Research On A Measurement System For Weak Microwave Fields Based On Diamond NV Centers

Alongside the rapid advancement of design and manufacturing processes in Integrated Circuit(IC)technology,the continuing decrease in internal feature size and line width,coupled with an increase in transistor count and decreasing power consumption of certain devices,necessitates a non-invasive,high-spatial-resolution microwave measurement device to tackle the challenges of surface microwave magnetic field characterization and chip electromagnetic compatibility testing.Among various diamond defects,the Nitrogen-Vacancy(NV)center,with its stable physical and energy level structures,is a promising candidate for quantum state manipulation and readout at room temperature.As such,it is highly suited for the field of quantum precision measurement in microwave fields.This thesis presents a non-invasive microwave field measurement system based on diamond NV centers,which enables high spatial resolution measurement of near-field microwave magnetic fields of antennas and chips.The system employs a fiber-optic NV center probe as a sensor,with spatial resolution that is determined by the size of the diamond particle.The use of NV center probes as sensors allows for the most accurate acquisition of microwave magnetic field information,as the probes are placed in close proximity to the measured device surface,and do not contain any metal components that could interfere with the measurement.The correctness and reliability of the system for measuring microwave magnetic fields and imaging near-field microwave magnetic fields of chips are validated by imaging experiments of microstrip antennas conducted using the system.In addition,this thesis optimized the signal-to-noise ratio of the detection system by analyzing the noise of the system and selecting suitable materials and processes for the optoelectronic detector.Based on this optimization,the system was used to obtain the minimum microwave input power for detecting optically detected magnetic resonance spectra using three devices-a limiter chip,a microstrip antenna,and a coplanar waveguide-at different microwave frequencies.By comparing the data curves with the variation trends of the S11 curves measured by the vector network analyzer,the reliability of the system was verified under conditions of low operating power and weak microwave magnetic field radiation on the surface of the device.