"Lessons in Electric Circuits, Volume III -- Semiconductors"
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RF Power Generation I
RF Power Generation I Gridded Tubes and Solid-state Amplifiers Professor R.G. Carter Engineering Department, Lancaster University, U.K. and The Cockcroft Institute of Accelerator Science and Technology Overview • High power RF sources required for all accelerators > 20 MeV • Amplifiers are needed for control of amplitude and phase • RF power output – 10 kW to 2 MW cw – 100 kW to 150 MW pulsed • Frequency range – 50 MHz to 50 GHz • Capital and operating cost is affected by – Lifetime cost of the amplifier – Efficiency (electricity consumption) – Gain (number of stages in the RF amplifier chain) – Size and weight (space required) June 2010 CAS RF for Accelerators, Ebeltoft 2 General principles • RF systems – RF sources extract RF power from high charge, low energy electron bunches – RF transmission components (couplers, windows, circulators etc.) convey the RF power from the source to the accelerator – RF accelerating structures use the PRF in PP DC in RF out Heat RF power to accelerate low charge bunches to high energies PP • RF sources Efficiency RF out RF out PP P – Size must be small compared with DCin RFin DCin the distance an electron moves in one RF cycle PRF out Gain dB 10log10 – Energy not extracted as RF must be PRF in disposed of as heat June 2010 CAS RF for Accelerators, Ebeltoft 3 RF Source Technologies • Vacuum tubes • Solid state – High electron mobility – Wide band-gap materials (Si, GaAs, GaN, SiC, diamond) – Large size – Low carrier mobility – High voltage – Small size – High current • Tube types – Low voltage – Gridded -
Comparative Overview of Inductive Output Tubes
! ESS AD Technical Note ! ESS/AD/0033 ! ! ! ! ! ! !!!!!!!!!! ! !!!Accelerator Division ! ! ! ! ! ! ! ! ! ! Comparative Overview of Inductive Output Tubes Rihua Zeng, Anders J. Johansson, Karin Rathsman and Stephen Molloy Influence of the Droop and Ripple of Modulator onRebecca Klystron SeviourOutput June 2011 23 February 2012 I. Introduction An IOT is a beam driven vacuum electronic RF amplifier. This document represents a comparative overview of the Inductive Output Tube (IOT). Starting with an overview of the IOT, we progress to a comparative discussion of the IOT relative to other RF amplifiers, discussing the advantages and limitations within the frame work of the RF amplifier requirements for the ESS. A discussion on the current state of the art in IOTs is presented along with the status of research programmes to develop 352MHz and 704MHz IOT’s. II. Background The Inductive Output Tube (IOT) RF amplifier was first proposed by Haeff in 1938, but not really developed into a working technology until the 1980s. Although primarily developed for the television transmitters, IOTs have been, and currently are, used on a number of international high- powered particle accelerators, such as; Diamond, LANSCE, and CERN. This has created a precedence and expertise in their use for accelerator applications. IOTs are a modified form of conventional coaxial gridded tubes, similar to the tetrode, although modified towards a linear beam structure device, similar to a Klystron. This hybrid construct is sometimes described as a cross between a klystron and a triode, hence Eimacs trade name for IOTs, the Klystrode. A schematic of an IOT, taken from [1], is shown in Figure 1. -
ABBREVIATIONS EBU Technical Review
ABBREVIATIONS EBU Technical Review AbbreviationsLast updated: January 2012 720i 720 lines, interlaced scan ACATS Advisory Committee on Advanced Television 720p/50 High-definition progressively-scanned TV format Systems (USA) of 1280 x 720 pixels at 50 frames per second ACELP (MPEG-4) A Code-Excited Linear Prediction 1080i/25 High-definition interlaced TV format of ACK ACKnowledgement 1920 x 1080 pixels at 25 frames per second, i.e. ACLR Adjacent Channel Leakage Ratio 50 fields (half frames) every second ACM Adaptive Coding and Modulation 1080p/25 High-definition progressively-scanned TV format ACS Adjacent Channel Selectivity of 1920 x 1080 pixels at 25 frames per second ACT Association of Commercial Television in 1080p/50 High-definition progressively-scanned TV format Europe of 1920 x 1080 pixels at 50 frames per second http://www.acte.be 1080p/60 High-definition progressively-scanned TV format ACTS Advanced Communications Technologies and of 1920 x 1080 pixels at 60 frames per second Services AD Analogue-to-Digital AD Anno Domini (after the birth of Jesus of Nazareth) 21CN BT’s 21st Century Network AD Approved Document 2k COFDM transmission mode with around 2000 AD Audio Description carriers ADC Analogue-to-Digital Converter 3DTV 3-Dimension Television ADIP ADress In Pre-groove 3G 3rd Generation mobile communications ADM (ATM) Add/Drop Multiplexer 4G 4th Generation mobile communications ADPCM Adaptive Differential Pulse Code Modulation 3GPP 3rd Generation Partnership Project ADR Automatic Dialogue Replacement 3GPP2 3rd Generation Partnership -
Anchorage Amateur Radio Club Next Meeting November 4Th
Volume 34 No. 11: November 2005 Anchorage Amateur Radio Club Next Meeting November 4th Program for November communications support for this race since its inception in Jim Wiley, KL7CC 1973. Lee Wareham, KL7DTH, will speak about his adventures Gordon Hartlieb AL1W has again volunteered for the Start flying from Alaska to Norway and back over the pole in his Communications Coordinator and need over 35 Hams for the Cessna 185 - this is the adventure where Ron Sheardown lost 4th of March 2006. his Soviet built AN2 biplane through the ice. I saw the presentation a few years ago, just after the event, and it was Jim Bruton KL7HJ has volunteered to replace Dan O’barr absolutely fascinating. KL7BD as The Re-start Coordinator as Dan’s new job does not allow for the time required for this job. He will need more Lee has some audio tapes excerpts of the conversations on the than 35 hams for the “real” start on the 5th of March 2006. ham radio (between himself and Jerry Curry, KL7EDK, in Fairbanks), which kept up continuously for the whole flight, Kristin Young, (a poor unguided non ham) is the HQ across and back. There will be time for questions. coordinator and is in need of 144 volunteers to fill HQ shifts of which 33 are Ham required. This is a 24/7 operation with +++++++++++++++++++++++++ 6hr. shifts from the 2nd of March thru the 21st of March 2006. Bernadette Anne, (another poor unguided non ham), is the Trail Communications Coordinator and has 48 positions to fill of which 24 are Hams, 6 more than last year. -
3D Modeling, Analysis, and Design of a Traveling-Wave Tube
3D MODELING, ANALYSIS, AND DESIGN OF A TRAVELING-WAVE TUBE USING A MODIFIED RING-BAR STRUCTURE WITH RECTANGULAR TRANSMISSION LINES GEOMETRY by SADIQ ALI ALHUWAIDI B.S., University of Colorado, Boulder, 2011 M.S., University of Colorado, Colorado Springs, 2014 A dissertation submitted to the Graduate Faculty of the University of Colorado Colorado Springs in partial fulfillment of the requirements for the degree of Doctor of Philosophy Department of Electrical and Computer Engineering 2017 © 2017 SADIQ ALI ALHUWAIDI ALL RIGHTS RESERVED This dissertation for the Doctor of Philosophy degree by Sadiq Ali Alhuwaidi has been approved for the Department of Electrical and Computer Engineering by Heather Song, Chair T.S. Kalkur Charlie Wang John Lindsey Zbigniew Celinski Date 12/05/2017 ii Alhuwaidi, Sadiq Ali (Ph.D. Engineering - Electrical Engineering) 3D Modeling, Analysis, and Design of a Traveling-Wave Tube Using a Modified Ring- Bar Structure with Rectangular Transmission Lines Geometry Dissertation directed by Associate Professor Heather Song. ABSTRACT A novel slow-wave structure of the traveling-wave tube consisting of rings and rectangular coupled transmission lines is modeled, analyzed, and designed in the frequency range of 1.89-2.72 GHz. The dispersion and interaction impedance characteristics are investigated using High Frequency Structure Simulator, HFSS, and a power run is carried out using Finite-Difference Time-Domain (FDTD) code, VSim. The performance of the design providing a better output power, gain, bandwidth, and efficiency is compared to the conventional and existing designs by implementing cold- and hot-test simulations. In addition, an electron gun and periodic permanent magnet, PPM, is designed using EGUN code and ANSYS Maxwell, respectively. -
Use Style: Paper Title
Fast Opening Switch Approach for High-Voltage Vacuum Tube Protection Application Wolfhard Merz1, and Monty Grimes2 1DESY, Hamburg, Germany, [email protected] 2Behlke Power Electronics LLC, Billerica, MA, USA, [email protected] Abstract as well. Pulsed mode operation is characterized by 1 Hz repetition rate and duty factor ranging from 0.1 to 0.5 The operation of high-power, high-frequency vacuum tubes respectively. requires an appropriate protection method to avoid significant damages during arcing. Fast closing switches like spark gaps, thyratrons, ignitrons and semiconductors acting as charge- B. Preceding Closing Switch Protection diverting bypass switches are the most commonly used protection A preceding installation for operating a prototype of the method. These “crowbar” switches cause hard transient IOT within a Cryogenic Module Test Bench (CMTB) was conditions for all subcomponents involved and usually result in a accomplished by the application of the classic closing switch significant post-fault recovery period. The availability of fast approach by means of Light Triggered Thyristors (LTT) [1]. high-voltage semiconductor devices, with flexible on/off control For sufficient margin in case of arcing, additional current function, makes opening switch topologies possible and attractive limiting resistors had to be applied. The simplified topology is to improve this situation. This paper describes a circuit topology given in Fig. 1. The protection efficiency of this previous test to protect an Inductive Output Tube which is expected to operate configuration will be compared with the new opening switch within RF subsystems for accelerator applications. The topology approach. The general topology operating an opening switch as is characterized by using a commercial available high voltage MOSFET switch with direct liquid cooling and completed with a series connected device replacing the closing switch is given essential snubber extensions. -
LLRF9 Low-Level RF Controller
LLRF9 Low-Level RF Controller Technical User Manual Author: Revision: Dmitry Teytelman 1.3 March 13, 2019 Copyright © Dimtel, Inc., 2014{2017. All rights reserved. Dimtel, Inc. 2059 Camden Avenue, Suite 136 San Jose, CA 95124 Phone: +1 650 862 8147 Fax: +1 603 218 6669 www.dimtel.com CONTENTS Contents 1 Regulatory Compliance Information3 2 Introduction4 3 Installation and Maintenance6 3.1 Rack Mounting and Ventilation Requirements.........6 3.2 AC Power Connection......................6 3.3 IOC Setup.............................6 3.4 Intake Air Filter Maintenance..................9 4 Hardware 10 4.1 Overall topology......................... 10 4.2 LLRF4.6.............................. 11 4.3 RF input channels........................ 11 4.4 RF outputs............................ 12 4.5 LO signal generation....................... 12 4.5.1 500 MHz.......................... 12 4.5.2 476 MHz.......................... 14 4.5.3 204 MHz.......................... 14 4.6 Interlock subsystem........................ 14 4.7 Digital I/O............................ 15 4.8 Slow analog inputs........................ 15 4.9 Housekeeping........................... 16 5 Feedback 18 5.1 Cavity field control........................ 18 5.2 Setpoint profile.......................... 19 5.3 Tuner loop............................. 20 6 Acquisition and Diagnostics 22 6.1 Scalar acquisition......................... 22 6.2 Channel attributes........................ 22 6.2.1 Amplitude......................... 22 6.2.2 Phase........................... 23 6.3 Waveform acquisition....................... 24 6.4 Real-time Network Analyzer................... 24 1 of 41 CONTENTS 7 Interlocks 25 7.1 RF input interlocks........................ 26 7.2 Baseband ADC interlocks.................... 27 8 System configurations 28 8.1 One station, single cavity, single power source......... 29 8.2 One station, two cavities, single power source......... 29 8.3 Two stations, two cavities, two power sources........ -
Unusual Tubes
Unusual Tubes Tom Duncan, KG4CUY March 8, 2019 Tubes On Hand GAS-FILLED HIGH-VACUUM • Neon Lamp (NE-51) • Photomultiplier • Cold-cathode Voltage (931A) Regulator (0B2) • Magic Eye (1629) • Hot-cathode Thyratron • Low-voltage (12DY8) (884) • Space Charge (12K5) 2 Timeline of Related Events 1876, 1902 William Crookes Cathode Rays, Glow Discharge 1887 [1921] Hertz, Einstein Photoelectric Effect 1897 [1906] J. J. Thomson Electron identified 1920 Daniel Moore (GE) Voltage Regulator 1923 Joseph Slepian Secondary Emission (Westinghouse) 1928 Albert Hull, Irving Thyratron Langmuir (GE) [1928] Owen Richardson Thermionic Emission 1936 Vladimir Zworykin Photomultiplier (RCA) 1937 Allen DuMont Magic Eye 3 Neon Bulbs • Based on glow-discharge (coronal discharge) effect noticed by William Crookes around 1902. • Exhibit a negative incremental resistance over part of the operating range. • Light-sensitive: photo-ionization causes the ionization voltage to decrease with illumination (not generally a desirable characteristic). • Used as indicators , voltage regulators, relaxation oscillators , and the larger ones for illumination . 4 Neon Lamp/VR Tube Curves 80 Normal Abnormal Glow Glow 70 60 Townsend Discharge 50 Negative Resistance 40 Region 30 Volts across Device across Volts 20 10 Conduction Destroys Lamp Destroys Arc Conduction Arc Chart details (coronal) Glow depend on -5 element 10 -20 10 -15 10 -10 10 1 geometry and Current through Device (A) gas mixture. 5 Cold-Cathode Voltage Regulator Tubes • Very similar to neon bulbs: attention paid to increasing current-carrying capability and ensuring a constant forward voltage. • Gas sometimes includes radio-isotopes to reduce sensitivity to photo-ionization. • Developed at General Electric Research Labs by Daniel Moore around 1920. -
High Power Radio Frequency Solid-State Amplifiers and Combiners for Particle Accelerators
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 1881 High Power Radio Frequency Solid-State Amplifiers and Combiners for Particle Accelerators From module to system design approach LONG HOANG ACTA UNIVERSITATIS UPSALIENSIS ISSN 1651-6214 ISBN 978-91-513-0818-0 UPPSALA urn:nbn:se:uu:diva-397500 2019 Dissertation presented at Uppsala University to be publicly examined in Häggsalen, Ångströmlaboratoriet, Lägerhyddsvägen 1, Uppsala, Wednesday, 15 January 2020 at 09:15 for the degree of Doctor of Philosophy. The examination will be conducted in English. Faculty examiner: Professor Paul Tasker (School of Engineering, Cardiff University). Abstract Hoang, L. 2019. High Power Radio Frequency Solid-State Amplifiers and Combiners for Particle Accelerators. From module to system design approach. Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 1881. 98 pp. Uppsala: Acta Universitatis Upsaliensis. ISBN 978-91-513-0818-0. The rise of Big Science projects brings issues related to the energy consumption and the associated environmental impacts of such large-scale facilities. Therefore, environmentally- sustainable developments are undertaken towards the adoption of energy savings and improved energy-efficient approaches. The advent of the superconducting (SC) radio frequency (RF) accelerating cavity is bringing answers to these issues. Such superconducting RF (SRF) cavity is made of niobium that allows much higher accelerating gradients with a minimization of the energy consumption. The SC RF technology is increasingly used in many modern particle accelerators, including: the European Spallation Source (ESS), the X-ray Free Electron Laser (XFEL), the Linac Coherent Light Source (LCLS)-II and the proposed International Linear Collider (ILC). -
Radio Age 12 2020 DEC.Pdf
RADIO AGE The Vintage Radio Journal of the Mid-Atlantic Antique Radio Club Volume 45 December 2020 Number 12 The Midwest Radio Corporation By Brian Belanger ounded by A. G. Hoffman when he began prices. Midwest was unusual because it did not rely F making simple radios in his Cincinnati basement, on a dealer network and jobbers, but rather sold Midwest sold its first radio in 1920—the one-tube directly to customers. Its marketing strived to model shown on this page. convince potential buyers that they could save big money by ordering right from the factory. Of course The company introduced a number of models in its if you ordered a heavy console radio, the significant first few years, including the regenerative set shown shipping cost (usually railway express) had to be on page 3. But Alan Douglas says it was advertised considered. Midwest sometimes quoted prices only for one month, probably because the company without including the cabinet cost because the same did not have an Armstrong license and may have chassis could be used in more than one cabinet. been threatened with patent infringement unless it Midwest offered a time payment plan and a 30-day immediately ceased selling regenerative sets. trial period with a full refund if you were not satisfied. At first Hoffman used “Miraco” [MIdwest RAdio COrporation] as his brand name, but later, just In its first decade, Miraco did reasonably well Midwest. The company advertised widely in popular keeping up with changing technology and its com- magazines and bragged about its low “factory direct” (Continued on page 3) Midwest’s first radio (1920), called the Model VT. -
Review of Available Power Sources
Review of Available Power Sources Carl Beard CCLRC Daresbury Laboratory Keckwick Lane, Daresbury, Warrington WA4 4AD, UK Corresponding author: Carl Beard CCLRC Daresbury Laboratory Warrington WA4 4AD, UK Phone: +44 (0)1925 603588 FAX: +44 (0)1925 603124 e-mail: [email protected] ABSTRACT Klystrons and triodes have been the accepted choice for particle accelerators because they produce high power RF and offer high gain (60 dB) with efficiencies of ~50%. Although fairly new to the market, IOTs have become available at L-band frequencies and have maintained their high efficiency. The development of Superconducting RF at the L- band frequency allows IOTs to become the choice for future accelerator programs. Due to the operational nature of SRF technology in energy recovery mode, there is no longer the requirement for large amounts of RF power from single sources. This report reviews some of the developments in RF power sources suitable for ERLs. Keywords: Klystron, Inductive Output Tube, IOT, Power Sources, Radio Frequency. 1. KLYSTRONS Invented in the late 1930’s by the Varian brothers, Klystrons contain three separate sections, the gun region, the RF interaction region, and the collector (figure 1). A typical klystron would contain a thermionic gun, several RF cavities and a collector to retrieve the spent electrons. A DC electron beam is emitted from the gun, and in the absence of RF the electrons travel through the drift tube and would disperse in the collector. The electron beam is magnetically focused to counter the effect of space charge growth through the drift tube section. -
2011 IEEE International Vacuum Electronics Conference
2011 IEEE International Vacuum Electronics Conference (IVEC 2011) Bangalore, Karnataka, India 21 – 24 February 2011 IEEE Catalog Number: CFP11VAM-PRT ISBN: 978-1-4244-8662-5 Contents Foreword ............................................................................................................................................. iii IVEC-2011 Organising Committees ..................................................................................................... v EDS Technical Committee on Vacuum Devices .................................................................................. vi Inaugural Session PL-1: Relativistic Effects in Microwave Vacuum Electronics .................................................... 1 Michael I. Petelin (Institute of Applied Physics, Nizhny Novgorod, Russia) Plenary Session–1 PL-2: Microwaves and Particle Accelerators: A Fundamental Link .......................................... 5 Swapan Chattopadhyay (Cockcroft Institute of Accelerator Science & Technology, UK) PL-3: Vacuum Electronics in India ............................................................................................... 7 Lalit Kumar (Microwave Tube R&D Centre, Bangalore, India) PL-4: Vacuum Electronic Sources for High Power Terahertz-Regime ..................................... 11 John Booske (University of Wisconsin-Madison, USA ) Session–1: Traveling-Wave Tubes 1.1: Design and Development of 2 to 3 Octave Band Helix Mini-TWTs ................................. 15 Tushar K. Ghosh, Anthony J. Challis, Anthony Tokeley, Michael