CN113629372A

CN113629372A - S, C, X waveband strip line junction circulator and design method thereof

Info

Publication number: CN113629372A
Application number: CN202111062823.3A
Authority: CN
Inventors: 汪晶吟
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-09-10
Filing date: 2021-09-10
Publication date: 2021-11-09
Anticipated expiration: 2041-09-10
Also published as: CN113629372B

Abstract

The invention relates to an S, C, X waveband strip line junction circulator, which comprises a Y-shaped strip line structure used for transmitting line signals, and ferrites respectively positioned on the upper side and the lower side of the Y-shaped strip line structure, wherein a bias magnetic field with a direction vertical to the circulator is applied to the center of each ferrite; the Y-shaped strip line structure is composed of a conduction band and three ports which are uniformly distributed on the excircle of the conduction band, and the conduction band is of a disc or ring structure. The invention has the advantages that the volume of the circulator can be effectively reduced, the miniaturization, integration and high performance of the S, C, X waveband strip line junction circulator are realized, and the equilateral triangle corner cut is added at different positions to improve the standing wave, so that the performance of the circulator is more excellent.

Description

S, C, X waveband strip line junction circulator and design method thereof

Technical Field

The invention relates to an S, C, X waveband strip line junction circulator and a design method thereof, and belongs to the technical field of microwave passive devices.

Background

It is known that a circulator is an important microwave ferrite device, which utilizes the non-reciprocity of ferrite to realize the circulation, and has a wide application in various industries. The traditional S, C, X waveband strip line junction circulator is investigated, and the problem that the traditional S, C, X waveband strip line junction circulator still has a large volume is found, so that the traditional S, C, X waveband strip line junction circulator does not meet the current trend of integration and miniaturization development.

Through search, the Chinese patent with the publication number of CN111430862A discloses a double-Y-shaped patch type circulator, which comprises a double-Y-shaped micro-strip matching line, a center junction, an upper layer circular ferrite, a lower layer circular ferrite, a substrate and a metal grounding plate, wherein the double-Y-shaped micro-strip matching line comprises a large Y matching line and a small Y matching line, the large Y matching line and the small Y matching line are pasted between the upper layer circular ferrite and the lower layer circular ferrite through the center junction, the included angles of the three sides of the large Y matching line and the small Y matching line are both 120 degrees, the included angle of the adjacent side of the large Y matching line and the small Y matching line is 60 degrees, the structure design is simple and symmetrical, the size is small, and the weight is light. Chinese patent publication No. CN102664298A discloses a circulator strip-line non-reciprocal junction assembly, in which a strip line between two ferrite gyromagnetic pieces and ferrite gyromagnetic pieces form a non-reciprocal junction, the circulator strip-line non-reciprocal junction assembly comprises a central round junction assembly, a Y junction rent and at least three interface ends, the Y junction assembly and the three interface ends are distributed on the central round junction assembly at intervals, the Y structure forms a parallel inductor, the outlet of the interface ends forms a capacitor, the inductor and the capacitor form an LC matching section, and line matching is realized through the LC matching section. The above two patents adopt a waveguide structure and a strip line structure, respectively, and both are low-field structures, which has a problem of large size.

Disclosure of Invention

The invention aims to: aiming at the defects in the prior art, the S, C, X waveband strip line junction circulator with the extremely small size is provided, and the basic design principle is broken through.

In order to achieve the above purpose, the technical scheme of the invention is as follows:

an S, C, X waveband strip line junction circulator comprises a Y-shaped strip line structure used for transmitting line signals and ferrites respectively positioned at the upper side and the lower side of the Y-shaped strip line structure, wherein a bias magnetic field with a direction vertical to the circulator is applied to the center of each ferrite; the Y-shaped strip line structure is composed of a conduction band and three ports which are uniformly distributed on the excircle of the conduction band, and the conduction band is of a disc or ring structure.

The S, C, X waveband strip line junction circulator adopts a new design concept, and realizes the miniaturization, integration and high performance of a S, C, X waveband circulator. The invention adopts the strip line quasi-concentration structure design and the high-field structure design, and based on the design, the volume is microminiaturized while the high performance is ensured, the size is only 20 percent of that of the waveguide, and the sizes of other strip lines are 4-10 percent, even smaller, thereby being more beneficial to integration.

The technical scheme of the invention for further refining is as follows:

preferably, the ferrite is a cylinder, and the two ferrites are arranged symmetrically about the center of the dot of the Y-shaped strip line structure, and the material, radius and thickness of the two ferrites are the same; the two adjacent ports form a Y-shaped belt line structure at an angle of 120 degrees.

Preferably, a dielectric substrate is disposed above the Y-shaped stripline structure.

Preferably, three uniformly distributed grooves are formed on the inner circumferential surface of the circular ring structure, and the center lines of the grooves are positioned on the vertical line from the center of the conduction band to the port or form an included angle of 60 degrees with the vertical line.

Preferably, the outer circular surface of the circular ring structure is provided with three protrusions which are uniformly distributed, and the central lines of the protrusions and the vertical line from the center of the conduction band to the port form an included angle of 60 degrees.

Preferably, the cross sections of the grooves and the bulges are all equilateral triangles.

The invention relates to a design of equilateral triangle cut angles of inner and outer surfaces of a guide band, which adopts a compressed branch matching technology and a compressed stub matching technology, and generally adopts a quarter matching technology (with large size), wherein the design of the equilateral triangle cut angles of the inner surface of the guide band is used for improving the impedance of a branch structure, and the design of the equilateral triangle cut angles of the outer surface is used for additionally matching a stub so as to improve the impedance matching and the phase matching and ensure that the traveling wave of a device is better.

The invention also provides a design method of the S, C, X waveband strip line junction circulator, which comprises the following steps:

step 1, determining relevant parameters of a Y-shaped strip line structure according to a required transmission waveband, wherein the relevant parameters comprise a conduction band thickness t, a conduction band width w, a dielectric substrate thickness t1, a dielectric substrate width w1 and a dielectric substrate relative dielectric constant

；

Step 2, designing a ferrite junction, determining ferrite materials and the intensity of a saturated magnetic field, and determining the radius R and the height h of the ferrite;

step 3, determining the inner radius R1 and the outer radius R2 of the strip line central circular conduction band and an external bias magnetic field of ferrite based on the step 1 and the step 2, and adjusting parameters to obtain good transmission performance;

and 4, improving the conduction band of the Y-shaped strip line structure designed in the

steps

1, 2 and 3, wherein three uniformly distributed grooves are formed in the inner circular surface of the circular conduction band, and/or three uniformly distributed bulges are formed in the outer circular surface of the circular conduction band.

In the step 3, the radius R2 of the strip line central disc conduction band is determined based on the step 1 and the step 2.

Preferably, the central line of the groove is positioned on a vertical line from the centre of the conduction band to the port, or forms an included angle of 60 degrees with the vertical line from the centre of the conduction band to the port; the central line of the bulge and the vertical line from the center of the conduction band to the port form an included angle of 60 degrees.

The invention has the advantages that the volume of the circulator can be effectively reduced, the miniaturization, integration and high performance of the S, C, X waveband strip line junction circulator are realized, and the equilateral triangle corner cut is added at different positions to improve the standing wave, so that the performance of the circulator is more excellent.

Drawings

The invention is further described below with reference to the accompanying drawings.

FIG. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a perspective view showing a structure in which the center of the belt of the circulator is a circular disk in embodiment 1 of the present invention.

Fig. 3 is a schematic view of a disc-shaped Y-shaped strip line structure in embodiment 1 of the present invention.

Fig. 4 is a schematic structural view of a circulator according to embodiment 1 of the present invention, in which the center of the conduction band of the circulator is a circular ring.

Fig. 5 is a schematic view of a circular Y-shaped strip line structure in embodiment 1 of the present invention.

FIG. 6 shows a circulator in embodiment 1 of the present invention

A parametric curve.

Fig. 7 is a S-parameter graph of the circulator in embodiment 1 of the present invention.

Fig. 8 is a port impedance graph of the circulator in embodiment 1 of the present invention.

Fig. 9 is a schematic structural view of a circulator in embodiment 2 of the present invention.

Fig. 10 is a schematic view of a Y-shaped strip line structure in embodiment 2 of the present invention.

Fig. 11 is a schematic structural view of a circulator in embodiment 3 of the present invention.

Fig. 12 is a schematic view of a Y-shaped strip line structure in embodiment 3 of the present invention.

Fig. 13 is a schematic structural view of a circulator in embodiment 4 of the present invention.

Fig. 14 is a schematic view of a Y-shaped strip line structure in embodiment 4 of the present invention.

Fig. 15 is a schematic structural view of a circulator in embodiment 5 of the present invention.

Fig. 16 is a schematic view of a Y-shaped strip line structure in embodiment 5 of the present invention.

Fig. 17 is a schematic structural view of a circulator in embodiment 6 of the present invention.

Fig. 18 is a schematic view of a Y-shaped strip line structure in embodiment 6 of the present invention.

Fig. 19 is a S-parameter graph of the circulator in embodiment 2 of the present invention.

Fig. 20 is a S-parameter graph of the circulator in embodiment 3 of the present invention.

Fig. 21 is a S-parameter graph of the circulator in embodiment 4 of the present invention.

Fig. 22 is a S-parameter graph of the circulator in embodiment 5 of the present invention.

Fig. 23 is a S-parameter graph of the circulator in embodiment 6 of the present invention.

In the figure: the structure of the Y-shaped strip line is 1, ferrite and 3, a dielectric substrate.

Detailed Description

The present invention will be described in detail with reference to the following examples and drawings.

Example 1

An S, C, X waveband strip line knot circulator is shown in fig. 1 to 5, and comprises a Y-shaped strip line structure 1 for transmitting line signals and ferrites 2 respectively positioned at the upper and lower sides of the Y-shaped strip line structure 1, wherein the ferrites 2 are cylinders, the two ferrites 2 are arranged in central symmetry about a circular point of the Y-shaped strip line structure 1, and the materials, the radius and the thickness of the two ferrites 2 are the same. A bias magnetic field is applied in the center of the ferrite 2 in a direction perpendicular to the circulator. A dielectric substrate 3 is disposed above the Y-shaped stripline structure 1. The Y-shaped belt line structure 1 is composed of a belt guide center and three ports uniformly distributed on the excircle of the belt guide center, two adjacent ports form an angle of 120 degrees with each other to form the Y-shaped belt line structure 1, and the belt guide is of a disc or ring structure.

The design method of the S, C, X waveband strip line junction circulator comprises the following steps:

step 1, determining a required transmission waveband according to an electromagnetic field equation and a quadratic curve matching technology to determine relevant parameters of a Y-shaped strip line structure 1, wherein the relevant parameters comprise t = 0.001-0.4 mm of the conduction band thickness, w = 0.01-0.9 mm of the conduction band width, t1= 0.1-0.8 mm of the thickness of a dielectric substrate 3, w1= 0.2-3.5 mm of the width of the dielectric substrate 3, and the relative dielectric constant of the dielectric substrate 3

=10（2.1~30）。

Step 2, designing ferrite junctions, and determining the relative dielectric constant of the ferrite 2 material in a high-field working state from a high-field gyromagnetic device working interval

=14 (2.1-30) and saturation magnetic field strength 4

=2500~5200Guass，

=50

And determining the radius R = 0.15-5 mm and the height h = 0.1-0.8 mm of the ferrite 2.

And 3, calculating the internal junction impedance and relevant parameters of the external bias magnetic field and the quadratic curve matching according to the electromagnetic field equation based on the step 1 and the step 2, determining the inner radius R1= 0.1-2.5 mm and the outer radius R2= 0.2-3.5 mm of the conduction band of the central circular ring of the strip line and the external bias magnetic field of the ferrite 2 under the condition of good transmission performance, and adjusting the parameters to obtain good transmission performance (see figure 4). Meanwhile, the radius R2= 0.2-2.5 mm of the strip line central disc conduction band is determined based on the step 1 and the step 2 (see figure 2). The circulator obtained in the embodiment has a height of 0.25 to 3mm (the height of the upper and lower ferrites is 0.15 to 0.7mm, and the height of the dielectric substrate 3 is 0.15 to 0.8 mm).

Testing the S, C, X wave band line junction circulator to obtain S parameter and S₂₁Parameters, and port impedance, and plotted as a curve (see fig. 6, 7, and 8). As can be seen from FIGS. 6 and 7, the circulator of the embodiment achieves 20dB isolation in the range from 9.61GHz to 10.3GHz, the return loss is less than-20 dB, and the insertion loss is less than 0.54dB in the range from 9.4 GHz to 11.3 GHz. As can be seen from fig. 8, the impedance of the circulator port of this embodiment varies smoothly in the entire X-band, which is about 22.8

And convenience is provided for subsequent impedance matching.

Examples 2 to 6 differ from example 1 in that: the method also comprises a step 4 of improving the conduction band of the Y-shaped strip line structure 1 designed in the

steps

1, 2 and 3.

Example 2

As shown in fig. 9 and 10, the circulator of this embodiment is formed by making an equilateral triangle cut on the inner circle of the circular conduction band, i.e. forming a groove with an equilateral triangle section on the inner circle surface of the circular conduction band. The number of the grooves is three, and the central line of each groove is positioned on a vertical line from the circle center of the conduction band to the port of the conduction band end.

Example 3

As shown in fig. 11 and 12, the circulator of this embodiment is formed with three evenly distributed equilateral triangular grooves on the inner circular surface of the circular conduction band, and the center line of the groove forms an angle of 60 ° with the vertical line from the center of the conduction band to the end port of the conduction band.

Example 4

As shown in fig. 13 and 14, in the circulator of this embodiment, an equilateral triangle cut angle is added to the outer ring of the annular conduction band, that is, three protrusions with equilateral triangle cross section are formed on the outer ring surface of the annular conduction band, and the center line of each protrusion forms an included angle of 60 ° with the vertical line from the center of the conduction band to the port of the conduction band end.

Example 5

As shown in fig. 15 and 16, in the circulator of this embodiment, an equilateral triangle cut angle is made on the inner ring of the circular conduction band, the center line of the equilateral triangle cut angle is located on the vertical line from the center of the conduction band to the port of the strip end, and an included angle of 60 ° is formed between the center line of the equilateral triangle cut angle and the vertical line from the center of the conduction band to the port of the strip end. Thus, three grooves with equilateral triangle sections are formed on the inner circular surface of the circular conduction band, three bulges with equilateral triangle sections are formed on the outer circular surface, the grooves and the bulges are distributed at intervals, and the adjacent grooves and the bulges are separated by 60 degrees.

Example 6

As shown in fig. 17 and 18, in the circulator of the present embodiment, an equilateral triangle cut angle is made on the inner ring of the circular conduction band, and the center line of the equilateral triangle cut angle forms an angle of 60 ° with the vertical line from the center of the conduction band to the port of the strip end, and an equilateral triangle cut angle is added on the outer ring, and the center line of the equilateral triangle cut angle forms an angle of 60 ° with the vertical line from the center of the conduction band to the port of the strip end. Thus, three grooves with equilateral triangle sections are formed on the inner circular surface of the circular conduction band, three protrusions with equilateral triangle sections are formed on the outer circular surface, and the positions of the grooves and the protrusions are overlapped and are arranged at an angle of 60 degrees with the port.

The S parameters of the circulators described in examples 2 to 6 were observed after fine-tuning the parameters of the circulators to determine the center outer radius R2=0.2 to 2.45mm, the inner radius R1=0.2 to 2.3mm and the distance between the perpendicular lines of the equilateral triangle of 0.08 to 1.1mm, and as a result, as shown in FIGS. 19 to 23, the standing wave and isolation of the circulators were significantly better than the forms without the addition of the chamfer,

the lowest point of the plug is reduced to below-30 dB from-26 dB, wherein part of the structure can be more below-40 dB, and the plug is insertedThe input loss is also improved to be within 0.35dB from 0.54dB, and the performance is better.

The above is the preferred embodiment of the invention, and it should be noted that: it will be apparent to those skilled in the art that the present invention can be practiced without departing from its spirit or essential characteristics. Corresponding modifications are made in the invention and are intended to be considered within the scope of the invention.

Claims

1. An S, C, X wave band line junction circulator is characterized in that: the device comprises a Y-shaped strip line structure used for transmitting line signals and ferrites respectively positioned on the upper side and the lower side of the Y-shaped strip line structure, wherein a bias magnetic field with a direction vertical to a circulator is applied to the center of each ferrite; the Y-shaped strip line structure is composed of a conduction band and three ports which are uniformly distributed on the excircle of the conduction band, and the conduction band is of a disc or ring structure.

2. The S, C, X waveband stripline junction circulator of claim 1, wherein: the ferrite is a cylinder, the two ferrites are arranged in a central symmetry mode about a dot center of a Y-shaped strip line structure, and the two ferrites are made of the same material, the same radius and the same thickness; the two adjacent ports form a Y-shaped belt line structure at an angle of 120 degrees.

3. The S, C, X waveband stripline junction circulator of claim 2, wherein: and a dielectric substrate is arranged above the Y-shaped strip line structure.

4. The S, C, X waveband stripline junction circulator of claim 1, wherein: the inner circular surface of the circular ring structure is provided with three grooves which are uniformly distributed, and the center lines of the grooves are positioned on the vertical line from the center of the conduction band to the port or form an included angle of 60 degrees with the vertical line.

5. The S, C, X waveband stripline junction circulator of claim 1 or claim 4, wherein: the excircle surface of the circular ring structure is provided with three bulges which are uniformly distributed, and the central line of each bulge and the vertical line from the circle center of the conduction band to the port form an included angle of 60 degrees.

6. The S, C, X-waveband stripline junction circulator of claim 5, wherein: the cross sections of the grooves and the bulges are all equilateral triangles.

7. The design method of the S, C, X waveband stripline junction circulator as claimed in any one of claims 1 to 6, comprising the following steps:

；

and 4, improving the conduction band of the Y-shaped strip line structure designed in the steps 1, 2 and 3, wherein three uniformly distributed grooves are formed in the inner circular surface of the circular conduction band, and/or three uniformly distributed bulges are formed in the outer circular surface of the circular conduction band.

8. The design method of the S, C, X waveband strip line junction circulator of claim 7, wherein in step 3, the radius R2 of the strip line center disc conduction band is determined based on step 1 and step 2.

9. The design method of the S, C, X waveband strip line junction circulator of claim 7, wherein the cross sections of the grooves and the protrusions are equilateral triangles.

10. The design method of the S, C, X waveband strip line junction circulator of claim 9, wherein the central line of the groove is located on the vertical line from the conduction band center to the port or forms an angle of 60 ° with the vertical line from the conduction band center to the port; the central line of the bulge and the vertical line from the center of the conduction band to the port form an included angle of 60 degrees.