Design And Fabrication Of Pulse Power Amplifier In X Band

Microwave power amplifiers, the key equipment in modern wireless communication systems, have abroad applications for radar, satellite, airship and electronic counter measurement(ECM). Compared with traditional traveling wave tube amplifiers, microwave power amplifiers have small bulk, large dynamic range, low cost and long lifetime; because of the important roles in military field and personal communication system, it is necessary to develop high quality microwave power amplifiers. The research for this task is also meaningful.Microwave power amplifiers always output specified power in specified frequency range, and satisfy the requirements of linearity and high efficiency. Microwave power amplifiers work in large signal conditions. The design method is different from that of small signal amplifiers, and is more difficult.Now, GaAs MESFET implements are widely used in microwave power amplifiers because of low noise level, high efficiency and good linearity. This thesis discusses the model of GaAs MESFET implements, analyses the gain and stability of microwave power amplifiers with S Parameters, impedance matching networks and bias networks, and summarizes a few methods of microwave power amplifier designs.This thesis includes: the design of driving stage and the last stage of amplifiers, the design of the power supply board of the pulse power generator. We use Ansoft Designer software for simulation and design. After the topological structure is properly decided, the input/output matching networks are simulated, the cascaded multi-stage amplifier is optimized. The gate bias circuit and drain bias circuit designs are presented, and the method of avoiding self-oscillation is proposed. This paper also introduced the basic principle of pulse power amplifier, compared the two pulse modulation methods in different modes. Finally, the demerits of the designed circuits are discussed.