KR102550815B1 - A Small Waveguide Dual Function Bandstop Filter to Suppress 5G Mobile 28 GHz Band While Passing Sub-6 GHz Bands - Google Patents

Abstract

The subminiature waveguide band-stopping filter that removes signals in the 28 GHz band while passing 6 GHz or less for 5G mobile communication is a combined filter of waveguide and coaxial line. It blocks signals from mmWave, the structure of the filter is very small and light, and has the effect of being easy to integrate into the system.

Description

A Small Waveguide Dual Function Bandstop Filter to Suppress 5G Mobile 28 GHz Band While Passing Sub-6 GHz Bands}

The present invention relates to a subminiature waveguide band blocking filter, and more particularly, as a waveguide and coaxial line combined filter that passes signals in a low frequency band, such as Sub-6 GHz for 5G mobile communication, and signals in a high frequency band, mmWave It relates to a subminiature waveguide band-stop filter that removes signals in the 28 GHz band while passing below 6 GHz for 5th generation mobile communication that blocks

In the 5th generation mobile communication, wireless communication and mobile communication technology use high frequency bands such as 3.5 GHz and 28 GHz, which are Sub-6 GHz bands.

When the power of a high-frequency signal propagates in space, its attenuation is proportional to the square of the distance and inversely proportional to the square of the wavelength, so a very large loss is unavoidable. Accordingly, power loss in the mobile communication system must be minimized.

In the several GHz band, wireless communication circuits are made in the form of laminated boards that generate losses, and have been commonly used so far because they are easy to mass-produce at low cost.

However, in the millimeter wave band, such as in 5G, the loss of the multilayer board circuit increases rapidly, reducing communication quality, and cannot satisfy the demand for large-capacity data transmission.

In order to solve this problem, a waveguide with a structure confined by a metal wall was used instead of the laminated substrate exposed to the radiation space.

However, the conventional waveguide is a band blocking filter of a single band, and 20 GHz is a cut-off frequency and cannot pass all signals below 20 GHz, which causes a problem in that signals below Sub-6 GHz for 5G mobile communication cannot pass. do.

Korean Registered Patent No. 10-1331775

In order to solve this problem, the present invention is a waveguide and coaxial line combined filter that passes signals in the low frequency band, which is Sub-6 GHz for 5G mobile communication, and blocks signals in the high frequency band, mmWave. An object of the present invention is to provide a subminiature waveguide band-stop filter that removes signals in the 28 GHz band while passing 6 GHz or less for mobile communication.

The subminiature waveguide band-stop filter according to the features of the present invention for achieving the above object,

A waveguide having a constant size in such a way that the cross-sectional area of the waveguide increases sequentially at the input end and gradually decreases toward the output end through a middle portion of a certain length; and

It includes a coaxial line penetrating the inner center of the waveguide, and a combined filter of the waveguide and the coaxial line passes signals in a low frequency band and blocks signals in a specific high frequency band, mmWave.

The subminiature waveguide band-stop filter according to the features of the present invention,

It is connected to the coaxial line of the input port, constitutes a plurality of input converters in the form of gradually increasing cross-sectional area, the inner space part penetrates each other, and a first inner metal bar of a certain length is installed in the center of the inner space part. a first impedance matching unit penetrating;

It is connected to the first impedance matching unit to form an empty inner space with a predetermined length, a rectangular hollow cross section penetrates, and a second inner metal bar of a predetermined length passes through the center of the inner space, , An upper metal cylinder is formed on the upper surface at regular intervals, and a lower metal cylinder is formed on the lower surface at regular intervals, and a shorting pin made of metal is provided on each of the upper metal cylinder and the lower metal cylinder. a central waveguide for generating a required cut-off band by inserting; and

It is connected to the central waveguide to form a plurality of output transducers having gradually smaller cross-sectional areas, and the inner space passes through each other, and a third inner metal bar of a certain length passes through the center of the inner space, , A second impedance matching unit connecting the end of the third metal inner core bar to the coaxial line of the output port.

According to the configuration described above, the present invention has the effect of passing signals in a low-frequency band, which is Sub-6 GHz for 5G mobile communication, and blocking signals in a high-frequency band, mmWave, with a filter based on a waveguide.

The structure of the subminiature waveguide band-stop filter according to the present invention is very small and light, and has an effect of being easily incorporated into a system.

1 and 2 are diagrams showing the configuration of a subminiature waveguide band-stop filter that removes a signal of a 28 GHz band while passing a signal of 6 GHz or less for 5th generation mobile communication according to an embodiment of the present invention.
3 is a view showing a top view of a subminiature waveguide band-stop filter according to an embodiment of the present invention.
4 is a side cross-sectional view showing a subminiature waveguide band-stop filter according to an embodiment of the present invention.
5 is a view showing an example of a waveguide of the prior art and an embodiment of the present invention.
6 is a view showing a waveguide having a metal inner core bar and a shorting pin of the present invention and a prior art waveguide.
7 is a diagram showing an example of a single pole resonator according to an embodiment of the present invention.
8 is a diagram showing an example of a plurality of polar resonators according to an embodiment of the present invention.
9 is a view showing the structure of a first impedance matching unit and a second impedance matching unit according to an embodiment of the present invention viewed from top and side views.
10 is a diagram showing a cut-off band of a waveguide band-stop filter according to an embodiment of the present invention.
11 is a diagram showing frequency response characteristics of a waveguide band-stop filter according to an embodiment of the present invention.

Throughout the specification, when a certain component is said to "include", it means that it may further include other components without excluding other components unless otherwise stated.

5G mobile communication systems and devices that transmit and receive millimeter wave signals are dominated by waveguide circuits and components. These devices include Ka-band satellite communication, aviation communication, defense wireless communication, and the RF stage of radar for vehicle collision avoidance.

The present invention provides a band-stop filter based on a waveguide.

Signal transmission of the input/output signals of the communication device in the millimeter wave band and the signals of the performance measurement equipment is performed through the waveguide. The waveguide must block the inflow of 5G mobile communication frequency signals in the operating frequency band. To suppress such noise, a bandstop filter (BSF) that removes wideband noise from 25.5 GHz to 30.5 GHz must be made as a standard waveguide (WR-28) for the Ka band.

Conventional Ka-band standard waveguides have a cut-off frequency above 20 GHz, and thus cannot pass signals below the cut-off frequency.

The present invention performs a function of passing a signal of a low frequency band and blocking a signal of a desired specific frequency band.

1 and 2 are diagrams showing the configuration of a subminiature waveguide band-stop filter that removes a signal in the 28 GHz band while passing a signal of 6 GHz or less for 5th generation mobile communication according to an embodiment of the present invention, and FIG. 3 is an embodiment of the present invention. It is a view showing a top view of a subminiature waveguide band-stop filter according to an example, and FIG. 4 is a side cross-sectional view showing a subminiature waveguide band-stop filter according to an embodiment of the present invention.

1 is a top view of the subminiature waveguide band-stopping filter, and FIG. 2 is a view of the subminiature waveguide band-stopping filter from the bottom.

5G networks are largely divided into two bandwidths. There is a low frequency band of Sub-6 GHz (below 6 GHz) and a high frequency band above 28 GHz. Here, the high-frequency band is called mmWave (millimeter wave).

Subminiature waveguide band blocking filter 100 that removes signals in the 28GHz band while passing signals at 6GHz or less for 5th generation mobile communication according to an embodiment of the present invention passes through a middle portion of a certain length after the cross-sectional area of the waveguide increases sequentially at the input end It is a waveguide having a certain size in the form that the cross-sectional area of the waveguide gradually decreases as it goes to the output end.

It includes a coaxial line penetrating the inner center of the waveguide, and the combined filter of the waveguide and the coaxial line passes signals in a low frequency band and blocks signals in a specific high frequency band, mmWave.

The combined filter passes signals below Sub-6 GHz for 5G mobile communication and blocks signals in the 5G mobile frequency band among millimeter wave bands in the 25.5GHz to 30.5GHz band.

The subminiature waveguide band-stop filter 100 is composed of an input port 111 and an output port 139 on the leftmost and rightmost sides, and includes a first impedance matching unit 110, a central waveguide 120, and a second impedance matching unit. (130).

The subminiature waveguide band-stop filter 100 includes a first impedance matching unit 110 configured of a plurality of input converters having a gradually increasing cross-sectional area by connecting the waveguide to the coaxial line 111a of the input port 111, and the first impedance A central waveguide 120 having a metal housing that is connected to the matching unit 110 to form a certain length and creates a required cut-off band, and a plurality of output converters that are connected to the metal housing 121 and have gradually smaller cross-sectional areas. and a second impedance matching unit 1300 connected to the coaxial line 139a of the output port 139.

The first impedance matching unit 110, the central waveguide 120, and the second impedance matching unit 130 are made of a metal material.

The first impedance matching unit 110 has a shape in which the cross-sectional area of the waveguide from the input port 111 gradually increases.

The first impedance matching unit 110 includes an input port 111 into which a coaxial line 111a is inserted, a first input converter 112, a second input converter 113, a third input converter 114, and a fourth input converter. Transducer 115 is included.

The first impedance matching unit 110 communicates with the first input converter 112 having a rectangular first hollow cross section connected to the input port 111 and communicates with the first input converter 112 to have a width greater than the first hollow cross section. And a second input converter 113 having a large rectangular second hollow cross section, and a third rectangular hollow cross section that is in communication with the second input converter 113 and has a width and a larger rectangular hollow cross section than the second hollow cross section. It includes a three-input converter 114 and a fourth input converter 115 communicating with the third input converter 114 and having a rectangular fourth hollow section with a width and width larger than that of the third hollow section.

The first input converter 112, the second input converter 113, the third input converter 114, and the fourth input converter 115 are sequentially arranged and configured to be integrally formed.

Each of the first input converter 112, the second input converter 113, the third input converter 114, and the fourth input converter 115 has a rectangular parallelepiped shape as a whole and has a constant length, and has a rectangular hollow section passing through it. to be formed

In addition, the first input converter 112, the second input converter 113, the third input converter 114, and the fourth input converter 115 do not have the same hollow section and have different predetermined widths and heights. .

The first input converter 112, the second input converter 113, the third input converter 114, and the fourth input converter 115 have their hollow cross sections sealed by walls, and the first input converter 112 ), the width and width of the hollow section gradually increase toward the second input converter 113, the third input converter 114, and the fourth input converter 115.

The first input converter 112, the second input converter 113, the third input converter 114, and the fourth input converter 115 have internal spaces passing through each other, and a first input converter having a predetermined length in the center of the internal space. It passes through the inner metal bars 116, 117, 118, and 119, and one end of the first metal inner bars 116, 117, 118, and 119 is connected to the coaxial line 111a of the input port 111. connected

The sizes of the first metal inner core bars 116, 117, 118, and 119 are hollow in the first input converter 112, the second input converter 113, the third input converter 114, and the fourth input converter 115. The size gradually increases according to the cross-sectional area of the cross section, that is, the width and thickness of the first metal inner core bars 116, 117, 118, and 119 increase.

The first metal inner core bars 116, 117, 118, and 119 are connected to the coaxial line 111a of the input port 111 to match the impedance on a low frequency band such as several GHz and an ultra-wide band of millimeter wave band. do.

The central waveguide 120 is formed to be longer than the first impedance matching unit 110 and the second impedance matching unit 130, has a rectangular parallelepiped shape and a constant length as a whole, and has a metal housing through which a rectangular hollow section passes ( 121) form.

The metal housing 121 forms an empty inner space 122, and a second inner metal bar 123 having a predetermined length passes through the center. The inner space 122 of the metal housing 121 is filled with air.

The metal housing 121 is formed by spaced apart upper metal cylinder 124 at regular intervals on the upper surface, and formed by spaced apart lower metal cylinder 126 at regular intervals on the lower surface.

Each of the upper metal cylinder 124 and each of the lower metal cylinder 126 has a hexahedral shape of a certain size and has an empty inside, and communicates with the inner space 122 of the metal housing 121, and the metal housing 121 coupled in a vertical direction to the outer circumferential surface of

Each upper metal cylinder 124 inserts an upper shorting pin 125 made of metal in the center, and each lower metal cylinder 126 has a lower shorting pin made of metal in the center ( 127) is inserted.

Each upper shorting pin 125 is vertically inserted into the center of the upper metal cylinder 124 and passes through the inner space of the upper metal cylinder 124 to reach the vicinity of the second metal inner core bar 123 .

Each lower shorting pin 127 is vertically inserted into the center of the lower metal cylinder 126 and passes through the inner space of the lower metal cylinder 126 to reach the vicinity of the second metal inner core bar 123 .

Each of the upper shorting pins 125 and each of the lower shorting pins 127 is an inductor of a resonator composed of a series inductance in which a magnetic field in the traveling direction of the TE ₁₀ mode exists and a parallel inductance due to the effect connected in parallel play a role

A first gap 128 between the upper shorting pin 125 and the second metal inner core bar 123 and a second gap between the lower shorting pin 127 and the second metal inner core bar 123 (Gap) 129 serves as a capacitor of the resonator.

In the band-stop filter, a resonance phenomenon, which is a frequency selection characteristic that selects or filters out a specific frequency, occurs due to an inductor and a capacitor, and thus generates a pole frequency in a cut-off region.

The upper shorting pin 125, the upper metal cylinder 124, the lower shorting pin 127, and the inserted lower metal cylinder 126 are arranged in a row in the longitudinal axis direction according to the order of the band cut filter.

When the coupling between resonators is adjusted by the distance between the upper metal cylinders 124 and the distance between the lower metal cylinders 126 in the band cut filter, the positions of poles are also adjusted to form a noise suppression band.

The first gap 128 and the second gap 129 are capacitors of the resonator and may determine poles of the blocking region.

The arrangement and spacing of the plurality of upper metal cylinders 124 and the arrangement and spacing of the plurality of lower metal cylinders 126 form a blocking band through the spacing of a plurality of poles by the coupling amount of adjacent elements.

The upper metal tube 124 and the lower metal tube 126 serve as inductors of the resonator, and the grounding function of the upper shorting pin 125 and the grounding function of the lower shorting pin 127, and the second metal inner core bar 123 It can play a role of support when adjusting the distance between

The diameter and depth of the upper metal cylinder 124 and the lower metal cylinder 126 are changed to fine-tune the resonant frequency.

In contrast to the first impedance matching unit 110, the second impedance matching unit 130 has a shape in which the cross-sectional area of the waveguide gradually decreases.

The second impedance matching unit 130 includes a first output converter 131, a second output converter 132, a third output converter 133, a fourth output converter 134, and an output port 139 into which a coaxial cable is inserted. ).

The second impedance matching unit 130 communicates with the first output converter 131 having a rectangular first hollow cross section connected to the metal housing 121 and communicates with the first output converter 131 to have a width greater than the first hollow cross section. And a second output converter 132 having a large rectangular second hollow cross section and a third rectangular hollow cross section that is in communication with the second output converter 132 and has a width and a larger rectangular hollow cross section than the second hollow cross section. It includes a three-output converter 133 and a fourth output converter 134 communicating with the third output converter 133 and having a rectangular fourth hollow section that is larger in width and width than the third hollow section. The fourth output converter 134 is connected to the output port 139.

The first output converter 131, the second output converter 132, the third output converter 133, and the fourth output converter 134 are sequentially arranged and configured to be integrally formed.

The first output converter 131, the second output converter 132, the third output converter 133, and the fourth output converter 134 each have a rectangular parallelepiped shape as a whole and have a constant length, and a rectangular hollow cross section passes through them. to be formed

In addition, the first output converter 131, the second output converter 132, the third output converter 133, and the fourth output converter 134 do not have the same hollow section and have different predetermined widths and heights. .

The first output converter 131, the second output converter 132, the third output converter 133, and the fourth output converter 134 have their hollow cross-sections sealed by walls, and the first output converter 131 ), the second output converter 132, the third output converter 133, and the fourth output converter 134, the width and width of the hollow section gradually decrease.

The first output converter 131, the second output converter 132, the third output converter 133, and the fourth output converter 134 have internal spaces passing through each other, and a third output converter in the longitudinal direction is located at the center of the internal space. It passes through the inner metal bars 135, 136, 137, and 138, and one end of the third inner metal bars 135, 136, 137, and 138 is connected to the coaxial line 139a of the output port 139. connected

The third metal inner core bars 135, 136, 137, and 138 are hollow sections of the first output converter 131, the second output converter 132, the third output converter 133, and the fourth output converter 134. The size gradually decreases according to the cross-sectional area, that is, the width and thickness of the third metal inner core bars 135, 136, 137, and 138 decrease.

The third metal inner core bars 135, 136, 137, and 138 are connected to the coaxial line 139a of the output port 139 to match the impedance on a low frequency band such as several GHz and an ultra-wide band of millimeter wave band. do.

The first metal inner core bars 116, 117, 118 and 119, the second metal inner core bar 123 and the third metal inner core bars 135, 136, 137 and 138 serve as coaxial lines.

The subminiature waveguide band-cutting filter 100 blocks the millimeter wave band, passes through Sub-6 GHz for 5G mobile communication, and has a coaxial line passing through the inner center, and is a combined filter of a waveguide and a coaxial line.

The subminiature waveguide band-stop filter 100 has a very small and light structure, is easy to embed into the system, has an overall length of 56 mm, a length of the central waveguide 120 in the longitudinal direction of 7.11 mm, and an upper portion of the central waveguide 120. The length from the metal tube 124 to the lower metal tube 126 is 7.52 mm.

5 is a view showing an example of a waveguide of the prior art and an embodiment of the present invention.

As shown in Fig. 5, the left part of Fig. 5 is an ordinary metal waveguide (empty inside and filled with air or a single insulator).

The right part of FIG. 5 is the waveguide of the present invention, and a metal inner core bar penetrates the inner space of the waveguide.

A typical metal waveguide uses TE ₁₀ mode for signal transmission, and a coaxial wire uses TEM mode for signal transmission.

The present invention changes the TE ₁₀ mode by penetrating a metal centroid bar inside the waveguide to electrically and electromagnetically match the TEM mode.

6 is a view showing a waveguide having a metal inner core bar and a shorting pin of the present invention and a prior art waveguide.

In the present invention, the shorting pins 125 and 127 are inserted into the metal cylinders 124 and 126. The metal tubes 124 and 126 perform a grounding function of the shorting pins 125 and 127 and a support role when adjusting the distance of the second metal inner core bar 123.

In the waveguide of the present invention, the resonance frequency can be finely adjusted by the diameter of the metal cylinders 124 and 126 and the distance between the metal cylinders 124 and 126 and the shorting pins 125 and 127.

7 is a diagram showing an example of a single-pole resonator according to an embodiment of the present invention, and FIG. 8 is a diagram showing an example of a plurality of pole-point resonators according to an embodiment of the present invention.

As shown in Fig. 7, the metal cylinder has a shorting pin attached to the inner wall, and the shorting pin is disposed close to the metal inner core bar in the longitudinal direction. This type is used as a single pole resonator.

As shown in FIG. 8, the upper shorting pin 125 and the lower shorting pin 127 are arranged side by side in a row so that adjacent elements are coupled (Coupling, the coupling coefficient between the i-th resonator and the j-th resonator is M A cut-off band is formed by _ij ), and a plurality of poles are formed by adjusting their intervals to satisfy a necessary band (cut-off band of a band-stop filter).

9 is a view showing the structure of a first impedance matching unit and a second impedance matching unit according to an embodiment of the present invention viewed from top and side views.

The first impedance matching unit 110 is connected to the coaxial line of the input port to form a plurality of input transducers having a gradually increasing cross-sectional area.

The second impedance matching unit 130 constitutes a plurality of output converters having gradually smaller cross-sectional areas and is connected to the coaxial line of the output port.

The first impedance matching unit 110 and the second impedance matching unit 130 are transition type impedance matching devices that perform impedance matching between the waveguide and the coaxial line.

The width and thickness of the first metal inner core bars 116, 117, 118, and 119 and the third metal inner core bars 135, 136, 137, and 138 are determined according to the insertion loss and impedance matching satisfaction according to the frequency bandwidth.

10 is a diagram showing a cut-off band of a waveguide band-stop filter according to an embodiment of the present invention.

The waveguide band blocking filter 100 of the present invention requires the purpose of suppressing signals in the 28GHz band for 5G mobile communication, and suppresses signals in the 25.5GHz to 30.5GHz band with a waveguide, including the 5G Sub-6 GHz frequency band of 3.5 GHz. Passes signals in the following frequency bands.

11 is a diagram showing frequency response characteristics of a waveguide band-stop filter according to an embodiment of the present invention.

In the waveguide band-stop filter 100 of the present invention, S ₂₁ meaning the transfer coefficient of the entire component from the input port 111 to the output port 139 is more important than anything else. S ₂₁ has an edge frequency of -3dB or less at 25.5GHz to 30.5GHz and rapidly drops to -15dB or less within the target cutoff frequency range, showing excellent band-blocking characteristics.

The waveguide band blocking filter 100 of the present invention passes signals below Sub-6 GHz for 5G mobile communication and blocks signals in the 5G mobile frequency band (25.5 GHz to 30.5 GHz band) among millimeter wave bands.

The waveguide band-stop filter 100 of the present invention is connected to the coaxial line of the input port, constitutes a plurality of input transducers in a form in which the cross-sectional area gradually increases, the inner space part penetrates each other, and a certain length is formed in the center of the inner space part. a first impedance matching unit penetrating the first metal inner core bar;

It is connected to the first impedance matching unit to form an empty inner space with a predetermined length, a rectangular hollow cross section penetrates, and a second inner metal bar having a predetermined length passes through the center of the inner space, An upper metal cylinder is formed on the upper surface at regular intervals, and a lower metal cylinder is formed on the lower surface at regular intervals, and a shorting pin made of metal is inserted into each of the upper metal cylinder and the lower metal cylinder. a central waveguide that creates the required cutoff band; and

It is connected to the central waveguide to form a plurality of output transducers in which the cross-sectional area gradually decreases, the inner space passes through each other, and the third inner metal bar of a certain length passes through the center of the inner space, and a second impedance matching unit connecting an end of the third metal inner core bar to the coaxial line of the output port.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims are also included in the scope of the present invention. that fall within the scope of the right.

100: lens case 101: lens barrel
100: subminiature waveguide band blocking filter 110: first impedance matching unit
111: input port 111a: coaxial line
112: first input converter 113: second input converter
114: third input converter 115: fourth input converter
116, 117: 118, 119: first metal inner core bar
120: central waveguide 121: metal housing
122: inner space portion 123: second metal inner core bar
124: upper metal box 125: upper shorting pin
126: lower metal box 127: lower shorting pin
128: first gap 129: second gap
130: second impedance matching unit 131: first output converter
132: second output converter 133: third output converter
134 fourth output converter
135, 136: 137, 138: third metal inner core bar
139: output port 139a: coaxial line

Claims (12)

A waveguide having a constant size in such a way that the cross-sectional area of the waveguide increases sequentially at the input end and gradually decreases toward the output end through a middle portion of a certain length; and
It includes a coaxial line penetrating the inner center of the waveguide, and the combined filter of the waveguide and the coaxial line passes signals in a low frequency band and blocks signals in a specific high frequency band, mmWave,
The waveguide is connected to the coaxial line of the input port and includes a first impedance matching unit configuring a plurality of input transducers having a gradually increasing cross-sectional area;
a central waveguide having a metal housing connected to the first impedance matching unit to form a predetermined length and generating a required cut-off band; and
A subminiature waveguide band blocking filter comprising a second impedance matching unit connected to the metal housing to form a plurality of output converters having gradually smaller cross-sectional areas and connected to a coaxial line of an output port. The method of claim 1,
The combined filter is a subminiature waveguide band blocking filter that passes signals of Sub-6 GHz or less for 5G mobile communication and blocks signals of the 5G mobile frequency band among the millimeter wave bands of the 25.5 GHz to 30.5 GHz band. delete The method of claim 1,
The first impedance matching unit,
A first input converter having a rectangular first hollow cross section connected to the input port into which the coaxial line is inserted, and a rectangular second hollow cross section communicating with the first input converter and having a width and a larger width than the first hollow cross section A second input converter having a second input converter, a third input converter having a rectangular third hollow cross section that is in communication with the second input converter and having a rectangular third hollow cross section that is larger in width and width than the second hollow cross section, and that is in communication with the third input converter and has a third hollow cross section. A subminiature waveguide band-stop filter comprising a fourth input transducer having a rectangular fourth hollow cross-section with a width and width greater than the cross-section. The method of claim 4,
The first input transducer, the second input transducer, the third input transducer, and the fourth input transducer have inner spaces passing through each other and passing through a first inner metal bar having a predetermined length in the center of the inner space, , One end of the first metal inner core bar is connected to the coaxial line of the input port,
The first metal inner core bar gradually increases in width and thickness according to cross-sectional areas of hollow sections of the first input converter, the second input converter, the third input converter, and the fourth input converter, so that the millimeter wave in the low frequency band is formed. Miniature waveguide bandstop filter with up-to-band impedance matching. The method of claim 1,
The metal housing is formed to a certain length to form an empty inner space, a rectangular hollow cross section is penetrated, an upper metal cylinder is formed on the upper surface at regular intervals, and a lower metal cylinder is formed on the lower surface at regular intervals. Formed spaced apart from each other,
The upper metal cylinder and the lower metal cylinder are in communication with the inner space of the metal housing and coupled to the outer circumferential surface of the metal housing in a vertical direction, and the upper metal cylinder has an upper shorting pin made of metal at the center thereof. and inserting a lower shorting pin made of metal at the center of the lower metal tube. The method of claim 6,
The metal housing passes through a second metal inner metal bar having a predetermined length in the center of the inner space, and a first gap between the upper shorting pin and the second metal inner metal bar, and the lower A subminiature waveguide band-cutting filter for determining a pole of a blocking band by forming a second gap between a shorting pin and the second metal inner core bar. The method of claim 7,
The upper shorting pin is vertically inserted into the center of the upper metal cylinder and passes through the inner space of the upper metal cylinder to reach the vicinity of the second metal inner core bar, and the lower shorting pin is in the center of the lower metal cylinder. A subminiature waveguide band-stop filter that is inserted vertically and passes through the inner space of the lower metal cylinder to reach the vicinity of the second metal inner core bar. The method of claim 6,
When the distance between the upper metal cylinders and the distance between the lower metal cylinders are adjusted, a cutoff band is formed through the spacing of a plurality of pole points. The method of claim 1,
The second impedance matching unit,
A first output converter having a rectangular first hollow cross section connected to the metal housing, and a second output converter communicating with the first output converter and having a rectangular second hollow cross section having a width and a larger width than the first hollow cross section. And, a third output converter having a rectangular third hollow cross section that is in communication with the second output converter and has a width and width greater than that of the second hollow cross section, and a third output converter that is in communication with the third output converter and has a width and a width that are greater than the third hollow cross section a fourth output converter having a rectangular fourth hollow cross section with a large c, wherein the fourth output converter is connected to the output port. The method of claim 10,
The first output converter, the second output converter, the third output converter, and the fourth output converter have inner spaces passing through each other, and a third inner metal bar in the longitudinal direction at the center of the inner space. and one end of the third metal inner core bar is connected to the coaxial line of the output port,
The third metal inner core bar has a width and a thickness gradually reduced according to cross-sectional areas of the hollow sections of the first output converter, the second output converter, the third output converter, and the fourth output converter, so that the millimeter is reduced in the low frequency band. A subminiature waveguide bandstop filter that performs impedance matching down to the waveband. It is connected to the coaxial line of the input port, constitutes a plurality of input converters in the form of gradually increasing cross-sectional area, the inner space part penetrates each other, and a first inner metal bar of a certain length is installed in the center of the inner space part. a first impedance matching unit penetrating;
It is connected to the first impedance matching unit to form an empty inner space with a predetermined length, a rectangular hollow cross section penetrates, and a second inner metal bar of a predetermined length passes through the center of the inner space, , An upper metal cylinder is formed on the upper surface at regular intervals, and a lower metal cylinder is formed on the lower surface at regular intervals, and a shorting pin made of metal is provided on each of the upper metal cylinder and the lower metal cylinder. a central waveguide for generating a required cut-off band by inserting; and
It is connected to the central waveguide to form a plurality of output transducers having gradually smaller cross-sectional areas, and the inner space passes through each other, and a third inner metal bar of a certain length passes through the center of the inner space. , A subminiature waveguide band blocking filter comprising a second impedance matching unit connecting an end of the third metal inner core bar to a coaxial line of an output port.

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