JP3283457B2 - Airtight high-frequency window - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an airtight high-frequency window,
For example, the present invention relates to an airtight high-frequency window provided between a vacuum part and an external waveguide in a microwave tube such as a traveling wave tube or a klystron.

[0002]

2. Description of the Related Art Conventionally, a microwave tube such as a traveling wave tube or a klystron is an electron gun for emitting an electron beam, a collector for supplementing the electron beam, and a microwave amplifier for amplifying the microwave by interaction with the electron beam. , And an input / output coupling section that serves as a connection section between the microwave amplification section and the external waveguide. In the input / output coupling section, an airtight high-frequency window for maintaining the vacuum tightness inside the microwave tube and transmitting the microwave without loss is used. In order to transmit microwaves without reflecting them, it is necessary that the impedance of the microwaves be matched in the hermetic high-frequency window.

FIGS. 17 and 18 show Japanese Patent Application Laid-Open No. 54-1465.
1 shows an external view of a conventional general hermetic high-frequency window described in 61 and a 1/4 cut diagram thereof. FIG.
7, in FIG. 18, reference numerals 1a and 1b denote hollow rectangular waveguides, and a hollow circular waveguide is interposed between the rectangular waveguides 1a and 1b. In the middle of
The dielectric disk 3 is air-tight brazed so as to separate the left and right sides. This structure is called a pillbox type. The hermetic high-frequency window having the pill box structure has the following features. a, The dielectric disk 3 has a larger waveguide cross-sectional area than the rectangular waveguide 1, so that the electric field strength is reduced, and therefore, stress cracking of the dielectric due to local heat generation of the dielectric can be suppressed. . Therefore, the allowable microwave power is large. b. Matching of microwave impedance is performed by dielectric disc 3
By adjusting the combination of the thickness of the circular waveguide 2 and the diameter and length of the circular waveguide 2. Therefore, an airtight high-frequency window with small microwave reflection is formed. c, The dielectric disk 3 has a brazing structure at the circumferential portion, and the brazing strength is high due to the uniformity of the circumference. Further, since the dielectric disk 3 itself is circular, the uniformity is good. In addition, there is an advantage that the strength is high and the number of internal defects is small. Therefore, a highly reliable airtight high-frequency window can be obtained.

However, when microwaves having a higher peak power are passed through the hermetic high-frequency window, the electric field intensity increases, causing microwave discharge, and local heating and damage of the window. There has been a problem that a pinhole is formed in the ceramic portion and the airtightness of the window is broken. Therefore, to reduce the electric field strength of the dielectric,
S. Yu. Mr. Kazakov proposed a traveling-wave hermetic high-frequency window that does not allow a standing wave to stand (only a traveling wave) in the dielectric disk 3 (S. Michizo).
no et. al. Proc. 1994 Inter
n. LinacConf. (1994) pp. 457-
459 FIG. 3). 19, 20, and 21 are an external view showing the structure and a 1/4 cut diagram thereof.
19, 20, and 21, reference numerals 1a and 1b denote rectangular waveguides. A circular waveguide 2 is interposed between the rectangular waveguides 1a and 1b. The dielectric disk is air-tight brazed. In the pill box window structure, the microwave matching is determined for the entire window, but the traveling wave type airtight high frequency window is matched on the surface of the dielectric disk 3. Since matching is achieved on the dielectric surface, only a traveling wave component exists inside the dielectric. (Standing waves do not stand). Therefore, there is no portion having a strong electric field strength inside the dielectric (the electric field strength is uniform). This is expected to suppress the electric field strength of the window and suppress heat generation and discharge. In the traveling wave type airtight high-frequency window, it is necessary to match the surface of the dielectric disk 3 (independently on the input side and the output side), and the degree of freedom in shape is lower than that of the pillbox window. Rectangular waveguide 1a,
A matching circuit (iris) 5 is provided on the left and right sides of the converter 1b and the converter 4 of the circular waveguide 2 to create a susceptance component, and both of them are called. Even if a dielectric pillar or a capacitive pillar is used, it may be used instead of the iris because it performs the same function.

[0005]

In the conventional traveling-wave type hermetic high-frequency window, it is necessary to match on both the input and output surfaces of the dielectric disk, and the degree of freedom of the shape is limited to that of the pill box window. In the method of providing a matching circuit (iris) 5 at the conversion part of the square / circular waveguide and achieving matching, the circular waveguide becomes longer and the window becomes larger, thereby increasing the weight. There was a problem.

The present invention has been made to solve the above problems, and has as its object to reduce the size of a traveling wave window structure.

[0007]

Means for Solving the Problems According to claim 1 of the present invention.
Airtight high-frequency windows have a pair of rectangular conductors with long and short sides.
Waveguide and a circular waveguide inserted between these rectangular waveguides
Tube and a dielectric disc provided in the middle of this circular waveguide
Between the pair of rectangular waveguides and the circular waveguide.
Length of the rectangular waveguide facing the high frequency electric field converter
A first matching circuit formed on each side;
Matching formed on opposing short sides of a rectangular waveguide
A first matching circuit having a depth and a width.
And the position of the second matching circuit,
Impedance matching between the rectangular waveguide and the circular waveguide
It is intended to be taken.

[0008]

[0009]

[0010]

[0011]

[0012]

[0013]

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 4, reference numerals 1a and 1b denote rectangular waveguides as end waveguides, and a circular waveguide 2 as an intermediate waveguide is formed between the isotropic waveguides 1a and 1b. And in the middle of the circular waveguide 2,
There is a dielectric disk 3. The circumferential portion of the dielectric disk 3 is metallized, and vacuum tightness is maintained with the circular waveguide 2 by brazing or the like. In addition to providing a matching circuit (iris) 5 in the converter 4 of the rectangular / circular waveguide, a matching circuit (iris) 6 is newly provided in the rectangular waveguides 1a and 1b. The iris 6 is formed by depressing the side surfaces of the rectangular waveguides 1a and 1b in a concave shape. The dimensions and positions of the irises 5 and 6 and the length of the circular waveguide 2 are adjusted to achieve matching on the surface of the dielectric disk 3 (independently of the input side and the output side). That is, the magnitude of the microwave impedance is determined by the depth and width of the concave iris 6, and the phase of the microwave impedance is determined by the front and rear positions of the iris 6. Matching is achieved by combining them so as to cancel the impedance change that occurs during waveguide exchange. In this configuration, the rectangular waveguide 1
Since the iris 6 is provided in the middle of a and 1b for alignment, the circular waveguide 2 can be configured to be short, so that the size of the window can be reduced to the extent that it does not change as compared with the conventional pill box structure. The same operation is performed by using an inductive column or a capacitive column instead of the iris 6.

Embodiment 2 5 to FIG.
It is a figure showing other embodiments of an airtight high-frequency window according to the present invention. This has a configuration of a traveling-wave window substantially the same as that of the conventional traveling-wave window shown in FIGS. 17 and 18, but has a smaller diameter than the circular waveguide 2 as an insertion waveguide. The waveguides 7a and 7b are inserted between the rectangular waveguides 1a and 1b and the circular waveguide 2 and added. The length and radius of these two circular waveguides 7a and 7b are adjusted, and
By adjusting the depth and width of the concave matching circuit (iris) 5 provided in the converter 4 of the circular waveguide, the surface of the dielectric disk 3 (input side and output side, respectively) Independently) and take alignment. In this case, the circular waveguide 7a,
The diameter of the window 7b is made smaller than the diameter of the original circular waveguide 2 and the window is made smaller (lighter) by adjusting the diameter by selecting an appropriate size.

Embodiment 3 Further, in the second embodiment, the circular waveguide 2 and the circular waveguides 7a and 7b are configured in two steps, but as shown in FIG. 9 and FIG.
Outside the circular waveguides 7a and 7b, circular waveguides 7c and 7d each having a smaller diameter may be added to provide an insertion waveguide consisting of three steps. The same effect as that of the embodiment is exerted. That is, the circular waveguide 2,
The lengths and diameters of 7a, 7b, 7c, 7d can be adjusted to achieve matching, thereby reducing the size.

Embodiment 4 In the second embodiment, the circular waveguides 2, 7a, and 7b are configured in a two-step shape. However, in the second embodiment, FIGS.
As shown in the figure, the outside of the circular waveguide 2 and the circular waveguides 7a and 7
The iris 8a, 8b may be added to the step portion between b and b to adjust the depth and width so as to match.

Embodiment 5 In the above embodiment, the case where the diameter of the circular waveguide as the insertion waveguide changes stepwise has been described. However, as shown in FIGS. The waveguides 70a, 70b are gradually expanded in the direction of the circular waveguide 2 from the side of the rectangular waveguides 1a, 1b, so that the outer peripheral surface has a tapered surface. By adjusting the lengths of the circular waveguides 70a and 70b for matching, the same effects as in the above embodiment can be obtained.

Embodiment 6 FIG. Further, in the above-described embodiment, an example in which the radius of the inserted waveguide changes stepwise has been described. However, as shown in FIGS. 15 and 16, the rectangular waveguide 1 a, Even if rectangular waveguides 1c and 1d having a diameter larger than 1b are added, even if the rectangular waveguide changes stepwise as an insertion waveguide, these rectangular waveguides 1a, 1b and 1c can be used. , 1d by adjusting the length and diameter to achieve the same effect as in the above embodiment.

[0020]

As described above, according to the first aspect of the present invention, the rectangular waveguide is provided with the second iris for matching.
As a result, the circular waveguide can be made short, and the conventional pipe
The size of the window remains the same as compared to the box structure
Can be made smaller.

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[Brief description of the drawings]

FIG. 1 is a perspective view showing an airtight high-frequency window according to Embodiment 1 of the present invention.

FIG. 2 is a perspective view showing a quarter cut view of the hermetic high-frequency window according to Embodiment 1 of the present invention.

FIG. 3 is a sectional view showing an airtight high-frequency window according to Embodiment 1 of the present invention.

FIG. 4 is a front view showing an airtight high-frequency window according to Embodiment 1 of the present invention.

FIG. 5 is a perspective view showing an airtight high-frequency window according to Embodiment 2 of the present invention.

FIG. 6 is a perspective view showing a quarter cut view of an airtight high-frequency window according to Embodiment 2 of the present invention.

FIG. 7 is a sectional view showing an airtight high-frequency window according to a second embodiment of the present invention.

FIG. 8 is a front view showing an airtight high-frequency window according to a second embodiment of the present invention.

FIG. 9 is a sectional view showing an airtight high-frequency window according to a third embodiment of the present invention.

FIG. 10 is a front view showing an airtight high-frequency window according to Embodiment 3 of the present invention.

FIG. 11 is a perspective view showing an airtight high-frequency window according to Embodiment 4 of the present invention.

FIG. 12 is a perspective view showing a quarter cut view of an airtight high-frequency window according to Embodiment 4 of the present invention.

FIG. 13 is a perspective view showing an airtight high-frequency window according to a fifth embodiment of the present invention.

FIG. 14 is a perspective view showing a quarter cut view of an airtight high-frequency window according to a fifth embodiment of the present invention.

FIG. 15 is a perspective view showing an airtight high-frequency window according to Embodiment 6 of the present invention.

FIG. 16 is a perspective view showing a quarter cut view of an airtight high-frequency window according to a sixth embodiment of the present invention.

FIG. 17 is a perspective view showing a conventional hermetic high-frequency window.

FIG. 18 is a perspective view showing a quarter cut view of a conventional hermetic high-frequency window.

FIG. 19 is a perspective view showing a conventional airtight high-frequency window.

FIG. 20 is a perspective view showing a quarter cut view of a conventional hermetic high-frequency window.

FIG. 21 is a sectional view showing a conventional hermetic high-frequency window.

[Explanation of symbols]

1a, 1b, 1c, 1d Rectangular waveguide, 2, 7a, 7
b, 7c, 7d circular waveguide, 3 dielectric disk, 4 waveguide converter, 5, 6 iris,

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-145201 (JP, A) JP-A-53-54945 (JP, A) JP-A-57-46450 (JP, A) 31204 (JP, A) JP-A-60-134501 (JP, A) JP-A-61-216501 (JP, A) JP-A 55-95301 (JP, U) JP-A 4-105701 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01P 1/08 H01J 23/36

Claims (1)

(57) [Claims] 1. A pair of rectangular waveguides having a long side and a short side.
And a circular waveguide interposed between these rectangular waveguides
And a dielectric disk provided in the middle of this circular waveguide
Between the pair of rectangular waveguides and the circular waveguide.
Length of the rectangular waveguide facing the high frequency electric field converter
A first matching circuit formed on each side;
Matching formed on opposing short sides of a rectangular waveguide
A first matching circuit having a depth and a width.
And the position of the second matching circuit,
Impedance matching between the rectangular waveguide and the circular waveguide
An airtight high-frequency window characterized by being taken .