阅读说明：本技术 一种用于金刚石nv色心微波磁场测量的微波耦合器 (Microwave coupler for measuring NV color center microwave magnetic field of diamond ) 是由 孙悦 马菁汀 齐文超 唐倩 于 2019-09-05 设计创作，主要内容包括：本发明公开了一种用于金刚石NV色心微波磁场测量的微波耦合器,解决了微波场高密度集中问题。本发明包括微波腔体、传输波导(6)、微波馈线装配孔(4)和耦合窗口(5)。所述微波腔体包括方型筒(1)、腔体左侧盖(2)和腔体右侧盖(3)。所述的微波馈线装配孔(4)设置在方型筒(1)侧壁上的一端；所述的耦合窗口(5)设置在微波馈线装配孔(4)同一侧壁上的另一端,其位置设置在方形筒(1)微波场强最强的位置。所述传输波导(6)设置在微波腔体内,并将微波馈线装配孔(4)和耦合窗口(5)相连接。本发明实现了微波场高密度集中,为解决金刚石NV色心与微波相互作用问题提供了重要途径。(The invention discloses a microwave coupler for measuring a diamond NV color center microwave magnetic field, which solves the problem of high-density concentration of a microwave field. The microwave cavity comprises a microwave cavity body, a transmission waveguide (6), a microwave feeder line assembling hole (4) and a coupling window (5). The microwave cavity comprises a square cylinder (1), a cavity left side cover (2) and a cavity right side cover (3). The microwave feeder line assembling hole (4) is arranged at one end of the side wall of the square cylinder (1); the coupling window (5) is arranged at the other end of the same side wall of the microwave feeder line assembling hole (4), and the position of the coupling window is arranged at the position where the microwave field intensity of the square cylinder (1) is strongest. The transmission waveguide (6) is arranged in the microwave cavity and connects the microwave feeder line assembling hole (4) with the coupling window (5). The invention realizes high-density concentration of the microwave field and provides an important way for solving the problem of interaction between the NV color center of the diamond and the microwave.)

1. A microwave coupler for measuring a diamond NV color center microwave magnetic field is characterized in that: the microwave cavity comprises a microwave cavity body, a transmission waveguide (6), a microwave feeder line assembling hole (4) and a coupling window (5);

the microwave cavity comprises a square cylinder (1), a cavity left side cover (2) and a cavity right side cover (3); the cavity left side cover (2) and the cavity right side cover (3) are fixedly and hermetically arranged at the left end and the right end of the square cylinder (1);

the microwave feeder line assembling hole (4) is arranged at one end of the side wall of the square cylinder (1); the coupling window (5) is arranged at the other end of the same side wall of the microwave feeder line assembling hole (4), and the position of the coupling window is arranged at the position where the microwave field intensity of the square cylinder (1) is strongest;

the transmission waveguide (6) is arranged in the microwave cavity and connects the microwave feeder line assembling hole (4) with the coupling window (5).

2. The microwave coupler for the measurement of the NV color center microwave magnetic field of the diamond according to claim 1, wherein: the transmission waveguide (6) is rectangular, the caliber size of the transmission waveguide is determined by the working frequency, and the following relational expression is satisfied:

a < λ <2a, λ >2b, where a, b are the cross-sectional dimensions and λ is the operating wavelength.

3. The microwave coupler for the measurement of the NV color center microwave magnetic field of the diamond according to claim 1, wherein: the microwave field intensity is obtained through HFSS simulation of electromagnetic field simulation software.

4. The microwave coupler for the measurement of the NV color center microwave magnetic field of the diamond according to claim 1, wherein: the square cylinder (1) is made of an aluminum alloy material.

5. The microwave coupler for the measurement of the NV color center microwave magnetic field of the diamond according to claim 1, wherein: the length of the cavity square cylinder (1) is 300mm, and the wall thickness is 6 mm; the transmission waveguide (6) is rectangular, and the caliber is 76mm multiplied by 30 mm; the coupling window (5) is arranged in the middle of the cavity and has the thickness of 6 mm.

Technical Field

The invention relates to the field of microwave magnetic field measurement, in particular to a microwave coupler for measuring a diamond NV color center microwave magnetic field.

Background

In recent years, the detection performance of the traditional radar is close to the limit of classical physics, the system performance and the detection index of the radar are difficult to improve by the traditional means, and the increasingly complex military requirements cannot be met. With the continuous progress of quantum measurement and quantum regulation, it is becoming a research hotspot of scientists to improve the performance of radar by introducing quantum technology. At present, the quantum detection technology has the characteristics of long detection distance, low noise, high signal-to-noise ratio and high distance resolution, and can obtain more target characteristic information. Among them, quantum detection technology represented by quantum sensors based on diamond NV color centers has been rapidly developed in the field of microwave detection. The diamond NV color center is formed by replacing C atoms in diamond crystal lattices with N atoms to form N substituted positions and connecting C vacant positions, is an ideal solid quantum bit at room temperature, has good optical characteristics, paramagnetism and decoherence characteristics, can realize polarization, reading and operation of the state at room temperature, and can also realize better isolation from the environment so as to keep longer coherence time.

The microwave magnetic field sensor based on the diamond NV color center can normally work at room temperature, and has the advantages of wide detection range, good confidentiality and high sensitivity. Under the condition of no external magnetic field, the NV color center of the diamond has zero field splitting energy of 2.87GHz, when the external magnetic field exists, the NV color center of the diamond is degenerated and dual-state Zeeman splitting occurs, the energy level of the NV color center of the diamond is greatly influenced by the magnetic field, and different magnetic field directions have different influences on the energy level. Under the condition of an external magnetic field, a microwave field is applied to the NV color center of the diamond to generate the draw ratio oscillation, so that the intensity of the microwave field to be measured can be measured. Therefore, radar detection requires designing a microwave coupler that confines a dispersed microwave field to one place so that the NV color center of the diamond and the microwave field interact to the maximum extent and realize the pull-ratio oscillation between energy levels. At present, the application of diamond NV color center microwave magnetic field measurement is not seen in the field of radar detection.

Disclosure of Invention

The invention aims to provide a microwave coupler for measuring a diamond NV color center microwave magnetic field, which solves the problem of high-density concentration of a microwave field and provides a way for realizing interaction of the diamond NV color center and microwaves.

In order to solve the technical problem, the invention provides a microwave coupler for measuring a diamond NV color center microwave magnetic field, which adopts the following technical scheme:

the microwave cavity comprises a microwave cavity body, a transmission waveguide, a microwave feeder line assembly hole and a coupling window;

the microwave cavity comprises a square cylinder, a cavity left side cover and a cavity right side cover; the left side cover of the cavity and the right side cover of the cavity are fixedly and hermetically arranged at the left end and the right end of the square cylinder;

the microwave feeder line assembling hole is arranged at one end of the side wall of the square cylinder; the coupling window is arranged at the other end of the same side wall of the microwave feeder line assembling hole, and the position of the coupling window is arranged at the position with the strongest microwave field intensity of the square cylinder;

the transmission waveguide is arranged in the microwave cavity and connects the microwave feeder line assembling hole with the coupling window.

Further, the transmission waveguide is rectangular, and the caliber of the transmission waveguide is determined by the working frequency.

According to the technical scheme, the invention has the beneficial effects that:

the invention collects the microwave field intensity by using the microwave feeder line assembling hole, concentrates the weak microwave field intensity in the microwave cavity body at high density, and provides an important approach for solving the problem of the interaction between the NV color center of the diamond and the microwave.

The invention has the advantages of simple structure and stable cavity frequency and bandwidth, is suitable for measuring the microwave magnetic field based on the NV color center of the diamond, and has important application value in the fields of radar detection, aviation diving detection, precise nondestructive detection of parts of aircraft engines and the like.

Drawings

FIG. 1 is a top view of a microwave coupler of the present invention for microwave magnetic field measurement of a diamond NV color center;

FIG. 2 is an AA cross-sectional schematic view of a microwave coupler of the present invention for microwave magnetic field measurement of diamond NV color centers.

In the figure:

1. square tube

2. Cavity left side cover

3. Cavity right side cover

4. Microwave feeder line assembly hole

5. Coupling window

6. Transmission waveguide

Detailed Description

The technical solution of the present invention is specifically described below by way of examples with reference to the accompanying drawings.

The microwave coupler for measuring the diamond NV color center microwave magnetic field comprises a microwave cavity, a transmission waveguide 6, a microwave feeder line assembling hole 4 and a coupling window 5, and is shown in figures 1 and 2.

The microwave cavity comprises a square cylinder 1, a cavity left side cover 2 and a cavity right side cover 3, wherein the cavity left side cover 2 and the cavity right side cover 3 are fixedly and hermetically arranged at the left end and the right end of the square cylinder 1 to form the microwave cavity. The microwave cavity is cut and processed by adopting metal materials such as aluminum alloy, copper and the like, so that the high-efficiency transmission of a microwave field is ensured.

The microwave feeder line assembling hole 4 is arranged at one end of the side wall of the square cylinder 1 and can be used for connecting a horn antenna to feed a microwave field. The coupling window 5 is in the shape of a cambered surface rectangle and the like, is arranged at the other end of the same side wall of the microwave feeder line assembling hole 4, and is arranged at the position where the microwave field intensity of the square barrel 1 is strongest. And (3) obtaining the field intensity distribution of the electromagnetic field by HFSS simulation of professional electromagnetic field simulation software, and selecting the position with the strongest field intensity to set a microwave coupling window 5.

The transmission waveguide 6 is arranged in the microwave cavity and connects the microwave feeder line assembling hole 4 with the coupling window 5. The transmission waveguide 6 is rectangular, the caliber size is determined by the working frequency, and the following relation is satisfied:

a < λ <2a, λ >2b, where a, b are the cross-sectional dimensions and λ is the operating wavelength.

The working principle of the invention is as follows: microwave energy is fed into the transmission waveguide 6 through a coaxial cable arranged at a microwave feeder line assembling hole 4 of the cavity, and the microwave is transmitted to the microwave coupling window 5 to be coupled and interacted with the NV color center of the diamond.

Examples

The present embodiment is based on the working frequency f₀In order to increase the coupling efficiency of the coupler as much as possible, the size of the coupler is designed to be 3GHz, and an aluminum alloy is used as a material for the coupler. The length of the cavity square tube 1 is 300mm, and the wall thickness is 6 mm. The transmission waveguide 6 is rectangular in shape and has a diameter of 76mm × 30mm. The cavity left side cover 2 and the cavity right side cover 3 are welded with the cavity square tube 1, and the welding quality is ensured. The microwave feeder line assembly hole 4 is circular, the diameter of the microwave feeder line assembly hole is 10mm, the thickness of the microwave feeder line assembly hole is 6mm, and the microwave feeder line assembly hole 4 is connected with the transmission waveguide (6). The coupling window 5 is in the shape of a cambered rectangle, the size of the coupling window is 30mm multiplied by 2mm, the thickness of the coupling window is 6mm at the middle position of the cavity, and the coupling window 5 is ensured to be connected with the transmission waveguide 6.

The microwave field strength of the coupling window 5 can reach 0.09A/m through HFSS simulation.

In conclusion, the invention has the advantages of simple structure and stable cavity frequency and bandwidth, and solves the key technology based on the interaction of the diamond NV color center sensor and the microwave field at room temperature.