| With the advances in modern medical technology, the treatment of manydiseases is changed due to more and more new techniques. As an adjuvant therapyfor cancer, microwave hyperthermia is getting more and more attention in recentyears. microwave hyperthermia has a lot of advantages: greater depth ofpenetration, better heating speed of the tissues and organs, good temperaturecontrolling character, has the ability of selective heating, high security andreliability, application convenient, etc. With the deepening of the research on theinteraction between the electromagnetic field and tissue, high-frequencyelectromagnetic field is gradually applied to medical diagnosis and treatment. Thetreatment effect of Hyperthermia treatment is directly determined by the powercontrolling and effectiveness of microwave radiation, therefore the desi gn ofhighly efficient power amplification system and the optimization of the radiationantenna is particularly important.Based on the application requirement, this subject proposes the research anddesign of power amplifier and antenna respectively.First, the design theory of power amplifier is introduced in detail, includingthe classification of the amplifier, basic characteristics and the design technology.Based on the theory, the design of a multistage amplifier is proposed, and theADS2009(Advance Design System) is used to simulate. The amplifier has goodinput matching character in the frequency rang from0.88GHz to0.98GHz, thepower efficiency of the last stage can reach to49.7%. The eventually optimizecircuit is processed and measured.Second, the Doherty amplifier is proposed to take place the output amplifieraiming to increase the efficiency, the design process is introduced and a efficiencyof55.3%is obtained.Last, the design of the ridge waveguide radiometer is proposed, after theintroduction of waveguide antenna theory, the initial value of the parameters of theantenna is determined by using the equivalent area theory. Simulation softwareCST Studio is use to realize the modeling, optimization and simulation. Goodmatching and radiation character is obtained. |
