Research On Nondestructive Testing Technology Of Microwave Passive Surface Mounted Components

With the development of science and technology and the acceleration of industrialization,miniaturization and low power consumption of devices and systems have become the hotspot people pursued currently.Under such a circumstance,surface mounted passive components have become an indispensable component in the design and manufacture of RF microwave circuits.Since the current measurement of surface mounted passive components is still concentrated in the lower frequency band,Therefore,it is of long-term significance to study the test method of surface mounted passive components in the microwave band and accurately obtain their characteristic parameters for improving the production efficiency and accuracy of passive components and promoting the development and progress of microwave circuits.In this paper,passive components are tested in the frequency range of 10MHz¹4GHz,and a simple analysis,simulation and removal of the discontinuity in the actual test are performed.The results of the last repeated experiments verified the accuracy and reliability of the test method and test fixture.The main research work of this paper includes:First of all,the development of test equipment and the update of calibration theory are reviewed.Then,the testing methods and the corresponding fixtures of passive components are discussed.Due to the need to measure the high-frequency data of passive components,a vector network analyzer and test fixture are chosen for non-destructive testing.Secondly,based on meticulously examining the error of vector network analyzer,the error model of vector network analyzer is analyzed and deduced.According to the testing requirements of this paper,a calibration method combining SOLT and TRL is used to achieve an ideal calibration result over a wide frequency range.Corresponding fixtures and calibration parts were designed and use the calibrated vector network analyzer to verify the calibration kits.The verification results showed that it can meet the nondestructive test design requirements of the surface mounted components.Then,the high-frequency equivalent model of surface-mount passive components was analyzed.Based on this,the equivalent circuit of the test was established and the discontinuity in the test circuit was discussed.The software was used to simulate the effect of discontinuity and a data processing program was written using MATLAB.After removing the effect of discontinuity,the data is written into the S2P file and its characteristic parameters are obtained.Finally,the commonly used surface mounted passive components were measured,and the obtained S-parameters were processed to obtain the component characteristic parameters.After multiple measurements,the test results are compared with the results given by the manufacturer and error analysis and consistency verification are performed.The actual results show that the proposed SOLT and TRL combined method can complete the fixture calibration within the frequency range of 10MHz¹4GHz.The resonant frequency error measured of the chip inductor is within 3%.And the resistance of the chip resistor within 1GHz is within 5%.The results of repeated tests show that the amplitude difference of S₂₁ is less than 0.5dB and the phase difference is less than 1.2°.The test system has good consistency.The above results verify the reasonableness of the discontinuity equivalence discussed in this paper and the feasibility of the designed calibration fixture and test scheme.