Microwave Performance Testing Techniques For Digitally Encoded Functional Material Modulation Elements

With the rapid development of electronic communication technology,the emergence of artificial functional materials has made it possible to artificially modulate electromagnetic waves.Digital coded functional materials achieve electromagnetic properties that are difficult to achieve with conventional materials by means of specific arrangements of artificial structural units,of which the modulating elements play a crucial role.The current test methods for this type of modulating element are mainly transmission and reflection methods and traditional analogue circuit methods,both of which are tested in the low frequency band and cannot meet the current demand for digital coding functional materials in the high frequency band,and the test accuracy and sensitivity are low.Therefore,it is important to study the testing techniques of modulated components and accurately obtain their high-frequency characteristic parameters to improve the design efficiency of digital coded functional materials and help their development in the microwave field.In this study,we have designed a microwave performance test system based on the microwave resonance method for digital coding functional materials and control elements operating at 8-18 GHz,after reviewing and analysing the relevant research background at home and abroad and comparing the existing test methods and research status.A microstrip resonant test circuit was designed and developed to accurately measure the characteristic parameters of the control element;a DC bias circuit was designed to apply a bias voltage to the control element while reducing the influence of the DC power supply on the main test circuit;a complete set of test crimping fixtures was designed and machined to meet the requirements of rapid and repeatable testing,and a complete test system was built.Based on the microwave resonance method and the equivalent circuit method,the test equivalent circuit was calculated and the test algorithm and corresponding test software were written.Finally,the test system built above was used to test high-frequency capacitors and resistors,and the results were within 5% error,verifying the test accuracy of the test system;subsequently,several regulation components were tested,and the test results were compared and analysed.The consistency and reliability of this thesis' s test system was verified through multiple repetitive tests and simulation tests on small units of digitally encoded functional materials,and an error analysis of the system was carried out.The experimental results show that the microwave performance test system developed in this thesis for digitally encoded functional material modulation elements is combined with accurate and reliable testing,and can test a wide range of modulation elements with high test frequency and accurate and stable results,meeting the test requirements.