Research On Microwave Target Passive Direction Finding System Based On Diamond Nitrogen Vacancy Color Center

Microwave target direction finding is widely used in military science,astronomical observation,traffic command and other military and civilian fields.Passive microwave direction finding technology,as a kind of technology that realizes the direction detection of microwave source through passive reception,has extremely high application value in the field of electronic reconnaissance and anti-reconnaissance due to its non-radiation.In recent years,with the rapid development of quantum measurement technology,it has exceeded the traditional measurement limit in many fields.Among them,the solid state atomic spin quantum sensing platform based on the color center of diamond nitrogen vacancy has become an important research target of ultra-high precision sensing technology and miniaturization applications.Therefore,this paper proposes and designs a miniaturized microwave target passive direction finding system based on diamond nitrogen vacancy color center.In this paper,the research status of microwave measurement of diamond nitrogen vacancy color center and the research and application status of passive microwave direction finding technology are introduced.At the same time,the spin energy level structure characteristics of diamond nitrogen vacancy color center are introduced in detail,and the microwave sensing mechanism of diamond nitrogen vacancy color center is described by Hamiltonian equation model.At the same time,the optical detection magnetic resonance technology,which is commonly used to extract the electron spin information inside the diamond nitrogen vacancy color center,is introduced.Based on this technology,the corresponding optical detection magnetic resonance diamond nitrogen vacancy color center electron spin information extraction system is designed and built.At the same time,the dynamic extraction system of nitrogen vacancy color center Optically Detected Magnetic Resonance spectral information based on microwave frequency proportion-integral-derivative locking is introduced,and the magnetic detection is taken as an example for practical testing.Secondly,based on the characteristics of energy level drift caused by magnetic field and temperature,a two-way magnetic sensing method is proposed.Through the feedback between the two spin information,the differential cancellation of temperature noise is realized at the same time.A two-way system scheme is designed for this method.The microwave is frequency modulated by applying different frequency modulation signals,and the red light signal is demodulated respectively to realize the separation of the two spin states.Proportion-integral-derivative frequency locking technology is used to lock one of the spin states,and its drift is negatively fed back to the other spin state to realize common mode cancellation of temperature noise.At the same time,the two-channel microwave coherent population oscillation effect of diamond nitrogen vacancy color center is introduced in detail.Based on this effect,a microwave frequency detection system of diamond nitrogen vacancy color center is established.By using the microwave frequency control to lock the resonant peak of the coherent population oscillation,the detection of the unknown micro-wave frequency is realized.Its microwave frequency detection sensitivity is 1.21 m V / k Hz,and the minimum detectable microwave frequency of the system is 2.06 k Hz according to the actual test;At the same time,a specific microwave frequency recognition method based on machine learning is introduced.By using the dense connection convolution neural network,the Optically Detected Magnetic Resonance spectral image under the coherent population oscillation effect in the microwave detection frequency range is trained to complete the identification of the corresponding unknown micro-wave frequency to be measured,with a recognition rate of 99.16%.At the same time,the identification test of network noise resistance is completed by simulating noise interference data and images.Finally,based on the introduction of the microwave intensity detection method of the diamond nitrogen vacancy color center based on the dual-channel coherent microwave population oscillation effect,the microwave intensity dynamic detection system is built by using the microwave frequency proportion-integral-derivative locking system,and the exponential fitting of the microwave intensity to be measured and the locking curve is completed by the microwave intensity scanning method.Based on this system,the minimum microwave frequency detection intensity is-20 d Bm;The microwave source direction detection system is designed and built.Through the detection of the microwave intensity of the space point,the microwave field distribution matrix is constructed by using the three-bound spline interpolation method,and the weighted global least squares field distribution matching algorithm is used to restore the microwave source method.The optimal direction finding parameters are determined by experiments,and the average angle error is 0.24 °.In this paper,the passive direction finding method of microwave target based on the color center of diamond nitrogen vacancy has been explored and studied.Based on the microwave sensitivity of electron spin of diamond nitrogen vacancy color center and the effect of microwave coherent population oscillation,the detection of unknown microwave frequency and intensity has been realized,and the measurement of its microwave source direction has been completed.This work has realized the substitution of diamond nitrogen vacancy color center for traditional electronic devices,It has realized the practical application of quantum devices in the traditional microwave direction finding field,and provided a new idea for the engineering application of emerging quantum sensor devices represented by diamond nitrogen vacancy color centers.