JPS5846701A - Waveguide band stop filter - Google Patents

Abstract

PURPOSE:To form a waveguide band stop filter having the attenuation with >=2 frequencies and a reduced length in the axial direction of a rectangular waveguide, by connecting the resonators having different resonance frequencies to >=2 side faces of the waveguide at the approximately same positions in the axial direction of the waveguide. CONSTITUTION:The resonators 2, 3 and 4 having the 1st resonance frequency f1 are connected to the coupling parts 5, 6 and 7 on the side faces of a waveguide 1. At the same time, the resonators 8, 9 and 10 having the 2nd resonance frequency f2 are connected to the coupling part 11, 12, and 13 respectively. The resonators 2 and 8, 3 and 9 and 4 and 10 are located at approximately same positions in the axial direction of a waveguide on the faces opposite to each other. No connection is given between the resonators 2-4 and 8-10 since they have different resonance frequencies from each other. Thus the frequency characteristics having the attenuation with the frequencies f1 and f2 can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a waveguide band-stop filter coupled with a WJK resonance of a rectangular waveguide.

Conventionally, in a waveguide band-stop filter in which a resonator is coupled to the side surface of a rectangular waveguide, one side of the waveguide is connected to both sides of the waveguide, as shown in FIGS. It was constructed by combining resonators with the same resonant frequency. In other words, in the case of a three-stage band-stop wave device, one side of the waveguide body 1 is
couples three resonators 2, 3.4 having the same resonant frequency by coupling s5°6.7 on both sides. Resonator 2, 3
．． The spacing b in the axial direction of the 46 waveguides is approximately λg/4 or an odd multiple thereof.

When blocking two frequencies with such a band-stop filter, the resonators for each frequency are placed side by side in the axial direction of the waveguide as shown in Figure 3, and a good structure is used. ,
That is, if the two frequencies to be blocked are fl and fl shown in FIG. Resonators 2, 3, .
The resonators 8, 1, and 1 are arranged at intervals of 2g and 74 (), and are coupled to the optical waveguide body 1 by wA11, 12.13.
A three-stage wave device with frequency f, which stops at the castle, is constructed.
11 Filter IsI! i as a whole is 1 as shown in Figure 4.
Goose0jlIfII1. The length of the ζO filter O waveguide in the axial direction, which exhibits a frequency characteristic that is attenuated by the number f1 and fl, is the same as that of the resonator 4.If the interval of masochism is t7, then λg+t (that is, 1/4× (11 + λg/4 x 100%) and the disadvantage is that the axial dimension becomes larger.

The present invention has been made with a focus on tkN111iK, and its purpose is to block a round band by hiding the axial dimension of the waveguide when constructing a multi-stage band-stop filter of ttz or more. It is said to provide.

In order to achieve the above object, the band-stop filter according to the present invention has a resonator tube coupled to the side surface of the rectangular waveguide to effectively eliminate the waveguide band. It is also possible to connect resonators having different resonant frequencies to two or more sides of a rectangular waveguide at the same location.
Team.

Therefore, in the band-stop filter according to the present invention, the dimension of the waveguide in the axial direction can be shortened.

Hereinafter, the filter according to the present invention will be explained in more detail with reference to the drawings.

FIG. S is a diagram showing an embodiment of a filter according to the present invention. A resonator 2.3.4fr having the first resonant frequency f1 is coupled to the coupling part S, @, 7 on the side surface of the waveguide 1 to constitute a three-stage band-stop wave device. coupling part 11,
12. Resonate four second resonance frequencies f3 at 13 -..., S
, 10 are combined to form a three-stage band-elimination filter.

Resonators 2 and It, 3 and 1, and 4 and 10 are respectively arranged at substantially the same position in the axial direction of the waveguide and on opposing sides. Since resonators 2 to 4 and resonators 8 to 1° have different resonance frequencies, they are not coupled, and the overall Ktj 4th
Kfl and f as shown in the figure.

It shows the frequency characteristics that are attenuated by and. With this configuration, the axial dimension is λg/2 (i.e. λg/1)
xz) 9, which is less than 1/2 that of the conventional one.

Although the above embodiment shows an example in which RTR three-stage band-stop filters are arranged on the side of the waveguide, it is also possible to use a number of stages of wave filters that block individual OIF filters.

Moreover, if three or more side surfaces of the waveguide are used, a multistage band-stop filter having frequencies of three or more than K can be constructed.

Furthermore, the resonator is not limited to a light or waveguide type, but other structures such as a coaxial type can also be used.

As explained above, in the present invention, t in the axial direction of the rectangular waveguide
At the same position as iPl, the higher side of the waveguide tiK respectively Jl! By coupling resonators with different resonant frequencies, it is possible to construct a band-stopping filter that has attenuation at frequencies higher than 100% by shortening the axial dimension of the waveguide.

[Brief explanation of the drawing]

FIGS. 1 and 2 are diagrams showing different examples of conventional band-stop wave devices, and FIGS. 1(a) and 2(a) are side views, respectively. Figure (B) and U Figure 2 (B)
are front views of each. ' Fig. 3 Fi Conventional model with attenuation characteristics at two frequencies! #Is a side view of a blocking filter. Figure 4' is a characteristic diagram of a band-elimination filter with one attenuation characteristic at two frequencies. ° □-7,゛ No. 55i5 is a side view showing an embodiment of the present invention. 1... Rectangular waveguide '2' 4.8 to 10'... Resonator -5 to F, 11 to 1'3... Coupling portion Patent applicant NEC Corporation Agent Patent attorney Shi I no Ro Jusai Figure 1 (a) (b) Figure 22 (Island): Figure 3 ↑ I T2 g, -3 Sumire Figure 5

Claims (1)

[Claims] In a wave device that blocks a good waveguide band by coupling a resonator to the side surface of a rectangular waveguide, two or more sides of the rectangular waveguide have different resonance frequencies at approximately the same position in the axial direction of the rectangular waveguide. A waveguide band-stop filter coupled with a resonator and characterized by nine features.