ISSN:0377-2063    

DOI:10.1080/03772063.1993.11437142

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

An improved small signal model (SSM) of a practical helix travelling wave tube (TWT) with a sever, an arbitrary attenuator, a negative step taper and mismatches at the input and output couplers was developed to calculate the small signal gain of the tube. For better accuracy of the small signal analysis, the solutions of the fourth order determinantal equation were used, and the effects of plasma frequency reduction factor and space charge potential depression were included. A modified formula for the loss due to a sever of finite length was given. The accuracy of the SSM was checked against the validated one-dimensional large-signal model (LSM). The SSM was found to be a very useful tool for preliminary design of a TWT because of its very fast speed of computation and reasonably good accuracy for all tubes, and particularly, for low space charge tubes.

ISSN:0377-2063    

DOI:10.1080/03772063.1993.11437143

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

In this paper, a computer aided study of the re-entrant cavity structures, which are of practical utility and widely employed in klystrons, has been done. For these cavities, the behavioral aspects of the cavity parameters are studied by changing the gaps and the drift tube profile. The URMEL group of computer code has been employed for this purpose.

ISSN:0377-2063    

DOI:10.1080/03772063.1993.11437144

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

AD/E band, 1 kW CW four cavity klystron tube has been successfully developed at the Central Electronics Engineering Research Institute (CEERI), Pilani. The main building blocks of this tube are electron gun, magnetic focussing system, RF cavities and collector. Design of each of these has been worked out and is presented in this paper.

ISSN:0377-2063    

DOI:10.1080/03772063.1993.11437145

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

In this paper, a detailed design procedure for designing a thin disc pill-box type microwave window, operating in narrow frequency range at S-band and at a power level of 5 MW, has been given. The design criteria and a generalised design flow chart have been presented and discussed in detail. A method has been suggested for quicker experimental optimisation of the length of the circular waveguide section, which results in substantial saving of time and material. This design methodology can easily be adopted for designing practical pill-box type high power microwave windows.

ISSN:0377-2063    

DOI:10.1080/03772063.1993.11437146

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

The effect of optical illumination on the microwave characteristics of a conventional HEMT has been studied theoretically. The paper describes an integral approach to the problem which includes the calculation of the capacitance and the sheet concentration of the 2-D electron gas in the illuminated condition. The Y-parameters of the device under direct optical control at microwave frequencies have been calculated by considering the changes in the various intrinsic parameters of the device under illuminated condition. The lumped circuit model of the device in the illuminated condition has been obtained with the various components determined from the Y-parameters. The attractive feature of the present model is that it is fully compatible with commonly used circuit simulation packages like SPICE.

ISSN:0377-2063    

DOI:10.1080/03772063.1993.11437147

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

A method for design of high frequency IMPATT, operating in MITATT mode is presented which can compensate for the deterioration in device performance due to loss of carrier build up phase delay caused by tunneling current. The results for 94 GHz Si DDR indicate that the device performance of MITATT diodes would be improved considerably with the modulation of diode design parameters based on phase distortion. The suggested method would provide a realistic approach for design consideration of any form of high frequency IMPATTs operating in mixed tunneling and avalanche mode.

ISSN:0377-2063    

DOI:10.1080/03772063.1993.11437148

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

The phenomenal development of strategic electronics systems, in recent years, and their rapidly growing deployment in civil and defence applications prompted us to study critically how India can exploit the art for national interest. Keeping in mind that India with its vast population needs special attention to mass communication by radio and TV broadcasts, telecommunication, visual communication, disaster and environmental monitoring and warning gadgets, remote sensing of agricultural fields, soil condition and water resources and collision avoidance of fast vehicles, besides a host of defence applications, we were prompted to study the cases one by one and tried to look into the prospects of their development in the Indian context.

ISSN:0377-2063    

DOI:10.1080/03772063.1993.11437149

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

A simple model is developed for the analysis of a broadband slow-wave structure, for a travelling-wave tube, consisting of a helix supported by a dielectric in a metal envelope provided with metal vanes. Simplified models such as one in which the vanes are replaced by an axially conducting cylindrical sheath at the vane tips and the other in which the vanes are azimuthally smoothed out have been tried out, but with limited success. The combination of the results on the dispersion of the structures obtained using the first of these models with those obtained elsewhere by a rigorous field analysis, considering the angular harmonic effects of the vanes, both the results being interpreted in the framework of equivalent circuit analysis, however, proved to be fairly successful, as evidenced by the validation of the approach against the rigorous field theory.

ISSN:0377-2063    

DOI:10.1080/03772063.1993.11437150

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

An experimental study for electrodeposition of gold metal on the silicon wafer for the formation of an integral heat sink of IMPATT diodes is presented in this paper. The rate of deposition is 5.0 microns/hr to 8.0 microns/hr with optimized plating parameters.

ISSN:0377-2063    

DOI:10.1080/03772063.1993.11437151

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor