阅读说明：本技术 基于m型六角铁氧体纳米线阵列的自偏置毫米波环行器 (Self-biased millimeter wave circulator based on M-shaped hexagonal ferrite nanowire array ) 是由 韩满贵 卢宪强 刘孝波 于 2019-08-23 设计创作，主要内容包括：基于M型六角铁氧体纳米线阵列的自偏置毫米波环行器,属于微波铁氧体器件技术领域。该环行器包括介质层、铁氧体、中心结导体、微带Y结匹配线、50Ω微带馈线和接地导体面,介质层为六棱柱形状,铁氧体为圆片状、位于介质层中心,中心结导体为圆形贴片、位于铁氧体的正上方,匹配线采用两段式Y型微带线,馈线也采用微带线形式,其特征在于,所述铁氧体为圆片状的M型六角铁氧体纳米线阵列,且嵌入介质层的上表面内。本发明提供的一种基于M型六角铁氧体纳米线阵列的自偏置毫米波环行器,工作于毫米波频段且具有自偏置功能,无需外加偏置永磁体即可正常工作,具有体积小、重量轻、隔离度高、插入损耗低等特点。(A self-biased millimeter wave circulator based on an M-shaped hexaferrite nanowire array belongs to the technical field of microwave ferrite devices. The circulator comprises a dielectric layer, a ferrite, a center junction conductor, a micro-strip Y-junction matched line, a 50 omega micro-strip feeder line and a grounding conductor surface, wherein the dielectric layer is in a hexagonal prism shape, the ferrite is in a circular sheet shape and is positioned in the center of the dielectric layer, the center junction conductor is a circular patch and is positioned right above the ferrite, the matched line adopts a two-section Y-shaped micro-strip line, and the feeder line also adopts a micro-strip line form. The self-biased millimeter wave circulator based on the M-type hexagonal ferrite nanowire array provided by the invention works in a millimeter wave frequency band, has a self-biasing function, can normally work without an additional biased permanent magnet, and has the characteristics of small volume, light weight, high isolation degree, low insertion loss and the like.)

1. The self-biasing millimeter wave circulator based on the M-shaped hexagonal ferrite nanowire array comprises a dielectric layer (1), a ferrite (2), a central junction conductor (3), a microstrip Y-junction matched line (4), a microstrip feeder line (5) and a ground conductor surface (6), wherein the dielectric layer (1) is in a hexagonal prism shape, the ferrite (2) is located in the center of the dielectric layer, the central junction conductor (3) is a circular patch and is located right above the ferrite, and the self-biasing millimeter wave circulator is characterized in that the ferrite (2) is a disk-shaped M-shaped hexagonal ferrite nanowire array and is embedded into the upper surface of the dielectric layer.

2. The M-type hexaferrite nanowire array-based self-biased millimeter wave circulator of claim 1, wherein the ferrite is an M-type barium ferrite or an M-type strontium ferrite nanowire array with a thickness of 30-70 μ ι η; the array pitch of the nano-wire arrays is 10 nm-60 nm, the length of a single nano-wire is 30 μm-70 μm, and the diameter is 10 nm-60 nm.

3. the M-type hexaferrite nanowire array-based self-biased millimeter wave circulator of claim 1, wherein the diameter of the ferrite is 1.2 times the diameter of the central junction conductor.

4. The M-type hexaferrite nanowire array-based self-biased millimeter wave circulator of claim 1, wherein in the microstrip Y-junction match line, a length of a first segment of microstrip line is equal to a difference between a radius of the ferrite and a radius of the central junction conductor.

5. the M-type hexaferrite nanowire array-based self-biased millimeter wave circulator of claim 1, wherein the dielectric layer is in a hexagonal prism shape and is made of polytetrafluoroethylene.

Technical Field

The invention belongs to the technical field of microwave ferrite devices, and particularly relates to a self-biased millimeter wave circulator based on an M-shaped hexagonal ferrite nanowire array, which is applied to a radio frequency signal receiving and transmitting module of a microwave system, particularly a millimeter wave radar.

Background

the circulator is one of the most important elements in the field of microwave devices, and generally has three ports, and since ferrite is placed inside the circulator, the three ports have the characteristic of non-reciprocity, electromagnetic wave signals can realize the circulation transmission along a certain specific direction (such as clockwise or counterclockwise), and signals cannot be transmitted along the reverse direction, so that the characteristics of specific port transmission and isolation are realized. Due to the characteristics of the circulator, the circulator is widely applied to a signal transceiving module of a microwave system, realizes the unification of transceiving antennas, thoroughly solves the problem that two pairs of antennas are needed to be respectively used for receiving and transmitting electromagnetic wave signals, and greatly saves the cost and the volume of a communication system.

One of the most important application scenarios for circulators is radar, which is one of the most common applications for microwave systems. The radar may be classified into an over-the-horizon radar, a centimeter wave radar, and a millimeter wave radar according to the operating frequency band. With the rapid development of the space radar technology, the millimeter wave radar has a very wide prospect, works in a millimeter wave frequency band, and has the characteristics of high resolution, less interference, small volume and light weight. Millimeter wave radar is the high accuracy sensor of measuring measured object relative distance, relative speed, position, and earlier was applied to the military field, and in recent years, along with the development and the progress of radar technique, millimeter wave radar began to be applied to a plurality of fields such as unmanned driving, unmanned aerial vehicle, intelligent transportation. However, the requirement of the millimeter wave radar on microwave devices is high, for the active phased array millimeter wave radar, the number of antenna units is as many as several tens of thousands, the transceiver module of each unit is independent, and in order to reduce the number of antenna units, the transceiver antennas must be unified, so that each unit needs to be provided with a circulator. Therefore, the number of circulators required by one active phased array millimeter wave radar is up to tens of thousands, the size of the circulator is required to be in millimeter level, and the circulator has higher requirements on the volume, the quality and the working frequency band of the microwave device.

in recent years, circulators are continuously developing towards miniaturization and light weight, and a Self-Biased Microstrip circulator is proposed by a few scholars, and a Self-Biased circulator Based on a Ferrite Barium continuous film is proposed by Peng Bin et al (Peng Bin, et al, "Self-Biased Microstrip Circuit Based on Barium Ferrite Thin Films for Monolithic microwave Integrated circuits," IEEE Transactions on Magnetics 47.6(2011):1674-1677), wherein the whole Ferrite Barium film is deposited on a sapphire substrate, so that the dielectric loss and the magnetic loss are high, the performance is poor, the insertion loss is 1.2dB, and the bandwidth is only 0.1 GHz. The circulator designed by the bear fly et al (patent number CN206163671U) adopts a waveguide structure, and the upper and lower parts of the ferrite are respectively provided with a metal matching block, so that the circulator has large volume and heavy weight and cannot be applied to a microstrip circuit system. The ferrite micro-strip circulator proposed by cheng et al (patent number CN102386469A) needs to be added with a cylindrical bias permanent magnet with a thickness of 0.8mm and a radius of 3.4mm, has no self-bias function, works in an X-band, and has the defects of large volume, heavy weight, low working frequency band and the like. Therefore, by adopting the traditional block ferrite or ferrite film, the circulator can not realize the self-bias function, or has low working frequency and can not reach the millimeter wave frequency band, or has poor performance and high insertion loss.

Disclosure of Invention

The invention aims to solve the technical problem of providing a self-biased millimeter wave circulator with low insertion loss, small size and light weight based on an M-type hexagonal ferrite nanowire array.

The technical scheme adopted by the invention for solving the technical problems is as follows:

The self-biasing millimeter wave circulator based on the M-shaped hexagonal ferrite nanowire array comprises a dielectric layer (1), a ferrite (2), a central junction conductor (3), a microstrip Y-junction matched line (4), a 50 omega microstrip feeder line (5) and a ground conductor surface (6), wherein the dielectric layer (1) is in a hexagonal prism shape, the ferrite (2) is in a circular sheet shape and is located in the center of the dielectric layer, the central junction conductor (3) is a circular patch and is located right above the ferrite, the matched line (4) adopts a two-section Y-shaped microstrip line, and the feeder line (5) also adopts a microstrip line form, and is characterized in that the ferrite (2) is a circular sheet-shaped M-shaped hexagonal ferrite nanowire array and is embedded into the upper surface of the dielectric layer.

Further, the ferrite (2) is M-type barium ferrite (BaFe)₁₂O₁₉) Or M type strontium ferrite (SrFe)₁₂O₁₉) Array of nanowires, thicknessThe degree is 30-70 μm, and the preparation is carried out by adopting an electron beam lithography process or a template method; the array pitch of the nano-wire arrays is 10 nm-60 nm, the length of a single nano-wire is 30 μm-70 μm, and the diameter is 10 nm-60 nm.

Further, the diameter of the ferrite is 1.2 times of the diameter of the central junction conductor.

Further, in the microstrip Y-junction matching line, the length of the first section of microstrip line is equal to the difference between the radius of the ferrite and the radius of the central junction conductor.

Furthermore, the dielectric layer (1) is in a hexagonal prism shape, made of polytetrafluoroethylene and twice as thick as the M-type hexagonal ferrite nanowire array layer (30-70 microns), a circular groove is dug in the center of the dielectric layer and used for placing a circular sheet-shaped M-type hexagonal ferrite nanowire array, and the size of the groove is completely matched with that of the M-type hexagonal ferrite nanowire array layer.

Further, the central junction conductor (3) is a circular patch and is made by gold coating etching.

furthermore, the circulator is of a Y-shaped junction structure and is provided with three input and output ports, and every two ports are 120 degrees. The impedance matching line adopts a two-section structure, the first section is used as the transition between the central junction conductor and the output end, and the second section is a quarter-wavelength impedance converter which plays a role in impedance matching; the feed line adopts a 50 omega microstrip line, which is convenient for being directly integrated with a microstrip circuit.

in the self-biased millimeter wave circulator provided by the invention, the ferrite (2) adopts M-type hexagonal ferrite (M-type barium ferrite BaFe)₁₂O₁₉or M type strontium ferrite SrFe₁₂O₁₉) The magnetic spectrum and the magnetic hysteresis loop of the nanowire array are calculated by adopting micro-magnetic simulation software, and the dielectric constant of the nanowire array is calculated by Spiegel et al (Spiegel, Judith, et al. 'Permitity Model for Ferromagnetic Nanowired substrates.' IEEE Microwave&Wire Components Letters 17.7(2007): 492-.

The invention adopts three-dimensional electromagnetic simulation software to model and simulate the designed circulator to obtain the performance parameters of the circulator.

The invention has the beneficial effects that:

1. The self-biased millimeter wave circulator based on the M-type hexagonal ferrite nanowire array provided by the invention works in a millimeter wave frequency band, has a self-biasing function, can normally work without an additional biased permanent magnet, and has the characteristics of small volume, light weight, high isolation degree, low insertion loss and the like.

2. The self-biased millimeter wave circulator provided by the embodiment of the invention realizes normal work under the condition of not adding a bias magnet, and the working frequency band is 42.95 GHz-43.95 GHz; and at the center frequency, the isolation is more than 40dB, and the insertion loss is less than 0.5 dB.

Drawings

FIG. 1 is a schematic structural diagram of a self-biased millimeter wave circulator based on an M-type hexaferrite nanowire array according to the present invention; the structure comprises a dielectric layer 1, a 2-M type hexagonal ferrite nanowire array, a 3-center junction conductor, a 4-microstrip matching line, a 5-50 omega microstrip feeder line and a 6-grounding conductor plane, wherein the dielectric layer is a metal layer;

FIG. 2 is a hysteresis chart of the M-type barium ferrite nanowire array obtained by changing the diameter, the spacing and the length respectively by using the M-type barium ferrite nanowire array with the diameter of 50nm, the spacing of 20nm and the length of 500nm as original parameters, and data is calculated by micro-magnetic simulation software; wherein, FIG. 2a is a magnetic hysteresis loop diagram of M-type barium ferrite nanowire arrays with diameters of 10nm, 50nm and 60nm respectively, FIG. 2b is a magnetic hysteresis loop diagram of M-type barium ferrite nanowire arrays with distances of 10nm, 20nm and 60nm respectively, and FIG. 2c is a hysteresis loop diagram of M-type barium ferrite nanowire arrays with lengths of 150nm, 500nm and 800nm respectively; as can be seen from the figure, the remanence ratio of the M-type barium ferrite nanowire array is close to 1, the relative change of a magnetic hysteresis loop along with the diameter, the interval and the length is very small, and the remanence ratio indicates that the M-type barium ferrite nanowire array has good self-bias effect and can be used in a self-bias circulator;

FIG. 3 is a magnetic spectrum diagram of the M-type barium ferrite nanowire array obtained by changing the diameter, the spacing and the length respectively by using the M-type barium ferrite nanowire array with the diameter of 50nm, the spacing of 20nm and the length of 500nm as original parameters, wherein the magnetic spectrum diagram comprises a real part curve and an imaginary part curve of the magnetic conductivity, and data are obtained by calculation of micro-magnetic simulation software; wherein, FIG. 3a is a magnetic spectrum diagram of M-type barium ferrite nanowire arrays with diameters of 10nm, 50nm and 60nm respectively, FIG. 3b is a magnetic spectrum diagram of M-type barium ferrite nanowire arrays with distances of 10nm, 20nm and 60nm respectively, and FIG. 3c is a magnetic spectrum diagram of M-type barium ferrite nanowire arrays with lengths of 150nm, 500nm and 800nm respectively; it can be seen from the figure that the resonance frequency of the magnetic conductivity imaginary part of the M-type barium ferrite nanowire array is above 49GHz, the relative change of the magnetic spectrum with the diameter, the spacing and the length is small, the resonance frequency is as high as 49GHz, and the M-type barium ferrite nanowire array is in the millimeter wave frequency band, which indicates that the M-type barium ferrite nanowire array can be used in a millimeter wave circulator;

FIG. 4 is a dielectric constant spectrogram of an M-type barium ferrite nanowire array obtained by changing the diameter, the spacing and the length respectively by using the M-type barium ferrite nanowire array with the diameter of 50nm, the spacing of 20nm and the length of 500nm as original parameters, including a real part curve and an imaginary part curve of the dielectric constant, and data obtained by calculating a model of the effective dielectric constant of the nanowire array; wherein, fig. 4a is a dielectric constant spectrogram of an M-type barium ferrite nanowire array with diameters of 10nm, 50nm and 60nm respectively, fig. 4b is a dielectric constant spectrogram of an M-type barium ferrite nanowire array with distances of 10nm, 20nm and 60nm respectively, and fig. 4c is a dielectric constant spectrogram of M-type barium ferrite nanowire arrays with different lengths; as can be seen from the figure, the real part of the dielectric constant of the M-type barium ferrite nanowire array is constantly equal to 1, the imaginary part is very small and close to 0, the change of the dielectric constant along with the diameter and the distance is very small, and the dielectric constant does not change along with the change of the length, which shows that the dielectric loss of the M-type barium ferrite nanowire array is very small and is suitable for the design of a low insertion loss circulator;

FIG. 5 is a graph of simulation results of return loss of a self-biased millimeter wave circulator based on an M-type barium ferrite nanowire array according to an embodiment;

FIG. 6 is a graph of simulation results of isolation of a self-biased millimeter wave circulator based on M-type barium ferrite nanowire arrays according to an embodiment;

FIG. 7 is a graph of simulation results of insertion loss of a self-biased millimeter wave circulator based on M-type barium ferrite nanowire arrays according to an embodiment;

FIG. 8 is a graph showing simulation effects of electromagnetic energy transmission of a self-biased millimeter wave circulator based on an M-type barium ferrite nanowire array according to an embodiment.

Detailed Description

The technical scheme of the invention is detailed below by combining the accompanying drawings and the embodiment.

the invention designs a self-biased millimeter wave circulator based on the M-shaped hexagonal ferrite nanowire array on the premise of obtaining the electromagnetic parameters of the M-shaped hexagonal ferrite nanowire array by using micro-magnetic simulation software and a magnetic material nanowire array effective dielectric constant model, and performs modeling simulation by using three-dimensional electromagnetic simulation software to obtain the performance parameters of the circulator.

FIG. 1 is a top view and a cross-sectional view of a self-biased millimeter wave circulator based on M-type hexaferrite nanowire arrays according to the present invention; the circulator comprises a dielectric layer 1, ferrite 2, a central junction conductor 3, a microstrip Y-junction matched line 4, a 50 omega microstrip feeder line 5 and a grounding conductor surface 6, wherein the dielectric layer is in a hexagonal prism shape, and a circular groove is dug in the center of the dielectric layer and used for placing a circular sheet-shaped ferrite nanowire array layer; the ferrite adopts a disk-shaped M-shaped hexagonal ferrite nanowire array, is placed in a groove of the dielectric layer and is positioned right below the central junction conductor; the central junction conductor adopts a circular patch and is placed right above the ferrite; the circulator adopts a Y-shaped junction circulator structure and a three-input-output port structure, the three ports are 120 degrees, and the impedance matching line adopts two sections of microstrip lines.