CN111540992B

CN111540992B - Miniaturized circulator circuit and circulator composed of same

Info

Publication number: CN111540992B
Application number: CN202010666369.1A
Authority: CN
Inventors: 陈宁; 李扬兴; 高男; 刘红; 罗治涛; 孙静; 王玉龙
Original assignee: CETC 9 Research Institute
Current assignee: CETC 9 Research Institute
Priority date: 2020-07-13
Filing date: 2020-07-13
Publication date: 2020-10-09
Anticipated expiration: 2040-07-13
Also published as: CN111540992A

Abstract

The invention discloses a miniaturized circulator circuit, which belongs to the technical field of microwave components and comprises a nonreciprocal junction circuit positioned in the middle and a matching circuit positioned at the periphery, wherein the matching circuit is composed of at least two transmission lines and a connecting node which are matched with each other, the transmission lines are connected with the connecting node, and the length of the transmission lines is not more than 1/8; the invention also discloses a miniaturized circulator, which comprises a permanent magnet, an insulator, a ferrite substrate, the circuit and a base, wherein the ferrite substrate is arranged above the base, the permanent magnet and the circuit are arranged on the ferrite substrate, and the insulator is arranged between the permanent magnet and the ferrite substrate; by using the circulator circuit structure of the invention, the low impedance of a wideband circulator (less than or equal to 60 percent of relative bandwidth) can be matched to 50 omega, and the size of the matching circuit can be shortened by more than 1/2 compared with the size of the conventional 1/4 wavelength matching circuit, thereby smoothly realizing the miniaturization requirement of the circulator.

Description

Miniaturized circulator circuit and circulator composed of same

Technical Field

The invention relates to the technical field of microwave components, in particular to a miniaturized circulator circuit and a circulator consisting of the same.

Background

The circulator has the characteristic of unidirectional transmission of microwave signals, is generally used in a microwave circuit system, and plays the roles of co-frequency simultaneous duplex, impedance matching and the like.

The circulator generally comprises a permanent magnet, an insulator, a ferrite substrate, a circuit and a base, and the typical structure is shown in fig. 1.

The existing circulator has a large volume, such as: the plane size of a Ku wave band (17.7-19.7 GHz) is 4.5mm multiplied by 4.5mm, and the requirement of a system for 3mm multiplied by 3mm cannot be met; the plane size of the X wave band (8-12 GHz) is 6mm multiplied by 6mm, and the requirement of a system of 4mm multiplied by 4mm cannot be met. The reason is that the bandwidth of the existing circulator needs to be widened, a matcher needs to be arranged in the circuit, the length size of the matcher needs to reach 1/4 wavelength generally for the relative bandwidth to meet the use requirement, the size of the matcher directly influences the size of the circulator, and the size of the matcher in the existing circulator circuit is large, so that the miniaturization of the plane size of the circulator is limited.

There is therefore a need in the art to design a new architecture of miniaturized circulator circuit to reduce the circulator size.

Disclosure of Invention

It is an object of the present invention to provide a miniaturized circulator circuit to solve the above-mentioned problems of the circulator.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows: a miniaturized circulator circuit comprising a non-reciprocal junction circuit and at least three matching circuits, said at least three matching circuits being distributed around said non-reciprocal junction circuit, characterized in that: each matching circuit is composed of at least two transmission lines and a connecting node which are matched with each other, the transmission lines are connected with the connecting node, and the length of each transmission line is not more than 1/8;

as a preferred technical scheme: the electromagnetic fields between the transmission lines are coupled to each other through the connection nodes.

The invention utilizes the difference of amplitude and phase of electromagnetic fields at the coupling position of two (or more) transmission lines with the length not more than 1/8 wavelengths and a non-reciprocal junction circuit, and the electromagnetic field after coupling transition is matched with a port transmission line through the coupling of the two (or more) transmission lines and the interaction of a connecting node. The matching circuit of the invention greatly reduces the volume, and the obtained echo loss energy reaches or is superior to the effect of an 1/4 wavelength matcher.

As a preferred technical scheme: the transmission line adopts a bent structure, so that the size of the matching circuit can be shortened to 1/3 of the original matching circuit.

As a preferred technical scheme: the area of the connecting node is 0.0025mm²-4mm²。

The second purpose of the invention is to provide a miniaturized circulator, which comprises a permanent magnet, an insulator, a ferrite substrate, a base and the miniaturized circulator circuit, wherein the ferrite substrate is arranged above the base, the permanent magnet and the miniaturized circulator circuit are arranged on the ferrite substrate, and the insulator is arranged between the permanent magnet and the ferrite substrate.

The miniaturized circulator circuit keeps the nonreciprocal junction circuit unchanged, and mainly innovates a matching circuit part.

Compared with the prior art, the invention has the advantages that: the circuit structure of the miniaturized circulator can match the low impedance of the circulator with a wide frequency band (less than or equal to 60 percent of relative bandwidth) to 50 omega, the transmission line can be shortened by more than 1/2 compared with the conventional 1/4 wavelength matching circuit, and the transmission line adopts a bent structure to shorten the size of the matching circuit to more than 1/4 of the original matching circuit, thereby smoothly realizing the miniaturization of the circulator to meet the requirement.

Drawings

FIG. 1 is a block diagram of a typical circulator of the prior art;

fig. 2 is a schematic diagram of a circulator circuit of embodiment 1;

FIG. 3 is a graph showing simulation results of the circulator of example 1;

FIG. 4 is a schematic diagram of the circuit configuration of the circulator of comparative example 1;

FIG. 5 is a graph showing simulation results of the circulator of comparative example 1;

fig. 6 is a schematic diagram of a circulator circuit of embodiment 2;

FIG. 7 is a graph showing simulation results of the circulator of example 2;

FIG. 8 is a schematic diagram of the circuit configuration of the circulator of comparative example 2;

fig. 9 is a graph of simulation results of the circulator of comparative example 2;

FIG. 10 is a schematic diagram showing the circuit configuration of the circulator according to embodiment 3;

FIG. 11 is a graph showing simulation results of the circulator of example 3;

FIG. 12 is a schematic diagram of the circuit configuration of the circulator of comparative example 3;

fig. 13 is a graph of simulation results of the circulator of comparative example 3.

In the figure: 1. a permanent magnet; 2. an insulator; 3. a ferrite substrate; 4. a base; 5. a circuit; 51. a non-reciprocal junction circuit; 52. a matching circuit; 521. a transmission line; 522. and connecting the nodes.

Detailed Description

The invention will be further explained with reference to the drawings.

Example 1:

ku band (17.7-19.7 GHz) circulator

Referring to fig. 1 and 2, the ferrite magnetic core comprises a permanent magnet 1, an insulator 2, a ferrite substrate 3, a circuit 5 and a base 4, wherein the ferrite substrate 3 is arranged above the base 4, the permanent magnet 1 and a circulator circuit 5 are arranged on the ferrite substrate 3, the insulator 2 is arranged between the permanent magnet 1 and the ferrite substrate 3, the circulator circuit 5 comprises a nonreciprocal junction circuit 51 positioned in the middle and three matching circuits 52 positioned at the periphery, and the matching circuits 52 comprise two transmission lines 521 which are matched with each other and have the length of 0.52mm and one matching circuit 52 with the area of 0.021mm²A connection node 522, wherein the two transmission lines 521 are connected with the connection node 522;

the plane size of the circulator of the embodiment is 3mm multiplied by 3mm, the simulation result of the circulator at the frequency of 17.7 GHz-19.7 GHz is shown in FIG. 3, and the return loss of the three ports is smaller than-15.24 dB as can be seen from FIG. 3;

comparative example 1

Referring to fig. 4, the present comparative example is similar to example 1 in that the matching circuit 52 is formed by a transmission line having a length of 0.8mm, the planar dimensions of the circulator are 4.5mm × 4.5mm, and the rest is the same as example 1; the simulation results of the circulator of the comparative example at the frequencies of 17.7 GHz-19.7 GHz are shown in FIG. 5, and the return loss of the three ports is smaller than-14.1 dB as can be seen from FIG. 5.

Compared with the prior circulator, the circulator of the matcher consisting of two or more transmission lines matched with each other and a connection node with a larger area is reduced by half, and the return loss is better than that of the prior structure.

Example 2:

x-band (8-12 GHz) circulator

Referring to fig. 6, in comparison with example 1, the matching circuit 52 of the present comparative example is composed of two transmission lines 521 having a length of 0.82mm and an area of 0.104mm which are fitted to each other²The connection node 522 is formed, the plane size of the circulator of the embodiment is 4mm × 4mm, the rest is the same as that of the embodiment 1, the simulation result of the circulator of the embodiment at the frequency of 8-12 GHz is shown in FIG. 7, and the return loss of the three ports is smaller than-15.5 dB as can be seen from FIG. 7.

Comparative example 2

Referring to fig. 8, the matching circuit 52 is formed by a transmission line with a length of 1.1mm, the planar size of the circulator is 6mm × 6mm, and the rest is the same as that of embodiment 2; the simulation result of the circulator of the comparative example at the frequency of 8-12 GHz is shown in FIG. 9, and it can be seen from FIG. 9 that the return loss of the three ports is less than-15.3 dB.

Compared with the prior circulator, the circulator of the invention, which adopts the matcher consisting of two or more transmission lines and connecting nodes which are matched with each other, has the advantages that the volume is reduced by half, and simultaneously, the return loss is better than that of the prior structure.

Example 3:

920-plus 960MHz frequency band circulator

Referring to fig. 10, in comparison with embodiment 1, the matching circuit 52 is composed of three transmission lines 521 of 2.06mm in length and 0.205mm in area²The connection node 522 is formed, the planar size of the circulator of this embodiment is 10mm × 10mm, the rest is the same as that of embodiment 1, the simulation result of the circulator of this embodiment at the frequency of 920-960MHz is shown in FIG. 11, and as can be seen from FIG. 11, the return loss of the three ports is smaller than-15.26 dB.

Comparative example 3

Referring to fig. 12, the matching circuit 52 is formed by a transmission line with a length of 1.8mm, the planar size of the circulator is 14mm × 14mm, and the rest is the same as that of embodiment 3; the simulation results of the circulator of the present comparative example at the frequency of 920-960MHz are shown in FIG. 13, and it can be seen from FIG. 13 that the return loss of all three ports is less than-12.62 dB.

Compared with the prior circulator, the circulator of the invention which adopts the matcher consisting of three or more transmission lines and connecting nodes which are matched with each other has the advantages that the volume is reduced by half, and simultaneously, the return loss is better than that of the prior structure.

It should be noted that, in the above three embodiments, three matching circuits are taken as an example, and of course, circulators with the remaining number of matching circuits are also suitable for structural improvement of the present invention. In addition, the three embodiments of the present invention take a microstrip circulator as an example, and a circulator with a strip line and a coaxial structure and an isolator manufactured by using the circulator are also applicable.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. A miniaturized circulator circuit comprising a non-reciprocal junction circuit and at least three matching circuits, said at least three matching circuits being distributed around said non-reciprocal junction circuit, characterized in that: each matching circuit is composed of at least two transmission lines and a connecting node which are matched with each other, the transmission lines are connected with the connecting node, and the length of each transmission line is not more than 1/8; the nonreciprocal circuit is connected with at least two transmission lines of each matching circuit, the at least two transmission lines are respectively connected to different positions of the nonreciprocal circuit, and the connection nodes are connected with ports.

2. The miniaturized circulator circuit of claim 1 wherein: the transmission line adopts a bending structure.

3. The miniaturized circulator circuit of claim 1 wherein: the electromagnetic fields between the transmission lines are coupled to each other through the connection nodes.

4. The miniaturized circulator circuit of claim 1 wherein: the area of the connecting node is 0.0025mm²-4mm²。

5. The utility model provides a miniaturized circulator, includes permanent magnet, insulator, ferrite substrate, circuit and base, wherein, the base top sets up the ferrite substrate, the upper surface of ferrite substrate sets gradually circuit, insulator and permanent magnet from supreme down, its characterized in that: the circuit employs the miniaturized circulator circuit of any one of claims 1-4.