| Fourier telescopy is a high-resolution active imaging technique for remoteobjects. Fourier telescope system modulates laser beams with the help of frequencysynthesizers and acousto-optic modulators, and it can simulate the atmosphericturbulence effects by changing the output frequency and power of the frequencysynthesizer. In general, acousto-optic modulator cannot obtain sufficient drive powerfrom the frequency synthesizer. The purpose of this subject is to design a suitablefeed-forward power amplifier, which is used to enlarge the output RF signal power ofthe frequency synthesizer, in order to effectively drive the acousto-optic modulator towork properly for Fourier telescope system.Firstly, this paper introduces the basic theory of the power amplifiers in whichcontains features, technical specifications, power relations and stability; thendiscusses in detail power amplifier linearization techniques: power back-off technique,pre-distortion technique, negative feedback technique and feed-forward technique,with emphasis on some of the advantages of feed-forward technique; followed bysteps in accordance with the design of power amplifiers, a power amplifier is designedwith the Advanced design System (ADS) simulation software of Agilent; Finally, setforth the power amplifier debugging and testing processes, and brings forwardsolutions for some problems encountered during the processes. |
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