Study On The Measurement Method Of Variable Temperature High Frequency Impedance In Coaxial Transmission Line Structure

In the field of electronic information,electronic measurement is a very important part.The rapid development of the electronic information industry certainly cannot be separated from the support of electronic measurement.Impedance measurement is a very important part of electronic measurement.Reliable impedance measurement method is very important to improve the accuracy and accuracy of impedance test.This paper mainly studies and discusses the impedance measurement problem under variable temperature and high frequency conditions,and designs a suitable method for thin films.The fixture of the solid sample was made and feasibility analysis was done.In order to solve the problem of impedance measurement of samples with a solid thin-sheet structure with a diameter of less than 7mm under high temperature and high temperature conditions,based on the temperature characteristics and frequency characteristics of the coaxial transmission line,this paper designs and processes a full-metal structure based on APC-7 coaxial transmission line.Fix the fixture and analyze the problem with a distributed parameter analysis method.A vector network analyzer,a PID controller,and an oven cavity are used in the measurement system.The PC port is connected to the LAN port and the serial port respectively.Through programming,the frequency range is 300KHz-3GHz and the temperature range is RT.-300? automatic measurement process.The reliability of a solid sheet-like sample impedance measurement system having a diameter of less than7 mm under high temperature conditions was verified.This paper mainly carried out the following innovative research work:(1)This paper mainly studies the measurement method of the impedance value of the measured sample with a small enough measurement size.The measurement frequency range is 300KHz-3GHz.When the temperature range is RT-300?,it starts from the problem of high temperature destroying the instrument port.Based on the basic theoretical knowledge of the transmission line,impedance measurement fixtures for APC-7 coaxial transmission line structures were designed and fabricated.Self-made fixtures can measure the impedance values ??of thin-film solid samples with a diameter of less than 7mm,providing an effective impedance analysis for such samples.Measuring fixture.Through theoretical calculations,this paper analyzes that the error of thermal expansion,contraction,and skin effect brought about by variable-temperature high-frequency is within 1%,and the built-in impedance measurement system measures the self-made fixture of lamellar solid sample and passes it.Data analysis confirmed the feasibility of this self-made fixture and can be used for impedance measurement of subsequent samples.(2)In the actual measurement process,in order to improve the stability of themeasurement environment temperature,a fuzzy PID controller is used to control the temperature so that the measured sample as a whole reaches the real-time temperature of the temperature control box.At the same time,the LAN port connection vector network analyzer is programmed to realize The PC side automatically completes the measurement in the frequency range of 300KHz-3GHz.The entire test system in the MATLAB environment,automatic measurement.The related research results of this dissertation provide an effective measurement method for the measurement of the resistance value of a thin solid sample with a diameter of less than 7mm under both variable temperature and high frequency conditions.