JP5677133B2 - Waveguide feeder - Google Patents

Description

  The present invention relates to a waveguide feeder having high assemblability.

A waveguide feeding unit formed of a dielectric material may be molded using, for example, an injection molding technique. As shown in FIG. In order to distribute the images, there are those in which distribution units and the like are arranged in a tournament (see, for example, Patent Document 1).
When the waveguide feeding portion having such a structure is applied to a one-dimensional active phased array antenna, the weight can be reduced as compared with the case where the array antenna is formed of metal parts. Moreover, it can contribute to size reduction from a viewpoint of dielectric constant.
In addition, by adopting an injection molding technique using a mold, low cost can be achieved during mass production.
In addition, since it has a waveguide shape, the loss is lower than when it is routed with a resin multilayer substrate, and the feeding portion and the element antenna can be integrally formed, so that the assembly cost can be reduced. it can.

JP 2008-271498 A (paragraph number [0010], FIG. 1)

Since the conventional waveguide feeder is configured as described above, the structure is held at each branch when applied to a one-dimensional active phased array antenna. However, when the number of distributions is large, mechanical rigidity cannot be maintained particularly at the root branch portion, and there is a problem that the distance between the distal radiating elements cannot be maintained.
Moreover, in order to hold | maintain the radiation | emission element of a front-end | tip, another support structure was needed and the subject that a number of parts increased occurred.
Further, when applied to a two-dimensional active phased array antenna, since one active circuit (amplifier / phase shifter) is required for each element, all feed lines are divided. For this reason, the number of parts increases because the number of elements requires as many feed lines. Further, since a separate support structure for fixing the position of the feeder line is required, there is a problem that the assemblability is significantly deteriorated.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain a waveguide feeding portion that can maintain high rigidity without preparing a special support structure.

  The waveguide feeder according to the present invention includes a plurality of main waveguides that are filled with a dielectric and are plated with a conductor around the input / output portion, and a transmission frequency band of the main waveguide. A sub-waveguide having a high cut-off frequency, and the sub-waveguide is disposed between the plurality of main waveguides, and one end of the sub-waveguide is attached to a wall surface of one of the main waveguides. The other end of the sub-waveguide is connected to the wall surface of the main waveguide different from the main waveguide.

  According to the present invention, a plurality of main waveguides that are filled with a dielectric and conductor-plated around the input and output portions, and have a cutoff frequency higher than the transmission frequency band of the main waveguide. The sub-waveguide is disposed between the plurality of main waveguides, and one end of the sub-waveguide is connected to the wall surface of one of the main waveguides. Since the other end of the waveguide is connected to the wall surface of the main waveguide different from the main waveguide, there is an effect that high rigidity can be maintained without preparing a special support structure. .

It is a perspective view which shows the waveguide electric power feeding part by Embodiment 1 of this invention. 3 is a cross-sectional view showing an opening of the main waveguide 1. FIG. It is explanatory drawing which shows the reflection characteristic and isolation characteristic of a waveguide electric power feeding part at the time of changing the diameter of the waveguide bridge 4. FIG. It is a perspective view which shows the other waveguide electric power feeding part by Embodiment 1 of this invention. It is a perspective view which shows the waveguide electric power feeding part by Embodiment 2 of this invention. It is explanatory drawing which shows the principle by which the reflection characteristic in the input-output parts 2 and 3 of a waveguide electric power feeding part is improved. It is explanatory drawing which shows the reflective characteristic of the input-output part 2a when one waveguide bridge 4 is connected between the two main waveguides 1, and when two are connected. It is a block diagram which shows the waveguide feed part of another structure from the waveguide feed part of FIG. It is a block diagram which shows the waveguide electric power feeding part by Embodiment 3 of this invention. It is a block diagram which shows the waveguide electric power feeding part by which the waveguide bridges 6a and 6b are arrange | positioned at the main waveguide 1a, and the waveguide bridges 6c and 6d are arrange | positioned at the main waveguide 1c. It is a perspective view which shows the waveguide electric power feeding part by Embodiment 4 of this invention. It is the top view which looked at the waveguide electric power feeding part of FIG. 11 from the top. It is a block diagram which shows the waveguide electric power feeding part by Embodiment 5 of this invention. It is explanatory drawing which shows arrangement | positioning of the waveguide bridge | bridging 8 in the waveguide electric power feeding part of FIG. It is a perspective view which shows the waveguide electric power feeding part currently disclosed by patent document 1. FIG.

Embodiment 1 FIG.
1 is a perspective view showing a waveguide feeding portion according to Embodiment 1 of the present invention.
In FIG. 1, main waveguides 1a and 1b (hereinafter, the main waveguides 1a and 1b may be collectively referred to as main waveguide 1) are filled with a dielectric, and the surroundings are plated with a conductor. It is a small and lightweight waveguide that has been applied.
That is, after the main waveguide 1 is integrally formed of resin, the input / output units 2a, 2b, 3a, 3b (hereinafter, the input / output units 2a, 2b are collectively referred to as the input / output unit 2, the input / output units 3a, 3b). This is a resin waveguide in which conductor plating is applied to the resin surface (except for the case where the input / output unit 3 may be collectively referred to).
The main waveguides 1a and 1b are integrated with the element antenna.

The waveguide bridge 4, which is a sub-waveguide, is integrally formed of resin and has a cutoff frequency higher than the transmission frequency band of the main waveguide 1.
The waveguide bridge 4 is disposed between the main waveguide 1a and the main waveguide 1b, and one end of the waveguide bridge 4 is connected to the wall surface of the main waveguide 1a. The end is connected to the wall surface of the main waveguide 1b.

FIG. 2 is a cross-sectional view showing the opening of the main waveguide 1.
In the example of FIG. 2, the dimensions of the input / output portions 2 and 3 that are openings of the main waveguide 1 are “a × b”, and the conductor plating 5 is applied around the main waveguide 1.

In the waveguide feeding section of FIG. 1, the main waveguides 1a and 1b are rectangular waveguides having openings as shown in FIG. 2, and the waveguide bridge 4 is a cylindrical waveguide. However, the main waveguides 1a and 1b may be cylindrical waveguides, and the waveguide bridge 4 may be a rectangular waveguide.
Further, in the waveguide feeding section of FIG. 1, the waveguide bridge 4 is disposed at the center of the wide surface of the main waveguides 1a and 1b, but may be disposed at a position shifted from the center of the wide surface.

FIG. 3 is an explanatory diagram showing the reflection characteristics and isolation characteristics of the waveguide feeding section when the diameter of the waveguide bridge 4 is changed.
The horizontal axis is normalized by the a dimension of the openings of the main waveguides 1a and 1b.
As is clear from FIG. 3, the smaller the diameter of the waveguide bridge 4 is, the better the reflection characteristics and isolation characteristics of the waveguide feeding portion are. However, the support structure for the main waveguides 1a and 1b is more rigid. It is necessary to ensure.

1 has a planar structure, the main waveguide 1a and the main waveguide 1b do not need to be parallel, and as shown in FIG. 4, the main waveguide 1a and the main waveguide 1b You may arrange | position in the position of a twist.
The position of such a twist is not limited to the case where there are two main waveguides 1, and the same applies when there are three or more main waveguides 1.
Further, the main waveguides 1a and 1b and the waveguide bridge 4 do not have to be linear.

In the first embodiment, the waveguide bridge 4 is arranged between the plurality of main waveguides 1 each having a dielectric formed therein. The waveguide bridge 4 is transmitted through the main waveguide 1. Since the cutoff frequency is higher than the frequency band, the electromagnetic wave transmitted by the main waveguide 1 is not transmitted by the waveguide bridge 4.
For this reason, the plurality of main waveguides 1 are equivalent to a state in which the waveguide bridge 4 is physically connected but not electrically connected. Therefore, the waveguide bridge 4 is the main waveguide 1. The mechanical properties are hardly affected and the mechanical rigidity is increased.
Therefore, a special support structure for fixing the plurality of main waveguides 1 is not required, and high assemblability can be realized.

Embodiment 2. FIG.
5 is a perspective view showing a waveguide feeding portion according to Embodiment 2 of the present invention. In the figure, the same reference numerals as those in FIG.
The waveguide bridge 4 a is integrally formed of resin, like the waveguide bridge 4 of FIG. 1, and has a cutoff frequency higher than the transmission frequency band of the main waveguide 1.
The waveguide bridge 4a is disposed between the main waveguide 1a and the main waveguide 1b, and one end of the waveguide bridge 4a is connected to the wall surface of the main waveguide 1a. The end is connected to the wall surface of the main waveguide 1b.

Similarly to the waveguide bridge 4a, the waveguide bridge 4b is integrally formed of resin and has a cutoff frequency higher than the transmission frequency band of the main waveguide 1.
The waveguide bridge 4b is disposed between the main waveguide 1a and the main waveguide 1b, and one end of the waveguide bridge 4b is connected to the wall surface of the main waveguide 1a. The end is connected to the wall surface of the main waveguide 1b.
The waveguide bridge 4a and the waveguide bridge 4b (hereinafter, the waveguide bridges 4a and 4b may be collectively referred to as the waveguide bridge 4) are the tubes of the main waveguides 1a and 1b. In the axial direction, they are spaced apart by a length that is an odd multiple of one-fourth of the guide wavelength λg at the center frequency of the transmission frequency band of the main waveguides 1a and 1b.
In the example of FIG. 5, the waveguide bridge 4a and the waveguide bridge 4b are arranged at an interval of λg / 4.

  By arranging the waveguide bridge 4a and the waveguide bridge 4b at an interval of λg / 4, the rigidity of the waveguide feeding portion by the waveguide bridge 4 is improved, and the reflection at the input / output portions 2 and 3 is improved. The characteristics are improved.

FIG. 6 is an explanatory diagram showing the principle that the reflection characteristics at the input / output units 2 and 3 of the waveguide feeding unit are improved.
In FIG. 6, point A represents the intersection of the main waveguide 1a and the waveguide bridge 4a, and point B represents the intersection of the main waveguide 1a and the waveguide bridge 4b.
Similarly, the point C represents the intersection between the main waveguide 1b and the waveguide bridge 4a, and the point D represents the intersection between the main waveguide 1b and the waveguide bridge 4b.

The waveguide bridges 4a and 4b have a cutoff frequency higher than the transmission frequency band of the main waveguides 1a and 1b, but at points A, B, C, and D, which are discontinuous portions of the structure. Some electromagnetic waves are reflected.
Here, the reflection coefficient at point A is ΓA, the reflection coefficient at point B is ΓB, the magnitude of reflection coefficient ΓA is | ΓA |, and the magnitude of reflection coefficient ΓB is | ΓB |.
In this case, if the structure is the same and the passage loss between the points A and B is extremely small, | ΓA | = | ΓB |.
When | ΓA | = | ΓB |, if the distance between point A and point B is an odd multiple of λg / 4, a phase difference of an odd multiple of 180 degrees occurs in the round trip, and the reflected wave at point A and point B Since the reflected waves at are overlapped with opposite phases, the amplitude of the synthesized wave becomes “0”.

FIG. 7 is an explanatory diagram showing the reflection characteristics of the input / output unit 2a when one waveguide bridge 4 is connected between two main waveguides 1 and when two are connected.
From FIG. 7, it can be seen that when the frequency is 47 GHz, the reflection characteristics in the input / output unit 2a are greatly improved. The improvement of the reflection characteristics is the same in the input / output units 2b, 3a, 3b.

In the example of FIG. 5, two linear main waveguides 1 are shown, but three linear main waveguides 1 may be arranged. Further, the main waveguide 1 may be bent.
When the main waveguide is long, the waveguide bridges 4a and 4b are connected to the input / output units 2a and 3a, and the waveguide bridges 4a and 4b are connected to the input / output units 2b and 3b. It may be.

FIG. 8 is a block diagram showing a waveguide feeder having a structure different from that of FIG.
In the waveguide feeding section of FIG. 8, the eight main waveguides 1a to 1h are bent twice, and two waveguide bridges 4a and 4b are respectively provided at the input / output sections 2 and 3 at intervals of λg / 4. Is arranged.
Also in this case, as in the case of the waveguide power supply unit in FIG. 5, the rigidity of the waveguide power supply unit can be increased and the reflection characteristics in the input / output units 2 and 3 can be improved.

Embodiment 3 FIG.
FIG. 9 is a block diagram showing a waveguide feeding portion according to Embodiment 3 of the present invention. In the figure, the same reference numerals as those in FIG.
Similarly to the waveguide bridge 4a, the waveguide bridge 4c is integrally formed of resin and has a cutoff frequency higher than the transmission frequency band of the main waveguide 1.
The waveguide bridge 4c is disposed between the main waveguide 1b and the main waveguide 1c, and one end of the waveguide bridge 4c is connected to the wall surface of the main waveguide 1b. The end is connected to the wall surface of the main waveguide 1c.

Similarly to the waveguide bridge 4c, the waveguide bridge 4d is integrally formed of resin and has a cutoff frequency higher than the transmission frequency band of the main waveguide 1.
The waveguide bridge 4d is disposed between the main waveguide 1b and the main waveguide 1c, and one end of the waveguide bridge 4d is connected to the wall surface of the main waveguide 1b. The end is connected to the wall surface of the main waveguide 1c.
The waveguide bridge 4c and the waveguide bridge 4d are one-fourth of the guide wavelength λg at the center frequency of the transmission frequency band of the main waveguides 1b and 1c in the tube axis direction of the main waveguides 1b and 1c. They are spaced apart by an odd number of times.
In the example of FIG. 9, the waveguide bridge 4b and the waveguide bridge 4c are arranged at an interval of λg / 4.

In the waveguide feeding section of FIG. 9, the main waveguides 1a, 1b, and 1c are arranged in a horizontal row, and the two waveguide bridges 4 are symmetrically provided between the main waveguide 1a and the main waveguide 1c. Are connected, but two waveguide bridges 4 are connected to the left and right sides of the main waveguide 1b.
Therefore, the reflection coefficients at the connection points of the waveguide bridges 4 in the main waveguides 1a, 1b, and 1c are different. As a result, the reflection characteristics of the input / output units 2a to 2c and 3a to 3c vary.
In order to minimize the influence of variation in characteristics at the waveguide feeding section on the antenna characteristics, waveguide bridges 6a and 6b are arranged on the left side of the main waveguide 1a in the drawing as shown in FIG. The waveguide bridges 6c and 6d may be arranged on the right side of the main waveguide 1c in the drawing.
Thereby, the reflection coefficients at the respective connection points are uniform, and variations in the reflection characteristics at the input / output units 2a to 2c and 3a to 3c are reduced.

  In the third embodiment, three linear main waveguides 1 are shown. However, the number of main waveguides 1 is not limited. Even when four or more main waveguides 1 are arranged, The number and shape of the waveguide bridges 4 (or 6) connected to the main waveguide 1 are the same, and the positional relationship between the main waveguide 1 and the waveguide bridge 4 (or 6) is axisymmetric. Or if it is a rotationally symmetrical form, the reflection coefficient in each connection point will be equal, and the dispersion | variation in the reflection characteristic in the input-output parts 2 and 3 will be reduced.

Embodiment 4 FIG.
FIG. 11 is a perspective view showing a waveguide feeding portion according to Embodiment 4 of the present invention, and FIG. 12 is a top view of the waveguide feeding portion of FIG. 11 as viewed from above.
11, when viewed from the top, as shown in FIG. 12, three cylindrical main waveguides 1a to 1c are arranged in a triangle.
In FIGS. 11 and 12, the waveguide bridge 7a is integrally formed of resin and has a cutoff frequency higher than the transmission frequency band of the main waveguide 1 in the same manner as the waveguide bridge 4 in FIG. .
The waveguide bridge 7a is disposed between the main waveguide 1a and the main waveguide 1b, and one end of the waveguide bridge 7a is connected to the wall surface of the main waveguide 1a. The end is connected to the wall surface of the main waveguide 1b.

Similarly to the waveguide bridge 7a, the waveguide bridge 7b is integrally formed of resin and has a cutoff frequency higher than the transmission frequency band of the main waveguide 1.
The waveguide bridge 7b is disposed between the main waveguide 1b and the main waveguide 1c, and one end of the waveguide bridge 7b is connected to the wall surface of the main waveguide 1b. The end is connected to the wall surface of the main waveguide 1c.
Similarly to the waveguide bridge 7a, the waveguide bridge 7c is integrally formed of resin and has a cutoff frequency higher than the transmission frequency band of the main waveguide 1.
The waveguide bridge 7c is disposed between the main waveguide 1c and the main waveguide 1a, and one end of the waveguide bridge 7c is connected to the wall surface of the main waveguide 1c. The end is connected to the wall surface of the main waveguide 1a.

In the waveguide feeding portion of FIG. 11, the main waveguides 1a to 1c and the waveguide bridges 7a to 7c are rotationally symmetric at 120 ° with the center point of the waveguide feeding portion as the center. (See FIG. 12), the reflection coefficients at the connection points of the waveguide bridges 7a to 7c coincide.
Thereby, the reflection coefficients at the respective connection points are uniform, and variations in the reflection characteristics at the input / output units 2a to 2c and 3a to 3c are reduced.

  In the fourth embodiment, three cylindrical main waveguides 1 are shown. However, the number of main waveguides 1 is not limited, and even when four or more main waveguides 1 are arranged, If the number and shape of the waveguide bridges 7 connected to the main waveguide 1 are the same and the positional relationship between the main waveguide 1 and the waveguide bridge 7 is axially symmetric or rotationally symmetric, each connection The reflection coefficients at the points are uniform, and variations in reflection characteristics at the input / output units 2 and 3 are reduced.

In the array antenna, a triangular array or a square array is often used, but a resin waveguide horn antenna in which element antennas are integrally formed in the input / output sections 2a to 2c and 3a to 3c of the waveguide feeding section in FIG. The element arrangement with little positional variation is possible without adding another support structure.

Embodiment 5 FIG.
13 is a block diagram showing a waveguide feeding portion according to Embodiment 5 of the present invention. In the figure, the same reference numerals as those in FIG.
The waveguide bridge 8 is integrally formed with the main waveguide 1 and resin, like the waveguide bridge 4 of FIG. 1, and has a cutoff frequency higher than the transmission frequency band of the main waveguide 1 which is a rectangular waveguide. have.
The waveguide bridge 8 is disposed at the center of the wide surface of the main waveguide 1 which is a rectangular waveguide.
FIG. 14 is an explanatory view showing the arrangement of the waveguide bridges 8 in the waveguide feeding section of FIG.

When the two waveguide bridges 4a and 4b are arranged at an interval of λg / 4 for the purpose of improving the reflection characteristics as in the second embodiment, it cannot be realized by the injection molding manufacturing method. is there.
That is, in the millimeter wave band, λg / 4 is short (in the case of a dielectric material with εr = 2.3, λg / 4 = 1.44 mm at 47 GHz), and the opening dimensions of the waveguide bridges 4a and 4b are φ1 mm. In this case, since the gap between the two waveguide bridges 4a and 4b is less than 0.5 mm, it may not be realized by the injection molding manufacturing method.

In the fifth embodiment, manufacturing problems are avoided by integrating the two waveguide bridges 4a and 4b.
When the two waveguide bridges 4a and 4b are integrated, the impedance of the main waveguide 1 in the input / output units 2 and 3 is Z0, and the main waveguide from the end 8a to the end 8b of the waveguide bridge 8 is used. When the impedance of 1 is Z1, the reflection coefficient ΓE at the end 8a of the waveguide bridge 8 and the reflection coefficient ΓF at the end 8b of the waveguide bridge 8 are as follows.
ΓE = (Z0−Z1) / (Z0 + Z1)
ΓF = (Z1−Z0) / (Z1 + Z0)
For this reason, the reflection coefficient ΓE at the end portion 8a of the waveguide bridge 8 and the reflection coefficient ΓF at the end portion 8b have the same amplitude and are inverted in phase.

In order to improve reflection at the end portions 8a and 8b of the waveguide bridge 8, it is necessary that the phases of the reflection coefficient ΓE and the reflection coefficient ΓF differ by “180 ° + n × 360 °”.
For this reason, the condition for reversing the phase difference for the round trip is expressed by the following equation (1), where θ is the phase passing through the length L.
180 ° + 2θ = 180 ° + n × 360 ° (n = 0, 1, 2,...) (1)
Therefore, since θ ≠ 0 in terms of structure, if n = 1 is selected, θ = 180 ° and the length L is λg / 2.

Moreover, even if the waveguide bridge 8 has a length of λg / 2 in the axial direction of the main waveguide 1, the TE10 mode of the main waveguide 1 is sufficient as long as it is arranged at the center of the wide surface of the rectangular waveguide. Therefore, the central portion 8c and the central portion 8d of the waveguide bridge 8 have the same potential.
Therefore, the waveguide bridge 8 does not work as a waveguide that transmits the TE10 mode of the main waveguide 1, and isolation from the adjacent waveguide feeder is ensured.
As a result, the waveguide power feeding section of FIG. 11 can maintain the rigidity by avoiding the manufacturing limit, and can improve the reflection characteristics.

  In the present invention, within the scope of the invention, any combination of the embodiments, or any modification of any component in each embodiment, or omission of any component in each embodiment is possible. .

  1a to 1h Main waveguide, 2a to 2c, 3a to 3c I / O section, 4, 4a to 4d, 6a to 6d, 7a to 7c Waveguide bridge (sub waveguide), 5 conductor plating, 8 waveguide Bridge (sub-waveguide), 8a, 8b End portion of the waveguide bridge 8, 8c, 8d Center portion of the waveguide bridge 8.

Claims (7)

A plurality of main waveguides that are filled with a dielectric and are plated with a conductor around the input / output portion, and a sub-waveguide having a cutoff frequency higher than the transmission frequency band of the main waveguide And
The sub waveguide is disposed between said main waveguide of multiple, one end of the sub-wave tube is connected to the wall surface of any of the above main waveguide, the other end of the sub-wave tube There waveguide feed section, characterized in that it is connected to the wall surface of the main waveguide and another of the main waveguide. Characterized in that one of the odd multiple of spacing of a quarter of the guide wavelength, a plurality of the sub-wave tube to the tube axis direction of the main waveguide is located at the center frequency of the transmission frequency band of the main waveguide The waveguide feeding portion according to claim 1. If three or more of the main waveguide are arranged, each of which the number of the main waveguide said sub waveguide which is connected to and shape match, the position of the main waveguide and the sub waveguide 3. The waveguide feeding portion according to claim 1, wherein the relationship is axially symmetric or rotationally symmetric. Waveguide feeding unit according to any one of claims 1 to 3, characterized in that the sub waveguide is arranged on both the input side and the output side of the main waveguide. If the main waveguide has a rectangular waveguide, any of claims 1 to 4, the sub-wave tube is characterized in that it is arranged on the wide surface center of the rectangular waveguide 2. A waveguide feeding unit according to item 1. To the tube axis direction of the main waveguide, that the sub-wave tube having a one-half of an integral multiple of the length of the guide wavelength at the center frequency of the transmission frequency band of the main waveguide is located The waveguide power feeding unit according to claim 5, wherein: Waveguide feeding unit according to any one of claims 1 to 6 in which the input and output portions of the plurality of the main waveguide is characterized in that it is integrally molded with the antenna element.

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