High-frequency Measurement And Equivalent Circuit Modeling Of Complex Components In High-speed PCB

Since the Printed Circuit Board(PCB)board-level circuits continue to develop with the trend of high frequency and high device density,the electromagnetic compatibility(EMC)and electromagnetic interference(EMI)problems have become more serious than before.Besides,the iterative cycle of electronic products continues to shorten.These factors impose higher requirements on the accuracy of electromagnetic compatibility simulation of electronic products during the design phase.In the actual PCB board-level circuit and system design,various surface-mounted devices(SMD)and power distribution networks(PDN)are used as typical passive devices and structures in a large number.The accuracy of the electromagnetic model of the above-mentioned SMDs and PDNs directly affects the overall simulation accuracy of the circuit system.From the view of practical engineering applications,this paper focuses on three aspects which are the technology of highfrequency modeling,parameter extraction and measurement of surface-mounted devices and power distribution networks.The relationship between electricity and magnetic field energy storage conversion in passive structures and LC resonance in equivalent circuits is developed,and the same model is constructed for both surface-mount components and power distribution networks.1?Based on the theoretical analysis of the two de-embedding methods of automatic fixture removal(AFR)and thru-reflect-line(TRL),the impact of each de-embedding method on the error of the SMD measurement is evaluated.And test fixtures based on the two de-embedding methods are designed and fabricated separately to achieve a high precision of the scattering parameter extraction of the SMDs.Besides,long-short line de-embedding method is used to extract dielectric constant(DK)and dissipation factor(DF)of the PCB board with the combination of the full-wave simulation method.After that,the measurement accuracy of the SMDs is verified through the AFR and TRL measurement and full-wave simulation results of a T-type filter structure.2?For the measurement of SMD capacitors and inductors,a de-embedding method which can be used for the de-embedding of asymmetric fixtures is porposed.The proposed method breaks through the limitation that the insertion loss of the fixtures must be the same in the AFR method,so that the measurement structures possess greater design freedom.When the fixtures are asymmetric,the proposed method needs fewer tests and the calculation steps are more concise,at the same time,the de-embedding accuracy has not become worse comparing to the AFR method.When calculating the parameters of the DUTs,the proposed method has a certain correction effect on the fabrication errors of the “Through” calibration structure.The proposed de-embedding method possesses the value of practical engineering measurement.3?Equivalent circuit models of SMD capacitors and inductors are proposed,and the proposed circuits are consistent with the actual physical characteristics of the devices.The parasitic parameter extraction technology of the capacitors and the inductors is studied and the calculation of each parameter in the equivalent circuit model is completed.An LC resonant measurement method is proposed to extracted the small parasitic resistance.And the proposed method is applied to the efficiency calculation of a mobile phone antenna at the resonant frequencies,the results validate that the proposed method is able to improve the simulation accuracy of mobile phone antennas.Finally,the equivalent circuit model accuracy of the surface-mounted capacitors and inductors is verified based on the PI-type filter structure.4 ? Based on the analysis of the electromagnetic modal and high-frequency resonance characteristic of plane/grid PDN,two equivalent circuits are proposed and the calculation method of the parasitic parameters in the equivalent circuit is given.The proposed equivalent circuit method can be used for the modeling of irregular-shaped,non-uniform,and via-loaded PDN.The extraction of all parameters in the proposed series-formed circuit modeling method can be completed based on the full-wave simulation or measurement impedances at a few ports,and then the extracted equivalent circuit can be used to predict the impedance of the port at any positin of the overall PDN.Therefore,the calculation efficiency of the PDN impedance is promoted.