CN106953149A

CN106953149A - Microwave isolator based on ferrite magnetic linkage

Info

Publication number: CN106953149A
Application number: CN201710236697.6A
Authority: CN
Inventors: 鞠成; 伍瑞新
Original assignee: Nanjing University
Current assignee: Nanjing University
Priority date: 2017-04-12
Filing date: 2017-04-12
Publication date: 2017-07-14
Anticipated expiration: 2037-04-12
Also published as: CN106953149B

Abstract

The invention discloses a kind of microwave isolator based on ferrite magnetic linkage, including some soft magnetic ferrite posts, and it is covered in the upper metallic plate and lower metallic plate of soft magnetic ferrite post upper and lower surface, some soft magnetic ferrite posts constitute an orthogonal array, orthogonal array is made up of the first linear array and the second linear array, two groups of linear arrays connect in end, between into 90 degree of angles；Two groups of linear arrays are placed in air ambient, and additional axialy offset magnetic field, magnetic direction added by two groups of linear arrays is opposite.The microwave isolator of the present invention has filter with low insertion loss, the high advantage of isolation, and has simple in construction, and handling ease is with low cost, it is easy to accomplish the integrated advantage with planar microwave circuit.

Description

Microwave isolator based on ferrite magnetic linkage

Technical field

The present invention relates to a kind of microwave isolator, specifically a kind of ferrite microwave isolator, more specifically one kind is based on The microwave isolator of ferrite magnetic linkage.

Background technology

In a communications system, in order to ensure the stability of signal source, it is necessary to which reflected signal is to signal when reducing signal transmission The isolator of the interference in source, wherein high-isolation is played a very important role.Between two stage power device, it is high performance every It is even more essential device from device.In recent years, with the development of microwave communication techniques, performance, volume to microwave isolator, Particularly Planar integration ability proposes higher requirement.The isolator of microwave section generally loads ferrite material using metal waveguide Expect to constitute, although be resistant to higher microwave power, but structure is typically complex, and is not easy to the collection of planar microwave circuit Into, it is impossible to meet requirement integrated to device in present microwave communication application.

The content of the invention

Goal of the invention：The problem of existing for above-mentioned prior art and deficiency, it is an object of the invention to provide a kind of structure Simply, it is easily achieved, the convenient and integrated high performance microwave isolator of planar circuit.

Technical scheme：For achieving the above object, the technical solution adopted by the present invention is：

A kind of microwave isolator based on ferrite magnetic linkage, including some soft magnetic ferrite posts, and it is covered in soft magnet The upper metallic plate of oxysome post upper and lower surface and lower metallic plate, some soft magnetic ferrite posts constitute an orthogonal array, orthogonal array Be made up of the first linear array and the second linear array, two groups of linear arrays connect in end, between into 90 degree of angles；Two groups of linear arrays It is placed in air ambient, additional axialy offset magnetic field, magnetic direction added by two groups of linear arrays is opposite；First linear array and the second line The angular bisector direction of array is parallel with electromagnetic wave incident direction.

Further, lower metallic plate is offered in through hole, through hole at soft magnetic ferrite post opposite position and is provided with to be soft Magnetic iron oxide scapus provides the permanent-magnet ferrite post in axialy offset magnetic field.

Further, the material of soft magnetic ferrite post is yttrium iron garnet ferrite, magnesium Mn ferrite or nickel-zinc ferrite.

Further, the material of permanent-magnet ferrite is strontium ferrite or barium ferrite.

Further, soft magnetic ferrite post is cylindrical shape.

Further, permanent-magnet ferrite post is cylindrical shape.

Operation principle：Sub-wavelength resonance plays key player in manual electromagnetic structure, can be with using sub-wavelength resonance Desired effective dielectric constant and magnetic conductivity is obtained, many novel phenomenons are produced.For dielectric cylinder linear array, when plane electricity When magnetic wave is incided on dielectric cylinder array (direction of an electric field is axial along cylinder), the scattered field of each dielectric cylinder is in space during resonance Phase Stacking or counteracting, the diffraction coefficient of ranks different on cylinder linear array produces influence, when the interval between cylinder is met During certain condition, it is possible to achieve the negative sense deflection of electromagnetic wave.And when cylinder is made up of Ferrite Material, due to the magnetic conductance of material There is the non-master diagonal element of non-zero in rate tensor, easily realize the nonreciprocal control to electromagnetic wave.Consider such ferrite circle Post linear array, when externally-applied magnetic field is axial along cylinder, it is possible to achieve the negative sense deflection of electromagnetic wave, and when the reversion of externally-applied magnetic field direction When, electromagnetic wave can be totally reflected, and the ferrite cylinder linear array under two kinds of bias states is mutually perpendicular to place, iron oxygen is utilized This non-electromagnetic propagation phenomenon that appears alternatively of body cylinder linear array, it is possible to achieve the one-way transmission of electromagnetic wave, builds isolator.

Beneficial effect：The present invention proposes a kind of mutually orthogonal ferrite column linear array embedded in parallel-plate waveguide system Microwave isolator.This isolator has filter with low insertion loss, the high advantage of isolation, and simple in construction, handling ease, low cost It is honest and clean, it is easy to accomplish integrated with planar microwave circuit.The micro- of different frequency range is can be designed that by changing the size of externally-applied magnetic field Isolator.

Brief description of the drawings

Fig. 1 is three-dimensional structure diagram of the invention.

In Fig. 1,1：Soft magnetic ferrite cylinder, metallic plate, 3 on 2：Lower metallic plate, 4：Permanent-magnet ferrite cylinder.

Fig. 2 is structural parameters schematic diagram of the invention.

Fig. 3 is operation principle schematic diagram of the present invention.

Fig. 4 is S parameter simulation result figure of the present invention when impressed field is 800Oe.

Fig. 5 is S parameter simulation result figure of the present invention when impressed field is 700Oe and 850Oe.

Embodiment

Structure Figure and specific embodiment below, the present invention is furture elucidated, it should be understood that these examples are merely to illustrate this Invention rather than limitation the scope of the present invention, after the present invention has been read, those skilled in the art are various to the present invention's The modification of the equivalent form of value falls within the application appended claims limited range.

Fig. 1 shows the 3-D solid structure of microwave isolator of the present invention.One kind that this example is provided is based on iron The microwave isolator of oxysome magnetic linkage.The two groups of magnetic of composition of soft magnetic ferrite cylinder 1 are single-stranded, including the first linear array and the second linear array Row, two linear arrays connect in end, between into 90 degree of angles, constitute a kind of orthogonal array.Soft magnetic ferrite can be with Using yttrium iron garnet ferrite, magnesium Mn ferrite or nickel-zinc ferrite.Cylinder upper and lower surface is provided with conductive metal layer (above and below i.e. Metallic plate 2,3), constitutes parallel-plate waveguide system, generally metallic aluminium.In the corresponding positions of soft magnetic ferrite cylinder 1 on lower metallic plate 3 Through hole is equipped with, for placing the permanent-magnet ferrite cylinder 4 for providing bias-field, its material uses strontium ferrite or barium ferrite.

Fig. 2 shows the two-dimensional structure parameter schematic diagram of the embodiment of emulation testing of the present invention.In the present embodiment, soft magnetism Ferrite cylinder linear array is placed under air background, soft magnetic ferrite cylindrical radius r=5mm, array lattice constant d= 20.5mm, the cylinder of corner two is apartYttrium iron garnet ferrite saturation magnetization 4* π * Ms= 1884Gauss, relative dielectric constant ε=15.26.Externally-applied magnetic field size added by array is 800Oe, and the first linear array (1) is added Inwards, the vertical paper of magnetic direction is outside added by the second linear array (2) for the vertical paper of magnetic direction.

Fig. 3 a-c show the principle schematic used by the present invention.For ferrite cylinder array, it is axially added additional The direction in magnetic field and the angle change of electromagnetic wave incident all can produce influence to its diffraction characteristic, produce nonreciprocal electromagnetic propagation Phenomenon.Such as Fig. 3 (a), when the vertical paper of externally-applied magnetic field is outside, when plane wave is with 45 degree of angles incidence, it can almost be totally reflected, with- , then can be along the outgoing of negative refraction direction when 45° angle is incident；When the vertical paper of externally-applied magnetic field is inside, plane wave is incident with 45° angle When, can along the outgoing of negative refraction direction, and with -45° angle it is incident when, can be reflected.Such as Fig. 3 (b), (c), when two row ferrite cylinders During the mutually orthogonal placement of linear array, when plane wave is along orthogonal array inner interweaver propagated forward, plane wave successively by reflection, The step of negative refraction two can be by ferrite array, and during plane wave backpropagation, electromagnetic wave will be directly reflected, it is impossible to pass through Ferrite array, reverse isolation before being formed.

The S parameter simulation result of microwave isolator when Fig. 4 shows externally-applied magnetic field 800Oe.Simulation result shows, isolator Centre frequency 8.95GHz, preceding reverse transfer difference -35dB, insertion loss is less than 4dB, and there is this isolator good forward direction to pass Defeated and reverse isolation characteristic.

Fig. 5 shows that externally-applied magnetic field is 700Oe, the S parameter simulation result of microwave isolator during 850Oe.Externally-applied magnetic field is During 700Oe, isolator centre frequency is 8.81GHz, and preceding reverse transfer difference -40dB, insertion loss is less than 4dB；Externally-applied magnetic field During for 850Oe, isolator centre frequency is 9.05GHz, and preceding reverse transfer difference -35dB, insertion loss is less than 4dB.Therefore, may be used With the size by changing added permanent-magnet ferrite Surface field, to meet the isolator design demand of different frequency.

Claims

1. a kind of microwave isolator based on ferrite magnetic linkage, it is characterised in that：Including some soft magnetic ferrite posts, and covering In the upper metallic plate and lower metallic plate of soft magnetic ferrite post upper and lower surface, some soft magnetic ferrite posts constitute a right angle battle array Row, the orthogonal array is made up of the first linear array and the second linear array, and two groups of linear arrays connect in end, between into 90 degree Angle；Two groups of linear arrays are placed in air ambient, and additional axialy offset magnetic field, magnetic direction added by two groups of linear arrays is opposite；The One linear array is parallel with electromagnetic wave incident direction with the angular bisector direction of the second linear array.

2. microwave isolator according to claim 1, it is characterised in that：The lower metallic plate is relative in soft magnetic ferrite post Answer and through hole is offered at position, provided with the permanent-magnet ferrite that axialy offset magnetic field is provided for soft magnetic ferrite post in the through hole Post.

3. microwave isolator according to claim 1, it is characterised in that the material of the soft magnetic ferrite post is yttrium iron stone Garnet ferrite, magnesium Mn ferrite or nickel-zinc ferrite.

4. microwave isolator according to claim 2, it is characterised in that the material of the permanent-magnet ferrite is strontium ferrite Or barium ferrite.

5. microwave isolator according to claim 1, it is characterised in that the soft magnetic ferrite post is cylindrical shape.

6. microwave isolator according to claim 2, it is characterised in that the permanent-magnet ferrite post is cylindrical shape.