Microwave and Millimeter-Wave Vacuum Electron Devices: Inductive Output Tubes, Klystrons, Traveling-Wave Tubes, Magnetrons, Crossed-Field Amplifiers, and Gyrotrons

Microwave and Millimeter-Wave
Vacuum Electron Devices Inductive Output Tubes, Klystrons,Traveling-Wave Tubes, Magnetrons,Crossed-Field Amplifiers, and Gyrotrons
	Contents
	Preface
	Chapter 1
Introduction
		1.1 THE DOMAIN OF RF VACUUM ELECTRON DEVICES
		1.2 CLASSIFICATION OF RF VACUUM ELECTRON DEVICES
			1.2.1 Inductive Output Tubes
			1.2.2 Linear Beam Devices
			1.2.3 Crossed-Field Devices
			1.2.4 Gyro-Devices
		1.3 CAPABILITIES OF RF DEVICES
		1.4 OVERVIEW OF THIS BOOK
		REFERENCE
	Chapter 2 Basic Properties of Electromagnetic Waves
		2.1 WAVE PROPAGATION
		2.2 GROUP AND PHASE VELOCITY
		2.3 DISPERSION
			2.3.1 Coaxial Line
			2.3.2 Rectangular Waveguide
		2.4 MODES
			2.4.1 Modes in Rectangular Waveguide
			2.4.2 Modes in a Circular Waveguide
		2.5 PERIODICALLY LOADED WAVEGUIDE
		2.6 EFFECT OF SKIN DEPTH
		REFERENCE
	Chapter 3
Vacuum Requirement
		3.1 VACUUM LEVEL
			3.1.1 Gas Density
			3.1.2 Monolayer Formation Time
			3.1.3 Viscous and Molecular Flow
			3.1.4 Bakeout
			3.1.5 Materials Selection
	Chapter 4
Thermionic Cathodes
		4.1 THERMIONIC EMISSION
			4.1 Thermionic Emission
			4.1.1 Schottky Effect
			4.1.2 Space-Charge Limitation
		4.2 EVOLUTION OF THERMIONIC CATHODES
		4.3 DISPENSER CATHODES
			4.3.1 Fabrication
			4.3.2 Controlled Porosity Reservoir Cathodes
			4.3.3 Operation of Dispenser Cathodes
			4.3.4 Miram Curves
			4.3.5 Work Function Distribution
		4.4 SCANDATE CATHODES
			4.4.1 Background
			4.4.2 Structure and Fabrication
			4.4.3 Operation
			4.4.4 Electron Cooling
			4.4.5 Emission Uniformity
			4.4.6 Scandate-Cathode Life
			4.4.7 Robustness
			4.4.8 Anomalous Behavior
		4.5 LIFE CONSIDERATIONS
			4.5.1 Grant and Falce Life Prediction Model
			4.5.2 Longo Life Prediction Model
		4.6 DISPENSER CATHODE SURFACE PHYSICS
		4.7 HEATERS
			4.7.1 Conventional Heater Assemblies
			4.7.2 Fast Warm-Up Heaters
			4.7.3 Heater Testing
			4.7.4 Effect of Filament Magnetic Field
		REFERENCES
	Chapter 5 Cold Cathodes
		5.1 SECONDARY EMISSION CATHODES
			5.1.1 Introduction
			5.1.2 Characteristics of Secondary Emission
			5.1.3 Energy of Impacting Primary Electrons
			5.1.4 Angle of Incidence of Primary Electrons
			5.1.5 Secondary Emitting Properties of Surfaces
			5.1.6 Energy Distribution of Secondary Electrons
			5.1.7 Modeling of Secondary Emission Characteristics
			5.1.8 Operation of Cathodes in Crossed-Field Devices
		5.2 FIELD EMISSION CATHODES
			5.2.1 Field Emission
			5.2.2 Cathode Assembly
			5.2.3 Proof of Principle Tests
			5.2.4 Cathode Failure Mechanisms and Failure Prevention
		REFERENCES
	Chapter 6 Electron Guns for Linear-Beam Tubes
		6.1 PIERCE GUNS
			6.1.1 Focus Electrodes for Parallel Flow
			6.1.2 Focus Electrodes for Convergent Flow
			6.1.3 Defocusing Effect of Anode Aperture
			6.1.4 Formation of Minimum Beam Diameter
			6.1.5 Thermal Velocity Effects
			6.1.6 Effects of Patchy Emission and Cathode Roughness
		6.2 BEAM CONTROL TECHNIQUES
			6.2.1 Cathode Pulsing
			6.2.2 Modulating Anode
			6.2.3 Control Focus Electrodes
			6.2.4 Grids
			6.2.5 Summary of Beam Control Electrode Characteristics
		REFERENCES
	Chapter 7
Electron Beams from Pierce Guns
		7.1 UNIFORM-FIELD FOCUSING AND LAMINAR FLOW
			7.1.1 Brillouin Flow
			7.1.2 Scalloping
			7.1.3 Confined (Immersed) Flow
		7.2 UNIFORM-FIELD FOCUSING AND NONLAMINAR FLOW
		7.3 FOCUSING WITH PERMANENT MAGNETS
			7.3.1 Overview
			7.3.2 Laminar Flow, No Cathode Flux
			7.3.3 Laminar Flow with Cathode Flux
			7.3.4 Nonlaminar Flow
		REFERENCES
	Chapter 8
Beam Modulation in Linear Beam Tubes
		8.1 BEAM MODULATION
			8.1.1 Density Modulation
			8.1.2 Velocity Modulation
			8.1.3 Gridded (Planar) Gaps
			8.1.4 Gridless (Nonplanar) Gaps
		8.2 BEAM LOADING
		8.3 BUNCHING
			8.3.1 Ballistic Bunching
			8.3.2 Bunching with Space-Charge Forces
		8.4 TRANSITION TO LARGE SIGNAL BUNCHING
			8.4.1 Bunching with and without Space-Charge Effects
			8.4.2 Mihran’s Experimental Results
			8.4.3 Webber’s Disk and Ring Model Results
		REFERENCES
	Chapter 9 Current Induction and Circuit ResponseIn
		9.1 CURRENT INDUCTION
			9.1.1 Ramo’s Theorem
			9.1.2 Induced Current Waveform
			9.1.3 RF Current Induced by an Electron Beam
		9.2 CIRCUIT RESPONSE
			9.2.1 Parallel RLC Circuit
			9.2.2 Resistive Load
			9.2.3 Inductive Load
			9.2.4 Capacitive Load
			9.2.5 Total Cavity Response
		REFERENCE
	Chapter 10
Inductive Output Tubes
		10.1 INTRODUCTION
		10.2 HISTORY AND BASIC OPERATION OF THE IOT
		10.3 ELECTRON GUN
			10.3.1 Grid
			10.3.2 Density Modulation
			10.3.3 Transit Time, Frequency Limit
			10.3.4 Linearity
			10.3.5 Efficiency
		10.4 OUTPUT CIRCUIT
			10.4.1 Bandwidth
			10.5 COLLECTOR
			10.6 POWER
			10.7 SIZE AND WEIGHT
			10.8 APPLICATIONS
				10.8.1 IOTs for Television
				10.8.2 Single-Beam IOTs for Accelerators
				10.8.3 Multiple-Beam IOTs for Accelerators
		REFERENCES
	Chapter 11 Basic Klystrons and Their Operation
		11.1 INVENTION OF THE KLYSTRON
			11.1.1 Reflex Klystrons
		11.2 BASIC OPERATION OF A KLYSTRON
			11.2.1 Cavity Operation
			11.2.2 Coupling to a Cavity
			11.2.3 Tuners and Tuning
		11.3 KLYSTRON DRIVER SECTIONS
			11.3.1 Gain and Bandwidth
		11.4 KLYSTRON OUTPUT SECTION
		REFERENCES
	Chapter 12
Klystron Performance
		12.1 LEGACY KLYSTRONS
		12.2 POWER
			12.2.1 Pulsed Operation
			12.2.2 Limits on Beam Voltage
			12.2.3 Limits on Beam Current
			12.2.4 Estimate of Obtainable Power
			12.2.5 CW Operation
		12.3 BANDWIDTH
			12.3.1 Driver Section
			12.3.2 Output Sections
		12.4 EFFICIENCY
			12.4.1 Background
			12.4.2 The Need for Extremely High Efficiency
			12.4.3 COM and BAC Tuning
		12.5 MULTIPLE BEAM KLYSTRONS
			12.5.1 Background
			12.5.2 Fundamental Mode Resonators
			12.5.3 Higher-Order Mode Resonators
		12.6 MILLIMETER-WAVE EXTENDED-INTERACTION KLYSTRONS
			12.6.1 EIK Components
			12.6.2 EIK Operation
			12.6.3 Applications
		REFERENCES
	Chapter 13 Traveling-Wave Interaction
		13.1 INVENTION OF THE HELIX TWT
			13.1.1 Haeff
			13.1.2 Lindenblad
			13.1.3 Kompfner
		13.2 BASIC OPERATION OF THE HELIX TWT
			13.2.1 The Helix
			13.2.2 Space-Charge Waves
			13.2.3 Plasma Frequency Reduction Factor
			13.2.4 Experimental Verification
		13.3 TWT GAIN
			13.3.1 Effect of Loss
			13.3.2 Effect of Space Charge
		3.4 SATURATION
			13.4.1 Discussion of Interactions
			13.4.2 Estimates of Maximum Efficiency
		REFERENCES
	Chapter 14
Helix TWT Performance
		14.1 BANDWIDTH
			14.1.1 Dispersion
			14.1.2 Dispersion Control
		14.2 GAIN
			14.2.1 Transitions
			14.2.2 Attenuators and Severs
		14.3 POWER
			14.3.1 Peak Power
			14.3.2 Average Power
			14.3.3 Repetition Rate Limitations
		14.4 EFFICIENCY
		14.5 SATELLITE COMMUNICATIONS
		14.6 DUAL-MODE OPERATION
		14.7 MICROWAVE POWER MODULES
		14.8 RING-BAR and RING-LOOP TWTS
		REFERENCES
	Chapter 15
Coupled-Cavity TWTs
		15.1 BASIC OPERATING PRINCIPLES
			15.1.1 Beam-Circuit Interaction
			15.1.2 Cavity-to-Cavity Coupling
		15.2 FUNDAMENTAL BACKWARD-WAVE OPERATION
			15.2.1 Dual Inline Slot
			15.2.2 Staggered Slot
			15.2.3 Millimeter-Wave Construction Techniques
			15.2.4 Dual-Staggered Slot
		15.3 FUNDAMENTAL FORWARD-WAVE OPERATION
		15.4 TWYSTRONS
		15.5 CURNOW-GITTINS EQUIVALENT CIRCUIT
		REFERENCES
	Chapter 16
Collectors for Linear-Beam Tubes
		16.1 POWER DISSIPATION
		16.2 POWER RECOVERY
			16.2.1 Power Flow
			16.2.2 Power Recovery with a Depressed Collector
			16.2.3 Electron Energy Distribution
			16.2.4 Spent Beam Power
			16.2.5 Effect of Body Current
			16.2.6 Multistage Depressed Collectors
			16.2.7 Individual Lens Collectors
			16.2.8 Operation at Reduced Drive Levels
			16.2.9 Efficiency vs. Number of Depressed Stages
			16.2.10 Secondary Electrons in Depressed Collectors
			16.2.11 Power Supply Considerations
		16.3 COLLECTOR COOLING
			16.3.1 Conduction Cooling
			16.3.2 Convection Cooling
			16.3.3 Forced-Air Cooling
			16.3.4 Forced-Flow Liquid Cooling
			16.3.5 Vapor Phase Cooling
			16.3.6 Radiation Cooling
		REFERENCES
	Chapter 17 Distortion in Linear-Beam Tubes
		17.1 DISTORTION RESULTING FROM SATURATION EFFECTS
			17.1.1 AM/AM Conversion
			17.1.2 AM/PM Conversion
			17.1.3 Harmonic Generation
			17.1.4 Intermodulation Products
		17.2 DIGITAL COMMUNICATIONS
			17.2.1 QPSK and 16QAM
			17.2.2 Data Characteristics
			17.2.3 Amplifier Design to Reduce Distortion
		17.3 SIGNAL CAPTURING
		17.4 VARIATIONS WITH FREQUENCY
			17.4.1 Broadband Gain Variations
			17.4.2 Narrowband Gain Variations
			17.4.3 Phase Nonlinearities or Time-Delay Distortion
		17.5 PUSHING AND PULLING
			17.5.1 Amplitude Pushing
			17.5.2 Phase Pushing
			17.5.3 Pulling
		REFERENCES
	Chapter 18
Noise in Linear-Beam Tubes
		18.1 THERMAL AGITATION NOISE
		18.2 DEFINITIONS OF NOISE FIGURE
		18.3 OVERVIEW OF NOISE PHENOMENA
		18.4 NOISE IN ELECTRON GUNS
		18.5 NOISE GENERATION AT THE CATHODE
			18.5.1 Shot Noise
			18.5.2 Velocity Noise
			18.5.3 Other Noise Generation Mechanisms
		18.6 THE SPACE-CHARGE MINIMUM REGION
			18.6.1 Rack Noise Invariance
			18.6.2 Shot Noise Reduction
			18.6.3 Other Noise Effects
			18.6.4 Noise Space-Charge Waves
		18.7 RF SECTION NOISE PHENOMENA
			18.7.1 Impedance Transformation
			18.7.2 Lens Effects
			18.7.3 Circuit Loss
			18.7.4 Partition Noise
			18.7.5 Secondary Electron InteractionsThe electron beam striking the collector generates
		18.8 OTHER NOISE SOURCES
		REFERENCES
	Chapter 19
Magnetrons
		19.1 ELECTRON FLOW WITH NO RF FIELDS
		19.2 TYPES OF MAGNETRONS
			19.2.1 Cyclotron-Frequency Magnetrons
			19.2.3 Traveling-Wave Magnetrons
		19.3 OPERATION OF THE TRAVELING-WAVE MAGNETRON
			19.3.1 Hub Formation
			19.3.2 The Hartree Voltage
			19.3.3 Spoke Formation
			19.3.4 Conversion of Potential Energy to RF Energy
			19.3.5 RF Circuit Operation
		19.4 MODING
		19.5 COAXIAL MAGNETRONS
		19.6 INVERTED MAGNETRONS
		19.7 MAGNETRON TUNING
		19.8 OUTPUT COUPLERS AND TRANSFORMERS
		19.9 CATHODE AND HEATER OPERATION
		19.10 PERFORMANCE
			19.10.1 Voltage-Current Characteristics
			19.10.2 Frequency Pushing
			19.10.3 Frequency Pulling
			19.10.4 Thermal Drift
		19.11 APPLICATIONS OF MAGNETRONS
			19.11.1 Conventional Magnetrons
			19.11.2 Frequency-Agile Magnetrons
			19.11.3 Signal Injected Magnetrons
			19.11.4 Beacon Magnetrons
			19.11.5 Microwave Oven Magnetrons
			19.11.6 Industrial Heating Magnetrons
			19.11.7 Low-Noise Magnetrons
			19.11.8 Magnetrons for Power Beaming
			19.11.9 Relativistic Magnetrons
		19.12 SUMMARY OF POWER CAPABILITIES
		REFERENCES
	Chapter 20
Crossed-Field Amplifiers
		20.1 INTRODUCTION
			20.1.1 Injected-Beam CFAs
			20.1.2 Distributed Emission CFAs
		20.2 CFA OPERATION
			20.2.1 Electron Emission and Hub Formation
			20.2.2 Spoke Formation and Growth
		20.3 CFA SLOW-WAVE CIRCUITS
		20.4 CFA PERFORMANCE
			20.4.1 Forward-Wave CFAs
			20.4.2 Backward-Wave CFAs
			20.4.3 DC Operation
			20.4.4 Gain and Operating Limits
			20.4.5 CFA Phase Characteristics
			20.4.6 Weight and Size Considerations
		20.5 POWER CAPABILITIES
		20.6 THERMAL CONSIDERATIONS
		20.7 CFA POWER SUPPLY CONSIDERATIONS
			20.7.1 DC-Operated Supplies
			20.7.2 Cathode-Pulsing Supplies
		REFERENCES
	Chapter 21
Gyrotrons
		21.1 INTRODUCTION
		21.2 BASIC INTERACTION MECHANISM
		21.3 MAGNETRON INJECTION GUNS
			21.3.1 MIG Configurations
			21.3.2 First-Order Design
			21.3.3 MIG Performance
		21.4 BEAM-WAVE INTERACTION
			21.4.1 Cavities
			21.4.2 Harmonic Operation
		21.5 GYRO-AMPLIFIERS
			21.5.1 Gyro-Klystrons
			21.5.2 Gyro-TWTs
			21.5.3 Gyro-Twystrons
		21.6 MEGAWATT-CLASS GYROTRONS
			21.6.1 Applications for MW Gyrotrons
			21.6.2 The Year of the Gyrotron
		21.7 ENABLING TECHNOLOGIES FOR MEGAWATT GYROTRONS
			21.7.1 Mode Converters
			21.7.2 Coaxial MIGs
			21.7.3 Coaxial Cavities
			21.7.4 Step Frequency Tuning
			21.7.5 Collectors
		REFERENCES
	Chapter 22
Windows
		22.1 BACKGROUND
		22.2 COAXIAL WINDOWS
		22.3 CONVENTIONAL WAVEGUIDE WINDOWS
		22.4 MEGAWATT AVERAGE POWER WINDOWS
			22.4.1 Step Tuning
		22.5 SCALING OF WINDOWS
		REFERENCES
	Appendix A
Useful Constants and Conversions
	Appendix B Vacuum Technology
		B.1 UNITS OF MEASUREMENT
		B.2 RANGES OF OPERATION
		B.3 SOURCES OF GAS
			B.3.1 Backstreaming
			B.3.2 Permeation
			B.3.3 Diffusion
			B.3.4 Desorption
			B.3.5 Vaporization
			B.3.6 Virtual Leaks
			B.3.7 Real Leaks
		B.4 VACUUM SYSTEMS
		B.5 ROUGHING PUMPS
			B.5.1 Oil-Filled Mechanical Pumps
			B.5.2 Scroll Pumps
			B.5.3 Sorption Pumps
			B.5.4 Venturi Pumps
		B.6 HIGH-VACUUM PUMPS
			B.6.1 Diffusion Pumps
			B.6.2 Ion Pumps
			B.6.3 Turbomolecular Pumps
			B.6.4 Cryogenic Pumps
			B.6.5 Nonevaporable Getters
		B.7 VACUUM GAUGES
			B.7.1 Thermocouple Gauge
			B.7.2 Ionization Gauge
		B.8 BAKEOUT
		B.9 MICROWAVE TUBE MATERIALS
		B.10 JOINING TECHNIQUES
			B.10.1 Brazing
			B.10.2 Welding
		REFERENCES
	Appendix C
Magnetics
		C.1 MAGNETIC QUANTITIES
		C.2 MAGNETIC CIRCUITS
		C.3 MAGNETIC MATERIALS
			C.3.1 Ferromagnetic Materials
			C.3.2 Normal and Intrinsic Hysteresis Curves
			C.3.3 Energy Product
			C.3.4 Rare Earth Magnet Materials
		C.4 PERMANENT MAGNETS
			C.4.1 Straight-Field Magnets
			C.4.2 Periodic Permanent Magnets
			C.4.3 Double-Period and Long-Period Focusing
		C.5 POLE PIECES
		C.6 ELECTROMAGNETS
		REFERENCES
	Appendix D
Cyclotron, Larmor, and Scallop Frequencies
		D.1 CYCLOTRON FREQUENCY
		D.2 BUSCH’S THEOREM
		D.3 LARMOR FREQUENCY
		D.4 SCALLOP FREQUENCY
	Appendix E
Breakdown and Protection
		E.1 FIELD ENHANCEMENT
		E.2 DC BREAKDOWN IN VACUUM
			E.2.1 Electrode Phenomena Leading to Breakdown
			E.2.2 Avoiding Breakdown
			E.2.3 Vacuum Arcs
		E.3 DC BREAKDOWN ON INSULATOR SURFACES
		E.4 RF BREAKDOWN IN VACUUM
			E.4.1 Two-Surface Multipactor with No Magnetic Field
			E.4.2 Two-Surface Multipactor in Combined Fields
			E.4.3 Single-Surface Multipactor with No Magnetic Field
			E.4.4 Single-Surface Multipactor in Combined Fields
		E.5 RF BREAKDOWN OF INSULATORS
		E.6 DC BREAKDOWN IN GAS
		E.7 RF BREAKDOWN IN GAS
		E.8 FAULT DETECTION AND TUBE PROTECTION
			E.8.1 Excess Body Current
			E.8.2 Excess Reflected RF Power
		REFERENCES
	Glossary
	About the Author
	Index