Via the comparison of the simulation results of the cold test model with the cold test data of the model, a method for determining the resonant characteristics of the operating mode TE_(021)/TE_(031) and the main competing modes TE_(511) and TE_(221) is tried.

Finally, a output cavity loaded with a filter is computed and the computed result is analyzed and compared with cold test data in order to conform the reliability of this simulated computation method.

The second, a complete simulation computation method for output circuit of broadband klystron is developed, basing on existing program ISFEL3D for simulation computation of three dimensions electromagnetic field, principle of output circuit of broadband klystron and microwave network theory. Some practical examples are calculated and the calculated results are compared with cold test results, so that the reliability of the simulation computation method is proven.

The coincidence between the cold test data and the calculation result to a certain extent preliminarily verified the reliability of the field analysis method.

The results show that its bandwidth is above 18.0%(7.1GHz-8.5GHz) and its fluctuating gain is under 1dB; at the same time its maximum output power reaches 2.5kW, and its gain is 18dB, and its efficiency is above 18.4%.

As an example illustrates,the maximum resulting error between field analysis method and equivalent gap impedance method is less than 1.5%,and the maximum error between mode overlapping method and measurement data is 10%.

The quasi-periodic boundary conditions in the computer code MAFIA is used to determine the effect on dispersion and on-axis interaction impedance of helical slow-wave structure parameter variations ,including width,thickness and relative dielectric constant of the support rods.

In This paper, the basic principle and practical methods of widening the operating frequency band of TWT are deacribcd. In particular, a new mcthod of calculation, the region-separation method, is given for the axially slotted shield helix. Cold measurement on this loaded slowwase circuit has been done. By comparison between the results of the cold measurement and of theoretical calculation, if is shown that this new method gives more accurate results than S. F. Paik's method.

A computation method used for doubly reentrant cylindrical cavity of klystron is developed in this paper. According to equivalent principle of field the cavity is divided into three regular regions. The field in each region is supported by proper surface magnetic current density on the common surface and can be expressed as integrals of Green functions.The magnetic fields of two neighbouring regions are then matched on the common surface to yield a set of integral equations. By use of Galerkin's method these...

A computation method used for doubly reentrant cylindrical cavity of klystron is developed in this paper. According to equivalent principle of field the cavity is divided into three regular regions. The field in each region is supported by proper surface magnetic current density on the common surface and can be expressed as integrals of Green functions.The magnetic fields of two neighbouring regions are then matched on the common surface to yield a set of integral equations. By use of Galerkin's method these integral equations are transformed into a set of linear algebraic equations from which the eigenvalue, i. e. resonant frequency of the cavity, and magnetic current densities can be solved. And then another important parameter R/Q may be determined on the basis of the field distribution. Some computation results of cavities with typical dimensions are given and compared reasonably well with experimental data. It is shown that this method is superior to other numerical method (finite difference method or finite element method) in the following aspects: simplicity, higher accuracy, less inner stores, and less computing time.

This paper presents a new problem on the filter properties of the axial conductor loaded helix. By using the equivalent transmission network analysis, it shows that the filter properties are different from those of the structures as suggested in narrow band TWT. In this kind of structure, the TWT can be constructed not only in narrow band operation, but also can be constructed in super-wide band operation.The theoretical analysis of the axial conductor loaded helix shows that its transverse impedance can be...

This paper presents a new problem on the filter properties of the axial conductor loaded helix. By using the equivalent transmission network analysis, it shows that the filter properties are different from those of the structures as suggested in narrow band TWT. In this kind of structure, the TWT can be constructed not only in narrow band operation, but also can be constructed in super-wide band operation.The theoretical analysis of the axial conductor loaded helix shows that its transverse impedance can be loaded lower enough even to 50 ohms and easy matched to the external coaxial coupler directly, while at the same time, it still maintains the coupling impedance in rather higher values and obtains high gain in TWT.The one of the distinguished advantage of the filter type slow wave circuit using in TWT is its property of suppression the BWO. Axial conductor loaded helix also has such kind of property. Dr. Otto Sauseng of USA in 1970 had adopted this kind of slow wave circuit in his TWT, no BWO occured, yet he gave no explaination. Actually, as shown in this paper, the suppression of BWO is due to the filter property of the structure. The TWT when using this kind of structure shows that the operation is quite stable. The theoretical calculation method of the axial conductor loaded helix as used in USA is the S. F. Paik's method, while in USSR the H. H. method is used. But these two methods mainly gave out the dispersion relations, no filter properties were pointed out, and no such kind of characteristics as the pass-band, the stop band, the suppression of BWO, the effect of the numbers of metalic conductor, the effect of the dimensions of the metalic conductor, and the effect of the position of the coaxial coupler, were revealed out. While in this paper, all these problems are analyzed and relations are given. Besides, the cold circuit experiment has been performed and the dispersion curve obtained is shown more close in this method than in S. F. Paik's method, and the match of the input coupler in super-wide band is also quite well. Therefore this filter analyzing method can be used to design such kind of loaded helix for super-wide band TWT.