Research On Active Probe Of Electromagnetic Interference Detection System Based On Near-field Measurement

At present,the integrated circuit chips are developing in the direction of high speed,high density and miniaturization,and its electromagnetic interference problem is getting more and more serious,which is worthy of attention.The electromagnetic near-field scanning technology can analyze and quickly diagnose electromagnetic interference problems of highspeed circuits in real time without probing the internal structural details of the chip,showing great market application value.Domestic research in this area is developing rapidly,but Europe and the United States still occupy the leading position in near-field measurement.Aiming at the problem of electromagnetic interference positioning in electronic systems,this thesis proposes a small,broadband,non-contact active magnetic field detection method,and probe.The magnetic field detection method adopts active magnetic field detection technology,using a multilayer printed circuit board(Printed Circuit Board,PCB)to make passive probes.Based on passive probes,an active amplifier module and its supporting power management chip are added.Improve the transmission gain of the ultra-wideband type probe.The thesis conducts detailed research and analysis of the probe from the four perspectives of frequency response,spatial resolution,calibration factor,and differential electric field suppression capability,and expounds on the advantages of active probes over passive probes.The thesis completed the functional verification of the overall near-field measurement system.The actual measurement results show that the probe has a transmission gain of-20 d B,a spatial resolution of 900 ?m,and a good differential electric field suppression capability.The probe can be used for ultra-wideband measurement of PCB boards and more complex integrated circuits.Based on the previous research,the thesis designed an ultra-wideband,high-gain,lownoise amplifier for active near-field probes based on the TSMC 65 nm CMOS process to amplify the electrical signals transmitted by the passive probes.The Low Noise Amplifier(LNA)uses a cascode cascade architecture to solve the problem of high gain in the design index;the equivalent inductance calculated based on the circuit feedback mechanism and the theoretical calculation of the input matching network solves the problem Broadband matching problem;the use of series peak inductance technology solves the problem of high-frequency gain reduction and gain flatness caused by device parasitic capacitance.To verify the feasibility of the detection method,the thesis designed two probes.The test results show that the working frequencies of the two probes cover 1GHz-15 GHz,and their spatial resolution is 0.9 mm.Among them,the S21 of the active probe is-30 d B?-15.6 d B,the passive probe is-46 d B?-30.8d B,and the overall active probe is 15 d B higher than the passive probe.The thesis designed an ultra-wideband low-noise amplifier with a gain of 21.2d B,a gain flatness of 1.06 d B,and a noise figure of 3.59 d B from 1 to 21 GHz.The abovementioned design performance has reached the design index.Compared with other domestic research results,the spatial resolution,working bandwidth,and gain of active probes have certain advantages.The research results of this thesis have been applied to the integrated circuit chip and module surface electromagnetic field scanning detection system of the Fifth Institute of Electronics of the Ministry of Industry and Information Technology.