JPH0574005U - Waveguide blocking cavity resonator - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a waveguide blocking cavity resonator which can keep away unnecessary electromagnetic field mode resonance even if the no-load Q is raised. [Structure] A cavity 3 of a TE ₁₀₄ mode rectangular resonator body 2 is coupled to a waveguide through a coupling hole 4. A TE ₁₀₄ mode rectangular resonator at a position of about ¼ of the dimension a that governs the TE ₁₀ mode cutoff of the cavity 3 and at a position of about 1/2 of the TE ₁₀₄ mode resonance axis length dimension L of the cavity 3. At the inner wall surface position of the main body 2, a metal post 5 is provided so as to project toward the inside of the cavity 3.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a waveguide blocking cavity resonator used in the microwave region.

[0002]

[Prior Art]

In order to reduce the power loss of the waveguide blocking filter, it is necessary to realize a large no-load Q of the blocking cavity resonator. This unloaded Q tends to decrease as the frequency of use of microwaves increases. For example, when a TE ₁₀₁ mode cavity resonator is formed by a standard rectangular waveguide in the frequency region of 14 to 14.5 GHz, The unloaded Q is practically the best value of about 5500.

Therefore, in order to set the substantial no-load Q to 10,000 or more, the size of the resonator cavity is made larger than the wavelength used, but on the other hand, the resonator cavity and the waveguide are The coupling holes to be coupled and the resonance frequency fine-tuning mechanism make it easy to induce other unnecessary electromagnetic field mode resonance.

FIG. 5 shows a conventional waveguide blocking cavity resonator. In the figure, 1 is a waveguide, 2 is a square TE ₁₀₄ mode cavity resonator body, and 3 is the square TE _104. cavity modes cavity co oscillator body 2, 4 waveguide 1 and the rectangular TE ₁₀₄ mode cavity resonator comprising type TE at an overlapping portion between the body 2 ₁₀₄ mode cavity cavity 3 of the resonator body 2 Is a coupling hole coupled to the waveguide 1.

FIGS. 6A and 6B are a horizontal sectional view and a vertical sectional view showing the dimensional relationship of the rectangular TE ₁₀₄ mode cavity resonator body 2 used in FIG. In the figure, a is the height of the cavity resonator body 2, that is, a dimension that governs the blocking of the TE ₁₀ mode, b is the width of the cavity resonator body 2, and L is the length of the cavity resonator body 2. That is, it is the resonance axis length.

In this figure, when a = 22 mm and b = 17 mm are selected, the TE ₁₀₄ mode resonance axis length in the resonance frequency range of 14 to 14.5 GHz is as shown in FIG. Q is about 11,500. The dimensions a and b are selected so that the other unwanted electromagnetic field mode resonances do not overlap with the range of 14 to 14.5 GHz and the cavity is small as much as possible. FIG. 7 also shows the resonance frequency of the electromagnetic field mode which may cause unnecessary resonance.

[0007]

[Problems to be solved by the device]

However, in the above-mentioned conventional waveguide blocking cavity resonator, unnecessary TE ₂₀₁ mode and TE ₁₀₂ mode resonance is calculated to be 14 GHz or less, and resonance in the band of 14 to 14.5 GHz is avoided. However, since it is very close to 14 GHz, the unnecessary TE ₂₀₁ mode and TE ₁₀₂ mode are generated due to the shape and size of the coupling hole 4 between the waveguide 1 and the TE ₁₀₄ mode resonance frequency fine adjustment mechanism. The resonance of may move within the required band and may have an adverse effect.

An object of the present invention is to provide a waveguide blocking cavity resonator that can keep away unwanted electromagnetic field mode resonance even if the no-load Q is raised.

[0009]

[Means for Solving the Problems]

To explain the structure of the present invention which achieves the above object, the present invention relates to a waveguide blocking cavity resonator in which a cavity of a TE ₁₀₄ mode rectangular resonator body is coupled to a waveguide through a coupling hole. , The TE ₁₀₄ mode rectangular resonance which is at a position of about ¼ of the dimension that governs the TE ₁₀ mode cutoff of the cavity and at a position of about ½ of the TE ₁₀₄ mode resonance axis length dimension of the cavity. A metal post is provided so as to project toward the inside of the cavity at the position of the inner wall surface of the container body.

[0010]

[Action]

Thus, the TE ₁₀₄ mode square, which is at about 1/4 of the dimension governing the TE ₁₀ mode cutoff of the cavity, and at about 1/2 of the TE ₁₀₄ mode resonant axis length dimension of the cavity. When a metal post is provided at the inner wall surface of the resonator body so as to project toward the inside of the cavity, the unnecessary electromagnetic field mode resonance can be kept away even if the dimension of the cavity is increased and the no-load Q is increased.

[0011]

【Example】

 1 and 2 show an embodiment of a waveguide blocking cavity resonator according to the present invention. The parts corresponding to those in FIGS. 5 and 6A and 6B are designated by the same reference numerals.

In the waveguide blocking cavity according to the present embodiment, at the position of about 1/4 of the dimension a that controls the TE ₁₀ mode cutoff of the cavity 3 of the TE ₁₀₄ mode rectangular cavity body 2. and the inner wall surface at about 1/2 the TE ₁₀₄ is the position of the mode rectangular resonator body 2 of the TE ₁₀₄ mode resonator axial length dimension L of the cavity 3, the metal posts 5 in the air cylinder 3 It is projected toward. In addition to the positions where the metal posts 5 are indicated by solid lines, there are three positions indicated by broken lines, and any one of the four positions, any two positions, any three positions, or all positions. It can also be provided at a location.

By doing so, even if the dimension of the cavity 3 is increased and the no-load Q is increased, the unnecessary electromagnetic field mode resonance can be kept away.

The reason will be described in detail below. Unnecessary TE ₂₀₁ mode and TE ₁₀₂ mode resonance electromagnetic fields are shown in FIGS. 6 (A) and 6 (B), in the direction of the TE ₁₀₄ mode resonance axis length dimension L of the cavity 3, the both end wall surfaces of the dimension L are short-circuited. Then, the resonant standing wave having the maximum voltage is formed only at the position of 1/2 of the dimension L. On the other hand, in the direction of the dimension a of the cavity 3, both end wall surfaces of the dimension a are short-circuited surfaces, and a resonant standing wave having a maximum voltage is formed at positions ¼ of the dimension a from both short-circuited surfaces. The lines of electric force of all the voltages are oriented in the direction of the dimension b, and as a result, the resonance standing wave is at the maximum voltage at the position of 1/4 of the dimension a and 1/2 of the dimension L. Since a metal post 5 having a parallel capacitive reactance is installed in this position in the direction of the dimension b as shown in FIGS. 1 and 2A and 2B, unnecessary TE is formed. ₂₀₁ mode and TE ₁₀₂ mode the resonant axial length L and resonant axial length a in Runode Kuwawa electrical length elongation due to the parallel capacitive reactance, there is effect to reduce the resonant frequency of the unwanted TE ₂₀₁ mode and the TE ₁₀₂ mode .

On the other hand, in the required TE ₁₀₄ mode resonance, in the direction of the resonance axis length dimension L, both end wall surfaces of the dimension L are short-circuited surfaces, and 1/4 of the dimension L including the position of 1/2 of the dimension L. An equivalent short-circuit plane, that is, a resonance voltage standing wave at which the voltage is zero is formed at each interval. Therefore, since it is difficult for the voltage to grow at a position of 1/2 of the dimension L, which is the installation position of the metal post 5 described above, the necessary TE ₁₀₄ mode resonance causes the influence of the expansion and contraction of the electrical length due to the presence of the metal post 5. Do not suffer.

As described above, the positions where the metal posts 5 can be installed are four in total as shown in FIGS. 1 (A) and 1 (B). Therefore, the height of each metal post 5 can be increased as required. By installing multiple metal posts 5 while maintaining low, unnecessary mode resonance can be removed in a state where problems such as voltage breakdown are unlikely to occur in cavity resonators for microwave high power. .

Moreover, the high no-load Q that can be realized can reduce the power loss by an inverse ratio of the high no-load Q. Furthermore, since the lost power becomes heat in the cavity resonator, unnecessary temperature rise of the cavity resonator is greatly reduced when using high microwave power.

The performance of the above-described waveguide blocking cavity resonator of the present invention was confirmed by experiments, and will be described in detail below.

FIG. 3 is a waveguide having the conventional structure shown in FIGS. 5 and 6A and 6B and the above-mentioned dimensions, and the TE ₁₀₄ mode resonance required in FIG. 7 is set to 14.25 GHz. It is a graph which measured the return loss of a blocking cavity resonator. In FIG. 3, when the anti-resonance frequencies of a, b, and c are identified according to FIG. 7, it can be seen that a is TE ₂₀₁ mode and TE ₁₀₂ mode, b is TE ₁₀₄ mode, and c is TE ₂₀₂ mode. Recognize. Unnecessary TE ₂₀₁ mode and TE ₁₀₂ mode resonances for the required band of 14 to 14.5 GHz are well below 14 GHz, but the effect shows the worst return loss of 9 dB at 14 GHz.

FIG. 4 shows the return loss when the structure of the present invention shown in FIGS. 1A and 1B and FIG. 2 has the above-described dimensions and only one metal post 5 is provided. In FIG. 4, (a), (b) and (c) are the same anti-resonance frequencies in the electromagnetic field mode as in FIG. Unnecessary T E ₂₀₁ mode and TE ₁₀₂ mode resonance goes far below 14 GHz, the return loss at 14 GHz is greatly improved to 30 dB, and only the TE ₁₀₄ mode required in the required 14 to 14.5 GHz band. It became a single resonance pattern. Further, due to the metal post 5, the required resonance frequency of the TE ₁₀₄ mode is hardly affected. Furthermore, it was found that the unloaded Q of the cavity resonator in this state was about 11000, and there was almost no deterioration due to the installation of the metal post 5.

[0021]

[Effect of the device]

As described above, the waveguide blocking cavity resonator according to the present invention is provided at the position of about 1/4 of the dimension that governs the TE ₁₀ mode cutoff of the cavity and the TE ₁₀₄ mode of the cavity. At the inner wall surface position of the TE ₁₀₄ mode rectangular resonator main body, which is a position of about 1/2 of the oscillation axis length, a metal post is projected toward the inside of the cavity. Even if the no-load Q is increased, unnecessary electromagnetic field mode resonance can be kept away. Therefore, according to the present proposal, a waveguide-blocking cavity resonator that has a large unloaded Q and that can eliminate unnecessary electromagnetic field mode resonance outside the required frequency band is easy with a simple structure. Can be realized.

[Brief description of drawings]

1A and 1B are a horizontal sectional view and a vertical sectional view of a TE ₁₀₄ mode rectangular resonator body used in a waveguide blocking cavity resonator according to the present invention.

FIG. 2 is a partially cutaway perspective view showing an embodiment of a waveguide blocking cavity resonator according to the present invention.

FIG. 3 is a return loss characteristic diagram of a conventional waveguide blocking cavity resonator.

FIG. 4 is a return loss characteristic diagram of a waveguide blocking cavity resonator according to the present invention.

FIG. 5 is a partially cutaway perspective view of a conventional waveguide blocking cavity resonator.

6A and 6B are a horizontal sectional view and a vertical sectional view of a TE ₁₀₄ mode rectangular resonator main body used in a conventional waveguide blocking cavity resonator.

FIG. 7 is a dimension vs. resonance frequency characteristic diagram of a rectangular TE ₁₀₄ mode rectangular resonator body.

[Explanation of symbols]

1 ... Waveguide, 2 ... Rectangular TE ₁₀₄ mode cavity resonator body,
3 ... Cavity, 4 ... Coupling hole, 5 ... Metal post

Claims (1)

[Scope of utility model registration request] 1. A waveguide blocking cavity resonator in which a cavity of a TE ₁₀₄ mode rectangular resonator body is coupled to a waveguide through a coupling hole, which governs TE ₁₀ mode blocking of the cavity. About 1/4 of the size
At a position corresponding to the inner wall surface of the TE ₁₀₄ mode rectangular resonator main body at a position of about 1/2 of the TE ₁₀₄ mode resonant axis length of the cavity, and a metal post projects toward the inside of the cavity. A waveguide blocking cavity resonator characterized by being provided.