The Design Of High Power Automated Tuner’s Driving Circuits And Study Of Noise Test Mothed

With the rapid development of modern communication technology, the demand of the wide band, high power, and low noise microwave devices is becoming stronger and stronger, the difficulty of designing is becoming larger and larger, it’s becoming increasingly important to have this type of microwave device quickly and precisely measured and modeled. On many occasions, the extraction of corresponding parameters of the microwave devices need to be achieved by changing the source impedance and load impedance, and the automated tuner is the best choice to realize this function.This paper firstly embarked from the basic theory, introduced the tuner design theory, and expounded the principle of how the tuner change the source impedance and load impedance. Then, this paper summarized the mechanical mechanism of automated tuner, and analyzed the key technologies of designing 26.5～40 GHZ waveguide type tuner which is made of the BJ-320 standard waveguide, and gave the final design parameters. Then, the paper analyzed the application requirements of automated tuner, selected ST microelectronics company’s STM32F407 which is based on ARM’s Cortex-M4 kernel as core controller, studied the principle and control method of stepper motor which is used as the power source of tuner’s metal diaphragm and the implementation method of USB2.0 interface which is used as computer communication interface, designed the drive circuits of automatic tuner with Altium Designer, and completed the debugging of hardware circuits. Considering the circumstance of using automated tuner and the convenience and reliability of operation, developed the corresponding underlying control driver and communication interface program on the Keil integrated development environment, realized the manual control and computer automatic control of tuner. Then, this paper introduced the test system framework based on automated tuner, proposed the imagine of development a complete set of automated test software platform of microwave devices, which is based on the NI’s virtual instrument development environment LabWindows/CVI, described the automatic test software platform and general test process using the platform. And the calibration module, for example, for this article, the development process of traditional calibration method was described and the proposed fast fitting calibration method was introduced in detail, the experimental results were given, which proven the feasibility of new method. Finally, the paper analyzed the importance of noise measurement. The mothed of noise factor measurement, error correction and improving measuring precision of microwave device were studied, and the extraction methods of noise parameter were briefly introduced, which laid the foundation of realizing the noise parameter measurement function in the automated test software platform in the future.