THE CENTIPEDE STRUCTURE IN PRACTICAL MEGAWATT TUBES P.S.Matthews, V.J.Matthews, D.Perring ABSTRACT This paper gives the advantages and design criteria of centipede slow wave structures for megawatt broadband amplifiers. The importance of matching for pi-mode oscillation and the design principles of the velocity taper for improving efficiency are discussed. Results are given for two hybrid am

DESIGN LIMITATIONS AND EXPERIfn~NTAL RESULTS OF HIGH TWT's FROM 30 TO 50 GHz. POWER CW PPM-FOCUSED H. Seunik, F. Gross, F. Weinzierl EXTENDED ABSTRACT For mobile millimeter wave satellite communications terminals two types of TWT have been developed: A Ka band tube with an output power exceeding 1 kW in the band 36.7 to 38.2 GHz (1) and a Q band (40 to 50 GHz) TWT with an output power of more t



RECENT STUDIES CATHODES OF THE CHEMICAL AND PHYSICAL PROCESSES IN THERMIONIC M.C.Green, ABSTRACT R.A.Tuck The reason for the reduced effective work function of osmium coated dispenser cathodes has been investigated using emission microscopy, scanning electron microscopy, electron microprobe analysis and X-ray photo electron spectroscopy. The results indicate that the presence of osmium increa

ROLE OF THE SPACE DEVICES CHARGE AND THE VELOCITY DISTRIBUTION IN GYROTRONS AND RELATED G. MOURIER * ABSTRACT The active role of the electrons in a gyrotron can be expressed, in the linear approximation, by a tensorial polarizability. Having calculated that quantity for a given electron beam it is possible to predict a number of effects due to the self-field of the beam. 

SMITH-PURCELL EFFECT (DIFFRACTION RADIATION) AND ITS APPLICATIONS A.A.SHMATKO, O.A.TRETIAKOV * ABSTRACT. smith-Purcell effect (diffraction radiation) is a phenomenon of electron kinetik energy converting into a plane waves spectrum which appears when a single electron or an electron beam is moving along any periodic structure. The theory of the effect has opened a new field in electronics and

A SUPERHETRODYNE RECEIVER FROM 350 - 400 GHz G.T. Wrixon ABSTRACT A superhetrodyne receiver operating in the frequenCY range 350 - 400 GHz has been constructed. The mixer consists of a low capacitance GaAs Schottky barrier diode, contacted by means of an ultra small inductance spring, mounted across a reduced height waveguide which is fed by a corrugated horn. The quasi-optical diplexer consists

DIRECT AND ACCURATE MEASUREMENTS OF MIXER EQUIVALENT NOISE TEMPERATURES S. Nightingale* and B. Schiek ABSTRACT: A new measuring technique has been developed, which enables the effective noise temperature Teff and intrinsic conversion loss Li of a lossy 2-port network to be determined directly. This technique when applied to a mixer, yields results which are in agreement with theoretical predictio

A Monolithic GaAs Schottky-Barrier Diode Mixer for 15 GHz D. Ristow, N. Enders, and H. Kniepkamp ABSTRACT A planar GaAs Schottky-barrier diode was built by distributing several capacitance of 1 x 2µm over the whole width of a transmission line and connecting them in parallel. These diodes were used in a monolithically integrated balanced mixer on GaAs. The technology was chosen to obtain the s

HIGH RELIABILITY FOR GALLIUM ARSENIDE SCHOTTKY DIODES SPACE APPLICATION P. GIBEAU - J.P. : DUCHEMIN - J. LACOMBE - J. NOGER - A B S T R ACT We describe here the manufacturing process and reliability tests adopted for gallium arsenide Schottky diodes designed for a space programm (TDRSS programm). Due to a new epitaxial process and a multilayer type contact, it has been possible to