CN110828946A

CN110828946A - Phase shifter, millimeter wave circulator and radar system

Info

Publication number: CN110828946A
Application number: CN201910964618.2A
Authority: CN
Inventors: 沈凌平; 张春荣; 史利剑; 唐宗伟; 刘博�
Original assignee: TIANWEI ELECTRONIC SYSTEM ENGINEERING Co Ltd XI'AN
Current assignee: TIANWEI ELECTRONIC SYSTEM ENGINEERING Co Ltd XI'AN
Priority date: 2019-10-11
Filing date: 2019-10-11
Publication date: 2020-02-21
Anticipated expiration: 2039-10-11
Also published as: CN110828946B

Abstract

The present application relates to a phase shifter, a millimeter wave circulator and a radar system, wherein the phase shifter includes a housing, a waveguide, a ferrite, a first magnet, a second magnet and a cooling flow channel. The shell defines an accommodating space; the waveguide tube is arranged in the accommodating space; the ferrite is attached to the inner wall of the waveguide tube; the first magnet is positioned in the accommodating space and is attached to the outer wall of the waveguide tube, and the first magnet and the shell define a first cavity; the second magnet is positioned in the accommodating space and is attached to the outer wall of the waveguide tube, the second magnet is opposite to the first magnet, and a second cavity is defined by the second magnet and the shell; the cooling flow channel is arranged on the shell and is used for penetrating through the first cavity and the second cavity. The phase shifter, the millimeter wave circulator and the radar system provided by the application have the advantages of good cooling effect, high power and small loss.

Description

Phase shifter, millimeter wave circulator and radar system

Technical Field

The application relates to the technical field of microwaves, in particular to a phase shifter, a millimeter wave circulator and a radar system.

Background

With the continuous development of the technical fields of aerospace, electronic countermeasure and the like, the requirement of a microwave system on a ferrite device is higher and higher. Miniaturization, wide band, high power, low loss, etc. have become the focus of research on ferrite devices.

Millimeter wave circulators are an important type of ferrite devices. Millimeter wave circulators have wide application in millimeter wave radar systems. The millimeter wave circulator is mainly used for controlling unidirectional transmission of energy in a loop, is generally used as a radar receiving and transmitting switch, and plays a role in protection in an antenna feeder and a transmitting device in a radar system.

The millimeter wave circulator generally consists of a bridge, a folded double-T and a phase shifter. Wherein the phase shifter includes a permanent magnet and a ferrite. With the development of the millimeter wave circulator towards high power, the heating and cooling problems of ferrite in the phase shifter are more and more ignored. In the phase shifter in the conventional technology, cooling channels are mainly arranged in a cavity of the phase shifter along the extending direction of the magnet, and cooling liquid is injected into the cooling channels to realize cooling of the millimeter wave circulator.

However, such a phase shifter and a millimeter wave circulator have a problem of poor cooling effect.

Disclosure of Invention

In view of the above, it is necessary to provide a phase shifter, a millimeter wave circulator and a radar system in view of the above problems.

A phase shifter, comprising:

the shell defines an accommodating space;

a waveguide disposed in the accommodation space;

a ferrite attached to an inner wall of the waveguide;

the first magnet is positioned in the accommodating space and is attached to the outer wall of the waveguide tube, and the first magnet and the shell define a first cavity;

the second magnet is positioned in the accommodating space and is attached to the outer wall of the waveguide tube, the second magnet is opposite to the first magnet, and a second cavity is defined by the second magnet and the shell;

and the cooling flow channel is arranged on the shell and is used for penetrating through the first cavity and the second cavity.

In one embodiment, the first magnet and the second magnet are both attached to the inner wall of the housing, and the phase shifter further includes:

the first cover plate is provided with a first water hole and is attached to the shell, and the first magnet, the shell and the first cover plate define the first cavity;

the second cover plate is provided with a second water hole, the second cover plate is attached to the shell, and the second magnet, the shell and the second cover plate define the second cavity.

In one embodiment, the phase shifter further comprises:

the first water nozzle is arranged in the first water hole;

and the second water nozzle is arranged in the second water hole.

In one embodiment, the phase shifter further includes a first flange and a second flange, the first flange and the second flange are respectively disposed at two ends of the housing, the first cover plate is attached to the first flange, and the second cover plate is attached to the second flange.

In one embodiment, the phase shifter further comprises:

the first fixing piece penetrates through the first cover plate and abuts against the first magnet;

and the second fixing piece penetrates through the second cover plate and abuts against the second magnet.

In one embodiment, the waveguide is an over-mode waveguide.

In one embodiment, the length of the cross-section of the waveguide is 0.4mm to 0.7mm greater than the length of the cross-section of a standard waveguide, and the width of the cross-section of the waveguide is 0.2mm to 0.5mm greater than the width of the cross-section of the standard waveguide.

A millimeter wave circulator comprises the phase shifter, the bridge and the folded double T, wherein the bridge and the folded double T are respectively connected to two ends of the phase shifter.

In one embodiment, the millimeter wave circulator further includes:

and the bridge and the folded double T are respectively connected to two ends of the phase shifter through the choke flanges, and the opening size of a choke groove of each choke flange is matched with that of the waveguide tube.

A radar system comprising a millimeter wave circulator as described above.

In the phase shifter, the millimeter wave circulator and the radar system provided in the embodiment of the present application, the phase shifter includes the housing, the waveguide, the ferrite, the first magnet and the second magnet. The housing wall is provided with the cooling flow passage, and the cooling flow passage can penetrate through the first cavity and the second cavity. The cooling flow channel arranged in the direction enables cooling fluid to cool the first magnet, the waveguide tube, the ferrite and the second magnet simultaneously along the section direction, and the cooling effect can be improved. In addition, compare in the phase shifter that sets up cooling runner along magnet extending direction in the prior art, the phase shifter that this application embodiment provided can set up the area increase of cooling runner processing, just the area increase that cooling runner 160 can trompil, consequently easier, and practice thrift the space, can set up more quantity cooling runner 160 to further improve the cooling effect.

Drawings

Fig. 1 is a schematic elevation view, partially in section, of a phase shifter according to an embodiment of the present application;

fig. 2 is a schematic top view of a phase shifter (without a first cover plate and a second cover plate) according to an embodiment of the present application;

fig. 3 is a schematic bottom view of a phase shifter (without a first cover plate and a second cover plate) according to an embodiment of the present disclosure;

fig. 4 is a schematic side perspective view of a phase shifter (without a first cover plate and a second cover plate) and a choke flange according to an embodiment of the present application;

fig. 5 is a schematic top view of a millimeter wave circulator according to an embodiment of the present disclosure;

fig. 6 is a schematic diagram of a test curve of a millimeter wave circulator according to an embodiment of the present application.

Description of reference numerals:

millimeter wave circulator 10

Phase shifter 100

Accommodation space 101

First cavity 102

Second cavity 103

Casing 110

First flange 111

Second flange 112

Waveguide 120

Ferrite 130

First magnet 140

Second magnet 150

Cooling channel 160

First cover plate 170

First water hole 171

First water nozzle 172

Second cover plate 180

Second water hole 181

Second water nozzle 182

First fixing member 191

Second fixing member 192

Electric bridge 200

Folding double T300

Choke flange 400

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is further described in detail below by way of embodiments and with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

The numbering of the components as such, e.g., "first", "second", etc., is used herein only to distinguish the objects as described, and does not have any sequential or technical meaning. The term "connected" and "coupled" when used in this application, unless otherwise indicated, includes both direct and indirect connections (couplings). In the description of the present application, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present application and for simplicity in description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be considered as limiting the present application.

In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through intervening media. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

Referring to fig. 1 to 4, an embodiment of the present application provides a phase shifter 100 including a housing 110, a waveguide 120, a ferrite 130, a first magnet 140, and a second magnet 150. The housing 110 defines an accommodating space 101. The waveguide 120, the ferrite 130, the first magnet 140, and the second magnet 150 are disposed in the accommodating space 101.

The material of the housing 110 may be, but is not limited to, copper. The housing 110 may be round, square, or other irregular structures. The housing 110 has a certain thickness. The housing 110 may be a closed structure or a structure with two open ends. The wall of the housing 110 surrounds the receiving space 101 formed. The housing 110 may have a symmetrical structure, and includes an upper housing and a lower housing, which are coupled to each other. The upper case and the lower case together define the receiving space 101.

The waveguide 120 is disposed in the accommodating space 101. When the housing 110 has a structure with two open ends, the extending direction of the waveguide 120 may be parallel to the plane of the open end of the housing 110, and two sides of the housing 110 may be correspondingly opened with openings, so that the waveguide 120 can be communicated with an electrical bridge and/or a folded double T. That is, the phase shifter 100 may be an H-plane phase shifter. The number of the waveguides 120 may be two. The waveguide 120 may be a rectangular waveguide. The specific material, structure and specific arrangement position of the waveguide 120 may be selected according to actual requirements, and this embodiment is not limited.

The ferrite 130 may be attached to an inner wall of the waveguide 120 along an extending direction of the waveguide 120. The number of the ferrites 130 may be 4, and one ferrite may be disposed on each of two opposite inner walls of the waveguide 120. The specific size and structure of the ferrite 130 and the connection mode with the inner wall of the waveguide 120 are not limited in this application, and can be selected according to actual requirements.

The first magnet 140 and the second magnet 150 are both attached to the outer wall of the waveguide tube 120, and the first magnet 140 and the second magnet 150 are oppositely disposed. That is, the first magnet 140 and the second magnet 150 are respectively attached to the outer sides of two opposite walls of the waveguide 120. The first magnet 140 and the second magnet 150 may be attached to the housing 110, or may be spaced apart from the housing 110.

The first magnet 140 is spaced from the edge of the housing 110 such that the first magnet 140 and the housing 110 form a first cavity 102. When the housing 110 is a two-end sealed structure, the first cavity 102 is a sealed cavity. When the housing 110 has a structure with two open ends, the first cavity 102 has a structure with one open side. The size of the first cavity 102 can be set according to actual requirements.

Similarly, the second magnet 150 is also spaced from the edge of the housing 110, so that the second magnet 150 and the housing 110 form a second cavity 103. When the housing 110 is a two-end sealing structure, the second cavity 103 is a sealed cavity. When the housing 110 has a structure with two open ends, the second cavity 103 has a structure with one open side. The size of the second cavity 103 can be set according to actual requirements.

The wall of the housing 110 is formed with a cooling channel 160. The shape, size, number, etc. of the cooling flow channels 160 are not limited. The cooling flow passage 160 penetrates through the wall of the housing 110 and is in through communication with the first cavity 102 and the second cavity 103. Thus, the cooling flow channel 160 is arranged at the side of the first magnet 140 and the second magnet 150, and forms a certain angle with the extending direction of the first magnet 140 and the second magnet 150. In a specific embodiment, the cooling flow passage 160 may be perpendicular to the extending direction of the first and

second magnets

140 and 150. The cooling flow passage 160 is used for circulating a cooling fluid. Specifically, the cooling fluid flows through the cooling channel 160, and can cool the first magnet 140, the waveguide 120, the ferrite 130, and the second magnet 150 along the cross-sectional direction, thereby improving the cooling effect. In addition, the cooling channels 160 are disposed along such a direction, and more cooling channels 160 may be disposed, for example, two rows of cooling channels 160 may be disposed on two opposite side walls of the housing 110, so that the cooling liquid simultaneously cools two sides of the first magnet 140, the waveguide 120, the ferrite 130, and the second magnet 150, thereby further improving the cooling effect.

The phase shifter 100 provided in this embodiment includes the housing 110, the waveguide 120, the ferrite 130, the first magnet 140, and the second magnet 150. The wall of the housing 110 is opened with the cooling channel 160, and the cooling channel 160 can penetrate through the first cavity 102 and the second cavity 103. The cooling flow channel 160 disposed in such a direction can cool the first magnet 140, the waveguide 120, the ferrite 130, and the second magnet 150 simultaneously along the cross-sectional direction, thereby improving the cooling effect. In addition, compare in the phase shifter that the magnet extending direction set up the cooling runner in the prior art, the phase shifter 100 that this application embodiment provided can set up the area increase of cooling runner 160, just the area increase that cooling runner 160 can trompil, therefore the processing is easier, and practices thrift the space, can set up more quantity cooling runner 160 to further improve the cooling effect.

In one embodiment, the first magnet 140 and the second magnet 150 are attached to the inner wall of the housing 110. The phase shifter 100 further includes a first cover plate 170 and a second cover plate 180. The first cover plate 170 and the second cover plate 180 are respectively attached to two ends of the housing 110. The first magnet 140, the inner wall of the housing 110, and the first cover plate 170 surround and form the first cavity 102. The second magnet 150, the inner wall of the housing 110, and the second cover plate 180 surround to form the second cavity 103.

The first cover plate 170 is opened with a first water hole 171. The second cover plate 180 is provided with a second water hole 181. The first water hole 171 and the second water hole 181 are used for water injection or water discharge. For example, when the first water hole 171 is used as a water injection hole and the second water hole 181 is used as a water discharge hole, the cooling fluid is injected from the first water hole 171 into the first cavity 102. The first magnet 140 serves as a bottom surface of the first cavity 102, which greatly increases a contact area with a cooling fluid, so that the cooling fluid can sufficiently cool the first magnet 140. Meanwhile, the fluid in the first cavity 102 may flow into the second cavity 103 through the cooling flow passage 160. The process of flowing the cooling fluid through the cooling flow passage 160 cools the first magnet 140 side, the waveguide 120 side, the ferrite 130 side, and the second magnet 150 side. In addition, after the cooling fluid flows into the second cavity 103, the second cavity 103 is filled with the cooling fluid, and the second magnet 150 serves as the top of the second cavity 102, so that the contact area with the cooling fluid is greatly increased, and the cooling fluid can sufficiently cool the second magnet 150. In this way, the cooling fluid is equivalent to wrap the devices in the accommodating space 101, so that a plurality of surfaces of the devices in the accommodating space 101 are all cooled, and the cooling efficiency is greatly improved.

In one embodiment, the phase shifter 100 further includes a first water nozzle 172 and a second water nozzle 182. The first water nozzle 172 is disposed in the first water hole 171. The second water nozzle 182 is disposed in the second water hole 181. The first water nozzle 172 is used for sealing the first water hole 171 and injecting or discharging the cooling fluid. The second water nozzle 182 is used for sealing the second water hole 181 and injecting or discharging cooling fluid. Through the arrangement of the first water nozzle 172 and the second water nozzle 182, the first cavity 102 and the second cavity 103 are sealed cavities, so that the use is convenient, and the practicability is improved.

In a specific embodiment, both ends of the housing 110 may be provided with a first flange 111 and a second flange 112, respectively. The two end surfaces of the wall of the housing 110, on which the cooling channel 160 is formed, may be flush with the first magnet 140 and the second magnet 150, or slightly higher than the first magnet 140 and the second magnet 150. The first flange 111 and the second flange 112 further enlarge the space of the first cavity 102 and the second cavity 103. The first cover plate 170 is attached to the first flange 111, and the second cover plate 180 is attached to the second flange 112. The first cover plate 170, the first flange 111, the housing 110, and the first magnet 140 constitute the first sealed cavity 102. The second cover plate 180, the second flange 112, the housing 110, and the second magnet 150 form the sealed second cavity 103.

In one embodiment, the phase shifter 100 further includes a first anchor 191 and a second anchor 192. The first fixing member 191 passes through the first cover plate 170 to abut against the first magnet 140. The second fixing member 192 passes through the second cover plate 180 to abut against the second magnet 150. The first fixing member 191 and the second fixing member 192 may be, but not limited to, screws, bolts, etc. The structure, size, number, material and the like of the first fixing member 191 and the second fixing member 192 may be selected according to actual requirements. The first and second fixing

pieces

191 and 192 can effectively fix the first and

second magnets

140 and 150, thereby improving the structural stability of the phase shifter 100. In addition, a gasket, a sealing ring, etc. may be further disposed between the first fixing member 191 and the first cover plate gasket, and between the second fixing member 192 and the second cover plate 180. A spacer or the like may be further disposed between the first fixing member 191 and the first magnet 140, and between the second fixing member 192 and the second magnet 150, so as to fix the first magnet 140 and the second magnet 150 more firmly.

The waveguide 120 will be described in detail with reference to the following examples.

In one embodiment, the waveguide 120 is an over-mode waveguide. The over-mode waveguide refers to a waveguide having a cross-sectional dimension larger than a standard dimension. The waveguide 120 is configured as an over-mode waveguide, which can improve the transmission power of the waveguide and reduce the transmission loss.

In one embodiment, the length of the cross-section of the waveguide 120 is 0.4mm to 0.7mm greater than the length of a standard waveguide cross-section. The width of the cross-section of the waveguide 120 is 0.2mm-0.5mm greater than the width of the standard waveguide cross-section. The length and width of the waveguide 120 may be selected from the above ranges according to practical requirements. The phase shifter 10 and the circulator with the waveguide 120 in the size range can ensure high output power and effectively avoid high-order mode and power breakdown.

In one embodiment, the waveguide 120 has dimensions of 7.6mm by 3.8 mm. The millimeter wave frequency band is 31.5GHz-32.5 GHz. In this frequency band, the standard rectangular waveguide has dimensions of about 7.112mm by 3.556 mm. In this embodiment, the size of the waveguide 120 is increased to 7.6mm × 3.8mm, which can reduce loss and increase power capacity, so that the millimeter wave circulator formed by the phase shifter 100 has the characteristics of a wide frequency band, high power and low insertion loss. It should be noted that the present embodiment provides the waveguide 120 with a specific size, which is used as a preferred embodiment to illustrate the waveguide 120, and is not used to limit the waveguide 120, and the waveguide and the phase shifter within a certain error range of the size are all within the protection scope of the present application.

Referring to fig. 5, an embodiment of the present application further provides a millimeter wave circulator 10. The millimeter wave circulator 10 includes a phase shifter 100, a bridge 200, and a folded double T300 as described above. The bridge 200 and the folded double T300 are connected to both ends of the phase shifter 100, respectively. The bridge 200 may be an H-plane 3dB bridge. The folded double T300 may be an H-sided folded double T. The phase shifter 100 is an H-plane pi/2 difference phase shifter. The specific structure, size, material and connection mode of the bridge 200 and the folded double T300 to the phase shifter 100 are not limited in any way, and can be selected according to actual requirements.

The millimeter wave circulator 10 provided in this embodiment includes the phase shifter 100, and therefore has all the advantages of the phase shifter 100, and details thereof are not repeated herein.

Referring to fig. 4 and 5, in one embodiment, the millimeter wave circulator 10 further includes a choke flange 400. The bridge 200 and the folded double T300 are connected to both ends of the phase shifter 100 through the choke flange 400, respectively. The choke flange 400 includes two flanges. The flanges may be fixed to the bridge 200, the folded double T300, and the phase shifter 100, respectively, by fastening screws. And the flange plate is provided with a choke groove. The opening of the choke groove is sized to match the waveguide 120. When the waveguide 120 is an over-mode waveguide, the choke flange 400 is an over-sized choke flange. The choke groove opening of the oversized choke flange is sized to match the oversized waveguide. In a specific embodiment, the size of the waveguide 120 is 7.6mm × 3.8mm, and the diameter of the choke groove opening circle of the choke flange 400 may be about 9.5 mm. The bridge 200 and the folded double-T300 are connected to both ends of the phase shifter 100 through the choke flanges 400 matched with the waveguide 120, respectively, so that the transmission power of the millimeter wave circulator 10 can be further improved, the phenomenon of sparking of the millimeter wave circulator 10 under high power is effectively avoided, and the stability of the millimeter wave circulator 10 is improved.

Referring to fig. 6, in an embodiment, a port of the bridge 200 of the millimeter wave circulator 10 and the H port of the folded double T are connected to a matched load, and the millimeter wave circulator 10 is tested by a vector network analyzer, so as to obtain a test curve shown in fig. 6. In the figure, the abscissa is frequency, the ordinate is dB value, and the abscissa is 31.5GHz-32.5 GHz. It can be known from the figure that the return loss of the port of the millimeter wave circulator is basically below 20dB in the frequency range of 31.5GHz-32.5GHz (in fig. 6, S11 represents the return loss of the input port, and the S22 curve represents the return loss of the output port, and as can be known from the curves, the return loss of the input port and the return loss of the output port are both less than or equal to 20 dB); the isolation is less than 21dB (in fig. 6, S12 represents the isolation, and as can be seen from the graph, the isolation is less than or equal to 21 dB); the insertion loss is only 0.73dB (in fig. 6, S21 represents the insertion loss, and as can be seen from the graph, the insertion loss is 0.73dB or less).

An embodiment of the present application also provides a radar system. The radar system includes a millimeter wave circulator 10 as described above. The millimeter wave circulator 10 can be applied to an antenna feeder and a transmitter of the radar system, and is used for controlling unidirectional transmission of energy in a loop. The millimeter wave circulator 10 can effectively protect an antenna feeder and a transmitter.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A phase shifter, comprising:

a housing (110) defining an accommodating space (101);

a waveguide (120) provided in the accommodation space (101);

a ferrite (130) attached to an inner wall of the waveguide (120);

the first magnet (140) is positioned in the accommodating space (101) and is attached to the outer wall of the waveguide tube (120), and the first magnet (140) and the shell (110) define a first cavity (102);

the second magnet (150) is positioned in the accommodating space (101) and is attached to the outer wall of the waveguide tube (120), the second magnet (150) is arranged opposite to the first magnet (140), and the second magnet (150) and the shell (110) define a second cavity (103);

a cooling flow channel (160) provided in the housing (110), the cooling flow channel (160) being configured to penetrate the first cavity (102) and the second cavity (103).

2. The phase shifter of claim 1, wherein the first magnet (140) and the second magnet (150) are each disposed in close contact with an inner wall of the housing (110), the phase shifter further comprising:

the first cover plate (170) is provided with a first water hole (171), the first cover plate (170) is attached to the shell (110), and the first magnet (140), the shell (110) and the first cover plate (170) define the first cavity (102);

the second cover plate (180) is provided with a second water hole (171), the second cover plate (180) is attached to the shell (110), and the second magnet (150), the shell (110) and the second cover plate (180) define the second cavity (103).

3. The phase shifter of claim 2, further comprising:

a first water nozzle (172) disposed in the first water hole (171);

and the second water nozzle (182) is arranged on the second water hole (181).

4. The phase shifter according to claim 2, further comprising a first flange (111) and a second flange (112), wherein the first flange (111) and the second flange (112) are respectively disposed at two ends of the housing (110), the first cover plate (170) is closely disposed at the first flange (111), and the second cover plate (180) is closely disposed at the second flange (112).

5. The phase shifter of claim 2, further comprising:

a first fixing member (191) which passes through the first cover plate (170) and abuts against the first magnet (140);

and the second fixing piece (192) passes through the second cover plate (180) and abuts against the second magnet (150).

6. Phase shifter according to claim 1, characterized in that the waveguide (120) is an overmoulded waveguide.

7. Phase shifter according to claim 5, characterized in that the length of the cross section of the waveguide (120) is 0.4-0.7 mm larger than the length of a standard waveguide cross section, and the width of the cross section of the waveguide (120) is 0.2-0.5 mm larger than the width of the standard waveguide cross section.

8. A millimeter wave circulator comprising a phase shifter (100), a bridge (200) and a folded double T (300) according to any one of claims 1 to 7, the bridge (200) and the folded double T (300) being connected to both ends of the phase shifter (100), respectively.

9. The millimeter wave circulator of claim 8, further comprising:

a choke flange (400), the bridge (200) and the folded double T (300) being connected to both ends of the phase shifter (100) through the choke flange (400), respectively, an opening size of a choke groove of the choke flange (400) being matched with the waveguide (120).

10. A radar system, characterized in comprising a millimeter wave circulator (10) as claimed in claim 8 or 9.