Analysis And Design Of Microwave Low Noise Transistor Amplifiers

With the colligation of the developing history of the world's research on low noise amplifiers, after studying shortcomings and advantages of many LNA's, the working theory of microwave transistor LNA is researched, and a well worked LNA is designed. With the development of the computer, more and more software for microwave simulation come out. The traditional ways of design is so complicated with low design efficiency, and it is hard to validate the results. We use the newest microwave simulation software combine with the common amplifier design theory, after starting with the one-order narrowband model, then several-order broadband, finally reached at the super broadband LNA. In the design process, we choose the precise component model, so the function of the simulation software is fully exerted and the research efficiency is increased. At the same time when based on the traditional theories, we give some our own opinions on how to rise the LNA's stability, lower it's noise, and broaden it's working frequency range by use negative feedback techniques. After finishing the simulation, we choose common ratio frequency components, use the mixed matching method and then get a well performed LNA. Finally we test our product with the net-analyzer, power-analyzer, noise-analyzer and some other apparatus. By the comparison of the simulation result and the tested result, we finally come to a way of design many kinds of microwave transistor LNA according to different demands by combining the modern microwave simulation software with the basic theories.