Research On Technology Of Microwave Source Temperature Control System

Each part of the electronic system has different sensitivity to the influence of temperature.The change of temperature will affect the performance of the electronic system,especially in the frequency source,the output power and output frequency will be affected,and the frequency stability will also change significantly.Using the temperature control device can make the microwave source work in a stable temperature environment.Traditional temperature control systems have some problems,such as poor robustness,slow response speed and excessive overshoot,which are not suitable for temperature control of microwave source.Therefore,in order to improve the accuracy and response speed of temperature control and optimize the robustness of temperature control system,a fuzzy proportional-integral-derivative(PID)microwave source temperature control system is studied in this thesis.The main contents of this thesis are as follows:Firstly,based on the traditional temperature control theory and consulting a large number of relevant literature at home and abroad,this thesis studies the application of fuzzy theory in temperature control system,and designs a fuzzy PID temperature control algorithm.Secondly,the scheme of microwave source temperature control system is designed.In terms of hardware,Thermoelectric Cooler(TEC)has the characteristics of small size,small thermal inertia and no pollution.Therefore,it is selected as the actuator of microwave source temperature control in this thesis.In terms of temperature measurement,platinum Resistance Temperature Detector(RTD)is used as temperature sensor in this thesis.This thesis takes STM32 Microcontroller Unit(MCU)as the control core,designs hardware circuits such as power supply circuit,TEC driving circuit,display circuit and communication interface circuit,and selects the transducer as the temperature signal processing module to obtain the target temperature value.In terms of software,this thesis uses C language for software design,adopts the idea of software modular design,and designs temperature acquisition module,fuzzy PID control algorithm module,Pulse Width Modulation(PWM)control module and host computer module respectively.The VOFA+ software is applied in the host computer module to realize the functions of temperature signal acquisition,temperature curve display,PID parameter regulation,result analysis and so on.The vector network analyzer test software is designed to test the resonant frequency fluctuation of the microwave resonator.Finally,experiments of the microwave source temperature control system are carried out.The experimental results show that in the range of 20?55 ?,the fluctuation of control stability of the microwave source temperature control system designed in this thesis is less than ±0.2 ?,and the fluctuation of the resonant frequency of the microwave source is small.The temperature control system has the characteristics of small overshoot,fast response speed and strong robustness,and achieves the expected design goal.