A surface waveguide microstrip antenna for solid color center spin

Abstract

This invention discloses a surface waveguide microstrip antenna for solid-state color center spin. The surface waveguide microstrip antenna includes an outer antenna, a middle antenna, and an inner antenna on a diamond substrate. Blind holes are formed on the substrate, and the diamond is nested within these holes, with the upper surface of the diamond flush with the upper surface of the substrate. The outer, middle, and inner antennas are all square ring-shaped and nested sequentially from the outside to the inside. Each of the outer and middle antennas has an opening on its side, located on opposite sides of their respective antennas. The outer, middle, and inner antennas together form the surface waveguide microstrip antenna with a resonant frequency of 2.87 GHz. Electromagnetic waves are transmitted between the surface waveguide microstrip antennas via radiation, generating resonance. This invention not only offers high power and high uniformity of the microwave magnetic field but also eliminates the need for additional flying wires, simplifying the installation process.

Description

Technical Field

[0001] This invention relates to the field of magnetic field measurement, and more specifically to a surface waveguide microstrip antenna for solid color center spin. Background Technology

[0002] The testing of weak magnetic fields has wide applications in various fields such as physics research, biomedicine, and deep space exploration. Among them, solid-state spin quantum magnetometers are a type of magnetic field sensor that has attracted much attention in recent years. The principle utilizes the spin resonance characteristics of defects in solid materials, primarily using diamond NV centers. This material undergoes energy level splitting under the influence of an external magnetic field. Quantum weak magnetic field measurement technology, developed by combining this technology with MEMS microfabrication technology, quantum manipulation, and other technologies, is an important component of quantum sensing technology. Domestic and international research has focused on key technical challenges such as diamond NV center optical field modulation technology and microwave circular polarization technology. The emphasis is on improving the ability of microstrip antennas to propagate microwave energy, thereby improving fluorescence contrast. Currently, common antenna methods used for diamond NV centers include surface waveguides with antennas and electrodes deposited on the diamond sample surface. The drawbacks are that the surface antenna structure needs to be connected to an external PCB board via electrodes, resulting in complex manufacturing processes, easy damage to the electrodes, and inability to withstand high-power microwaves. Alternatively, copper plating can be used to fabricate the antenna structure on a PCB board before attaching the diamond to the PCB surface. However, this method results in the diamond being on top of the PCB, with the microwave energy transmitted by the antenna occurring on the lower surface of the diamond, while the laser directly excites the upper surface of the diamond, leading to significant microwave power loss. Therefore, there is a need to invent a microwave antenna with a simple manufacturing process that can be applied to solid-state spin-reflection fluorescence collection of diamond NV centers. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a surface waveguide microstrip antenna for solid color center spin, which can reduce microwave power loss while ensuring high excitation power.

[0004] A surface waveguide microstrip antenna for solid color center spin, the surface waveguide microstrip antenna comprising an outer antenna, a middle antenna on a substrate, and an inner antenna on diamond;

[0005] Blind holes are formed on the substrate, and the diamond is nested in the blind holes, with the upper surface of the diamond flush with the upper surface of the substrate.

[0006] The outer antenna, middle antenna, and inner antenna are all square ring shaped and nested from the outside to the inside; the outer antenna and the middle antenna each have an opening on their side, and the openings of the outer antenna and the middle antenna are located on opposite sides of their respective antennas.

[0007] The outer antenna, middle antenna, and inner antenna together form a surface waveguide microstrip antenna with a resonant frequency of 2.87 GHz. Electromagnetic waves are transmitted between the surface waveguide microstrip antennas by radiation, generating resonance.

[0008] Furthermore, the depth of the blind hole in the substrate is equal to the thickness of the diamond, and the shape of the blind hole is the same as the shape of the diamond, so that the diamond is just embedded in the blind hole, and the upper surface of the diamond is flush with the upper surface of the substrate.

[0009] Furthermore, the outer layer antenna, the middle layer antenna, and the inner layer antenna are all made of copper wire.

[0010] Furthermore, the diamond is a diamond with NV color centers.

[0011] Furthermore, the outer layer antenna and the middle layer antenna are connected by a connecting line.

[0012] Furthermore, the inner antenna is formed in the middle of the upper surface of the diamond by deposition.

[0013] The beneficial effects of this invention are as follows:

[0014] This invention employs a combination of on-substrate and surface-mount antennas on the diamond substrate, overcoming the drawback of low power caused by antennas only on the substrate, and also resolving the complexity of the process caused by simply plating copper on the diamond surface and requiring external connecting wires to the substrate. The designed surface waveguide microstrip antenna not only boasts high power and high uniformity of the microwave magnetic field, but also eliminates the need for additional connecting wires. The installation process is simple, requiring only the embedding of the diamond sample with NV centers into a blind via in the substrate. This invention can be applied to diamond NV center measurement systems using reflective fluorescence acquisition, reducing antenna transmission power and improving the sensor's signal-to-noise ratio. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of a device for a surface waveguide microstrip antenna with a solid color center spin, according to one embodiment of the present invention.

[0017] Figure 2 This is an exploded view of a surface waveguide microstrip antenna with a solid color center spin, according to one embodiment of the present invention.

[0018] Appendix Figure 1 The markings are listed below: 1. Substrate; 2. Outer antenna; 3. Middle antenna; 4. Diamond; 5. Inner antenna; 101. Blind hole. Detailed Implementation

[0019] The present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments. The purpose and effects of the present invention will become clearer. It should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0020] like Figure 1 As shown, this invention proposes a surface waveguide microstrip antenna for solid color center spin, which can be applied to a reflective diamond NV magnetic field measurement system. Figure 1 As shown, the surface waveguide microstrip antenna includes an outer antenna 2, an intermediate antenna 3, and an inner antenna 5 located on a diamond 4, all on a substrate 1.

[0021] like Figure 2 As shown, diamond 4 is a diamond with NV color centers, and substrate 1 is a PCB board. A blind hole 101, the same size as the diamond, is located in the center of substrate 1. Diamond 4 is embedded in the blind hole, making the upper surface of diamond 4 and the antenna on substrate 1 coplanar. Inner antenna 5 is plated on the upper surface of diamond 4. Outer antenna 2, middle antenna 3, and inner antenna 5 are all square ring-shaped and nested sequentially from the outside to the inside. Both outer antenna 2 and middle antenna 3 have an opening on one side, and these openings are located on opposite sides of their respective antennas. The upper ends of outer antenna 2 and middle antenna 3 are connected by a connecting line. The outer antenna, middle antenna, and inner antenna together form a surface waveguide microstrip antenna, used to excite the upper surface of the diamond sample, with a resonant frequency of 2.87 GHz. Electromagnetic waves are transmitted between the surface waveguide microstrip antennas through radiation, generating resonance.

[0022] Because the upper surface of the diamond and the antenna surface are on the same horizontal plane, the excitation efficiency of the NV centers is high, and the diamond is embedded inside the square ring, resulting in high uniformity of the microwave magnetic field. This invention can be applied to a diamond NV center measurement system using reflective fluorescence acquisition, which can reduce antenna power and improve the sensor signal-to-noise ratio.

[0023] The optimal antenna size is obtained using the scanning parameter method. During scanning, the above parameters are input simultaneously, and a range is set for each parameter to be calculated separately. In one implementation, the main antenna size parameters include: substrate thickness 0.9mm; outer layer antenna side length 9.1mm, line width 0.8mm, and opening width 0.3mm; middle layer antenna side length 6.5mm, line width 0.5mm, and opening width 0.5mm; inner layer antenna side length 2.4mm, line width 0.8mm, distance between the three antenna layers (outer layer antenna to middle layer antenna 0.5mm, middle layer antenna to inner layer antenna 1.5mm), width of the connecting line between the middle layer antenna and the outer layer antenna 0.6mm, lead-out length 2.5mm and width 0.6mm, and solder joint length 9.3mm and width 1.6mm.

[0024] It will be understood by those skilled in the art that the above descriptions are merely preferred examples of the invention and are not intended to limit the invention. Although the invention has been described in detail with reference to the foregoing examples, those skilled in the art can still modify the technical solutions described in the foregoing examples or make equivalent substitutions for some of the technical features. All modifications and equivalent substitutions made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A surface waveguide microstrip antenna for solid-state color center spin, characterized in that, The surface waveguide microstrip antenna includes an outer antenna, a middle antenna, and an inner antenna on a diamond substrate. Blind holes are formed on the substrate, and the diamond is nested in the blind holes, with the upper surface of the diamond flush with the upper surface of the substrate. The outer layer antenna, the middle layer antenna, and the inner layer antenna are all square ring shaped and nested from the outside to the inside; the outer layer antenna and the middle layer antenna are connected by a connecting line; each of the outer layer antenna and the middle layer antenna has an opening on its side, and the openings of the outer layer antenna and the middle layer antenna are located on the left and right sides of their respective antennas in the direction perpendicular to the connecting line. The outer antenna, middle antenna, and inner antenna together form a surface waveguide microstrip antenna with a resonant frequency of 2.87 GHz. Electromagnetic waves are transmitted between the surface waveguide microstrip antennas by radiation, generating resonance.

2. The surface waveguide microstrip antenna applied to a solid color center spin as described in claim 1, characterized in that, The depth of the blind hole in the substrate is equal to the thickness of the diamond, and the shape of the blind hole is the same as the shape of the diamond, so that the diamond is just embedded in the blind hole, and the upper surface of the diamond is flush with the upper surface of the substrate.

3. The surface waveguide microstrip antenna applied to a solid color center spin as described in claim 1, characterized in that, The outer antenna, middle antenna, and inner antenna are all made of copper wire.

4. The surface waveguide microstrip antenna for solid color center spin as described in claim 1, characterized in that, The diamond is a diamond with NV color centers.

5. The surface waveguide microstrip antenna for solid color center spin as described in claim 1, characterized in that, The inner antenna is formed in the middle of the upper surface of the diamond by deposition.

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