Download or read book STUDY OF CROSSED FIELD AMPLIFIERS written by R. A. Rao and published by . This book was released on 1965 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contents: Shielded-gun crossed-field amplifier; Backward-wave noise-figure studies; Noise-figure studies on forwardwave crossed-field amplifier; Cathode-region studies on crossed-field tubes; Characteristics of the smooth-bore magnetron.
Download or read book EW CROSSED FIELD AMPLIFIER written by J. Hentschel and published by . This book was released on 1968 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt: The minimum signal required for efficient operation of an emitting sole crossed-field amplifier is correlated to the ratio of RF electric and dc electric field intensities at the Brillouin hub surface. During the evaluation of these amplifiers with low drive signal, a linear gain region of operation has been observed indicating exponential power growth along the circuit. The complete design procedure developed was applied in an effort to realize a dual mode EW crossed-field amplifier at X-band. A fine grained low velocity circuit with programmed interaction impedance was constructed for this purpose. Multipactor losses on the circuit prevented verification of the design procedure. (Author).
Download or read book Noise Figure of Crossed field Amplifiers written by Joseph Francis Rando and published by . This book was released on 1961 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Klystrons Traveling Wave Tubes Magnetrons Crossed field Amplifiers and Gyrotrons written by A.S. Gilmour Jr. and published by Artech House. This book was released on 2011 with total page 883 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microwave tubes are vacuum electron devices used for the generation and amplification of radio frequencies in the microwave range. An established technology area, the use of tubes remains essential in the field today for high-power applications. The culmination of the authorOCOs 50 years of industry experience, this authoritative resource offers you a thorough understanding of the operations and major classes of microwave tubes.Minimizing the use of advanced mathematics, the book places emphasis on clear qualitative explanations of phenomena. This practical reference serves as an excellent introduction for newcomers to the field and offers established tube engineers a comprehensive refresher. Professionals find coverage of all major tube classifications, including klystrons, traveling wave tubes (TWTs), magnetrons, cross field amplifiers, and gyrotrons."
Download or read book energy conversion characteristics of crossed field injected beam amplifiers written by joseph f. rowe, klaus i. volkholz and published by . This book was released on 1964 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Crossed Field Amplifier CFA Characterization and Theory written by Michael L. Cooke and published by . This book was released on 1973 with total page 71 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this program was the establishment of a computer program for optimizing the design of high power crossed-field amplifiers (C.F.A.'s). The basic tasks of this study were to: (1) Critically evaluate the predictive value of existing large signal Crossed-Field Amplifiers theories or computer codes, and improve their quantitative performance by revision of assumptions and physical concepts as emerging from the comparison between experimental and theoretical results. (2) Investigate the electron flow in the crossed-field gridded gun and resultant non-homogeneities. (3) Examine the electron flow (for the cold electron case) in the crossed-field gun, analytically and/or by numerical computations to achieve self consistency for the solutions of the dynamic and the field equations. (4) Compare theoretical results with actual data as obtained from experiments with gridded crossed-field guns and so assess the value of theoretical achievements. Incorporate for this purpose the functional dependence of the gun performance on various parameters which may be subject to variations in actual tube production and/or operation.
Download or read book A SMALL SIGNAL FIELD THEORY ANALYSIS OF CROSSED FIELD AMPLIFIERS written by BERNARD HERSHENOV and published by . This book was released on 1959 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Study of Crossed Field Amplifiers written by Whinnery John. R. and published by . This book was released on 1959 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book STUDY OF CROSSED FILED AMPLIFIERS written by J. Christensen and published by . This book was released on 1967 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of the work was to study the interaction of electromagnetic waves and electrons in vacuum and solids. Both theoretical and experimental studies of noise phenomena in crossed-field vacuum devices were conducted. The experimental work was a detailed investigation of the dependence of the noise figure of a crossed-field amplifier on various parameters when operated both in the forward-wave and backward-wave modes. The design of another amplifier utilizing the knowledge derived from experiments on the first one and on theoretical conclusions has been developed with the aim to attaining an evaluation of the minimum noise figures for comparison with the O-type amplifiers. One part of the theoretical work was aimed at modifying an existing theory of crossed-field noise figures to include additional effects in an effort to reach better agreement with the (lower) experimental values. Another phase of the theoretical work was directed toward developing a coupled-mode description of the crossed-field amplifier and generalized noise-figure expressions. A study of the crossed-field potential minimum using a feedback model to represent the two-dimensional processes involved in the space-charge effects on the emission perturbations has been made.
Download or read book Reduction of Noise in Crossed field Microwave Amplifiers written by Niladri Raju Mantena and published by . This book was released on 1966 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: The conditions for low-noise operation are established to be the following: (1) the use of a well-focused beam, (2) reduction of the diocotron gain of the gun and drift regions to a minimum possible value, (3) full exploitation of magnetic and space-change smoothing for maximum reduction of noise figure, (4) launching the beam very close to the circuit, (5) reducing the space-charge parameter S close to zero, (6) high power gain, and (7) minimizing the initial beam position fluctuations by reducing the cathode thickness. By combining optimum beam focusing, space-charge smoothing, and beam displacement, low noise figures of 10.5 db for the backward-wave amplifier and 18.4 db for the forward-wave amplifier have been obtained without using noise transducers. A better control of the above factors than was possible with the present experimental tube will result in still lower noise figures. With the noise transducing scheme added to the factors listed above, it should be possible to obtain extremely low noise figures as was done by Wadhwa and Van Duzer. (Author).
Download or read book Research and Development on L band Crossed Field Amplifier Chain written by H. L. McDowell and published by . This book was released on 1962 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nonlinear Analysis of Crossed field Amplifiers written by and published by . This book was released on 1960 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Simulation of Distributed Emission and Injected Beam Crossed Field Amplifiers Part I The Distributed Emission Crossed Field Amplifier written by Donald M. MacGregor and published by . This book was released on 1980 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerical models developed for the crossed-field electron gun predict the current and the beam shape and stability for varied voltages or magnetic field. These programs use a deformable triangular mesh to reproduce the realistic electrode boundaries. A static iterative analysis predicts beam currents about 5 percent higher than measured for a short Kino gun, but is not stable for long cathodes with returning electrons. However, the alternative time-dependent method predicts a stable, well-defined beam in both cases. Excess shot noise in a long-cathode crossed-field gun is believed to be due to cycloiding electrons which return to the cathode from well beyond the potential minimum. Of three theories compared here, only the Ho and Van Duzer model includes these electrons and predicts an instability. With added shot noise the computer simulation may be capable of reproducing the effect. Experimental measurements have been obtained by subcontract for a Northrop gridded crossed-field gun. The two-dimensional time-dependent analysis, which ignores the grids, predicts the beam current with good order-of-magnitude agreement.
Download or read book Printed circuit RF keyed Crossed field Amplifiers written by William E. Courtney and published by . This book was released on 1975 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Simulation of a Crossed field Amplifier Using a Modulated Distributed Cathode written by Marcus Pearlman and published by . This book was released on 2017 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Current crossed-field amplifiers (CFAs) use a uniformly distributed electron beam, and in this work, the effects of using a spatially and temporally controlled electron source are simulated and studied. Spatial and temporal modulation of the electron source in other microwave vacuum electron devices have shown an increase in gain and efficiency over a continuous current source, and it is expected that similar progress will be made with CFAs. Experimentally, for accurate control over the electron emission profile, integration of gated field emitter arrays (GFEAs) as the distributed electron source in a crossed-field amplifier (CFA) is proposed. Two linear format, 600 and 900 MHz CFAs, which use GFEAs in conjunction with hop funnels as an electron source, were designed, modeled in VSim, and built at BSU. The hop funnels provide a way to control the energy of the electron beam separately from the sole potential and to protect the GFEA cathode. The dispersion of the meandering microstrip line slow wave circuit used in the device and the electron beam characteristics were measured and validated the simulation model, but experiments failed to show electron beam interaction with the electromagnetic wave due to insufficient current from the available cathode. To complete the research, a working CFA built at Northeastern University (NU) was modeled. The NU CFA was a linear format, device operating at 150 MHz, with 10 W of RF input power, and typically 150 mA of injected beam current. The electrically short device (6 slow wave wavelengths long) achieved 7 dB of gain. After validating the Vsim model against the experimental results, an electrically longer version (9 wavelengths) was simulated with both an injected beam and distributed cathode. To model the distributed cathode computationally efficiently, where the emitted electron energy can be controlled separately from the sole potential, a new electron injection method was developed, using a divergence-free region. Static electron emission profiles showed no improvement over the injected beam model but the temporally modulated cathode was found to significantly improve the performance. It was found that the temporal modulation could improve the small-signal-gain from 13 dB for an unmodulated source to 25 dB with an injected current of 150 mA and 0.1 W of RF drive power. This improvement is only likely to be observed for higher power devices (>10 kW) because of the additional RF drive power required by the GFEA, however. For larger RF drive powers, the improvements to gain become much smaller. With an RF drive power of 10 W, the modulated cathode showed 9 dB of gain, and the injected beam variant showed 8 dB. The signal-to-noise ratio (SNR) using the modulated cathode was consistently at least 15 dB higher than the SNR of the unmodulated cathode. This reduces the likelihood of excitation of unwanted modes. Even though this device showed small improvements to gain at large RF drive powers, it is proposed here that improvements to maximum power in higher power devices are likely, due to the inherent mode-locking mechanism of the modulated cathode, but this still needs to be confirmed. Previous research studying the effects of a modulated cathode in a magnetron and the improvements to the SNR shown here, show promise in this regard."--Boise State University ScholarWorks.
Download or read book Analysis of Distributed Emission Crossed Field Amplifiers written by and published by . This book was released on 1977 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computer simulation has been used to aid in the development of the Raytheon QKS 1705 and QKS 1842 backward-wave distributed-emission crossed-field amplifiers. At present, Shared Applications, Inc. models a reentrant tube with a planar electrode configuration. The results give insight into the electron dynamics and show good qualitative agreement with measurements. Apparently no steady RF state exists; instead the output power and anode current fluctuate by several percent over the transit time around the tube (fifteen RF periods). To simulate a backward-wave amplifier with the planar model, it is necessary to supply an estimate of RF output power and derive the RF drive power. An alternative cylindrical model has demonstrated the ballistic starting mechanisms in the CFA. This model is capable of including the space-charge forces and the complete RF interaction in both forward- and backward-wave tubes and is recommended for further development.
Download or read book Study of Crossed field Amplifiers written by University of California, Berkeley. Electronics Research Laboratory and published by . This book was released on 1959 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt:
