De-embedding Testing Of RF Components And Research On Equivalent Circuits Modeling

Artificial intelligence,autonomous driving,high performance computing,5G communication technology and 6G communication,which is currently under development,promote the continuous development of high-speed and high-density circuits.The higher and higher working frequency and harmonic frequency of printed circuit board(PCB)lead to serious electromagnetic compatibility(EMC)problem of modern consumer terminal electronic products,which directly affects the time to market of products.In order to avoid EMC risks at the product design stage,there is a huge demand for accurate electromagnetic modeling of RF components.The component equivalent circuit models provided by component manufacturers are very limited in terms of frequency and precision,which can't meet the requirements of EMC simulation modeling.As the RF component models become more and more complex,the testing accuracy and modeling accuracy are challenged more and more.Therefore,it is an important step to improve the success rate of circuit design and ensure the reliability of products to test RF components more accurately,obtain their scattering parameters(S parameters),and accurately model them accordingly.Aiming at the problems encountered in the de-embedding testing and modeling of RF components in practical engineering,this paper cooperates with communication manufacturers to conduct detailed research from theoretical analysis,electromagnetic simulation and experimental measurement,mainly including the following aspects:1.The principle of the commonly used deembedding algorithm in engineering is summarized,including Thru-Reflect-Line(TRL)and Automatic Fixture Removal(AFR).Furthermore,it compares the accuracy of different fixtures with different physical structures and different de-embedding algorithms.2.The method of extracting the dielectric constant(DK)of PCB substrate is studied,and the effectiveness of the method is verified by simulation.Then PCB circuit is prepared to verify that the method can accurately extract the dielectric constant of PCB substrate.This method can effectively improve the simulation accuracy of PCB circuit,reduce the RF modeling error caused by the inability to accurately control the dielectric constant during PCB manufacturing process,and improve the consistency of simulation and test.3.A semi-analytical de-embedding algorithm is proposed,which combines time domain gating with frequency domain signal flow diagram,to accurately remove the effect of symmetric fixture on the S-parameter results of the dual port Device Under Test(DUT).This algorithm makes up for the deficiency of the existing algorithms requiring the fixture to have symmetry,and its implementation process is simple.It can directly obtain the S parameters of DUT without calculating all the S parameters of the fixture.The de-embedding method has great engineering application value.4.For the most commonly used RF components in terminal electronic products: capacitors and inductors in the Surface-Mounted Device(SMD),the equivalent circuit models are established and optimized by combining with the algorithm of dielectric constant extraction and de-embedding of PCB substrate developed in the second and third points.The accuracy and frequency of the model are much better than those provided by the component manufacturers,which has been verified by domestic communication manufacturer.Based on the equivalent model,Python software is written to realize automatic extraction and modeling of RF component parameters.In the school-enterprise cooperation project,the accuracy of the software has been verified by a communication manufacturer,and it has been applied in several landing projects and received favorable comments.