JPS5925481B2 - Circulator and isolator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in small, low cost circulators and isolators for use in the VHF, UHF and microwave bands.

Circulator as the most important part of microwave equipment
Isolators are widely used in the microwave field for purposes such as protecting transistors during high-power operation, matching between stages, and eliminating unnecessary radiation.

With the recent dramatic miniaturization of other microwave elements, the space occupied by circulators and isolators in the overall microwave apparatus has become quite noticeable.

For example, in such devices, it is not uncommon for these space factors to exceed 50 factors.

Furthermore, from the perspective of the overall cost of the microwave device, the price of the circulator/isolator accounts for a considerable amount.

For this reason, demands for smaller size and lower prices for circulators and isolators are becoming stronger day by day.

The present invention relates to structural improvements of circulators and isolators in order to meet the demands of industry for downsizing and lowering costs.

In general, the structure of a conventional circulator isolator is as shown in FIG.
a and 3b are attached above and below, and a ferrite core 6 and a center conductor 7 are placed on a grounding stand 4, surrounded by a shield plate 5, exactly in the central space.

Further, the upper permanent magnet 3b is moved vertically by the rotating screw 2, and the magnetic field applied to the ferrite core 6 is finely adjusted.

When aiming to make circulator isolators smaller and lower in price, it is clear that there are limits as long as such a structure is adhered to.

SUMMARY OF THE INVENTION An object of the present invention is to provide a circulator/isolator that challenges the limits of the prior art and is capable of withstanding high power and is small and inexpensive.

In order to achieve the above object, the circulator of the present invention
An isolator consists of a soft magnetic material with a grounding plate placed in close contact with the material, and a shielding plate containing one or more ferrite cores and one or more center conductors placed near the center of the upper part of the grounding plate. Further, a permanent magnet is placed on the top of the ferrite core in close contact with the ferrite core via a shield plate, and the bottom surface of the shield plate and the ground plate are integrated, and a protrusion is provided on the ground plate, and the protrusion and a part of the shield plate are integrated.

Hereinafter, the present invention will be explained in detail based on examples.

FIG. 2 is a sectional view showing a basic embodiment of the present invention.

Ground plate 10 on top of soft magnetic material 8 (iron plate 30x30x2)
Place them in close contact and secure with solder or eyelets.

Further, a shield plate 11 in which two disc-shaped ferrite cores 12 and three mesh-shaped central conductors 13 are housed is placed close to the upper center of the earth plate 10 by soldering.

Furthermore, permanent magnet 9 (rare earth magnet 18φ x 2.5t)
is placed on the top of the ferrite core 12 with the shield plate 11 interposed therebetween using an adhesive or the like.

Comparing these structures of the present invention (Fig. 2) and the structure of the prior art (Fig. 1), it is clear that only one permanent magnet is saved (in case 1 with a complex shape). The magnetic field adjustment screw 2 is replaced with a single soft magnetic plate 8, and it is clear that the simplification is remarkable.

Furthermore, when high power is passed through the circulator/isolator of this embodiment, the heat generated by the ferrite core 12 flows through the soft magnetic material 8 to the heat sink 20 such as an aluminum stand in the shortest distance. There is little temperature difference with other parts, making high power operation quite stable.

When a metal magnet such as a rare earth magnet having a small thermal resistance is used as the permanent magnet 9 as in this embodiment, the above effect becomes even more remarkable since the magnet itself has a heat dissipation effect.

In addition, in FIG. 2, other matching coils and capacitors necessary for circulator operation are omitted.

As a result of applying this example to a 30-hole 800MHz circulator, not only was the thickness reduced to about 1/2 or less, but the material cost was also considerably low at about 2/3, which is the effect of this structure. It can be seen that this is remarkable.

However, this structure also has one drawback.

As shown in FIG. 2, the shield plate 11 containing the ferrite core 12 and center conductor 13 is assembled separately and then fixed onto the ground plate 10 by soldering or the like.

This not only requires a large number of man-hours, but also requires two shield plates, and the permanent magnet 9 and the soft magnetic material 8 are too far apart, resulting in a structure that deteriorates the characteristics of the circulator/isolator.

Therefore, the present inventors invented a structure as shown in FIG. 3 in order to overcome the above-mentioned drawbacks.

That is, the part of the shield plate 11 that is to be brought into close contact with the ground plate 10 is brushed off and integrated with the ground plate 10.

FIG. 4 shows a method of assembling the shield plate 11 and the ground plate 10 in such a case.

A new protrusion 21 is attached to the ground plate 10, and the ferrite core 12 and center conductor 13 are inserted therein.

A shield plate 11 made up of a single plate is placed over the ferrite core 12 and soldered at the protrusion 21 portion.

In order to adopt such a structure, the structure shown in Fig. 2 required two shield plates 11 to assemble the shape of the shield plate 11, whereas one shield plate is required. It can be seen that there are extremely significant advantages in that it can be completed in time and the assembly man-hours can be greatly shortened.

Also, the distance between the permanent magnet 9 and the soft magnetic body 8 is determined by the shield plate 11.
Since the thickness is reduced by the same amount, the magnetic field distribution can be improved, and the characteristics of the circulator/isolator can be improved.

Figure 4 shows a 30-hole 800MH to which the embodiment of the present invention is applied.
FIG. 2 is a schematic assembly diagram of a z-band circulator.

In this figure, 16a, 16b, 16c are strip line terminals, 18 is a capacitor, 19 is a coil, 17
Although the printed boards 15a and 15b are integrated with the ground plate 10, they are ground terminals.

As can be seen from this figure, another problem with the present invention is that the matching coil 19 and capacitor 18 are exposed.

Depending on the situation, there is a risk that a worker may accidentally touch the coil 19 etc., deforming it and changing its electrical characteristics, and since the coil 19 is exposed, other circuits other than the circulator/isolator may It is possible that the interaction with

In order to solve these problems, an experiment was conducted in which a case like 14 in FIG. 3 was added to the above embodiment.

This case can be made of metal, non-metal, ferromagnetic material, or non-magnetic material, but in this embodiment, a copper case was used to achieve both the purpose of handling protection and electrical shielding.

As described above in detail using several embodiments of the present invention, it is clear that the present invention has remarkable effects in terms of miniaturization and cost reduction.

[Brief explanation of the drawing]

Fig. 1 is a schematic sectional view of the conventional product, Fig. 2 is a basic sectional view of the present invention, Figs. 3 and 5 are schematic sectional views of the inventive product, and Figs. 4 and 6 are A schematic assembly diagram of the product of the present invention. 8: Soft magnetic material, 9: Permanent magnet, 10: Earth plate, 11:
Shield plate, 12: Ferrite core, 13: Center conductor.

Claims (1)

[Claims] 1. A grounding plate is closely placed on a soft magnetic material, and a shielding plate containing one or more ferrite cores and one or more center conductors is placed on top of the grounding plate. In the circulator and isolator, a permanent magnet is disposed near the center of the ferrite core, and a permanent magnet is closely placed on the top of the ferrite core through a shield plate, and the bottom surface of the shield plate and the ground plate are integrated, and A circulator and an isolator characterized in that a protrusion is provided, and the protrusion and a part of the shield plate are integrated. 2. The circulator and isolator according to claim 1, characterized in that the circulator and isolator are covered with a case from above.