摘要:

The paper describes the design, construction and performance of an experimental sealed-off six-cavity S-band klystron.At 120 kV and 97 amp, a power of more than 2.5 MW was obtained over a 5.3% bandwidth, the r.f. drive being optimized, at each wave-length, in the range 2–41 watts. For a constant drive of 4.4 watts, 2.5 MW was produced over a 3.4% bandwidth. With the klystron adjusted for maximum efficiency, more than 4 MW was obtained. A gain of 86 dB resulted from tuning all the cavities to the same frequency.Characteristics of stagger-tuned klystron operation and correlation with theory are briefly discussed.

DOI:10.1049/pi-b-1.1958.0185

出版商:IEE    

年代:1958

数据来源: IET

DOI:10.1049/pi-b-1.1958.0187

出版商:IEE    

年代:1958

数据来源: IET

摘要:

An account is given of multipactor discharges occurring at 400 Mc/s in which electron transit times were much longer than the field period, and an analysis is developed, accounting reasonably well for the observed variations of discharge voltage with pressure. Evidence is obtained of the formation of emitting layers during these discharges, but it is shown that these do not appreciably affect the steady-state conditions.

DOI:10.1049/pi-b-1.1958.0189

出版商:IEE    

年代:1958

数据来源: IET

摘要:

In some applications, where it may be desirable to use a broadband klystron amplifier, a knowledge of the delay characteristics of the valve is required; for example, in television and pulse-signalling systems when it is necessary to maintain the original envelope of the input signals, and in systems using amplifiers in parallel when reproducible characteristics are essential.Measurements have been made on an S-band broadband klystron to determine its phase shift with frequency and the effect of variations in the staggering pattern and drive level. Results obtained by mixing the input and output signals of the pulsed klystron in a directional coupler, and observing the sum on an oscillograph, are given.

DOI:10.1049/pi-b-1.1958.0191

出版商:IEE    

年代:1958

数据来源: IET

摘要:

The paper describes the development of a 3-cavity pulsed klystron amplifier with the following parameters: Frequency coverage 900–1300 Mc/s; peak power output 9.0kW; minimum gain at full power 36 dB; maximum duty cycle 3%. The beam is switched by a l.v. low-current electrode which is biased beyond cut-off in the quiescent state. The peak pulsed power requirement is less than ½% of the peak input power.Typical performance data are included.

DOI:10.1049/pi-b-1.1958.0192

出版商:IEE    

年代:1958

数据来源: IET

摘要:

The quantityM2G0(R/Q) for the output cavity is a useful figure of merit for a broad-band power klystron since it is proportional to the product of bandwidth and efficiency. In this expressionMis the effective gap-coupling factor,G0is the d.c. beam conductance and (R/Q) is the ratio of the shunt impedance of the cavity to its Q-factor. The quantity has been evaluated for a commonly used shape of cavity at various values of beam perveance and axial magnetic field strength. It is found that, for any particular magnetic field strength, there is a perveance for which the figure of merit is a maximum. In practice, an upper limit may be set to the perveance that can be used by the debunching forces in the beam which, as the perveance is increased, reduce the maximum spacing permissible between successive cavities until the point is reached where the design is no longer realizable.

DOI:10.1049/pi-b-1.1958.0193

出版商:IEE    

年代:1958

数据来源: IET

摘要:

One of the earliest and simplest forms of velocity-modulation device is the 2-cavity klystron described by the Varian brothers in 1939. The theory of such a device has been studied by many authors, but the detailed comparison of the theory with practical results is generally difficult, owing to the high operating frequency. Moreover, the distribution of the r.f. current along the electron beam cannot be investigated, since a normal klystron has its output cavity at a fixed position, so that the drift length cannot be altered.Electrical measurements can more easily be made at a lower frequency. To study in detail the operation of a klystron, a valve was constructed in which the drift length could be varied. By using the comparatively low frequency of 300 M/s, electrical measuring difficulties are reduced and it is sufficient to use a relatively low beam-current density which facilitates the formation of the electron beam.In the first part of the paper, kinematic and space-charge wave theories of klystron operation are reviewed and the results of numerical calculations are discussed. The second part describes the experimental equipment used and compares the practical results with those obtained theoretically.

DOI:10.1049/pi-b-1.1958.0194

出版商:IEE    

年代:1958

数据来源: IET

摘要:

Some of the factors which must be considered in the design of a multi-cavity klystron are examined. The electron beam and cavities should be designed so as to maximize a figure of merit—the product of the voltage gain and the bandwidth of one stage of the amplifier. The limitations on the low-level bandwidth obtainable imposed by the effects of the couplings between non-adjacent cavities can be minimized by the appropriate choice of the number and separation of the cavities. In terms of the simple space-charge-wave theory the cavities should be separated by a quarter of a plasma wavelength, but consideration of the higher-order space-charge modes shows that the optimum spacing depends on the exact beam configuration. The high-level bandwidth can be maximized by the correct design of the output cavity and external circuit, but the results which can be obtained depend on the behaviour of the electron beam at high signal levels. The theory of this, and of the debunching behaviour of the beam at long drift lengths, is not well established, and an experimental approach is required.

DOI:10.1049/pi-b-1.1958.0195

出版商:IEE    

年代:1958

数据来源: IET

摘要:

A survey is given of the experience gained during the development of high-power klystron amplifiers, with reference to design principles, the application of getter pumps inside sealed-off valves, wide-band tuning mechanism, output windows, influence of secondary emission on tube performance, etc. Also, further experiments on broadbanding of multi-cavity amplifier systems are discussed.

DOI:10.1049/pi-b-1.1958.0197

出版商:IEE    

年代:1958

数据来源: IET

摘要:

The paper describes the design, construction and testing of a high-power klystron suitable for an output of 2 MW at 400 Mc/s and originally proposed for operation at 200 microsec pulse length and 50 pulses/sec, though not tested to this mean power.The valve was satisfactorily run up to 3.5 MW at 120kV 60 amp, and detailed contour diagrams of output power against detuning and input power were taken. The theoretical interpretation of these results is given, in particular a comparison with the theory of Warnecke, Guénard and others. A modification was made on the basis of this theory which improved the efficiency of the valve.

DOI:10.1049/pi-b-1.1958.0198

出版商:IEE    

年代:1958

数据来源: IET