Research And Application Of On-wafer Measurement Calibration Algorithm For RF Devices

RF on-wafer measurement is an important means to obtain the electrical characteristics of microwave millimeter wave devices.It is also the basis for accurately characterizing device characteristics.Therefore,the research on calibration methods and the error analysis of calibration are the hotspots of microwave research in the field of on-wafer measurement.With the development of information technology,the traditional small-signal S-parameter measurement can no longer meet the needs of circuit design.The parameters of the device in the nonlinear region,that is,under the large signal excitation,also need to be measured,that is,the large signal is measured on wafer.Therefore,this paper has carried out research and discussion on small signal vector calibration and large signal power calibration.The main content of the paper is divided into the following parts:1.It briefly introduces the common microwave millimeter wave device and the composition of the on-chip measurement system,introduces the measurement indicators of the RF on-wafer measurement,and summarizes the common test types and test methods of the on-wafer measurement for microwave millimeter wave devices.2.In this paper,the principle of small-signal measurement is introduced in detail.The hardware topology of several common vector network analyzers is analyzed.The working principle is briefly described.Eight error models and 12 error models are discussed.The physical meaning of each error term is introduced,and the mathematical formulas for calibration and error correction based on these two error models are derived based on the signal flow graph.The error term calculation formula of small signal vector calibration based on TRM calibration method is deduced,and the uncertainty propagation formula of TRM calibration method is deduced.Finally,a fast correction method for correcting the drift error of the on-chip test system is proposed.3.In the large signal measurement part,the basic principle and composition of the load traction measurement system are introduced.The comparison between the active load pull measurement system and the passive load traction test system is introduced.The basic principle of the power device load traction test is deduced.The calculation formula of the device large signal parameters.Based on this,a large signal load traction test system based on external coupler is introduced,and the basic principle of large signal calibration is introduced around the system.The traditional large-signal calibration method is studied.An improved large-signal calibration method is discussed.The effectiveness of the improved large-signal calibration method is verified by experiments.