JPS6261402A - microwave power divider - Google Patents

Abstract

PURPOSE:To attain an excellent distribution characteristic up to a high frequency by fitting a radio wave absorbing body to an internal prescribed position of a casing storing a base and a strip line so as to eliminate the adverse effect due to the harmonic mode. CONSTITUTION:A strip line 3 is branched into two at a branch point A, branched further into two at branch points B, C, the microwave power fed from an input connector 4 is divided equally into four and extracted through each output connector 5. Further, a radio wave absorbing body 7 is fitted to the lower face of a cover 6 of the casing 1. The electromagnetic wave of the harmonic mode generated due to the slight mismatching of impedance at the branch part is absorbed by simple constitution by fitting the radio wave absorbing body to a prescribed location of the casing to improve remarkably the variation in the distribution ratio at a high frequency region.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a microwave power divider, and more specifically, to a microwave power divider that can equally distribute microwave input power to obtain equal microwave output power. Regarding wave power dividers.

<Prior art> As shown in Fig. 4, conventional microwave power dividers have been constructed by attaching a strip line (13) on an insulating substrate (12) attached to the inside of a casing (11). A device is provided in which characteristic impedance conversion is performed by appropriately changing the width of the strip line (13) to achieve impedance matching, and the microwave input power supplied from the input connector (14) is equally distributed. The aim is to obtain equal microwave output power through multiple output connectors (15).

<Problems to be Solved by the Invention> In the microwave power divider having the above configuration, the strip line (13) is branched at a portion (a in the figure).

b, c), a slight impedance mismatch occurs, and as a practical matter, this impedance mismatch cannot be avoided.

Even with this impedance mismatch, the frequency of the microwave input power is low and the wavelength is
If the size is sufficiently large compared to the dimensions of 13), microwave input power can be distributed without any particular problem, but as the frequency becomes higher and the wavelength becomes smaller, the basic transmission mode, TEM mode Higher-order modes other than the above become more likely to occur.

This higher-order mode is an unnecessary mode in TEM wave transmission on the strip line (13), and as shown in Figure 3,
There is a problem in that the distribution ratio characteristics in high frequencies are adversely affected.

This invention was made in view of the above problems,
It is an object of the present invention to provide a microwave power divider that can eliminate the adverse effects of higher-order modes and achieve good distribution ratio characteristics up to high frequencies.

<Means for Solving the Problems> To achieve the above object, the microwave power divider of the present invention has a radio wave absorber attached at a predetermined position inside a casing that accommodates a substrate and a strip line. be.

With the microwave power divider with the above configuration, the radio wave absorber absorbs microwaves in higher-order modes as unnecessary modes, which are generated due to branches of strip lines, etc. distribution ratio characteristics can be improved.

<Example> Hereinafter, embodiments will be described in detail with reference to the accompanying drawings showing examples.

FIG. 1 is a schematic view showing an embodiment of a microwave power divider according to the present invention, and FIG. 1A is a plan view, and FIG. 8 is a longitudinal sectional view.

In the figure, inside the casing (1) there is an insulator board (
A shows the mounting, and the strip line (3) is mounted on the top surface of the insulator substrate (21).

This strip line (3) is made of a tapered line and acts as a characteristic impedance conversion line.

One end of the strip line (3) is connected to an input connector (4) that penetrates the casing (1) and is exposed to the outside, and the other four ends are connected to the input connector (4) that penetrates the casing (1) and is exposed to the outside. (1) and is connected to an output connector (5) that is exposed to the outside. To explain in more detail, the strip line (3) branches into two forks at a branch point A, and further branches at a branch point B.

At C, each branches into a bifurcated shape and is connected to an input connector (
The microwave power supplied from 4) is divided into four equal parts and can be taken out through each output connector (5).

Furthermore, a radio wave absorber (sword) is attached to the lower surface of the cover (6) of the casing (1).

With the microwave power divider having the above configuration, higher-order mode electromagnetic waves will be generated in the high frequency region due to the slight impedance mismatch in the branch parts A, B, and C. The generated electromagnetic waves are absorbed by a radio wave absorber (for example, 13 in Figure 3).
Although variations in the distribution ratio occurred in the frequency band of ~16(3)-IZ, according to the above example, as is clear from FIG. was able to be significantly improved.

Of course, the distribution ratio characteristics in a low frequency region where there is no risk of generating the above-mentioned higher-order modes are as good as in the conventional example.

Note that this invention is not limited to the above-described embodiments; for example, it is possible to attach the radio wave absorber to a predetermined position other than the bottom surface of the cover (6), and other modifications may be made without changing the gist of this invention. It is possible to make various design changes.

<Effects of the Invention> As described above, the present invention has a simple configuration in which a radio wave absorber is attached to a predetermined position of a casing, and can absorb high-order mode electromagnetic waves generated due to a slight impedance mismatch at a branch part. It has the unique effect of being able to significantly improve the dispersion of the distribution ratio in the high frequency region.

[Brief Description of the Drawings] Fig. 1 is a schematic diagram showing an embodiment of a microwave power divider, and Fig. 2 is a diagram showing distribution ratio characteristics on the high frequency side by the microwave power divider of Fig. 1. , Fig. 3 is a diagram showing the distribution ratio characteristics on the high frequency side by a conventional microwave power divider, and Fig. 4 is a schematic diagram of a conventional microwave power divider. (1)...Casing, t2J...Insulator board, (
3) Strip line, [7] Radio wave absorber patent applicant Sumitomo Electric Industries Co., Ltd. Representative Patent attorney Hirokatsu Kamei (and 2 others)

Claims (1)

[Claims] 1. A microwave power divider that achieves impedance matching by changing the width of strip lines on an insulating substrate, characterized in that a radio wave absorber is installed at a predetermined position inside the casing that accommodates the substrate and strip lines. microwave power divider.