De-embedding Research And Application Of Microwave/RF Probes

With the rapid development of microwave and RF technology,the integration of microelectronic products continues to increase,and the operating frequency is increasing too.More and more products work in the RF and microwave frequency band.In the case of high-speed and high-frequency,we not only needs to consider the electrical connection performance of the corresponding circuit,but also needs to determine its accurate high-frequency characteristic parameters.The parameters of these devices are related to the performance of the entire design system.The high-frequency characteristic parameters can be obtained by measurment,but the test methods,tools,and other factors unrelated to the DUT will have an impact on the test results.In this paper,the on-chip test of microwave and RF circuit is taken as the research background.From the perspective of microwave network research,the probe and de-embedding calibration piece for on-chip test,the method of eliminating the influence of factors unrelated to the DUT,measuring the dielectric constant of the PCB and so on are studied.This paper mainly introduces and analyzes the on-chip test and de-embedding techniques of single-ended and differential circuits,as well as the PCB dielectric constant measurement method derived from the de-embedding algorithm.It is gradually completed through theoretical derivation,simulation verification and experimental testing,from idea to design,and from theory to the process of verification.The research content of this paper is mainly divided into the following parts:Firstly,some basic theories which are used are introduced,mainly about the microwave network theory,including the network parameters and cascading characteristics of the two-port network and multi-port network;Secondly,the de-embedding methods of single-ended network and differential network are analyzed theoretically.Through the analysis of microwave network,the test system is seen as the cascade of multiple networks.The network parameters and matrix analysis are used to solve the real network parameters of the DUT,Thereby the conclusion that the influences of the intermediate structures such as the fixture,the probe,the test pad,and so on can be eliminated by the de-embedding calibration in the on-chip test is obtained;Thirdly,the design rules of the test probe and the de-embedded calibration component are analyzed and illustrated.Using HFSS,SolidWorks software designed the model of on-chip test probe and de-embedded calibration component respectively which can be applied to single-ended devices and differential devices.The de-embedded simulation of the de-embedded test piece are applied by the designed probe and de-embedded calibration piece,which verified the correctness and effectiveness of the two de-embedding methods.Lastly,the de-embedded probes and calibration components for the single-ended transmission network and the differential transmission network were tested experimentally,and the dielectric constant of the dielectric substrate was measured and calculated.Based on the classical differential probe structure,this paper designed a novel differential probe that can suppress the influence of common mode signals in differential testing.In addition,based on the straight-through calibration and line calibration components in the de-embedding algorithm,the method of measuring the dielectric constant of PCB is deduced,which has certain significance for the measurement of PCB parameters in practical engineering.