KR100597207B1 - Waveguide rotary joint structure using a Circular waveguide transformer - Google Patents

Abstract

The present invention is to simply improve the productivity by providing a wide bandwidth, as well as to improve the insertion loss characteristics by simply configuring the structure of the rotary joint (Rotary Joint) to the transmission mode is converted in the waveguide structure of the radar antenna A structure of a waveguide rotating connector using a circular waveguide transducer.

To this end, the present invention is a rotational connection for converting the transmission mode from the rectangular waveguide to the circular waveguide, and converts the transmission mode of the converted circular waveguide back to the transmission mode of the rectangular waveguide, the first having a predetermined width and height The first and second spherical waveguides each having a first transmission path and a predetermined diameter and having a second transmission path formed at right angles to an end portion of the first transmission path, and a transmission mode transmitted from the rectangular waveguide are circular waveguides. The second transmission path is connected in accordance with the combination of the first and second spherical waveguides so as to be converted into a transmission mode of a circular waveguide which provides a function as a waveguide transducer; The diameter of both ends of the circular waveguide is configured to be larger than the diameter of the center portion, and the bent interface of the first transmission path and the second transmission path is biased toward one side at the boundary of the second transmission path. A portion of the opening of the second transmission path is sealed; A choke for preventing the leakage of microwaves is formed on the outer peripheral surface of the central portion of the second transmission path.

Radar antenna, spherical waveguide, circular waveguide, rotary connector, transmission mode

Description

Waveguide rotary joint structure using a circular waveguide transformer

1 is a diagram illustrating a basic electromagnetic field mode inside a typical spherical waveguide.

a) shows a spherical waveguide,

b) represents the field mode (TE ₁₀ or H ₁₀ ) of the '1' portion of the spherical waveguide,

c) represents the field mode (TE ₁₀ or H ₁₀ ) of the '2' portion of the spherical waveguide,

d) represents the electromagnetic field mode (TE ₁₀ or H ₁₀ ) of the '3' portion of the spherical waveguide,

2 is a view for explaining the electromagnetic field mode (TM ₁₀ or E ₀₁ ) inside the circular waveguide,

3 is a diagram showing the distribution of TE ₁₁ (or H ₁₁ ) mode which is a basic mode of a circular waveguide,

4 is an embodiment view showing a waveguide rotary connector applied to transmit a signal from a spherical waveguide to a circular waveguide according to the prior art,

Figure 5 is a detailed cross-sectional view showing the structure of the waveguide rotary connector according to an embodiment of the present invention,

FIG. 6 is a detailed view showing a mode converter for converting a mode of microwaves in FIG. 5; FIG.

7 is a schematic diagram showing a mode conversion state by the rotary connector of FIG.

8 and 9 is a simulation result characteristic view of the rotating connector and the mode conversion unit of the present invention,

10 is a characteristic view of a measurement result for the rotary connector of the present invention.

* Description of the symbols for the main parts of the drawings *

102, 104: first and second spherical waveguides, 106: bearings,

112: nut, 114: cover,

122: choke, 140: circular waveguide,

142: mode conversion unit.

The present invention relates to a structure of a waveguide rotary connector using a circular waveguide transducer, and more particularly, by working with a simpler structure of the rotary connector installed between the radar antenna and the transmission line to mutually convert the transmission mode. A structure of waveguide rotating connectors using circular waveguide transducers to reduce man-hours and provide a wide bandwidth.

As is well known, the radar has a very narrow beam width, with very high directivity, with very high energy emitted from the antenna, which then hits a target and reflects a portion of that energy, resulting in the reception of the reflected wave. And a device for detecting the distance, the radar cross-sectional area of the target, the horizontal and vertical angle, the moving speed and the like. That is, the radio wave is sent to the target to receive the reflected wave of the propagation energy, and the position of the target is measured by the round trip time and the directivity of the antenna using the propagation straightness and constant speed.

In this case, the antenna must be rotated at a constant speed in order to measure the omnidirectional position in order to measure the position of the target by the antenna used in the radar system, on the contrary, by receiving a signal from the antenna to observe it or energy In order to transmit the data, a fixed transmission line must be provided.

The transmission line used in the radar system uses a waveguide that provides excellent characteristics such as less resistance loss, no dielectric loss, and no radiation loss than the parallel two-wire or coaxial cable in terms of propagation characteristics.

As an embodiment of such a waveguide, a rectangular waveguide and a circular waveguide are applied, and the electromagnetic field mode of the waveguide is shown in FIGS. 1 to 3.

First, referring to FIG. 1, which describes an electromagnetic field mode in a typical rectangular waveguide, a) shows a rectangular waveguide, b) shows an electromagnetic field mode of the '1' portion of the rectangular waveguide, and c) The electromagnetic field mode of the '2' portion of the spherical waveguide is shown, and d) represents the electromagnetic field mode of the '3' portion of the spherical waveguide.

As shown, it represents TE ₁₀ (or H ₁₀ ) mode, which is the basic transmission mode of the spherical waveguide, and the electric field (E) direction represents the direction perpendicular to the wave propagation direction. The electric field mode for the predetermined portion of the rectangular waveguide, that is, the '1', '2', and '3' portions of the rectangular waveguide may be known according to the direction in which the rectangular waveguide is divided in FIG. 1A.

In the drawing, the solid line indicates the electric field direction, and the dotted line indicates the magnetic field direction.

The rectangular waveguide is transmitted in a basic mode when a signal is transmitted to a standard waveguide, and when transmitted in a higher order mode, the signal rapidly decreases according to the transmission distance. In addition, the commercial band used in the standard waveguide uses only the band where no higher-order mode occurs.

Subsequently, FIG. 2 is a diagram illustrating an electromagnetic field mode inside a circular waveguide.

The figure shown shows the TM ₀₁ (or E ₀₁ ) mode, which is one of the higher order modes of the circular waveguide. The TM ₀₁ (or E ₀₁ ) mode has a structure symmetrical with respect to the direction of rotation in the circular waveguide.

The circular waveguide can block the transmission of the higher order mode according to the diameter, thus providing the characteristics of the high pass filter. Therefore, when the circular waveguide is applied to the rotating part of the rotary connector and rotated, the signal is efficiently transmitted without attenuation or distortion of the signal.

In the drawing, the solid line indicates the electric field direction, and the dotted line indicates the magnetic field direction.

3 is a diagram showing the distribution of the TE ₁₁ (or H ₁₁ ) mode which is a basic mode of a circular waveguide.

In general, TE ₁₁ (or H ₁₁ ) mode, which is a basic mode, is used for signal transmission in the circular waveguide. However, when applied to a rotating connector that changes the transmission mode, the mode distribution is different from the initial state depending on the rotation angle. Return loss and insertion loss due to rotation are different so that the TE ₁₁ (or H ₁₁ ) mode should be removed from the rotary connector.

When such a rectangular waveguide and a circular waveguide are used and applied to a radar antenna, the antenna is rotated and the transmission line is fixed, so that the antenna driven by rotation has a low loss and distortion with a radio frequency signal. In order to supply the rotary joint having a certain structure (Rotary Joint) is to be mounted between the antenna and the transmission line.

That is, FIG. 4 illustrates a prior art waveguide rotating connector that is applied to transmit a signal from a rectangular waveguide to a circular waveguide. This is described as follows.

As shown in FIG. 4A, a block structure 14 of predetermined size is mounted at the end of the spherical waveguide 10 at the junction of the spherical waveguide 10 and the circular waveguide 12 to provide mode matching.

In addition, FIG. 4B shows a pair of matching windows protruding from both side portions by a predetermined length such that the rectangular waveguide 10 and the circular waveguide 12 are connected to each other at a predetermined distance within the rectangular waveguide 10. window (16) is provided for mode matching.

In addition, referring to FIG. 4C, in which a suppressor window is formed inside the circular waveguide to perform mode matching, a rectangular waveguide 10 and a circular waveguide 12 are provided as shown, where the rectangular waveguide 10 is provided. ) Represents TE ₁₀ (or H ₁₀ ) mode, and the circular waveguide 12 represents TE ₁₁ (or H ₁₁ ) mode.

In order to match different modes of the TE ₁₀ (or H ₁₀ ) mode and the TE ₁₁ (or H ₁₁ ) mode, a suppressor window 20 is installed inside the circular waveguide 12.

Reference numeral 18, which is not described, is a choke provided outside the circular waveguide 12 to prevent leakage of the microwaves in the circular waveguide 12.

According to such a structure, the TE ₁₀ (or H ₁₀ ) mode of the spherical waveguide ₁₀ is changed to the TM ₀₁ (or E ₀₁ ) mode of the circular waveguide 12 by the Suppressor window 20. By using a structure that is converted and symmetrical with respect to the rotation direction of the circular waveguide 12, the signal is transmitted without signal attenuation or distortion.

At this time, a higher order mode is generated in the coupling portion where the spherical waveguide 10 and the circular waveguide 12 are coupled, and the diameter of the waveguide is adjusted so that a mode higher than the TM ₀₁ (or E ₀₁ ) mode is not transmitted among the higher wave modes. Although removing the higher order mode by adjusting the diameter than the TM ₀₁ (or E ₀₁ ) mode is actually affected by the TE ₁₁ (or H ₁₁ ) mode to the rotating connector (1).

That is, in the TE ₁₁ (or H ₁₁ ) mode, signal transmission in a general circular waveguide is normally performed, but when the transmission mode conversion is performed due to the rotation connector, the electromagnetic field distribution changes according to the rotation angle, which is an unnecessary mode.

Accordingly, in order to remove the TE ₁₁ (or H ₁₁₎ modes that affect the rotary connector body (1) by using the inhibition gichang 20, such as a ring filter to the inside of the circular waveguide the TE ₁₁ (or H ₁₁₎ Try to minimize the effect of the mode. The TE ₁₁ (or H ₁₁ ) mode is not completely removed by the ring filter but is removed to such an extent that it does not affect the electrical properties of the rotary connection 1.

However, in the rotating connector as described above, when the mode conversion from the rectangular waveguide to the circular waveguide and the mode conversion from the circular waveguide to the rectangular waveguide again, the mode matching member, that is, the ring filter used for the mode matching, Since the waveguide is formed inside the circular waveguide, the process of processing the waveguide is difficult, thereby weakening the competitiveness.

In addition, when the center frequency is 33.5 kHz when the signal is transmitted by the rotary connector, the bandwidth is 2.01 kHz, which has a narrow bandwidth (6%).

 Accordingly, the present invention has been made to solve the above problems, and provides a waveguide converter by a simpler manufacturing process instead of a ring filter to match a transmission mode that proceeds differently from each other in a waveguide structure in which a conventional waveguide and a circular waveguide are connected. It is an object of the present invention to provide a structure of a waveguide rotating connector using a circular waveguide transducer to match the different transmission modes.

The structure of the waveguide rotating connector using the circular waveguide transducer of the present invention for achieving the above object, the transmission mode conversion from the rectangular waveguide to the circular waveguide, and transfers the transmission mode of the converted circular waveguide again to the rectangular waveguide A rotation connector for converting to a mode, comprising: a first transmission path having a predetermined width and height and a second transmission path having a predetermined diameter and formed at right angles to an end of the first transmission path; The second transmission path is connected in accordance with the combination of the second spherical waveguide and the first and second spherical waveguides so that the transmission mode transmitted from the spherical waveguide is converted into the transmission mode of the circular waveguide, thereby providing a function as a waveguide transducer. A circular waveguide is formed; The diameter of both ends of the circular waveguide is configured to be larger than the diameter of the center portion, and the bent interface of the first transmission path and the second transmission path is biased toward one side at the boundary of the second transmission path. A portion of the opening of the second transmission path is sealed; A choke for preventing leakage of microwaves is formed on the outer circumferential surface of the central portion of the second transmission path.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

Figure 5 is a detailed cross-sectional view showing the structure of the waveguide rotary connector according to a preferred embodiment of the present invention, Figure 6 is a detailed view showing a mode conversion unit for converting the mode of the microwave in Figure 5, Figure 7 is a rotary connection of Figure 5 It is a schematic diagram showing the mode conversion state by the sieve.

As shown in FIG. 5, the structure of the waveguide rotating connector 100 of the present invention is subjected to mode conversion by a mode conversion unit formed at the interface portion between the spherical waveguide and the circular waveguide, and the circular waveguide and the spherical waveguide and the In order to perform mode conversion by the mode conversion part formed in the interface part of the two waveguides 102 and 104, the waveguide transducer 140 of a circular waveguide type (hereinafter referred to as a circular waveguide) is connected by the connection of the rectangular waveguides 102 and 104. Is formed).

In other words, the spherical waveguides 102 and 104 have a first transmission path having a predetermined width and height and a second transmission path having a predetermined diameter and formed at right angles to an end of the first transmission path. According to the combination of the spherical waveguides 102 and 104, the circular waveguide 140 is formed to provide a function as a waveguide transducer in a vertical direction.

In addition, the first spherical waveguide 102 and the second spherical waveguide 104 each have a predetermined portion coupled to each other, and the spherical waveguides 102 and 104 are rotated in one direction with the circular waveguide 140 as an axis. A bearing 106 provided with a ball 106a is provided in the outer surface portion of the circular waveguide 140.

The bearing 106 is installed between the outer wall 108 of the first spherical waveguide 102 and the inner wall 110 of the second spherical waveguide 104, respectively.

One portion of the lower end surface of the bearing 106 is supported by a nut 112 mounted on the upper surface and the upper surface of the second spherical waveguide 104.

In addition, a cover 114 having a substantially 'b' shape in contact with the outer wall 108 of the first spherical waveguide 102 is provided at the other end portion of the lower surface of the bearing 106. A constant separation space 116 is formed between the first spherical waveguide 102 and the cover 114 due to the mounting position of the bearing 106.

Subsequently, a curved spaced groove 118 is formed between the first spherical waveguide 102 and the second spherical waveguide 104 around the bearing 106, and the second second beneath the cover 114 is formed. The outer surface of the spherical waveguide 104 consists of a concave shape 120 to avoid contact with the cover 114 during rotation.

Here, although not shown in the drawing, the nut 112 is preferably engaged with a screw thread formed on the outer surface of the inner wall 110 of the second spherical waveguide 104.

In addition, the outer peripheral surface of the circular waveguide 140 generated by the connection between the first spherical waveguide 102 and the second spherical waveguide 104, that is, the outer peripheral surface of the central portion of the second transmission path, is physically spaced apart from each other. As a result, a choke 122 is formed in a short circuit to prevent leakage of microwaves.

6 is a detailed view illustrating a mode converter for converting a microwave mode in FIG. 5.

As shown, both ends (L ') of the circular waveguide 140 is configured to be slightly larger than the center portion (L), the circular waveguide 140 and formed by the combination of the spherical waveguides (102,104) and Since the spherical waveguides 102 and 104 are formed to be biased (θ) to one side, only a portion of the opening of the circular waveguide 140 is formed as a transmission path.

Accordingly, a mode conversion unit 142 for converting a transmission mode is provided at both end sides of the circular waveguide 140 positioned at the interface with the rectangular waveguides 102 and 104.

On the other hand, when the rotary connector is applied to any commercial standard rectangular waveguide standard, the rectangular waveguide input and output terminal of the waveguide rotary connector in inverse proportion to the frequency ratio is installed and used.

That is, the spherical waveguide connected to the rotating connector of the present invention satisfies the standard standard waveguide specification of 'WR28'. If the rotating connector is applied to another standard spherical waveguide, the size of the rotating connector is inversely proportional to the center frequency. The size is changed, and the square waveguide transducer is mounted at the input / output terminal of the rectangular waveguide.

Here, when the rectangular waveguide and the commercial standard rectangular waveguide standard, i.e., 'horizontal * vertical' do not match, the rectangular waveguide converter has a length 1/4 of the wavelength length of the center frequency and is derived from the Chebyshev response function. It consists of the length of the width * length extracted.

The operation of the waveguide rotating connector using the circular waveguide transducer configured as described above will be described.

The waveguide rotating connector 100 of the present invention is installed between the antenna and the transmission line so that any spherical waveguide coupled to the antenna rotates at a constant speed.

At this time, the microwave applied from the antenna is transmitted to the measurement system necessary for the actual measurement via the transmission line of the waveguide, TE ₁₀ (or H ₁₀ ) mode of the electromagnetic wave incident through the ends of the rectangular waveguides (102,104) mode, TM ₀₁ (or E ₀₁₎ is converted to a mode, wherein the conversion TM ₀₁ of the circular waveguide 140 (or E ₀₁₎ mode of the conversion unit 142, a circular waveguide 140 in the TE ₁₀ (or H ₁₀₎ The mode is converted and transmitted.

That is, as shown in FIG. 7, which shows a mode conversion state by the rotary connector 100 composed of the spherical waveguides 102 and 104 and the circular waveguide 140, the TE ₁₀ (or H ₁₀ ) mode characteristic of the spherical waveguides 102 and 104 is shown. It appears that, in the circular waveguide 140, it can be seen that the TE ₁₁ (or H ₁₁ ) mode of the basic mode and the TM ₀₁ (or E ₀₁ ) mode of the higher order mode.

In this case, the circular waveguide 140 should remove the TE ₁₁ (or H ₁₁ ) mode which is a basic mode. This is because the return loss and the insertion loss vary depending on the rotation angle of the rotation connector 100 as described above, so that the TE ₁₁ (or H ₁₁ ) mode depends on the initial field distribution and the rotation angle. This is because the mode distribution is different from the initial state.

Therefore, the TE ₁₁ (or H ₁₁ ) mode is converted to the TM ₀₁ (or E ₀₁ ) mode by the mode converter 142 provided in the circular waveguide 140 and then back to the TE ₁₀ (or H ₁₀ ) mode. Because of the conversion, the TE ₁₁ (or H ₁₁ ) mode is removed to such an extent that it does not affect the electrical properties of the rotary connection 100.

While performing the transmission mode conversion process as described above, when the center frequency is 33.5 kHz, the bandwidth is 3.4 보다 and the bandwidth (10%) is about 1.5 times wider than that of the conventional signal transmission. You can get it.

On the other hand, the insertion loss of the rotary connector 100 of the present invention is 0.05 kHz or less, 30 kHz frequency band when the rotary connector is made of brass made of copper (Cu), zinc (Zn) as the main element It is less than 0.4㏈ by reference. In addition, when the plated with gold and silver on the rotary connector 100, it is possible to provide a characteristic of up to 0.1㏈ or less.

This is shown in the simulation result characteristic diagram for the rotating connector and the mode converter of the present invention is shown in Figures 8 and 9.

8A and 8B are insertion loss and return loss characteristic diagrams for the rotating connector, and FIGS. 9A and 9B are insertion loss and return loss characteristics diagrams for the mode converter.

The characteristic diagram is a case where the rotary connector 100 of the present invention is manufactured as a complete conductor, and when the conductivity is increased by silver plating or gold plating on the rotary connector 100, the insertion loss characteristic can be lowered to 0.1㏈ or less. Will be.

10 is a characteristic view of a measurement result for a rotary connector.

This shows that the measurement results are different from each other depending on the input and output directions of the rectangular waveguides 102 and 104.

That is, FIG. 10A illustrates a state in which the angles of rotation of the rectangular waveguides 102 and 104 are the same, and the rotation angle is 0 °, and FIG. 10B illustrates a state in which the angles of rotation of the rectangular waveguides 102 and 104 are 90 °. 10C shows a rotation angle of 180 DEG in the direction in which the input and output directions of the spherical waveguides 102 and 104 are opposite to each other.

As described above, according to the structure of the waveguide rotary connector using the circular waveguide transducer of the present invention, the mode matching member applied as a conventional ring filter in the rotary connector for transmission mode conversion generated between the rectangular waveguide and the circular waveguide By using a circular waveguide transducer formed by using a rectangular waveguide without using the above, there is an effect that transmission mode conversion can be performed by a simpler structure.

Thus, due to the simplicity of the structure, it is possible to reduce the number of machining operations and the difficulty at the time of manufacturing can be expected to increase the productivity.

In addition, the application of the circular waveguide transducer of the present invention may have a bandwidth of about 1.5 times or more wider than the bandwidth provided when transmitting a signal by a conventional ring filter.                     

In addition, the insertion loss of the circular waveguide transducer of the present invention is theoretically 0.05 ㏈ or less, but the measurement result in the state made of brass is 0.4 ㏈, and when plating with silver or gold, the insertion loss is reduced to 0.1 ㏈ or less. It can be effective.

On the other hand, the present invention is not limited to the above-described specific preferred embodiments, and various changes can be made by those skilled in the art without departing from the gist of the invention claimed in the claims. will be.

Claims (6)

In the rotary connector for performing the transmission mode conversion from the rectangular waveguide to the circular waveguide, and converts the transmission mode of the converted circular waveguide back to the transmission mode of the rectangular waveguide, First and second spherical waveguides each having a first transmission path having a predetermined width and height, and a second transmission path having a predetermined diameter and formed at right angles to an end portion of the first transmission path, and from the spherical waveguide. The second transmission path is connected in accordance with the combination of the first and second spherical waveguides so that the transmission mode to be transmitted is converted into the transmission mode of the circular waveguide, thereby forming a circular waveguide for providing a function as a waveguide transducer; The diameter of both ends of the circular waveguide is configured to be larger than the diameter of the center portion, and the bent interface of the first transmission path and the second transmission path is biased toward one side at the boundary of the second transmission path. A portion of the opening of the second transmission path is sealed; The structure of the waveguide rotating connector using a circular waveguide transducer, characterized in that the choke to prevent the leakage of microwaves is formed on the outer peripheral surface of the central portion of the second transmission path by physically spaced short circuit. The method of claim 1, The bearing is provided at the junction between the outer wall of the first spherical waveguide and the inner wall of the second spherical waveguide so that the first spherical waveguide or the second spherical waveguide is selectively rotated about the circular waveguide. Equipped, The bottom surface of the bearing is installed in the form of a wrap around the 'b' shaped cover which is in contact with the outer wall of the first spherical waveguide part, There is a gap between the outer wall end and the cover of the first spherical waveguide and the upper portion of the inner wall of the first spherical waveguide and the second spherical waveguide so as to facilitate the rotation of the first spherical waveguide or the second spherical waveguide. A structure of a waveguide rotary joint using a circular waveguide transducer characterized in that. The method of claim 2, The outer surface of the second spherical waveguide located in the lower portion of the cover is of a concave shape recessed by a predetermined depth to avoid contact with the cover during the rotation operation of the waveguide rotary connector using a circular waveguide transducer rescue. The method of claim 1, The insertion loss in the state where the first spherical waveguide and the second spherical waveguide are made of brass is 0.4 kΩ or less, and the insertion loss in the silver and gold plating state is 0.1 kΩ or less. Rotating connector structure used. The method of claim 1, When the spherical waveguide connected to the rotating connector is applied as a standard spherical waveguide of any other standard that does not satisfy the provided commercial standard spherical waveguide standard, the specification of the rotating connector which is inversely proportional to the center frequency ratio is the center frequency. The size is changed in inverse proportion to the structure of the rotary waveguide using a circular waveguide transducer, characterized in that the rectangular waveguide transducer is mounted on the input and output terminals of the rectangular waveguide. The method of claim 5, If the specification of the rectangular waveguide does not match the standard commercial waveguide standard, the rectangular waveguide transducer has a length that is one-quarter of the wavelength length of the center frequency and has a length of width and length extracted from the Chebyshev response function. Structure of a rotary connection using a circular waveguide transducer, characterized in that configured.

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