阅读说明：本技术 一种紧凑脊波导级联四端口环行器 (Compact ridge waveguide cascade four-port circulator ) 是由 邓广健 李佳伟 黄文华 邵浩 郭乐田 谢少毅 方文饶 于 2019-11-05 设计创作，主要内容包括：本发明公开了一种紧凑脊波导级联四端口环行器。其主要技术特点是：脊波导四端口环行器由两个三端口脊波导结型环行器平行镜像排布,通过紧凑脊波导至同轴线过渡连接构成。本发明能够有效减小波导四端口环行器的截面尺寸及纵向长度,降低环行器的插入损耗,同时在较宽的带宽范围内实现低插入损耗及高隔离度,使得波导四端口环行器能够满足小尺寸、低插入损耗、大带宽要求下的应用。(The invention discloses a compact ridge waveguide cascaded four-port circulator. The main technical characteristics are as follows: the ridge waveguide four-port circulator is formed by arranging two three-port ridge waveguide junction-type circulators in parallel mirror image mode and transitionally connecting the compact ridge waveguide to a coaxial line. The invention can effectively reduce the section size and the longitudinal length of the waveguide four-port circulator, reduce the insertion loss of the circulator and simultaneously realize low insertion loss and high isolation in a wider bandwidth range, so that the waveguide four-port circulator can meet the application requirements of small size, low insertion loss and large bandwidth.)

1. A compact ridge waveguide cascaded four-port circulator, comprising: the three-port ridge waveguide junction circulator comprises two parallel mirror image arranged three-port ridge waveguide junction circulators and a compact ridge waveguide-to-coaxial line transition structure which is vertically arranged;

the three-port ridge waveguide junction type circulator comprises three single ridge waveguides which are integrally spliced into a T shape, wherein two single ridge waveguides which are positioned on the same straight line are marked as a first single ridge waveguide and a second single ridge waveguide, and the other single ridge waveguide is marked as a third single ridge waveguide; the joint of the ridge strips of the three single ridge waveguides forms a spine, wherein the corresponding first ridge strip and the corresponding second ridge strip form ridge waveguide bending at the position close to the spine, so that included angles of the joint of the three ridge strips are 120 degrees; the first ridge and the second ridge are both of step structures, and the part of the first ridge and the second ridge close to the spine is higher than the part far away from the spine; the third ridge has a height corresponding to the part close to the spine in the first ridge and the second ridge, and the length of the third ridge does not exceed the length of the part close to the spine; the surface of the spine is tightly attached with a ferrite sheet, and magnetic steel is embedded in the back of the spine at the corresponding position and used for providing a bias magnetic field for the ferrite sheet; the directions of magnetic steel fields in the two three-port ridge waveguide junction type circulators are the same;

the two three-port ridge waveguide junction circulators arranged in parallel and in a mirror image form butt joint by sharing one circulator cover plate, and the circulator cover plate keeps a gap with the ridge and the ferrite sheet;

the compact ridge waveguide-to-coaxial line transition structure comprises a coaxial line and two combined waveguides; the combined waveguide is formed by splicing a single-ridge waveguide and a rectangular waveguide, wherein one end, close to the rectangular waveguide, of a ridge strip of the single-ridge waveguide is cut to form a semi-cylindrical groove, and a port of the single-ridge waveguide is in adaptive butt joint with a port of the third single-ridge waveguide; the coaxial line is composed of a coaxial inner conductor, a coaxial outer conductor and a dielectric sleeve positioned between the coaxial inner conductor and the coaxial outer conductor, wherein the thickness of the coaxial outer conductor is equal to that of the dielectric sleeve and the thickness of the circulator cover plate, the coaxial outer conductor is also used as a combined waveguide cover plate and forms an integrated part with the circulator cover plate, the coaxial inner conductor penetrates through two ends of the dielectric sleeve, respectively extends into the semi-cylindrical grooves in the two combined waveguides, and keeps a distance with the semi-cylindrical groove wall and the rectangular waveguide wall.

2. The compact ridge waveguide cascaded four-port circulator of claim 1, wherein: the backbone comprises two concentric metal cylinders, wherein the small cylinder corresponds to the portion that is close to the ferrite piece, and the big cylinder corresponds to the portion that is far away from the ferrite piece.

3. The compact ridge waveguide cascaded four-port circulator of claim 1, wherein: the back of the waveguide cavity of the three-port ridge waveguide junction type circulator forms a groove structure corresponding to the position of the spine, and the magnetic steel is arranged at the bottom of the groove.

4. The compact ridge waveguide cascaded four-port circulator of claim 2, wherein: the ferrite sheet and the magnetic steel are both circular.

5. The compact ridge waveguide cascaded four-port circulator of claim 1, wherein: the medium sleeve is made of polytetrafluoroethylene materials.

6. The compact ridge waveguide cascaded four-port circulator of claim 1, wherein: in the combined waveguide, the width of the single-ridge waveguide is 11mm, the width of the single-ridge waveguide is 8mm, the height of the ridge is 6.32mm, the width of the ridge is 5mm, the cross section of the rectangular waveguide is 11mm multiplied by 8mm, and the diameter of the semi-cylindrical groove is 4.26 mm; the outer diameter of the coaxial inner conductor is 1.5mm, the inner diameter of the outer conductor is 4.1mm, the coaxial inner conductor extends into the semi-cylindrical groove of the single-ridge waveguide, the distance from the coaxial inner conductor to the wide side of the single-ridge waveguide is 1.55mm, and the distance from the coaxial inner conductor to a short circuit metal wall provided by the rectangular waveguide is 4.31 mm.

7. The compact ridge waveguide cascaded four-port circulator of claim 6, wherein: in the three-port ridge waveguide junction type circulator, the width of a single ridge waveguide is 11mm, the width of a narrow edge is 8mm, the height of a ridge is 6.32mm/5.5mm, and the width of the ridge is 5 mm.

8. The compact ridge waveguide cascaded four-port circulator of claim 4, wherein: the diameter of the small cylinder is 8.65mm, and the height of the small cylinder is 2.23 mm; the diameter of the large cylinder is 15.25mm, and the height of the large cylinder is 4.09 mm; the ferrite pieces were 11.66mm in diameter and 1.37mm in height.

9. The compact ridge waveguide cascaded four-port circulator of claim 1, wherein: the two three-port ridge waveguide junction type circulators cover the magnetic steel through the U-shaped connecting sheet and form a communicated magnetic circuit.

10. The compact ridge waveguide cascaded four-port circulator of claim 1, wherein: the four-port circulator is integrally fastened and locked at the corners through bolts.

Technical Field

The invention belongs to the field of circulators, and particularly relates to a ridge waveguide circulator.

Background

A circulator is one of the most commonly used microwave components, and in a microwave system, the circulator is often used as a transmit-receive switch of an antenna to achieve transmit-receive isolation. Circulators can be classified into microstrip, strip line, coaxial, waveguide, etc. types according to the form of transmission line. Waveguide circulators can be classified into junction type circulators and differential phase-shift circulators, depending on their structural forms. The waveguide junction type circulator is small in size and suitable for occasions with system compactness requirements.

Most of the existing waveguide junction type circulators are rectangular waveguide three-port structures, and in order to realize four-port circulation, two three-port circulators are required to be cascaded together to form a four-port circulator. At this time, the insertion loss of the circulator is the insertion loss of two three-port circulators, and the sectional dimension and the longitudinal length of the rectangular waveguide circulator are also large.

Disclosure of Invention

The invention aims to provide a compact waveguide junction type circulator, which effectively reduces the sectional dimension and the longitudinal length of a waveguide four-port circulator, reduces the insertion loss of the circulator, and simultaneously realizes low insertion loss and high isolation in a wider bandwidth range, so that the waveguide four-port circulator can meet the application requirements of small size, low insertion loss and large bandwidth.

In order to achieve the above object, the present invention proposes the following solutions:

the compact ridge waveguide cascade four-port circulator comprises: the three-port ridge waveguide junction circulator comprises two parallel mirror image arranged three-port ridge waveguide junction circulators and a compact ridge waveguide-to-coaxial line transition structure which is vertically arranged;

the three-port ridge waveguide junction type circulator comprises three single ridge waveguides which are integrally spliced into a T shape, wherein two single ridge waveguides which are positioned on the same straight line are marked as a first single ridge waveguide and a second single ridge waveguide, and the other single ridge waveguide is marked as a third single ridge waveguide; the joint of the ridge strips of the three single ridge waveguides forms a spine, wherein the corresponding first ridge strip and the corresponding second ridge strip form ridge waveguide bending at the position close to the spine, so that included angles of the joint of the three ridge strips are 120 degrees; the first ridge and the second ridge are both of step structures, and the part of the first ridge and the second ridge close to the spine is higher than the part far away from the spine; the third ridge has a height corresponding to the part close to the spine in the first ridge and the second ridge, and the length of the third ridge does not exceed the length of the part close to the spine; the surface of the spine is tightly attached with a ferrite sheet, and magnetic steel is embedded in the back of the spine at the corresponding position and used for providing a bias magnetic field for the ferrite sheet; the directions of magnetic steel fields in the two three-port ridge waveguide junction type circulators are the same;

the two three-port ridge waveguide junction circulators arranged in parallel and in a mirror image form butt joint by sharing one circulator cover plate, and the circulator cover plate keeps a gap with the ridge and the ferrite sheet;

the compact ridge waveguide-to-coaxial line transition structure comprises a coaxial line and two combined waveguides; the combined waveguide is formed by splicing a single-ridge waveguide and a rectangular waveguide, wherein one end, close to the rectangular waveguide, of a ridge strip of the single-ridge waveguide is cut to form a semi-cylindrical groove, and a port of the single-ridge waveguide is in adaptive butt joint with a port of the third single-ridge waveguide; the coaxial line is composed of a coaxial inner conductor, a coaxial outer conductor and a dielectric sleeve positioned between the coaxial inner conductor and the coaxial outer conductor, wherein the thickness of the coaxial outer conductor is equal to that of the dielectric sleeve and the thickness of the circulator cover plate, the coaxial outer conductor is also used as a combined waveguide cover plate and forms an integrated part with the circulator cover plate, the coaxial inner conductor penetrates through two ends of the dielectric sleeve, respectively extends into the semi-cylindrical grooves in the two combined waveguides, and keeps a distance with the semi-cylindrical groove wall and the rectangular waveguide wall.

Based on the above scheme, the invention further optimizes as follows:

optionally, the spine is comprised of two concentric metal cylinders, wherein the small cylinder corresponds to the portion closer to the ferrite piece and the large cylinder corresponds to the portion further from the ferrite piece.

Optionally, a groove structure is formed at a position, corresponding to the spine, of the back of the waveguide cavity of the three-port ridge waveguide junction circulator, and the magnetic steel is arranged at the bottom of the groove.

Optionally, the ferrite pieces and the magnetic steel are both circular. Further preferably, the small cylinder has a diameter of 8.65mm and a height of 2.23 mm; the diameter of the large cylinder is 15.25mm, and the height of the large cylinder is 4.09 mm; the ferrite pieces were 11.66mm in diameter and 1.37mm in height.

Optionally, the media sleeve is made of polytetrafluoroethylene.

Optionally, in the combined waveguide, the width of the single-ridge waveguide is 11mm, the width of the single-ridge waveguide is 8mm, the height of the ridge is 6.32mm, the width of the ridge is 5mm, the cross-sectional dimension of the rectangular waveguide is 11mm × 8mm, and the diameter of the semi-cylindrical groove is 4.26 mm; the outer diameter of the coaxial inner conductor is 1.5mm, the inner diameter of the outer conductor is 4.1mm, the coaxial inner conductor extends into the semi-cylindrical groove of the single-ridge waveguide, the distance from the coaxial inner conductor to the wide side of the single-ridge waveguide is 1.55mm, and the distance from the coaxial inner conductor to a short circuit metal wall provided by the rectangular waveguide is 4.31 mm.

Optionally, in the three-port ridge waveguide junction circulator, a width of the single ridge waveguide is 11mm, a width of the single ridge waveguide is 8mm, a height of the ridge is 6.32mm/5.5mm, and a width of the ridge is 5 mm.

Optionally, the two three-port ridge waveguide junction circulators cover the magnetic steel through the U-shaped connecting sheet and form a communicating magnetic circuit.

Optionally, the four port circulator is integrally fastened and locked at the corners by bolts.

Compared with the existing rectangular waveguide cascade four-port circulator and the conventional ridge waveguide circulator, the invention has the following beneficial effects:

the compact ridge waveguide cascaded four-port circulator adopts a compact ridge waveguide-coaxial transition structure to connect two three-port ridge waveguide junction circulators which are arranged in parallel in a mirror image manner, so that the structural compactness of the section size of the circulator is ensured; wherein, a wider working bandwidth is realized by introducing ridge step transition into the three-port ridge waveguide circulator and adopting ridge waveguide to coaxial transition of capacitive coupling; and because the ridge waveguide four-port circulator only passes through a single junction when transmitting in the forward direction, the circulator has low insertion loss.

The invention has compact structure, can realize good isolation and lower insertion loss in a wider bandwidth range, and can be widely applied to microwave systems with limited section size and high power capacity requirement.

In addition, compared with the conventional design idea, the three-port ridge waveguide junction type circulator designed in the invention also performs some important optimizations, such as: the spine is formed by two concentric metal cylinders, and the spine in the form of the spine also brings about multi-level impedance transformation, so that the working bandwidth can be effectively increased; meanwhile, the cylindrical groove is formed in the back of the large column of the spine, and the magnetic steel is embedded (in the structure, only one piece of magnetic steel needs to be arranged), so that the whole structure is more compact and smaller in size.

Drawings

FIG. 1 is a schematic view of an assembly structure of the present embodiment;

FIG. 2 is a schematic structural view of a three-port ridge waveguide junction circulator in the present embodiment;

fig. 3 is a top view of fig. 2 (ferrite sheet not shown).

FIG. 4 is an assembly diagram of a ridge waveguide to coaxial line transition structure in the present embodiment;

fig. 5 is an assembled front view of the present embodiment.

Fig. 6 is a plan view (symmetrical plane) with the cover plate removed.

FIG. 7 is a graph of simulation results of the reflection coefficient and isolation of the port of the circulator of the present invention;

fig. 8 is a graph of simulation results of the insertion loss of the circulator of the present invention.

The reference numbers are as follows:

1-a three-port ridge waveguide junction circulator;

2-transition of compact ridge waveguide to coaxial line;

3-circulator cover plate (and corresponding cover plate for compact ridge waveguide to coaxial line transition);

4-U-shaped connecting sheets;

101-single ridge waveguide; 102-a Y-shaped ridge waveguide junction; 103-ridge waveguide bending; 104-spine (metal block); 105-a ferrite piece; 106-magnetic steel; 107-first single ridge waveguide port; 108-a second single ridge waveguide port; 109-a third single ridge waveguide port; 110-grooves in the back of the waveguide cavity;

201-coaxial inner conductor; 202-a coaxial outer conductor; 203-a media sleeve; 204-a single ridge waveguide portion; 205-a rectangular waveguide section; 206-semi-cylindrical trough; 207-ridge waveguide port.

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings.

As shown in fig. 1, the compact ridge waveguide cascaded four-port circulator of the present embodiment includes two three-port ridge waveguide junction circulators 1 and one compact ridge waveguide-to-coaxial line transition 2. The two three-port ridge waveguide junction type circulators 1 are arranged in parallel mirror image mode, share a circulator cover plate 3 and are connected through transition 2 from compact ridge waveguides to coaxial lines, so that compact section size and low insertion loss are realized; the U-shaped connecting sheet 4 mainly plays a role in covering the magnetic steel and communicating the magnetic circuit.

As can be seen from fig. 1, the four-port circulator structure can be divided into an upper part, a middle part and a lower part, wherein the upper part and the lower part are mirror images of each other and are formed by adaptively splicing a three-port ridge waveguide junction circulator and a waveguide part (a single ridge + rectangular combined waveguide) in the transition from a compact ridge waveguide to a coaxial line; the middle part is composed of a cover plate shared by the upper part and the lower part and a coaxial line part in the transition from the compact ridge waveguide to the coaxial line. The magnetic steel is positioned in the middle of the three-port ridge waveguide junction type circulator, and correspondingly, the U-shaped connecting sheet covers the middle of the two three-port ridge waveguide junction type circulators and the single ridge and rectangular combined waveguide and is fixedly connected with the single ridge and rectangular combined waveguide through bolts.

The four-port circulator can be integrally fastened and locked at the corners through bolts.

Referring to fig. 2 and 3, the structure of the three-port ridge waveguide junction circulator in the present embodiment includes:

the Y-shaped three-port ridge waveguide joint is formed by arranging three single ridge waveguides with the width dimension of 11mm, the narrow edge dimension of 8mm, the ridge height of 6.32mm and the ridge width of 5mm at 120 degrees along the width direction; here, it is equivalent to consider the entire third single-ridge waveguide (the vertical waveguide shown in fig. 3) as part of the Y-shaped three-port ridge waveguide junction.

The metal block occupies the geometric center of the Y-shaped three-port ridge waveguide joint, and is expanded at the periphery of the joint of the three ridge strips to integrally form a spine structure consisting of two concentric metal cylinders; the diameter of the top metal cylinder is 8.65mm, the height of the top metal cylinder is 2.23mm, the diameter of the bottom metal cylinder is 15.25mm, and the height of the bottom metal cylinder is 4.09 mm;

a cylindrical ferrite sheet closely attached to the surface of the top metal cylinder, the diameter of the ferrite sheet is 11.66mm, and the height of the ferrite sheet is 1.37 mm;

two ridge waveguides which are connected with two ports of the Y-shaped ridge waveguide joint are bent and formed by 30-degree intersection of two single ridge waveguides with the size and two waveguides of the Y-shaped ridge waveguide joint, and the two bent ridge waveguides are coaxially arranged;

the width of each of the two single ridge waveguides connected with the ridge waveguide in a bending mode is 11mm, the width of each of the two single ridge waveguides is 8mm, the height of each ridge is 5.5mm, and the width of each ridge is 5 mm; here, it is equivalent to divide the first and second single-ridge waveguides (the left and right waveguides horizontally shown in fig. 3) into three segments (a part of the Y-shaped three-port ridge waveguide joint, a ridge waveguide bend, a single-ridge waveguide connected to the ridge waveguide bend, and the latter two form a step ridge);

and the magnetic steel is embedded in the groove at the back of the waveguide cavity corresponding to the position of the spine and provides a bias magnetic field for the ferrite sheet. The magnetic steel magnetic fields in the two three-port ridge waveguide junction type circulators have the same direction, and the magnetic steel is covered by the U-shaped connecting sheet 4 and communicated with the magnetic circuit.

Referring to fig. 4, the ridge waveguide-to-coaxial line transition structure in the present embodiment is composed of a coaxial line and a single ridge + rectangular combined waveguide arranged vertically: the outer diameter of the coaxial line inner conductor is 1.5mm, the inner diameter of the coaxial line outer conductor is 4.1mm, and polytetrafluoroethylene materials are filled between the coaxial line inner conductor and the coaxial line outer conductor; the size of the wide side of the single ridge and rectangular combined waveguide is 11mm, the size of the narrow side is 8mm, the height of the ridge is 6.32mm, and the width of the ridge is 5 mm; the coaxial line inner conductor extends into the single-ridge and rectangular combined waveguide, and the distance from the single-ridge waveguide to the wide side is 1.55 mm; at the cross section of the coaxial line in the single-ridge and rectangular combined waveguide, one side is a single-ridge waveguide, a semi-cylindrical groove with the diameter of 4.26mm is cut on the ridge and is separated from the coaxial inner conductor, the other side is a rectangular waveguide with the cross section size of 11mm multiplied by 8mm, and the distance between the inner wall (short circuit metal wall) of the rectangular waveguide and the center of the coaxial line inner conductor is 4.31 mm.

The ridge waveguide port 207 of the ridge waveguide-to-coaxial line transition structure shown in fig. 4 is adapted to mate with the third ridge waveguide port 109 of the three-port ridge waveguide junction circulator shown in fig. 2 and 3, thereby forming the upper/lower portion of fig. 1; in the transition structure from ridge waveguide to coaxial line shown in fig. 4, the thickness of the coaxial outer conductor 202 and the dielectric sleeve 203 made of teflon is equal to the thickness of the middle part (circulator cover plate 3) in fig. 1, the coaxial outer conductor 202 also serves as a combined waveguide cover plate and forms an integral body with the circulator cover plate 3, and the coaxial inner conductor 201 penetrates through two end faces of the dielectric sleeve and respectively extends into the corresponding semi-cylindrical grooves 206 in the two three-port ridge waveguide junction type circulators at the upper part and the lower part in fig. 1. See also fig. 5 and 6. As can also be seen from fig. 6, the dielectric sleeve and the coaxial inner conductor are coaxially fitted with the semicylindrical slot (the dielectric sleeve and the semicylindrical slot are concentrically positioned, but the sectional dimensions may be different).

The novel compact ridge waveguide cascaded four-port circulator provided in the embodiment connects two three-port ridge waveguide junction circulators which are arranged in parallel and in a mirror image mode through adopting the transition from the compact ridge waveguide to the coaxial mode, so that the structural compactness of the section size of the circulator is ensured. The wider working bandwidth is realized by introducing ridge step transition into the three-port ridge waveguide circulator and adopting ridge waveguide to coaxial transition of capacitive coupling; and because the ridge waveguide four-port circulator only passes through a single junction when transmitting in the forward direction, the circulator has low insertion loss. The ridge waveguide four-port circulator is compact in structure, can achieve good isolation and low insertion loss in a wide bandwidth range, and therefore is widely applied to microwave systems with limited section size and high power capacity requirements.

In the finally obtained compact ridge waveguide cascaded four-port circulator, the four ports respectively correspond to the upper left port, the upper right port, the lower left port and the lower right port in fig. 1 and are respectively marked as port 1, port 2, port 3 and port 4.

Referring to fig. 7 and 8, it can be seen from the two graphs that the simulation results of s (1,1), s (1,2), s (3,1), s (4,1), s (2,1), s (3,2) show that in the frequency range of 8.5-9.4GHz, the reflection coefficient of port 1 is less than-20 dB, the isolation between port 2 and port 1 is greater than 20dB, the isolation between port 1 and port 3 is greater than 20dB, the isolation between port 1 and port 4 is greater than 40dB, the insertion loss from port 1 to port 2 is less than 0.16dB, and the insertion loss from port 2 to port 3 is less than 0.29dB (i.e. the port has no reflection, the port 1 is transmitted to port 2, the port 2 is isolated from port 1 to port 3, the port 1 is isolated from port 4, and the characteristics between the rest of the ports are similar), and thus the requirements of the four-port waveguide circulator can be satisfied.

The cross-sectional dimension of the inner cavity of the ridge waveguide cascade four-port circulator is 23mm multiplied by 19.4mm, the cross-sectional dimension of the ridge waveguide cascade four-port circulator at the central frequency is 0.7 lambda multiplied by 0.6 lambda, the length of the ridge waveguide cascade four-port circulator is less than 40mm, and the bandwidth of the ridge waveguide cascade four-port circulator is 0.9 GHz.

The above description is only a preferred example of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.