present invention maintains the broadband performance of the circulator by placing a magnetic metal plate large enough to sufficiently cover the resonator conductor with an insulating plate in between. By arranging a magnet large enough to generate a magnetic field necessary and sufficient to obtain the effect of ferrite on a magnetic metal plate, it is attempted to reduce the adverse effects of leaked electromagnetic waves.

Hereinafter, the present invention will be described in detail with reference to an embodiment shown in FIG.

Figures 3a and 3b show an example of the configuration of a microstripline circulator according to the present invention, in which figure a is a plan view and figure b is a front view. Note that the same reference numerals are used for the same components as in the conventional example described above. This figure 3 a, b
, a resonator conductor 3 of an appropriate diameter and an appropriate thickness is formed at the center of the upper surface of the ferrite 1 formed in a columnar shape, and this resonator conductor 3
Line conductors 4a to 4c extend radially and symmetrically with respect to the outer circumferential direction of the ferrite 1.
These, the resonator conductor 3 and the line conductors 4a to 4c
is formed by means such as vapor deposition of a metal material or adhesion of metal foil, and constitutes an electromagnetic wave transmission path.

Next, a magnetic metal plate 8 is placed on the resonator conductor 3 via a suitable insulating plate 7 shown in FIG. The diameter of the magnetic metal plate 8 is set to be the same as or larger than the diameter of the resonator conductor 3, in order to apply a magnetic field to the entire resonator conductor of the circulator. Further, the thickness of the magnetic metal plate 8 can be made sufficiently thinner than that of the magnets 51 and 52.

On the other hand, a magnet 53 having a smaller diameter than the magnets 51 and 52 shown in FIGS. 1 and 2 is arranged on the magnetic metal plate 8. Further, a ground conductor 2 is formed over the entire surface of the back side of the ferrite 1, and a magnet 6 is further provided facing the magnet 53. That is, magnet 5
3 and the magnet 6, a magnetic metal plate 8, an insulating plate 7, a resonator conductor 3, a ferrite 1, a ground conductor 2,
The structure is such that they are sequentially interposed on approximately the same axis.

Next, the overall operation of the above embodiment will be explained. First, the magnetic flux generated by the magnet 53 is spread over a wide area by the magnetic metal plate 8, that is, an area that sufficiently covers the resonator conductor 3, and as a result, the magnetized area of the ferrite 1 is also spread by the magnet 53.
Since the diameter of the circulator is increased relative to the diameter of the circulator, the broadband performance of the circulator is maintained.

Note that the diameter of the magnetic metal plate 8 is formed to be the same as or larger than the diameter of the resonator and the conductor 3;
This is to apply a magnetic field to the entire resonator conductor of the circulator.

By the way, as described above, the microstripline circulator is shielded by a shield plate, and a portion of the radio waves incident from the line conductors 4a to 4c become leakage electromagnetic waves, reflected by the shield plate, and coupled to the magnet. However, in the present invention, the magnetic flux generated by the magnet 53 is spread over a wide area by a magnetic plate, so the shape of the magnet 53 can be made smaller than that of the conventional one.
3 and the leakage electromagnetic waves reflected from the shield plate can be prevented.

Further, a part of the electromagnetic waves incident from the line conductors 4a to 4c become leakage electromagnetic waves as described above, but they also try to electromagnetically couple with the magnetic metal plate 8 located closest to the electromagnetic waves. However, this effect is not as significant as the conventional effect where leaked electromagnetic waves are reflected on the shield plate and coupled to the magnet. Furthermore, regarding the coupling between the leaked electromagnetic waves and the magnet 53, the shape of the magnet 53 is different from that of the conventional one.
The diameter is made small, and the shielding effect of the magnetic metal plate 8 is combined to reduce the influence of leaked electromagnetic waves.

Note that, like the conventional example shown in FIG. 2, the insulating plate 7 is used to prevent an increase in loss in the forward direction since the magnetic metal plate 8 has conductivity.
Since this insulating plate 7 is interposed, the magnet 53
In addition to ferrite magnets, metal magnets such as alnico or rare earth magnets can also be used. Furthermore, by coating the surface of the magnetic metal plate 8 with a layer made of a metal or the like having good electrical conductivity, forward loss of the circulator can be more effectively prevented. Further, in the above embodiment, the magnetic metal plate 8 is shaped like a disk, but the present invention is not limited to this in any way, and may be formed into any other shape as long as it has the same effect. Good too.

Effects of the Invention As described above, according to the present invention, a magnetic metal plate capable of enclosing at least the resonator conductor is disposed on the resonator conductor constituting the circulator via an insulating plate, and a magnetic metal We decided to place enough magnets on the board to maintain the minimum effect of ferrite, thereby reducing the negative effects of leaked electromagnetic waves while maintaining the magnetic field sufficient to function as a circulator and the broadband properties of the circulator. It has the excellent effect of being able to

[Brief explanation of the drawing]

Figures 1 and 2 show an example of a conventional microstrip line circulator, of which Figure 1 shows a case using a ferrite magnet, and Figure 2 shows an example using an alnico magnet. In both cases, a is a plan view and b is a front view. FIG. 3 shows an example of the configuration of a microstripline circulator according to the present invention, in which FIG. 3A is a plan view and FIG. 3B is a front view. 1... Ferrite, 3... Resonator conductor, 7...
Insulating plate, 8...Magnetic metal plate.

Claims (1)

[Claims for Utility Model Registration] (1) A microstrip liner that includes ferrite, a resonator conductor formed on the ferrite, and a magnet placed on the resonator conductor, and is entirely shielded. In the curator, a magnetic metal plate having a size that sufficiently covers the resonator conductor is placed on the resonator conductor via an insulating plate, and the magnet is placed on the magnetic metal plate, and A microstripline circulator characterized in that the shape of the magnet is large enough to generate a magnetic field necessary and sufficient to function as a circulator. (2) The microstripline circulator according to claim 1, wherein a conductive layer is deposited on the surface of the magnetic metal plate.