Microwave Field Imaging Technology Of Microwave Integrated Circuit Surface

With the development of microwave technology,microwave integrated circuits have been widely used in mobile communication,millimeter wave radar,navigation and other fields.With the rapid progress of integrated circuit design and manufacturing technology,the size of monolithic microwave integrated circuit(MMIC)is becoming smaller and smaller,the circuit scale is increasing,and the functional complexity is also greatly improved,which brings new challenges to chip electromagnetic compatibility(EMC)testing and chip failure analysis.Traditional microwave near-field imaging technology can not meet the requirements of chip testing due to the limitations of low spatial resolution and limited working frequency band.Diamond Nitrogen-Vacancy Center(NV Center)is a solid-state quantum two-level system with good optical stability and long spin coherence time at room temperature,which can realize the manipulation and readout of the electron spin quantum state,and has unique advantages in the field of quantum precision measurement of microwave magnetic fields.In this paper,a microwave nearfield imaging system based on fiber-optic diamond NV color center probe is adopted,which has the characteristics of quantum calibration,high-resolution and non-destructive measurement,it can be used for microwave near-field high-resolution imaging of microwave integrated circuits and other microwave devices.In this paper,a fiber diamond NV color center probe is prepared,which is composed of a tapered optical fiber and a diamond NV color center crystal fixed on the tapered end face.Tapered fiber can be used to improve laser excitation efficiency and fluorescence collection efficiency.The size of crystal determines the spatial resolution of the probe.The resolution of the probe in this paper can reach the micrometer level.In this paper,the optical path module,hardware module and software control program are developed to complete the integration of the entire imaging system.The measurement noise is analyzed and a time-domain difference algorithm for optimizing the lowfrequency noise of the system is proposed.The optical detection magnetic resonance and Rabi oscillation measurement experiments are carried out with the self-built imaging system.Three different optical detection magnetic resonance measurement methods are analyzed and compared,and the signal-to-noise ratio of the signals under different measurement methods is calculated.The microwave near-field scanning imaging of Ga As monolithic integrated absorptive single pole double throw(SPDT)switch chip is carried out.The differences of microwave magnetic field radiated by the chip under different powers and frequencies of the input signal are compared.The capability of the system in high-resolution near-field microwave imaging at the wafer level is verified,and it is expected to provide a new test method for chip electromagnetic compatibility testing and chip failure analysis.