부산대학교 도서관

Traveling wave tubes (TWTs) are wideband microwave amplifiers offering high gain and efficiency. TWTs are the preferred choice of microwave amplifier in satellite transponder, and such TWTs are popularly called as space TWTs. Space TWTs have several special requirements, such as high efficiency, high gain, long life, and high linearity, etc. In order to achieve high overall TWT efficiency, each of the constituent efficiencies, namely the electronic, circuit, and collector efficiency, has to be maximized. However, it is not straightforward as it appears, as for example, when the electronic efficiency of the tube is increased, the spent beam becomes highly turbulent and chaotic, thereby placing a limit on the maximum achievable collector efficiency with a finite number of electrodes. Hence, collector efficiency enhancement in a high electronic efficiency space TWT requires adequate investigation. In this present work, the authors have designed a five-stage depressed collector for a high electronic efficiency space TWT and have compared the performance with a four-stage equivalent collector, which justifies the need for more number of collector electrodes for such a scenario.