`
`(cid:44)(cid:49)(cid:55)(cid:40)(cid:47) EXHIBIT 101(cid:22)
`
`
`
`Library of Congress Cataloging-in—Publication Data
`
`Gibilisco, Stan.
`Handbook of radio and wireless technology / Stan Gibilisco.
`p.
`cm
`Includes index.
`ISBN 0-07-023024-2
`1. Radio.
`2. Wireless communication systems.
`TK6550.G515
`1998
`621.382—dc21
`
`I. Title.
`
`98-8471
`CIP
`
`McGraw-Hill
`A Division of"I'heMcGraw-Hill Companies
`
`:2
`
`Copyright © 1999 by The McGraw-Hill Companies, Inc. All rights
`reserved. Printed in the United States of America. Except as permitted
`under the United States C0pyright Act of 1976, no part of this publication
`may be reproduced or distributed in any form or by any means, or stored
`in a data base or retrieval system, without the prior Written permission of
`the publisher.
`1234567890 DOC/DOC 90321098
`
`ISBN 0—07-023024—2
`
`The sponsoring editor for this book was Scott Grillo, the editing supervisor was
`Stephen M Smith, and the production supervisor was Pamela A. Pelton. It was set
`in Vendome ICC by Joanne Morbit and [Michele Zito of McGraw'I-Iill 's Hightstown,
`NJ, Professional Book Group composition unit.
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`
`This book is printed on recycled, acid-free paper containing
`a minimum of 50% recycled de-inked fiber.
`
`
`Information contained in this work has been obtained by The McGraw—
`Hill Companies, Inc. (“McGraw—Hill”) from sources believed to be reliable.
`However neither McGraw-Hill nor its authors guarantee the accuracy or
`completeness of any information published herein and neither McGraw-
`Hill nor its authors shall be responsible for any errors, omissions, or dam-
`ages arising out of use of this information. This work is published with
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`fessional should be sought.
`
`Page 2 of 9
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`62
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`Chapter 2
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`will radiate. Parasitic arrays, such as the Yagi antenna and the quad
`antenna, operate on this principle.
`
`Selective Filters
`
`The term selective filter refers to circuits designed to tailor the way an
`electronic circuit or system responds to signals at various frequencies.
`There are many kinds of selective filters. Some are used at AF; others are
`used at RF.
`
`Bandpass Filter
`
`Any resonant circuit, or combination of resonant circuits, designed to
`discriminate against all frequencies eXcept a specific frequency f0, or a
`band of frequencies between two limiting frequencies if] and fl, is called
`a bandpass filter: In a parallel LC circuit, a bandpass filter shOWs a high
`impedance at the desired frequency or frequencies, and a low imped-
`ance at unwanted frequencies. In a series LC configuration, the filter has
`a low impedance at the desired frequency or frequencies, and a high
`impedance at unwanted frequencies. Figure 2-9A shows a simple parallel-
`tuned LC bandpass filter; Fig. 2-9B shows a simple series-tuned LC band-
`pass filter.
`Some bandpass filters are built with components other than actual
`coils and capacitors, but all such filters Operate on the same principle.
`The crystal filter uses piezoelectric materials, usually quartz, to obtain a
`bandpass response. A mechanical filter uses Vibration resonances of cer-
`tain substances, usually ceramics. In Optics, a simple color filter, discrimi-
`nating against all light wavelengths except within a certain range, is a
`fOrm of bandpass filter.
`Bandpass filters are sometimes designed to have very sharp, defined,
`resonant frequencies. Sometimes the resonance is spread out over a fairly
`wide range. The attenuationversus-frequency characteristic of a bandpass fil-
`ter is called the bandpass response A bandpass filter can have a single,
`well—defined resonant frequency [0, as shown in Fig. 2-9C, or the
`response might be more or less rectangular, having two well—defined
`limit frequencies f0 and {1, as shown at D. The bandwidth might be only
`a few hertz, such as with an audio filter designed for reception of Morse
`code. Or the bandwidth might be several megahertz, as in a helical filter
`
`Page 3 of 9
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`Passive Electronic Components
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`63
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`Figure 2-9
`AtA, elementary par-
`allel—resonant band—
`pass filter. At B,
`elementary series—res-
`onant bandpass filter.
`At C, sharp bandpass
`response At D,
`broad bandpass
`response.
`
`Input
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`Output
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`Input
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`Output
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`w—W—ii—w
`
`A.
`
`B
`
`«‘3’
`5‘
`A:
`“:2
`E
`<1
`
`%
`3
`a:
`":34
`5
`<3
`
`Frequency
`
`Frequency
`
`C.
`
`D.
`
`designed for the front end of a VHF or UHF radio receiver. A bandpass
`response is always characterized by high attenuation at all frequencies
`eXcept Within a particular range. The actual attenuation at desired fre
`quencies is called the insertion loss.
`
`Band-Rejection Filter
`
`A band-rejection filter, also called a band-stop filter, is a resonant circuit
`designed to pass energy at all frequencies, eXcept within a certain
`range The attenuation is greatest at the resonant frequency f0, or
`between two limiting frequencies f0 and f1 Figure 2—913 shows a simple
`parallel-resonant LC band-rejection filter; drawing F shows a simple
`series-resonant LC band-rejection filter. Note the similarity between
`band-rejection and bandpass filters. The fundamental difference is that
`
`
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`Om—O
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`Input
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`Output
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`Chapter 2
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`Input
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`Output
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`:11
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`OFF:
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`Amplitude
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`Amplitude
`
`Frequency
`
`Frequency
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`G.
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`H.
`
`the band-rejection filter consists of parallel LC circuits connected in
`series with the signal path, or series LC circuits in parallel With the sig-
`nal path; in bandpass filters, series-resonant circuits are connected in
`series, and parallel-resonance circuits in parallel.
`Band-rejection filters need not necessarily be made up of coils and
`capacitors, but they often are. Quartz crystals are sometimes used as
`band-rejection filters. Lengths of transmission line, either short-circuited
`or open, are useful as band-rejection filters at the higher radio frequen-
`cies. A common example of a band-rejection filter is a parasitic suppressor,
`used in high-power RF amplifiers.
`All band-rejection filters show an attenuation-versus-frequency charac-
`teristic marked by low loss at all frequencies except Within a prescribed
`range Figure 2-9G and H ShOWS two types of band-rejection response.
`A sharp response (at G) occurs at or near a single resonant frequency 1%. A
`
`
`
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`64
`
`Figure 2-9 (cont)
`At E, elementary
`parallel—resonant
`band—rejection filter.
`At F, elementary
`series—resonant band-
`
`rejectlon filter At 6,
`sharp band—rejection
`response. At H,
`broad band—rejectlon
`response.
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`Passive Electronic Components
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`65
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`,
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`rectangular respOnse is characterized by low attenuation below a limit 1:)
`and above a limit 13, and high attenuation between these limiting fre-
`quencics.
`
`Notch Filter
`
`A notch filter is a narrowband—rejeetion filter. Notch filters are found
`in many radio communications receivers. The notch filter is extremely
`convenient for reducing interference caused by strong, unmodulated can
`riers Within the passband of a receiver
`Notch-filter circuits are generally inserted in one of the intermediate—
`frequency {IF} stages of a superheterodyne receiver, where the bandpass
`frequency is constant There are several different kinds of notch«filter
`circuit. One of the simplest is a trap configuration, inserted in series
`with the signal path (see Fig. 3913). The notch frequency is adjustable, so
`that the deep null can be tuned to any frequency Within the receiver
`passband.
`A properly designed notch filter can produce attenuation in excess of
`40 decibels (dB) in the center of the notch. Some SOphisticated types,
`especially AP designs, can provide 60 dB of attenuation at the notch fre-
`quency. Audio notch filters generally employ operational amplifiers
`with resistance—capacitance circuits. The frequency is adiusted by means
`of a potentiometer In some AF notch filters, the notch Width (sharpness)
`is adjustable.
`
`High-Pass Filter
`
`A highpass filter is a combination of capacitance, inductance, and/0r
`resistance, intended to produce large amounts of attenuation below a
`certain frequency and little or no attenuation above that frequency The
`frequency at which the transition occurs is called the cutoff frequency At
`the cutoff frequency, the power attenuation is 3 dB with respect to the
`minimum attenuation. Above the cutoff frequency, the power attenua-
`tion is less than 3 (13. Below the cutoff, the power attenuation is more
`than 3 dB.
`
`The simplest high~pass filter consists of a parallel inductor or a
`series capacitor. Generally, high-pass filters have a combination of par~
`allel inductors and series capacitors, such as the simple circuits shown
`in Fig. 2—91 and J. The filter at I is called an Erection high-pass filter,
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`Page 6 of 9
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`Chapter 2
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`Input
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`Output
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`I.
`H |—°
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`Input
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`Output
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`J.
`
`0
`"e
`B:1
`{3-1
`5<1
`
`f0
`
`Frequency
`
`K.
`
`that at J is called a Tsection high-pass filter. These names are derived
`from the geometric shapes of the filters as they appear in schematic
`diagrams.
`Resistors are sometimes substituted for the inductors in a high-pass
`filter. This is especially true if active devices are used, in which case
`many filter sections can be cascaded.
`High—pass filters are used in a wide variety of situations in electronic
`apparatus. One common use for the high-pass filter is at the input of a
`television (TV) receiver. The cutoff frequency of such a filter is about 40
`MHz. The installation of such a filter reduces the susceptibility of the
`TV receiver to EMT from sources at lower frequencies.
`A high—pass response is an attenuation-versus-frequency curve that
`shows greater attenuation at lower frequencies than at higher frequen-
`cies. The sharpness of the response can vary considerably. Usually, a
`high—pass response is characterized by a high degree of attenuation up
`to a certain frequency, where the attenuation rapidly decreases. Finally
`the attenuation levels off at near zero insertion 105s. The cutoff frequen-
`cy of a high-pass response is that frequency at which the insertion
`power loss is 3 dB With respect to the minimum loss. The ultimate attenu-
`ation is the level of power attenuation well below the cutoff frequency,
`where the signal is virtually blocked. A good high-pass response is
`shOWn in Fig. 2-9K. The curve is smooth, and the insertion loss is essen-
`tially zero everywhere well above the cutoff frequency.
`
`
`
`66
`
`Figure 2-9 (cont)
`At I, L-section high—
`pass filter. AtJ,
`T—section high-pass
`filter. At K, high—pass
`response.
`
`
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`Page 7 of 9
`Page 7 of 9
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`Passive Electronic Components
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`67
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`Low-Pass Filter
`
`A low—pass filter is a combination of capacitance, inductance, and/or resis—
`tance, intended to produce large amounts of attenuation above a certain
`frequency and little or no attenuation below that frequency The frequen-
`cy at which the transition occurs is called the cutoff frequency. At the
`cutoff frequency the power attenuation is 3 dB with respect to the mini—
`mum attenuation. Below the cutoff frequency the power attenuation is
`less than 3 dB. Above the cutoff, the power attenuation is more than 3 dB.
`The simplest low-pass filter consists of a series inductor or a parallel
`capacitor More SOphisticated low-pass filters have combinations of series
`inductors and parallel capacitors, such as the examples shown in Fig. 2-9L
`and M. The filter at L is an L-section low-pass filter; the circuit at M is a
`pi-section low-pass filter. As above, these names are derived from the geo-
`metric arrangement of the components as they appear in diagrams.
`Resistors are sometimes substituted for the inductors in a low-pass fil—
`ter. This is especially true when active devices are used, in which case
`many filter stages can be cascaded. This substitution reduces the physical
`bulk of the circuit, and it saves money.
`Low-pass filters are used in many different applications in RF elec-
`tronics. One common use of a low-pass filter is at the output of a high-
`frequency (HF) transmitter. The cutoff frequency is about 40 MHZ.
`When such a low-pass filter is installed in the transmission line between
`a transmitter and antenna, VHF harmonics are greatly attenuated. This
`
`
`
`f0
`
`Frequency
`
`N.
`
`%
`
`B7
`
`34
`8<3
`
`Figure 2-9 (cont)
`At L, L-section low—
`pass filter. At M,
`pi—section low-pass
`filter. At N, lovv~pass
`response.
`
`Input
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`Output
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`L.
`
`Input
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`Output
`
`M.
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`Page 8 of 9
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`68
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`Page 9 of 9
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`Chapter 2
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`reduces the probability of EMI to TV receivers using outdoor antennas,
`In a narrowband transmitter, a low—pass filter might be built in for
`reduction of harmOnic output.
`A low—pass response is an attenuation-versus-frequency curve that shows
`greater attenuation at higher frequencies than at lower frequencies. The
`sharpness of the response can vary considerably. Usually, a low-pass
`response is characterized by a low degree of attenuation up to a certain
`frequency; above that point, the attenuation rapidly increases. Finally
`the attenuation levels off at a large value. Below the cutoff frequency, the
`attenuation is practically zero.
`The cutoff frequency of a low-pass response is that frequency at which
`the insertion power less is 3 dB with respect to the minimum loss. The
`ultimate attenuation is the level of attenuation well above the cutoff fre-
`
`quency where the signal is Virtually blocked. A good low—pass response
`looks like the attenuation-versus-frequency curve shown in Fig. 2-9N.
`The curve is smooth, and the insertion 1055 is essentially zero every-
`where well below the cutoff frequency.
`
`Diodes
`
`The term diode means “two elements." Almost all diodes are made from
`
`silicon or other semiconducting materials.
`
`Theory of Operation
`
`When P-type semiconductor and N-type semiconductor materials are joined,
`a P—N junction is the result. Such a junction has prOperties that make
`semiconductor materials useful as electronic devices. A diode is formed
`
`by a single P—N junction. The N-type material comprises the cathode, and
`the P-type material forms the anode
`In a diode, electrons flow in the direction opposite the arrow in the
`schematic symbol. (Physicists consider current to flow from positive to
`negative, and this is in the same direction as the arrow points.) Current
`will not normally flow the other way unless the voltage is very high. If
`you connect a battery and a resistor in series with a P-N junction, cur-
`rent Will flow if the negative terminal of the battery is connected to the
`N-type material (cathode) and the positive terminal is connected to the
`P-type material (anode). No current will flow if the battery is reversed.
`
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