This document describes improvements to reflex klystrons. It discloses a reflex klystron design that avoids the formation of a virtual cathode in the reflector space by ensuring the ratio of the reflector surface area to the cathode surface area is more than twice the ratio of the length of the retarding path in front of the reflector to the length of the acceleration path in front of the cathode. The klystron is suitable for modulation purposes due to its relatively large bandwidth.
About Transmission Line.
Transmission Lines
Classification Of Transmission Lines
Overhead Power Line
Advantages Of Overhead Transmission Lines
Disadvantages Of Overhead Transmission Lines
Nominal “T” Method
Nominal “Pi” Model of a Medium Transmission Line
Underground Transmission Lines
Classification Of Underground Cables
Advantages Of Underground Cables
Disadvantages Of Underground Cables
About Transmission Line.
Transmission Lines
Classification Of Transmission Lines
Overhead Power Line
Advantages Of Overhead Transmission Lines
Disadvantages Of Overhead Transmission Lines
Nominal “T” Method
Nominal “Pi” Model of a Medium Transmission Line
Underground Transmission Lines
Classification Of Underground Cables
Advantages Of Underground Cables
Disadvantages Of Underground Cables
Effect of earth on transmission line, bundle conductor & method of gmdvishalgohel12195
Effect of earth on transmission line, Bundle conductor & Method of GMD
EFFECTS OF EARTH ON THE CAPACITANCE OF THREE PHASE TRANSMISSION LINES
Bundle Conductors
Complete details of EHV Transmission Line. Consolidated this presentation from those experts who had contributed separately on slider share and other web pages.Thanks for their valuable inputs.
Effect of earth on transmission line, bundle conductor & method of gmdvishalgohel12195
Effect of earth on transmission line, bundle conductor & method of gmd
EFFECTS OF EARTH ON THE CAPACITANCE OF THREE PHASE TRANSMISSION LINES
Bundle Conductors
A transmission line is characterized by four parameters:
series resistance (R) due to conductor resistivity
shunt conductance (G) due to currents along insulator strings and corona; effect is small and usually neglected
series inductance (L) due to magnetic field surrounding the conductor
shunt capacitance (C) due to the electric field between the conductors
These are distributed parameters.
The parameters and hence the characteristics of cables differ significantly from those of overhead lines because the conductors in a cable are
much closer to each other
surrounded by metallic bodies such as shields, lead or aluminum sheets, and steel pipes
separated by insulating material such as impregnated paper, oil, or inert gas
Resistance,bundled conductor,skin effect,proximity effect
Proximity effect depends on:
Frequency of the current
Conductor size
Permeability of material
A turnstile antenna, or crossed-dipole antenna,[1] is a radio antenna consisting of a set of two identical dipole antennas mounted at right angles to each other and fed in phase quadrature; the two currents applied to the dipoles are 90° out of phase.[2][3] The name reflects the notion the antenna looks like a turnstile when mounted horizontally. The antenna can be used in two possible modes. In normal mode the antenna radiates horizontally polarized radio waves perpendicular to its axis. In axial mode the antenna radiates circularly polarized radiation along its axis.
Effect of earth on transmission line, bundle conductor & method of gmdvishalgohel12195
Effect of earth on transmission line, Bundle conductor & Method of GMD
EFFECTS OF EARTH ON THE CAPACITANCE OF THREE PHASE TRANSMISSION LINES
Bundle Conductors
Complete details of EHV Transmission Line. Consolidated this presentation from those experts who had contributed separately on slider share and other web pages.Thanks for their valuable inputs.
Effect of earth on transmission line, bundle conductor & method of gmdvishalgohel12195
Effect of earth on transmission line, bundle conductor & method of gmd
EFFECTS OF EARTH ON THE CAPACITANCE OF THREE PHASE TRANSMISSION LINES
Bundle Conductors
A transmission line is characterized by four parameters:
series resistance (R) due to conductor resistivity
shunt conductance (G) due to currents along insulator strings and corona; effect is small and usually neglected
series inductance (L) due to magnetic field surrounding the conductor
shunt capacitance (C) due to the electric field between the conductors
These are distributed parameters.
The parameters and hence the characteristics of cables differ significantly from those of overhead lines because the conductors in a cable are
much closer to each other
surrounded by metallic bodies such as shields, lead or aluminum sheets, and steel pipes
separated by insulating material such as impregnated paper, oil, or inert gas
Resistance,bundled conductor,skin effect,proximity effect
Proximity effect depends on:
Frequency of the current
Conductor size
Permeability of material
A turnstile antenna, or crossed-dipole antenna,[1] is a radio antenna consisting of a set of two identical dipole antennas mounted at right angles to each other and fed in phase quadrature; the two currents applied to the dipoles are 90° out of phase.[2][3] The name reflects the notion the antenna looks like a turnstile when mounted horizontally. The antenna can be used in two possible modes. In normal mode the antenna radiates horizontally polarized radio waves perpendicular to its axis. In axial mode the antenna radiates circularly polarized radiation along its axis.
A management approach that has gained considerable momentum in recent years, value-based management (VBM) can help executives maximize profitability in the long term. At its most basic level, VBM seeks to maximize organizational value. Instead of thinking about short-term profits, executives using a VBM strategy carefully consider the effects of business decisions on sustainability and future cash flows. As such, VBM treats future cash flow and growth as the primary factors underlying a company’s value.
Analysis Of 3C-Sic Double Implanted MOSFET With Gaussian Profile Doping In Th...IJRES Journal
The present work aims at the design of 3C-SiC Double Implanted Metal Oxide Semiconductor Field Effect Transistor (DIMOSFET) with Gaussian doping profile in drift region for high breakdown voltages. By varying the device height ‘h’, function constant m and peak concentration 𝑁0, analysis has been done for an optimum profile for high breakdown voltage. With Gaussian profile peak concentration 𝑁0 = 1016 𝑐𝑚−3 at drain end and m as 1.496 ×10−2cm, highest breakdown voltage of 6.84kV has been estimated with device height of 200μm.
Design of Circularly Polarized Transmit array Antenna using Low-Profile Dual-...AJASTJournal
A low-profile dual-linearly-polarized unit cell in X-band, and its capability is demonstrated by a circularly polarized transmit array. The unit cell comprises three metallic layers etched on two dielectric slabs without air gap. Cross strips are inserted in cross slots on the top and bottom layers, and the T-slot structure is etched on the middle layer. The proposed unit cell has high isolation between the dual polarizations, and its total thickness of the unit cell is only 1 mm. Prototype of a 341-element transmit array, the incoming incident linearly polarized wave is transformed into the outgoing circularly polarized wave, is simulated. The measured results show that the proposed transmit array realizes 3.5% (9.8-10.15 GHz), axial ratio bandwidth and 4% (9.7-10.1 GHz) 1-dB gain bandwidth. The measured peak gain at 10 GHz is 21.9 dBi, with the aperture efficiency of 36%.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
Design and characterization of polarization reconfigurable heart shape monop...IJECEIAES
This article represented a heart shape reconfigurable monopole antenna with polarization diversity. The proposed antenna is fed by a 50 Ω microstrip feed line that is printed on a flexible FR-4 (εr=4.4) substrate. The antenna comprises a ring-slot, a cross slot and four positive-intrinsic-negative (PIN) diodes that are soldered on ring slot. Four PIN diodes act as a switch and by controlling these PIN diodes effective current direction is changed hence four various states of polarization are achieved. Four states of polarization such as horizontal linear polarization (H-LP), vertical linear polarization (V-LP), right-hand circular polarization (RHCP) and left-hand circular polarization (LHCP) can be switched easily with the help of these PIN diodes and achieved an efficiency of more than 90%. Proposed antenna shows voltage standing wave ratio (VSWR)<2 at all working frequency and -10 dB reflection coefficients (RC) bandwidths (BW) (i.e., S11≤-10 dB) about 32.86% for linear polarization (LP) states while RHCP and LHCP states possess BW of about 31.61% and 31.67% respectively. It also shows axial ratio (AR) BW of 3.41% and 2.44% for RHCP and LHCP, respectively. Besides, the antenna has a well-suited omnidirectional pattern with a positive gain of all working frequency of interest where crosspolarization level is much lower than that of antenna gain.
Сытник В. С. Основы расчета и анализа точности геодезических измерений в стро...Иван Иванов
В книге изложены вопросы теории и практики расчета, бценки
и анализа точности геодезических измерений, выполняемых при
возведении промышленных, жилых и общественных зданий й\цн-
женериых сооружений. На основе существующих в теории вероят^~—-
ностей
математической статистики и ошибок измерений рассмат
риваются методы расчета необходимой и достаточной точности гео
дезических измерений
применительно к определенным стадиям
строительно-монтажных работ и конструктивным решениям зданий
и сооружений. Значительное внимание уделено анализу точности
результатов геодезических измерений
Заковряшин А. И. Конструирование РЭА с учетом особенностей эксплуатацииИван Иванов
Показана роль конструкторского проектирования в обеспечении эффективности технического обслуживания РЭА по фактическому состоянию. В книге
взаимосвязанно решаются вопросы обеспечения ремонто- и контролепригодности
при конструировании РЭА. Ремонтопригодность рассматривается лак решающи”
фактор обеспечения эффективности применения аппаратуры. Область значений
конструктивных показателей РЭА определяется как результат решения задачи
оптимизации заданного качества функционирования.
1. * GB780044 (A)
Description: GB780044 (A) ? 1957-07-31
Improvements in or relating to reflex klystrons
Description of GB780044 (A)
A high quality text as facsimile in your desired language may be available
amongst the following family members:
CH324328 (A) DE1098626 (B) FR1144145 (A) US2881350 (A)
CH324328 (A) DE1098626 (B) FR1144145 (A) US2881350 (A) less
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The EPO does not accept any responsibility for the accuracy of data
and information originating from other authorities than the EPO; in
particular, the EPO does not guarantee that they are complete,
up-to-date or fit for specific purposes.
PATENT SPECIFICATION
780,044 0 Date of Application and filing Complete Specification: Dec.
23, 1954.
No. 37264/54.
Application made in Germany on Dec. 23, 1953.
Complete Specification Published: July 31, 1957.
Index at acceptance:-Class 39(1), D(16A2: 17A2B: 46A).
International Classification:-H01j.
COMPLETE SPECIFICATION
Improvements in or relating to Reflex Klystrons We, SIEMENS & HALSKE
AKTIENGESELLSCHAFT, a German Company, of Siemensstadt, Berlin,
Germany, and Wittelsbacher Platz 4, Munich 2, Germany, do hereby
declare the invention for which we pray that a patent may be granted
to us and the method by which it is to be performed, to be
particularly described in and by the following statement.This
invention relates to reflex klystrons.
2. With a view to producing a reflex klystron of high output, efforts
have been made to ensure that the electron current is as high as
possible and the accelerating voltage as low as possible. However, a
limit is set on the increase in output in this manner by two factors,
namely the emissive power of the cathode and the effect of the space
charge in the reflector space.
As is known, with constant current strength the space charge
progressively increases as the accelerating voltage decreases and at
the surface of reversal of the electrons in front of the reflector
plate it is theoretically infinitely great so that the electrons
spread out laterally instead of returning to the grid space by the
path along which they arrived. Efforts have been made to prevent this
spreading out at the reflector plate by appropriately shaping the
reflector plate and the parts surrounding it.
The invention consists in a reflex klystron having a cavity resonator,
wherein the ratio of the reflector surface area to the cathode surface
area is more than twice the ratio of the square of the length of the
retarding path in front of the reflector and the square of the length
of the acceleration path in front of the cathode.
Preferably the electron beam is made to diverge radially in all
directions at the end of the acceleration path. At high current
densities, a large outwardly directed force in any case exists also in
the unretarded part of the path owing to the large space charge, and
this force will preferably be utilised to produce the divergent beam.
Sprige, 3s. 6d.] The invention will be more particularly described
with reference to the accompanying drawings, in which two embodiments
of the invention are illustrated diagrammatically in greatly
simplified form, only -the parts essential to an understanding of the
invention being shown.
Figure 1 illustrates a reflex klystron in which a concave cathode 1 of
large surface and having relatively low current density is so employed
in known manner that a narrow beam is formed at a point in the
vicinity of the anode 10. This beam then diverges considerably owing
to the space charge forces described.
The walls of tile resonator, which are designated by 2 and 3, are
connected to the grid electrodes 4 and 5. A concave plate 6 is
provided as the reflector. The electron movement takes place within
the beam represented by the chain lines 7 and 8.
Figure 2 illustrates a further embodiment in which, instead of a
cathode of large surface, a high-power cathode of small cross-section
is employed, which is designated by 9. The said cathode may be, for
example, a storage cathode having high electron emissive power and is
disposed so close to the anode 10 that very high current strengths can
be produced at a relatively low anode voltage. A very divergent beam
3. is thus again produced.
In other respects, like parts are designated by the same references as
in Figure 1.
In order that a reflex klystron may operate in accordance with the
invention, it is necessary to prevent the formation of a virtual
cathode in the reflector space. It has been found by experiment and by
theoretical consideration that if a virtual cathode is formed, the
velocity of the returning electrons is only very vaguely defined,
which results in a very small slope of the characteristic
currentvoltage curve of the collector. This slope is a measure of the
quality of the phase focussing of a reflex klystron, because a small
slope indicates that only few electrons of a, particular velocity
group return into the grid I>.1_7L space, and thus that the
building-up of oscillations at a particular frequency is possible only
with low efficiency. Conversely, a large slope indicates the
building-up of oscillations at a particular frequency with high
efficiency.
The twvo grids of the oscillation circuit are shown concavely curved
towards the entering primary beam in the two figures and they
arepreferably also not disposed exactly at the narrowest point of the
beam, so that the arrangement may have a relatively high grid
capacity. The efficiency of the circuit is decreased by this
arrangement, but this is offset by the increased current strength and
by the improved conditions in the reflector space.
Reflex klystrons are particularly suitable for modulation purposes,
since they have a relatively large band width.
The condition essential to the avoidance of the formation of a virtual
cathode is theoretically exactly known. It is a limitation on the
length of the retarding path in front of the reflector and can be
stated matLiematically as a restriction of this length to 1/v2 of the
length of the acceleration path in front of the cathode, everything
being reduced to a plane arrangement. Accordingly, favourable
dimensions for the arrangement are obtained by conforming to the
following simplified formula:
F a-' 2K k= F being the effective reflector surface area, K the
effective cathode surface area, a the length of the retarding path in
front of the reflector, and k the length of the accelerating path in
front of the cathode.
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