waveguide power distributor

Abstract

To provide a waveguide power divider that can supply power with a desired / arbitrary phase difference.SOLUTION: In a waveguide power divider 1, a plurality of power feeding ports 3 each having a substantially rectangular cross section and extending substantially perpendicularly to a main wave pipe 2 from the long side of the main wave pipe 2 having a substantially horizontally rectangular cross section are installed at intervals along the longitudinal direction of the main wave pipe 2, and a desired phase difference is generated between adjacent power feeding ports 3, 3 by setting the length of the long side in the cross section of the main wave pipe 2 as the width dimension, and making at least one of the width dimensions between the adjacent power feeding ports 3, 3 different from the width dimension of the other parts.SELECTED DRAWING: Figure 1

Description

【Technical Field】 【0001】 This invention relates to a waveguide power divider used for power distribution and synthesis in the microwave, millimeter-wave band, etc. 【Background Art】 【0002】 A waveguide power divider for branching a waveguide to perform power distribution has been conventionally used (for example, see Patent Document 1, etc.). When applied to a radar antenna in which a plurality of slot waveguides are arranged in the vertical direction, a waveguide power divider 201 as shown in FIG. 8 has been conventionally used. This waveguide power divider 201 has a plurality of power supply ports 203 whose cross sections are substantially square and extend in the horizontal direction provided from the side surface of a main waveguide 202 whose cross section is substantially square and extends in the vertical direction. Further, the width dimension of the main waveguide 202 (the length in the direction substantially orthogonal to the direction in which the power supply port extends) is the same dimension over the entire length, and the cross section of the power supply port 203 is the same dimension over the entire length. 【Prior Art Documents】 【Patent Documents】 【0003】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 2020-188375 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0004】 By the way, in the conventional waveguide power divider 201, since the width dimension of the main waveguide 202 is the same dimension over the entire length, power supply with the same phase or opposite phase is possible, but power supply with a desired and predetermined phase difference cannot be provided. As a result, the side lobe cannot be controlled or suppressed by adjusting the power supply phase. 【0005】 Therefore, an object of the present invention is to provide a waveguide power divider capable of providing a desired and arbitrary phase difference for power supply. 【Means for Solving the Problems】 【0006】 To achieve the above objective, the invention described in claim 1 is a waveguide power distributor in which a plurality of power supply ports, each having a substantially rectangular cross-section and extending substantially perpendicular to the waveguide, are provided at intervals along the longitudinal direction of the waveguide, extending from the long side of the waveguide having a substantially rectangular cross-section, and between adjacent power supply ports Of the width dimension, which is the length of the longer side of the cross-section of the aforementioned leading wave tube, At least one of them, The main wave tube between other adjacent power supply ports The device is characterized in that, by setting a dimension different from the aforementioned width dimension, a desired phase difference is generated between the adjacent power supply ports. 【0007】 The invention described in claim 2 is characterized in that, in the waveguide power distributor described in claim 1, the power supply port is provided with a double-tube choke section for suppressing radio wave leakage between the power supply port and an external member connected to the power supply port. 【0008】 The invention described in claim 3 is characterized in that, in the waveguide power distributor described in claim 1 or 2, the waveguide is formed in a substantially L-shape, with the base end to which power is supplied being bent. [Effects of the Invention] 【0009】 According to the invention described in claim 1, at least one of the width dimensions of the leading waveform tube between adjacent power supply ports is set to a different dimension from the width dimensions of other parts, so that a desired phase difference is generated between these adjacent power supply ports, making it possible to supply power with a desired or arbitrary phase difference. In other words, even if the distance between adjacent power supply ports is the same, it is possible to supply power with a desired phase difference. As a result, it becomes possible to control and suppress side lobes by adjusting the feeding phase. Moreover, since it is only necessary to change (adjust) the width dimension of a part of the leading waveform tube, and does not require major structural changes or the addition of members or elements, the configuration is simple and costs can be reduced. 【0010】 According to the invention described in claim 2, since the power supply port is provided with a choke section for suppressing radio wave leakage, when an external component such as an antenna is connected to the power supply port, it is possible to suppress radio wave leakage between the external component and the power supply port (reduce the effects of radio wave leakage). Moreover, since the choke section is simply a double-tube shape, the structure is simple and it is possible to reduce costs. 【0011】 According to the invention described in claim 3, the base end of the waveguide is bent and the entire structure is formed in a substantially L-shape, making it possible to keep the overall height of the waveguide power distributor low. As a result, for example, when applied to a radar antenna, it is possible to keep the height of the radome low. [Brief explanation of the drawing] 【0012】 [Figure 1] These are a first perspective view (a) and a second perspective view (b) showing a waveguide power distributor according to Embodiment 1 of the present invention. [Figure 2] These are a first perspective view (a) and a second perspective view (b) showing a waveguide power distributor according to Embodiment 2 of the present invention. [Figure 3] Figure 2 shows a waveguide power distributor cut in half vertically (a) and a front view (b). [Figure 4] Figure (a) is a magnified view showing the end of the slot waveguide of the radar antenna, and Figure (b) shows the waveguide power divider shown in Figure 2 connected to this end. [Figure 5] Figure 2 is an enlarged view showing the waveguide power divider connected to the end of the slot waveguide of the radar antenna. [Figure 6] Figure (a) shows a radar antenna in which a waveguide power divider, as shown in Figure 2, is connected to the end of a slot waveguide, with the radome attached, and Figure (b) is an enlarged view showing the inside of the radome. [Figure 7] This figure shows the radiation characteristics of a radar antenna equipped with a waveguide power distributor and a conventional radar antenna. [Figure 8] This is a perspective view showing a conventional waveguide power distributor. 【Best Mode for Carrying Out the Invention】 【0013】 Hereinafter, this invention will be described based on the illustrated embodiments. 【0014】 (Embodiment 1) FIG. 1 is a first perspective view (a) and a second perspective view (b) showing a waveguide power divider 1 according to this embodiment. This waveguide power divider 1 is a waveguide type power divider used for power distribution and synthesis in the microwave, millimeter wave band, etc., and mainly includes a main waveguide 2 and a plurality of feeding ports 3. Here, in this embodiment, the case of including three feeding ports 3 will be mainly described below, but two or four or more may be included. 【0015】 The main waveguide 2 is a rectangular waveguide having a substantially horizontally long rectangular cross section (a rectangle composed of opposing long sides and short sides), with one end side open and the other end side closed. Three feeding ports 3 are provided from one side surface (wide wall surface) on the long side of the main waveguide 2. That is, the feeding port 3 is a tubular body / waveguide having a substantially rectangular cross section and extends substantially orthogonally to the longitudinal direction of the main waveguide 2. Three such feeding ports 3 are provided at predetermined intervals along the longitudinal direction of the main waveguide 2, and the main waveguide 2 and each feeding port 3 penetrate and communicate with each other. 【0016】 When the length of the long side in the cross-section of the main waveguide 2 (the width of the wide wall surface) is taken as the width dimension, at least one of the width dimensions between the adjacent feeding ports 3, 3 is set to a dimension different from the width dimensions of other portions. That is, the feeding port 3 closest to the open end (the open end of the base end portion) of the main waveguide 2 to which power is supplied is the first feeding port 31, the next closest feeding port 3 is the second feeding port 32, and the farthest feeding port 3 is the third feeding port 33. Then, the width dimension of the first main pipe portion (base end portion) 21 between the open end of the main waveguide 2 and the first feeding port 31 is the first width dimension D1, the width dimension of the second main pipe portion 22 between the first feeding port 31 and the second feeding port 32 is the second width dimension D2, and the width dimension of the third main pipe portion 23 between the second feeding port 32 and the third feeding port 33 is the third width dimension D3. 【0017】 In this case, in this embodiment, the first width dimension D1 and the second width dimension D2 are the same dimension, and the third width dimension D3 is set to be smaller than the first width dimension D1 and the second width dimension D2. And by making the third width dimension D3 smaller in this way, a desired phase difference is caused between the adjacent feeding ports 3, 3, that is, between the second feeding port 32 and the third feeding port 33. In other words, the third width dimension D3 is set to be smaller than the first width dimension D1 and the second width dimension D2 so that a desired phase difference occurs between the second feeding port 32 and the third feeding port 33. 【0018】 That is, when the dimension of the long side (width dimension) of the inner surface of the rectangular waveguide is D and the waveguide wavelength is λg, the following mathematical formula holds. 【Equation】 λ = C / f: Free space wavelength λc = C / fc = 2×D: Cutoff wavelength of the waveguide when the rectangular waveguide is in the TE10 mode C: Speed of light = 2.99792458×10 8 (m / sec) f: Frequency (Hz) fc: Cutoff frequency of the waveguide (Hz) 【0019】 The phase difference Δφ1 between the first power supply port 31 and the second power supply port 32, and the phase difference Δφ2 between the second power supply port 32 and the third power supply port 33 are calculated as follows. Δφ1 = λg2 / λg1 × 180° Δφ2 = λg3 / λg1 × 180° λg1: Wavelength inside the first main pipe section 21 λg (λc=2×D1) λg2: The wavelength inside the second main pipe section 22, λg (λc=2×D2) λg3: Wavelength inside the third main pipe section 23 λg (λc=2×D3) Therefore, the width dimensions D1, D2, and D3 should be calculated and set so that the desired phase differences Δφ1 and Δφ2 occur. 【0020】 Here, the width dimension refers to the inner dimension of the lead wave tube 2. If the wall thickness of the lead wave tube 2 is the same throughout, a smaller third width dimension D3 means that both the inner and outer dimensions are smaller. In this embodiment, the first width dimension D1 and the second width dimension D2 are the same, but if a desired phase difference is to occur between the first power supply port 31 and the second power supply port 32, the second width dimension D2 is set to a different dimension from the first width dimension D1. 【0021】 Furthermore, the distance / spacing between the first power supply port 31 and the second power supply port 32, and the distance between the second power supply port 32 and the third power supply port 33 are the same. In addition, the thickness of the main wave tube 2 (length of the short side in cross-section) is set so that the first main tube section 21 is the largest, the second main tube section 22 is the next largest, and the third main tube section 23 is the smallest, in order to obtain the desired characteristics. 【0022】 With a waveguide power distributor 1 configured in this way, at least one of the width dimensions of the main waveguide 2 between adjacent power supply ports 3, 3 is set to a different dimension from the width dimensions of other parts, so that a desired phase difference is generated between these adjacent power supply ports 3, 3, making it possible to supply power with a desired or arbitrary phase difference. In other words, by changing (adjusting) a part of the width dimension of the main waveguide 2, it is possible to control and adjust the wavelength inside the main waveguide 2, making it possible to supply power with a desired phase difference even if the distance between adjacent power supply ports 3, 3 is all the same. As a result, as will be described later, it is possible to control and suppress side lobes by adjusting the feeding phase. Moreover, since it is only necessary to change (adjust) a part of the width dimension of the main waveguide 2, and does not require major structural changes or the addition of materials or elements, the configuration is simple and low cost can be achieved. 【0023】 (Embodiment 2) Figure 2 shows a first perspective view (a) and a second perspective view (b) of the waveguide power distributor 10 according to this embodiment, and Figure 3 shows a perspective view (a) and a front view (b) of the waveguide power distributor 10 when it is cut in half vertically. This embodiment differs from Embodiment 1 in that a choke section 31 is provided in the power supply port 3 and the first main section (base end) 21 is bent. Components equivalent to those in Embodiment 1 are given the same reference numerals and their descriptions are omitted. 【0024】 Each power supply port 3 is provided with a double-tube-shaped choke section 31 to suppress radio wave leakage between the power supply port 3 and the external component connected to it. Specifically, a hollow choke section (annular cavity) 31 is provided around the power supply port 3 on the lead wave tube 2 side of the tip 32 of the power supply port 3 that is inserted into and connected to the external component, thereby restricting the electromagnetic waves and preventing them from leaking out. In other words, the shape and position of this choke section 31 are set to prevent electromagnetic waves from leaking out. 【0025】 Furthermore, the inside of the lead wave tube 2 is formed in a roughly L-shape, with the first main tube section 21, to which power is supplied, being bent. That is, the first main tube section 21 is bent in a semicircular shape from the first power supply port 31 side, and then extends approximately perpendicular to the lead wave tube 2 from the first power supply port 31 to the second power supply port 32. 【0026】 In this embodiment, as shown in Figures 4 to 6, the external member connected to the power supply port 3 is the slot waveguide 102 of the radar antenna 101. This slot waveguide 102 is a cylindrical body with a roughly square cross-section, and multiple slots / elongated holes are formed on the front surface along the longitudinal direction. Multiple such slot waveguides 102 (three in this embodiment) are arranged vertically, extending roughly horizontally and spaced apart by a predetermined interval. 【0027】 Then, by inserting the tip 32 of the power supply port 3 into each of the three ends of the slot waveguide 102, the slot waveguide 102 and the waveguide power distributor 10 are connected. Furthermore, by attaching the radome 103 in this state, the slot waveguide 102 and the waveguide power distributor 10 are housed inside the radome 103 to form a radar antenna 101. 【0028】 As described above, in this embodiment, since each power supply port 3 is provided with a choke section 31 to suppress radio wave leakage, when an external component such as a radar antenna 101 is connected to the power supply port 3, it is possible to suppress radio wave leakage between the external component and the power supply port 3 (reduce the effects of radio wave leakage). Moreover, since the choke section 31 is simply a double-tube shape, the configuration is simple and it is possible to reduce costs. 【0029】 Furthermore, since the first main tube section 21 of the main waveguide 2 is bent and the entire structure is formed in a roughly L-shape, it is possible to keep the overall height of the waveguide power distributor 10 low. As a result, for example, when applied to a radar antenna 101, it is possible to keep the height of the radome 103 low. 【0030】 Furthermore, similar to Embodiment 1, by changing (adjusting) a portion of the width dimension of the leading waveguide 2, it is possible to supply power with a desired phase difference. As a result, it becomes possible to control and suppress side lobes by adjusting the feeding phase. For example, when supplying power with a phase difference of 180° as in the conventional method, the radiation characteristics (vertical plane directivity) are as shown by characteristic curve L1 in Figure 7. In contrast, when supplying power with a phase difference of 160° in this waveguide power distributor 10, the characteristics are as shown by characteristic curve L2 in Figure 7, and it is possible to suppress side lobes (first lobes) compared to characteristic curve L1. 【0031】 Although embodiments of this invention have been described above, the specific configuration is not limited to the embodiments described above, and any design changes, etc., that do not depart from the gist of this invention are also included. For example, in Embodiment 2 described above, the case in which the external member connected to the power supply port 3 is a slot waveguide 102 was described, but other members may also be used. [Explanation of Symbols] 【0032】 1, 10 waveguide power divider 2 Main wave tube 21. First main section (base end) 22 Second Main Department 23 Third Main Department 3 Power supply ports 31 Chalk section 32 Tip 101 Radar antenna (external component) 102 Slot Waveguide 103 Radome D1 First width dimension D2 Second width dimension D3 Third width dimension

Claims

[Claim 1] Waveguide power distributor comprising a plurality of power supply ports, each having a roughly rectangular cross-section and extending substantially perpendicular to the waveguide, provided at intervals along the longitudinal direction of the waveguide, on the side of the longer side of the waveguide, the waveguide power distributor comprising a waveguide with a roughly rectangular cross-section, By making at least one of the width dimensions, which is the length of the longer side of the cross-section of the lead wave tube between adjacent power supply ports, different from the width dimension of the lead wave tube between other adjacent power supply ports, a desired phase difference is created between those adjacent power supply ports. A waveguide power distributor characterized by the following features. [Claim 2] The power supply port is provided with a double-tube choke section for suppressing radio wave leakage between the power supply port and an external member connected to it. Waveguide power distributor according to feature 1. [Claim 3] The aforementioned lead wave tube has its base end, to which power is supplied, bent, and the entire structure is formed in a roughly L-shape. A waveguide power distributor according to either claim 1 or 2.

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