JPS5815964B2 - stripline circulator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a small, low-cost, and high-performance circulator used in the microwave band.

Circulators, which are the most important component of microwave equipment, are used in a wide range of microwave fields for purposes such as matching between protection stages of transistors during high-power operation and removing unnecessary radiation.

Recently, with the rapid miniaturization of other microwave elements, the space occupied by the circulator in the entire microwave apparatus has become quite noticeable.

In fact, it is not uncommon for certain types of devices to have a space factor of more than 50.

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

Therefore, demands for smaller size and lower cost of circulators are becoming stronger day by day.

The present invention relates to an improvement in the structure of a circulator in order to meet the industrial demands for miniaturization and low cost.

In general, the structure of a conventional miniaturized stripline circulator has a center conductor (stripline) 3 on a ferrite core 2, as shown in FIG.
Furthermore, ferrite magnets 1a are adhered thereon by adhesive or the like.

On the other hand, a ground conductor 4 is attached to the bottom of the ferrite core 2, and a ferrite magnet 1b is attached to the bottom of the ground conductor 4 with an adhesive or the like.

5a, 5b, and 5c are grooves for attaching a circulator.

However, since this structure uses a ferrite magnet 1a having a circular cross section as shown in FIG. 1 as a permanent magnet, there is no degree of freedom in adjusting the electrical characteristics after the stripline circulator is assembled.

Therefore, the first dimensional design, i.e. ferrite core,
Once the dimensions of the permanent magnet, center conductor, etc. are determined, most of the main characteristics of the circulator are determined.

Therefore, when circulators of this structure are mass-produced, strict dimensional accuracy is required for each of the parts.

However, no matter how much dimensional accuracy is controlled, it is impossible to reduce the variation to zero, so it is inevitable that the characteristics of the circulator will change as well.

That is, increasing the dimensional accuracy of the parts will improve the yield of circulators, but on the other hand, if the dimensional accuracy decreases even slightly, this will be directly reflected in the failure rate of the X circulator.

In any case, these will have the effect of increasing the cost and cost of the final product, and there is a risk that it will not be possible to meet the industrial world's demand for lower prices.

The purpose of the present invention is to challenge the limits of the above-mentioned conventional technology, and to
An object of the present invention is to provide a stripline circulator that is inexpensive and operates stably at high frequencies.

In order to achieve the above object, the circulator of the present invention has a ground conductor 4 and a center conductor 3 closely attached to the upper and lower sides of one ferrite core 2, and permanent magnets are further closely attached to the upper and lower sides from the outside thereof, The permanent magnet is configured to be magnetized in the vertical direction, and is characterized in that a ferrite magnet 6 having a three-fold symmetry in cross section is used as the permanent magnet closely attached to the center conductor 3.

The present invention will be explained in detail below with reference to Examples.

FIG. 2 is an assembly diagram showing the structure of the present invention, and the positional relationship of each component is maintained, with spaces between each component so that the assembled state can be clearly understood.

FIG. 3 shows the parts shown in FIG. 2 assembled in close contact with each other.

FIG. 4 is a top view of the stripline circulator of the present invention.

In this embodiment, the ferrite core 2 is 14φ.
A 7φ×3t ferrite magnet was used as the permanent magnet 1b.

Well, the ferrite magnet 6 that is a feature of the present invention is 1
A triangular prism with 6 sides and 21 mm thickness was used.

A stripline circulator in the 6-7 GHz band was manufactured using this new structure.

The procedure for adjusting the circulator of the present invention is as follows: First, the permanent magnet 6 is not fixed at an arbitrary position, and the center conductor 3 is
While measuring the electric characteristics, the triangular prism permanent magnet 6 is rotated to obtain the optimum state.

Once the desired characteristics are obtained, the permanent magnet 6 is fixed at that position with an adhesive.

This is because the shape of the permanent magnet 6 attached to the top is three-fold symmetrical, and when it is rotated on the center conductor 3, the input/output impedance of each terminal of the circulator changes with the period of the rotation angle of 60°. This is due to changes in

These are the structure of the present invention shown in FIGS. 2, 3, and 4, and
As is clear from a comparison with the conventional structure shown in the figure, since the product of the present invention has an input/output impedance adjustment mechanism, it is possible to significantly improve the yield of the final product.

Using the structure of the present invention, it was possible to realize a stripline circulator that operates stably in the 6-7 GHz band.

In the above embodiment, a ferrite magnet was used as the lower permanent magnet 1b, but a metal magnet may also be used to strengthen the applied magnetic field.

Furthermore, when a high magnetic field is required, it is conceivable to arrange another metal magnet on top of the three-fold symmetrical ferrite magnet 6.

The shape of this magnet does not necessarily have to be the same as the ferrite magnet 6.

In the above embodiment, only a triangular prism was shown as the shape of the ferrite magnet 6, but since the purpose can be achieved with three-fold symmetry, various shapes as shown in FIG. 5 are also covered by the present invention. Of course.

In addition, although only one simple shape of the center conductor 3 is shown,
It is clear that the effect will not change at all even if other known shapes of the center conductor are used.

Further, in the above embodiments, the ground conductor and the center conductor are attached with an adhesive or the like, but the same effect can be expected even if other printing techniques, vapor deposition, sputtering, etc. are used.

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

[Brief explanation of drawings]

FIG. 1 is a schematic assembly diagram of a conventional product, FIGS. 2, 3, and 4 are schematic assembly diagrams of the present invention, and FIG. 5 is a sectional view of parts of another embodiment of the present invention.

Claims (1)

[Claims] A ground conductor 4 and a center conductor 3 are closely attached to the top and bottom of 11 ferrite cores 2, and permanent magnets are attached to the upper and lower sides from the outside, and the permanent magnets are magnetized in the vertical direction. A stripline circulator characterized in that a ferrite magnet 6 having a three-fold symmetry in cross section is used as a permanent magnet closely attached to a center conductor 3.