The Study Of Ka-band Ladde Line Circuit Traveling Wave Tube

The millimeter-wave vacuum devices are kinds of important electronic devices,which can be used in contemporary defense and national economy. The prominentfeature of these devices is high output power. They are the source of radar,communications, electronic warfare, radio broadcasting system and the heart of moderndefense electronic equipment.Currently coupled-cavity structure is used as slow wave circuit in vast majority ofhigh-power traveling wave tube; it is made of metal, so it has a lot of advantages suchas good heat dissipation and strong structural. Hughes coupled cavity slow-wave circuitrequire high accuracyly which is difficult to meet now, in order to solve this problem,we use ladder line slow-wave circuit. It is actually a variant of the coupled-cavity circuit,which has a lot of advantages such as simple processing, high-precision, low-cost.Energy in ladder line slow-wave circuit is coupled high efficiency between electronicand electromagnetic field. So the ladder line slow-wave circuits are researched in thisarticle, the achievements and major innovations are the followings:1. The effect of the sheet-beam channel on the high frequency properties and thebeam-wave interection were analyzed, the characteristics including the dispersionproperties, coupling impedance are obtained by HFSS. The beam-wave interation wassimulated by CST particle studio. The impact of the structural parameters of theslow-wave circuit was researched, and the optimized parameters provide the referencefor the design of traveling wave tube.2. The Ka-band single staggered ladder line slow-wave circuit was designed byemploying the sheet-beam channel and the beam-wave interation of this circuit wasstimulated.3. The Ka-band three staggered ladder line slow-wave circuit is designed. Theeffect of the sheet-beam channel on the high frequency properties and the beam waveinterection were analyzed by HFSS and CST. The results are compared with singlestaggered ladder line slow wave circuit.4. With the shortcomings of lower output power and gain of single ladder line slow-wave circuit, the ridge loaded ladder line slow-wave circuit was designed. Theresults showed that the greater output power and gain can be obtained, however, thebandwidth is slightly narrowed on ridge loaded ladder line slow-wave circuit.