ELECTRONIC AND
`
`RADIO ENGINEERING
`
`FOURTH EDITION
`
`FREDERICK EMMONS TERMAN
`
`Professor of Electrical Engineering
`Dean of the School of Engineering
`Stanford University
`
`Assisted by
`
`ROBERT ARTHUR HELLIWELL
`Associate Professor of Electrical Engineering
`Stanford University
`
`JOSEPH MAYO PETTIT
`Professor of Electrical Engineering
`Stanford University
`
`DEAN ALLEN WATKINS
`
`Associate Professor of Electrical Engineering
`Stanford University
`
`WILLIAM RALPH RAMBO
`Associate Director, Applied Electronics Laboratory
`Stanford University
`
`ASIAN STUDENT S'EDITION
`
`McGRAW—HILL BOOK COMPANY, INC.
`New York
`Toronto
`London
`
`KOGAKUSHA COMPANY LTD.
`TOKYO
`Momentum Dynamics Corporation
`Exhibit 1013
`Page 001
`
`Momentum Dynamics Corporation
`Exhibit 1013
`Page 001
`
`

`

`1922. 1932. 1937.1947
`
`ELECTRONIC AND RADIO ENGINEERING
`
`ASIAN S’I‘UDENTS' EDITION
`
`TOSHO PRINTING (20., 1.11).. TOKYO. JAPAN
`
`Momentum Dynamics Corporation
`Exhibit 1013
`Page 002
`
`Momentum Dynamics Corporation
`Exhibit 1013
`Page 002
`
`

`

`PREFACE
`
`This fourth edition has the same objective as the three prior editions,
`namely, to provide a text and reference book that summarizes in easily
`understandable terms those principles and techniques which are the
`basic tools of the electronic and radio engineer.
`In keeping with current
`trends, increased emphasis is placed on the general techniques of elec-
`tronics, without regard to the extent of their use in radio systems. This
`change is reflected in the new title, “ Electronic and Radio Engineering,”
`which is more descriptive of the subject matter actually covered in the
`present volume than is the previous title, “Radio Engineering.”
`The keynote continues to be thorough coverage combined with a pres-
`entation that allows the reader to study a particular topic without having
`to read the entire book. The level of presentation, particularly the
`mathematical level, remains unchanged. Thus the present volume is
`designed to serve as a text and reference for the same clientele that found
`the previous editions so useful.
`To keep pace with a rapidly advancing technology, new material has
`been added in practically every chapter. More than half the illustrations
`are new, and all have been redrawn to conform to new graphic standards.
`A new chapter dealing with microwave tubes makes available for the first
`time an explanation in simple language of the basic mechanism of oper-
`ation of traveling-wave tubes and backward-wave oscillators (carcino-
`trons).
`In the treatment of wideband video and tuned amplifiers,
`primary emphasis is placed on the rise time, overshoot, and sag, since
`these characteristics are more indicative of the performance under actual
`conditions than is the older approach in terms of amplitude and phase
`behavior as a function of frequency. The material on nonlinear wave-
`forms and pulse techniques has been greatly expanded to provide more
`complete coverage of this important aspect of electronics. The chapter
`on television has been thoroughly revised, and a compact and simple
`explanationrs given of the system of color television now standard in the
`United States.
`Increased attention is also placed on propagation
`phenomena involving the troposphere.
`Of particular importance is the chapter on Transistors and Related
`Semiconductor Devices, one of the longest in the book. Here is pre-
`sented a simple, straightforward explanation of the basic phenomena
`occurring inside the transistor, and of how these phenomena is“ to the
`terminal characteristics. This treatment is such that it can be under-
`
`stood by undergraduate students; at the same time, it is sufliciently com.
`Momentum Dynamics Corporation
`Exhibit 1013
`Page 003
`
`Momentum Dynamics Corporation
`Exhibit 1013
`Page 003
`
`

`

`Ti
`
`PREFACE
`
`plate and fundamental to provide a firm foundation for further study of
`this new and very important subject.
`Special attention has been given to the needs of the teacher. Because
`of the growth of electronics, it is no longer possible to cover every impor-
`tant topic adequately in a one-year course.
`”Electronic and Radio
`Engineering” provides the instructor with an opportunity to select those
`topics which he himself wishes to emphasize, and at the same time pro-
`vides the student with a reference book of comprehensive. coverage and
`continuing value.
`It will be observed that the book breaks down into
`three distinct parts, namely, a group of chapters dealing with circuitst
`(components,
`resonant circuits,
`transmission lines, waveguides, and f
`cavity resonators); a group of chapters concerned with the fundamentals
`of electronic engineering (vacuum tubes, transistors, amplifiers, oscil<
`lators, modulators, detectors, nonlinear waveforms, etc.), which are the
`heart of the book; and a concluding group of chapters concerned with
`radio systems and radio engineering (antennas, propagation, transmitters,
`receivers,
`television, radar, and radio aids to navigation). Thus an
`instructor can, if he desires, concentrate on the material concerned with
`fundamental electronics and regard the remaining subject matter as
`available to the student, should he need to extend his knowledge at a
`future date.
`'Alternatively, the instructor can choose to cover a series
`of selected topics, for example, waveguides, wideband systems, pulse
`circuits,
`television, etc. Another possibility is to concentrate on the
`material concerned primarily with radio systems. Many other combi-
`nations, are, of course, possible.
`An important feature for the teacher is the more than 1250 Problems
`and Exercises. Many of these involve numerical calculations, but more
`than half of them are thought questions that will require the student to
`give further consideration to topics covered in the text. Such Exercises
`can be used to extend and solidify the student’s knowledge; they are also
`suggestive of questions suitable for use on examinations. The number of
`Problems and Exercises is so large that the same problem need not be
`assigned to a class more often than once every two or three years.
`The collaborators listed. on the title page have made important con-
`tributions to the preparation of this volume. Dr. Helliwell worked on the
`sections dealing with ionospheric propagation, and Dr. Pettit is in large
`measure responsible for the general character of the chapter dealing with
`transistors and semiconductors. The treatment of traveling-wave tubes
`and backward-wave oscillators is due to Dr. Watkins. William Rambo
`
`prepared the background material used in revising the presentation on
`radar.
`In addition, acknowledgment
`is made to Dr. B. H. Wadia,
`Bruno Ludovici, and Arthur Vassilaides, graduate students at Stanford,
`for assistance in preparing illustrations.
`
`FREDERICK Euuons Tasman
`Momentum Dynamics Corporation
`Exhibit 1013
`Page 004
`
`Momentum Dynamics Corporation
`Exhibit 1013
`Page 004
`
`

`

`CONTENTS
`
`Preface....................v
`
`CHAPTER 1. The Elements of a System of Radio Communication
`
`CIRCUIT ELEMENTS AND CIRCUIT THEORY
`
`.
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`,2. Circuit Elements.
`3
`Properties of Circuits with Lunipecl Constants
`4. Transmission Lines
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`5 Waveguides and Cavity Resonators
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`ELECTRONIC ENGINEERING FUNDAMENTALS
`
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`6. Fundamental Properties of Electron Tubes
`.
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`7. Electron Optics and Cathode-ray Tubes .
`.
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`8. Voltage Amplifiers for Audio Frequencies.
`.
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`9. Voltage Amplifiers for Video Frequencies
`10. Amplifier Distortion, Power Amplifiers, and Amplifier Sys-
`tems
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`11. Negative Feedback1nAmplifiers .
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`12. Tuned Voltage Amplifiers
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`13. Tuned Power Amplifiers
`14. Vacuum-tube Oscillators
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`15. Amplitude Modulation .
`16. Detectors and Mixers
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`17. Frequency Modulation .
`18. Wave Shaping, Nonlinear Waves, and Pulse Techniques
`19. Microwave Tubes
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`20. Power for Operating Vacuum Tubes
`21. Transistors and Related Semiconductor Devices.
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`RADIO ENGINEERING AND RADIO SYSTEMS
`
`1
`
`II
`44
`82
`127
`
`169
`228
`252
`288
`
`319
`374
`400
`
`448
`489
`
`523
`547
`
`586
`618
`668
`
`702
`733
`
`.
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`803
`,
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`22. Propagation of Radio Waves
`864
`.
`7
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`23. Antennas.
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`24. Radio Transmitters, Receivers, and Communication System 935
`25. Television
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`977
`26. Radar and RadioAids to Navigation.
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`. 1015
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`Name Index;
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`Subjecllndez.
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`.1057
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`.1061
`
`Momentum Dynamics Corporation
`Exhibit 1013
`Page 005
`
`Momentum Dynamics Corporation
`Exhibit 1013
`Page 005
`
`

`

`CHAPTER 1
`
`THE ELEMENTS OF A SYSTEM
`
`OF RADIO COMMUNICATION
`
`1-1. Radio Waves. Electrical energy that has escaped into free space
`exists in the form of electromagnetic waves. These waves, which are
`commonly called radio waves, travel with the velocity of light and consist
`of magnetic and electric fields that are at right angles to each other and
`also at right angles to the direction of travel.
`If these electric and
`magnetic fluxes could actually be seen, the wave would have the appear-
`ance indicated in Fig. 1-1. One-halfflof the electrical energy contained
`
`i Will:
`ii
`if
`
`e o
`
`
`
`D0 0
`
`
`
`
`
`0
`
`(a) FRONT V|EW
`THROUGH PLANE 00
`
`(0) SIDE VIEW
`
`FIG. l-l. Front and side views of a vertically polarized wave. The solid lines repre-
`sent electric flux; the dotted lines and the circles indicate magnetic flux.
`
`in the wave exists in the form of electrostatic energy, while the remaining
`half is in the form of magnetic energy.
`.
`.
`The essential properties of a radio wave are the frequency, intensity,
`direction of travel, and plane of polarization. The radio waves produced
`by an alternating current will vary in intensity with the frequency of the
`current and will therefore be alternately positive and negative as shown
`in Fig. l-lb. The distance occupied by one complete cycle of such an
`alternating wave is equal to the velocity of the wave divided ,by the num-
`ber of cycles that are sent out each second and is called the wavelength.
`The relation between wavelength A in meters and frequency f in cycles
`per second is therefore
`
`= 300,000,000
`f
`
`*
`
`(14)
`
`The quantity 300,000,000 is the velocity of light in meters per second.
`The frequency is ordinarily expressed in kilocycles, abbreviated kc, or in
`megacycles, abbreviated Me. A low-frequency wave 18 seen from Eq.
`Momentum Dynamics Corporation
`Exhibit 1013
`Page 006
`
`Momentum Dynamics Corporation
`Exhibit 1013
`Page 006
`
`

`

`2
`
`SYSTEM OF RADIO COMMUNICATION
`
`{Clan}.
`
`(1-1) to have along wavelength, while a high frequency corresponds to a
`short wavelength.
`_
`The strength of a radio wave is measured in terms of the voltage stress
`produced in space by the electric field of the wave, and it is usually
`expressed in microvolts stress per meter. Since the.actual stress pro-
`duced at any point by an alternating wave varies sinusordally from instant
`to instant, it is customary to consider the intensity of such a wave to be
`the effective value of the stress, which is 0.707 times the maximum stress
`in the atmosphere during the cycle. The strength of the wave measured
`in terms of microvolts per meter of stress in space is also exactly the same
`voltage that the magnetic flux of the wave induces in a conductor 1 m
`long when sweeping across this conductor with the velocity of light.
`The minimum field strength required to give satisfactory reception of a
`wave depends upon a number of factors, such as frequency, type of signal
`involved, and amount of interference present. Under some conditions
`radio waves having signal strengths as low as 0.1 pv per m are usable.
`Occasionally signal strengths exceeding 1000 pv per m are required to
`ensure entirely satisfactory reception at all times.
`In most cases the
`weakest useful signal strength lies somewhere between these extremes.
`A plane parallel to the mutually perpendicular lines of the electric and
`electromagnetic flux is called the wavefront. The wave always travels
`in a direction at right angles to the wavefront, but whether it goes forward
`or backward depends upon the relative direction of the lines of magnetic
`and electric flux.
`If the direction of either the magnetic or electric flux
`is reversed, the direction of travel is reversed; but reversing both sets
`of flux has no effect.
`The direction of the electric lines of flux is called the direction of
`polarization of the wave.
`If the electric flux lines are vertical, as shown
`in Fig. l-l, the wave is vertically polarized; when the electric flux lines
`are horizontal and the electromagnetic flux lines are vertical, the wave
`is horizontally polarized.
`Propagation of Radio Warn of Different Frequencies. As radio waves
`travel away from their point of origin, they become attenuated or weak-
`ened. This is due in part to the fact that the waves spread out.
`In addition. however, énergy may be absorbed from the waves by the,
`ground or by the ionized regions in the upper atmosphere termed the
`ionosphere, and the waves may also be reflected or refracted by the iono-
`sphere, or_by conditions within the lower atmosphere, or by the ground.
`The resulting situation is quite complex and dili‘ers greatly for radio waves
`of different frequencies, as shown in Table 1-1, which summarizes the
`behavxor of different classes of radio waves.
`. 1-2. Radiation of Electrical Energy. Every electrical circuit carry-
`ing alternating current radiates a certain amount of electrical energy in
`the form of electromagnetic waves, but the amount of energy thus radi-
`Momentum Dynamics Corporation
`Exhibit 1013
`Page 007
`
`Momentum Dynamics Corporation
`Exhibit 1013
`Page 007
`
`

`

`Sac. 1-2]
`
`RADIATION OF ELECTRICAL ENERGY
`
`3
`
`ated is extremely small unless all the dimensions of the circuit approach
`the order of magnitude of a wavelength. Thus, a power line carrying
`(SO-cycle current with a 20ft spacing between conductors will radiate
`practically no energy because a wavelength at 60 cycles is more than
`3000 miles, and 20 ft is negligible in comparison. On the other hand, a
`coil 20 ft in diameter and carrying a 2000-kc current will radiate a con-
`siderable amount of energy because 20 ft is comparable with the l50-m
`TABLE l-l
`CLASSIFICATION OF RADIO WAVES
`
`
`Clue
`
`Frequency Wavelength
`range
`range
`
`.
`.
`.
`Propagation characteristics
`Typical uses
`
`
`Very low lre-
`quency (VLF)
`
`Low lrequenry
`(LF)
`
`lo—BO kc
`
`30—300 kc
`
`10,000 1000
`m
`
`30.000—10.000 Low attenuation at all times Lona-distance point-
`m
`of day and 0! year; rharac-
`to-point communica-
`teristics very reliable
`tion
`Propagation at night similar Long-distance point-
`to VLF but sliuhtly lees
`to-point service. me»
`reliable: daytime nbsorp-
`rine. navigational
`tiun greater than VLF
`aids
`Attenuation low at night Broadcasting. marine
`and high in daytime
`communication.
`navigation. harbor
`telephone. etc.
`Transmission over nonsider- Moderate and long-
`able distance depends
`distance cummunlelr
`solely on the ionosphere.
`tion of all types
`and so varies greatly with
`time of day, season, and
`inquency
`Shorbdistsnce corn-
`SubstantiAlly straight—line
`propagation snalmnius to munication. televi~
`that ol' lluht waves; un-
`sion. frequency mod-
`eflccted by ionosphere
`ulation. radar. sir‘
`plans navigation
`Short-distance com-
`munication. radar,
`relay systems. televi-
`sion. etc.
`Radar. radio relay.
`Same
`10 1 cm
`3000-30.000
`Super-high fre-
`navigation
`quency (SHFP Mc
`
`' Frequencies higher than about 2000 Me are frequently referred to as microwave frequencies.
`
`Medium Ire-
`quency (MF)
`
`High frequency
`(HF)
`
`SOD—3000 kc
`
`1000—100 m
`
`3—30 Mc
`
`100—10 m
`
`Very high fre-
`quency (VHF)
`
`30—300 Mo
`
`10-] rn
`
`Ultra-high {re-
`quency (UHFP
`
`300—3000 Mc
`
`100-10 cm
`
`Same
`
`wavelength of this radio wave. From these considerations it is apparent
`that the size of radiator required is inversely proportional to the fre-
`quency. High-frequency waves can therefore be produced‘ by a small
`radiator, while low-frequency waves require a large antenna system for
`eflective radiation.
`
`Every radiator has directional characteristics as a result of which it
`sends out stronger waves in certain directions than inothers. Directional
`characteristics of antennas are used to concentrate the radiation toward
`the point to which it is desired to transmit, or to favor reception of energy
`arriving from a particular direction.
`
`Momentum Dynamics Corporation
`Exhibit 1013
`Page 008
`
`Momentum Dynamics Corporation
`Exhibit 1013
`Page 008
`
`

`

`4
`
`[0342.1
`SYSTEM or RADIO COMMUNICATION
`and Control of Radio-frequency. Power: The radio-
`1-3. Generation
`d by a radio transmitter 13 practically always
`frequency power require
`tube oscillator or amplifier. Vacuum tubes can
`obtained from a vacuum-
`for all frequencies from the very lowest
`convert d—c power into are energy
`to 30 000 Me or even higher. Under most conditions the eficiency
`l\i'ri’th which this transformation takes place is in the neighborhood of 50
`per cent or higher. At frequencies up to well over 1000 Me, the amount of
`___E::li:l__@C74_
`
`(0'! YELEGRAPH CODE SIGNAL
`
`(d) SOUND VIBRATION
`
`
`
`(D) RADIO WAVE AFTER MODULATION BY
`TELERAPH CODE SIGNAL
`
`(4') RADIO WAVE AFTER MODULATION IV
`SOUND VIBRATION
`
`I
`
`IHHIHIHi Hill
`IIIIIIIIlIIIIIIIlIlIIIIIJ
`"mil“
`
`/35552'§5-
`
`(6)
`
`MODULATED VIAVES AFTER RECTIFICATION.
`SHOWING AVERAGE VALUES
`
`l-2. Diagram showing how a signal may be transmitted by modulating the
`Fm.
`amplitude of a radio wave, and how the original signal may be recovered from the
`modulated wave by rectification. For the sake of clarity the radio frequency is shown
`as being much lower than would usually be the case.
`
`power that can be generated continuously by vacuum tubes is of the order
`of kilowatts.
`'.
`Modulation.
`If a radio wave is to convey a message, some feature of
`the wave must be varied in accordance with the information to be trans-
`mitted. One way to do this. termed amplitude modulation, consists in
`yarymg the amplitude of the radiated wave.
`In radio telegraphy, this
`involves turning the radio transmitter on and off in accordance with the
`“‘5 and dashes 0‘ the telegraph code, as illustrated in Fig. 1.21».
`In
`radio-telephone transmission by amplitude modulation the radio-fre-
`quency wave is varied in accordance with the pressure of the sound wave
`being transmitted, as shown in Fig. 1-2e. Similarly in picture trans-
`““33.ion, the amplitude of the wave radiated at any one time is made
`Momentum Dynamics Corporation
`Exhibit 1013
`Page 009
`
`Momentum Dynamics Corporation
`Exhibit 1013
`Page 009
`
`

`

`Sac. 1—4)
`
`RECEPTION‘OF RADIO SIGNALS
`
`j
`
`.
`
`5
`
`proportional to the light intensity of the part of the picture that is being
`transmitted at that instant.
`'
`
`
`
`lb) SAME INFORMATION mAusmrTEo av
`FREQUENCV' MODULATED WAVE
`
`Intelligence may be transmitted by other means than by varying the
`amplitude. For example, one may maintain the amplitude constant and
`vary the frequency that is radiated in accordance with the intelligence,
`thus obtaining frequency modulation. This results in a wave such as
`shown in Fig. 1-3b, which is to be
`compared with the corresponding
`amplitude-modulated wave of Fig.
`13a. Frequency modulation is
`widely used in very high-frequency
`communication systems.
`1-4. Reception of Radio Signals.
`In the reception of radio signals it
`is first necessary to abstract energy
`from the radio wave passing the
`receiving
`point. Any
`antenna
`capable
`of
`radiating
`electrical
`energy is also able to absorb en-
`ergy from a passing radio wave.
`This occurs because the electro-
`
`Fla. ]-3. Character of waves produced by
`amplitude modulation and by frequency
`modulation, where the modulation is
`sinusoidal in both cases. For the sake
`of clarity the radio frequency is shown
`much lower than would usually be the
`
`magnetic flux of the wave, in cutting
`across the antenna conductor, in-
`duces in the antenna a voltage that
`varies with time in exactly the same
`cm‘
`way as does the current flowing in
`the antenna radiating the wave. This induced voltage, in association
`with the current that it produces, represents energy that is absorbed from
`the passing wave.
`Since every wave passing the receiving antenna induces its own voltage
`in the antenna conductor, it is necessary that the receiving equipment be
`capable of separating the desired signal from the unwanted signals that
`are also inducing voltages in the antenna. This separation is made on
`the basis of the difference in frequency between transmitting stations and
`is carried out by the use of resonant circuits which can be made to dis-
`criminate very strongly in favor of a particular frequency. The ability to
`discriminate between radio waves of different
`frequencies is called
`selectivity and the process of adjusting circuits to resonance with the fre-
`quency of a desired signal is spoken of as tuning.
`Although intelligible radio signals have been received from radio trans-
`mitters thousands of miles distant, using only the energy abstracted from
`the radio wave by the receiving antenna, much more satisfactory recep-
`tion can be obtained if the received energy is amplified. This amplifica-
`tion may be applied to the radio-frequency currents before detection, in
`Momentum Dynamics Corporation
`Exhibit 1013
`Page 010
`
`Momentum Dynamics Corporation
`Exhibit 1013
`Page 010
`
`

`

`6
`
`SYSTEM OF RADIO COMMUNICATION
`
`[Canal
`
`which case it is called radio-frequency amplification; 01' it may be applied
`to the rectified currents after detection, in which case it is called audio~
`,
`amplification. The use of amplification makes possible the
`“295::ng reception of signals from waves that would otherWIse be too
`:vaedk to give an audible response. The only satisfactory method of
`amplifying radio signals that has been discovered is by the use of‘vacuum
`tubes or transistors. Before vacuum tubes were discovered, radio recep-
`tion had available only the energy abstracted from the radio wave by the
`-
`'
`'
`ntenna.
`
`1.6333250: The process by which the message being transmitted is
`reproduced from the modulated radio-frequency current present in the
`receiver is called detection, or sometimes demodulation. With amplitude-
`modulated waves, detection is accomplished by rectifying the radio-
`frcquency currents to produce a current that varies in accordance with
`the modulation of the received wave. Thus, when the modulated wave
`shown at e of Fig. 1-2 is rectified, the resulting current, shown at f, is seen
`to have an average value that varies in accordance with the amplitude of
`the original signal.
`In the transmission of code signals by radio, the
`rectified current reproduces the (lots and dashes of the telegraph code, as
`shown at Fig.
`]—2c, and could be used to operate a telegraph sounder.
`When it is desired to receive the telegraph signals directly on a telephone
`receiver, it is necessary to break up the dots and dashes at an audible rate
`in order to give a note that can be heard, since otherwise the telephone
`receiver would give forth a succession of unintelligible clicks.
`The detection of a frequency-modulated wave involves two steps.
`First, the wave is transmitted through a. circuit in which the relative
`response depends upon the frequency. The wave that then emerges from
`the circuit is amplitude-modulated, since as the frequency of the constant-
`amplitude input wave changes, the output amplitude will follow the
`variation of circuit transmission with frequency. The resulting amplitude-
`modulated wave is then rectified.
`1-5. Nature of a Modulated Wave. A sine wave conveys very little
`information since it repeats over and over again. When a wave is modu-
`
`can be deduced by writing down the equation of the wave and making a
`mathematical analysis of the result. Thus, in the case of the simple
`sine-wave amplitude modulation shown in Fig. 1-3a, the amplitude of the
`radio-frequency oscillation is given by E = E, + mEo sin Zirf.t, in WhiCh
`It.) represents the average amplitude, f. the frequency at which the ampli-
`tude is varied, and m the ratio of amplitude variation from the average to
`the average amplituder which is called the degree of modulation. The
`
`Momentum Dynamics Corporation
`Exhibit 1013
`Page 011
`
`Momentum Dynamics Corporation
`Exhibit 1013
`Page 011
`
`

`

`Sac. 1-5)
`
`NATURE OF A MODULATED WAVE
`
`7
`
`equation of the amplitude-modulated wave can be hence written as
`
`e a Eo(1 + m sin 2rf.t) sin 21ft
`
`(1—2)
`
`in which f is the frequency of the radio oscillation. Multiplying out the
`right-th side of Eq. (1-2) gives
`
`9 = E, sin 21ft + mEo sin 2113‘ sin 21ft
`
`By expanding the last term into functions of the sum and difierence
`angles by the usual trigonometric formula, the equation of a wave with
`simple sine-wave amplitude modulation can be written in the form
`
`e = Eu sin 21ft + 12%" cos 2w — f.)t — 232% cos 2.0 +1.):
`
`(1—3)
`
`Equation (1-3) shows that the wave with sine-wave modulation consists
`of three separate waves. The first of these, represented by the term
`E0 sin 21ft,
`is called the carrier.
`Its amplitude is independent of the
`presence or absence of modulation and is equal to the average amplitude
`of the wave. The two other components are alike as far as magnitude is
`concerned, but the frequency of one of them is less than that of the
`carrier frequency by an amount equal to the modulation frequency, while
`the frequency of the other is more than that of the carrier by the same
`amount. These two components, called sideband frequencies, carry the
`intelligence that is being transmitted by the modulated wave. The fre-
`quency of the sideband components relative to the carrier frequency is
`determined by the modulation frequency. The relative amplitude of the
`sideband components is determined by the extent of the amplitude varia-
`tions that are impressed upon the wave, i.e., by the degree of modulation.
`When the modulation is more complex than the simple sine-wave
`amplitude variation of Fig. 1-3a, the effect is to introduce additional side-
`band components. Thus, if the wave of a radio—telephone transmitter is
`amplitude-modulated by a complex sound wave containing pitches of 1000
`and 1500 cycles, the modulated wave will contain one pair of 1000-cycle
`sideband components and one pair of 1500-cycle sideband components.
`The analysis of a frequency-modulated wave is somewhat more com-
`plex but leads to an analogous result. The principal difference is that the
`frequency-modulated wave not only contains the same 'sideband fre-
`quencies as does the corresponding amplitude—modulated wave, but in
`addition contains higher-order side bands. Thus, if a wave has its fre-
`quency varied at a rate of 1000 times per second, the resulting modulated
`wave will contain not only a pair of 1000-cycle sideband components,
`but in addition a pair of 2000-cyc1e sideband components, possibly a pair
`of 3000-cycle sideband components, etc. The amplitude of these various
`Momentum Dynamics Corporation
`Exhibit 1013
`Page 012
`
`Momentum Dynamics Corporation
`Exhibit 1013
`Page 012
`
`

`

`8
`
`SYSTEM OF RADIO COMMUNICATION
`
`[Cum 1
`
`sideband pairs will depend upon the extent and upon the rate of frequency
`variation.
`
`Significance of the Sidebands. The carrier and sideband frequencies are
`not a mathematical fiction, but have a real existence, as is evidenced by
`the fact that the various frequency components of a modulated wave can
`be separated from each other by suitable filter circuits. The sideband
`frequencies can be considered as being generated as a result of varying
`the wave. They are present only when the wave is being varied, and
`their magnitude and frequency are determined by the character of the
`modulation.
`
`It is apparent that the transmission of intelligence requires the use of a
`band of frequencies rather than a single frequency. Speech and music of
`the quality reproduced in standard broadcasting involve frequency com-
`ponents from about 100 cycles up to 5000 cycles; when modulated upon a
`carrier wave, the total bandwidth involved is therefore 10,000 cycles.
`If
`this entire band is not transmitted equally well through space, and by the
`circuits in both transmitter and receiver through which the modulated
`wave must pass, then the sideband frequency components that are dil-
`criminated against will not be reproduced in the receiving equipment with
`proper amplitude, and a loss in quality will result. With telegraph
`signalI, the required sideband is relatively narrow because the amplitude
`of the signals is varied only a few times a second, but a definite frequency
`band is still required.
`If some of the sideband components of the code
`signal are not transmitted,
`the received dots and dashes tend to be
`rounded off and run togethergand may become indistinguishable.
`1-6. The Decibel. The decibel (abbreviated db) is a logarithmic unit
`used in communication work to express power ratios.
`If the powers
`being compared are P, and Pa, then
`Decibels = 10 109.,“Pl
`
`(1-4)
`
`The sign associated with the number of decibels indicates which power is
`greater; thus a negative sign means P, is less than P,.
`The decibel has no other significance than that given in Eq. (1-4).
`Thus, if decibels are used to express amplification, this simply means that
`the presence of the amplification increases the power output by the num-
`ber of decibels attributed to the amplification. Again, under many
`conditions relative power is proportional to the square of the voltage E
`(or current I, or field B, etc.). Under these conditions
`(1-5)
`Decibels = 2010gm % = 20 log”;! = 201050-23. etc.
`I
`l
`I
`These relations must be used with caution, however, as they hold only
`when the resistance associated with E. (or I, or B,) is the same as asso-
`ciated with E1 (or I, or 13;).
`
`Momentum Dynamics Corporation
`Exhibit 1013
`Page 013
`
`Momentum Dynamics Corporation
`Exhibit 1013
`Page 013
`
`

`

`su, 1-6]
`
`THE DECIBEL
`TABLE 1~2
`(0) POWER, VOLTAGE, AND CURRENT RATIOS FOR ASSIGNED
`DECIBEL VALUES
`
`9
`
`Current md
`
` Db voltage ““0
`Loss
`
`-
`-
`0.0
`0.2 1.02 0.977
`0.4 1.05 0.955
`0.6 1.07 0.933
`0.8 1.10 0.912
`1.0
`1.12 0.891
`
`1.19 0.841
`1.5
`2.0 1.26 0.794
`2.5 1.33 0.750
`3.0 1.41 0.708
`3.5 1.50 0.668
`4.0 1.58 0.631
`
`-
`.95
`.91
`.871
`.832
`.794
`
`7
`63
`56
`50
`44
`39
`
`0.316
`0.251
`0.200
`0.158
`0.126
`0.100
`
`0.056
`0.032
`0.018
`0.010
`0.006
`0.003
`
`
`
`Power 11th
`Gain
`Loss
`
`10.00
`15.8
`25 1
`39.8
`63.1
`100.0
`
`0.100
`0.063
`0.040
`0.025
`0.016
`0.010
`
`3.16 X 10' 3.16 X 10"
`10‘
`10"
`3.16 X 10' 3.16 X 10“
`10‘
`10“
`3.16 X 10‘ 3.16 X 10“
`10‘
`10-‘
`
`10‘
`10"
`10'
`10'
`10“
`10“
`
`10"
`10"
`10"
`10"
`10‘"l
`10‘"
`
`4.5 1.68 0.596
`5
`1.78 0.562
`6
`2.00 0.501
`7
`2.24 0.447
`8
`2.51 0.398
`9
`2.82 0.355
`
`.82
`.16
`.98
`.01
`.31
`.94
`
`35
`316
`251
`
`1,0000.001
`3,1600.0003
`10,0000.0001
`31 6000.00003
`100,000 0.00001
`.
`.126 120 1,ooo,oooo.000001
`
`(b) DECIBEL EQUIVALENT OF POWER, VOLTAGE, AND
`CURRENT RATIOS
`
`Db equivalent
`
`Db equivalent
`
`Db equivalent
`
`R3110
`
`or “3110
`Volta
`curl-5:11.
`Power
`~60.00 ~120.00
`10"
`-50.00 -100.00
`10'|
`—-40.00 —80.00
`10-‘
`0.001 —30.00 —60.00
`0.003 -25.23 —50.46
`0.005 -23.01 —-46.02
`
`1.2
`1.4
`1.6
`1.8
`2.0
`2.5
`
`-40.00
`-20.00
`0.01
`-30.46
`0.03 —15.23
`0.05
`-13.01 —26.02
`0.10 —10.00
`-20.00
`0.15 —8 24
`-16.48
`0.20 —6 99
`-13.98
`
`-5.23 —10.46
`0.30
`-3.98
`-7.96
`0.40
`-3.01 —6.02
`0.50
`0.60 —2.22
`-4.44
`0.80 —-0.97 —1.94
`1.00
`0 00
`0.00
`
`3.0
`3.5
`4.0
`4.5
`5.0
`5.5
`
`6.0
`6.5
`7.0
`7.5
`8.0
`9.0
`
`owe!
`0.79
`1.46
`2.04
`2.55
`3.01
`3.98
`
`4.77
`5.44
`6.02
`6.53
`6.99
`7.40
`
`7.78
`8.13
`8.45
`8.75
`9.03
`9.54
`
`Voltage or Ratio
`current.
`1.58
`2.92
`4.08
`5.10
`6.02
`7.96
`
`10
`12
`14
`16
`18
`20
`
`9.54
`10.88
`12.04
`13.06
`13.98
`14 81
`
`15.56
`10.26
`16.90
`17.50
`18.06
`19.08
`
`25
`30
`40
`50
`60
`80
`
`100
`10I
`10‘
`10l
`10'
`10"
`
`‘
`
`Power
`10.00
`10.79
`11.46
`12.04
`12.55
`13.01
`
`13.98
`14.77
`16.02
`16.99
`17.78
`19 03
`
`20.00
`30.00
`40.00
`50.00
`60.00
`70.00
`
`9 or
`Vol
`wit-gut
`20.00
`21.58
`22.02
`24.08
`25.10
`26.02
`
`27.96
`29.54
`32.04
`33.98
`35.56
`38.06
`
`40.00
`60.1»
`80.00
`1111.00
`120.00
`140.00
`
`Momentum Dynamics Corporation
`Exhibit 1013
`Page 014
`
`Momentum Dynamics Corporation
`Exhibit 1013
`Page 014
`
`

`

`[0
`
`SYSTEM OF RADIO COMMUNICATION
`
`(CHM-.1
`
`The practical value of the decibel arises from its logarithmic nature.
`This permits the enormous ranges of power involved in communication
`work to be expressed in terms of decibels without running into incon-
`veniently large numbers, while at the same time permitting small ratios
`to be conveniently expressed. Thus,
`1 db represents a power ratio of
`approximately 5:4, while 60 db represents a. ratio of 1,000,000:1. The
`logarithmic character of the decibel also makes it possible to express the
`ratio of input to output powers of a complicated circuit as the sum of the
`decibel equivalent of the ratios of the input to output powers of the differ-
`ent parts of the circuit that are in cascade.
`Table 1-2 gives a convenient summary of decibel values.
`
`Momentum Dynamics Corporation
`Exhibit 1013
`Page 015
`
`Momentum Dynamics Corporation
`Exhibit 1013
`Page 015
`
`

`

`
`
`CH AP