The Research Of 6-18GHz Low Power And Gain Adjustable Power Amplifier Design Technology

Traveling wave tube cannot be substituted due to its wide band, single tube high gain, excellent performance, low noise, high efficiency, long service life and reliability in the harsh environment. In today’s microwave power device it occupies a very important position. Traveling wave tube has a very complex production process, especially in the testing stage, which is a waste of human and material resources, and relying on manual measurements will produce many uncertain factors, reducing the testing reliability. Our research group proposed the traveling wave tube automatic test system as the subject, and of the system of research, has achieved certain results.The content of this thesis is to design an ultra-wideband and gain adjustable power amplifier which can be applied to the automatic test system based on the knowledge of the structure and the theory of the ultra-wideband power amplifier. The main work is:1、Introduce the development of ultra-wideband amplifier at home and abroad, the GaN device simulation model and the corresponding passive device model. Analyze the type of power amplifier and a variety of evaluation of the performance of the theoretical indicators from the definition, for the simulation and testing to do a good job in theory.2、Describe broadband matching constraints and ultra-wideband matching theory systematically, deduce the formula of the impedance matching theory based on normalized low pass prototype filter structure, and apply the derived results to design a matching instances, which has proved preliminary validation of the theory, and laid the foundation for the design later.3、Design and research the ultra-wideband and gain adjustable power amplifier, build the small signal model and the large signal model of the GaN chip, which are close to the measured S parameters and the static working point is obtained. Design the driver stage amplifier, attenuator and the last stage power amplifier. Carry out the overall simulation of S parameter and the large signal simulation of the last stage power amplifier, some results have been obtained. After the simulation, the reality had been made and tested, and had achieved some progress, providing a reference for the construction of automatic test system.