SIST EN 60244-8:1999
(Main)Methods of measurement for radio transmitters -- Part 8: Performance characteristics of vestigial-sideband demodulators used for testing television transmitters and transposers
Methods of measurement for radio transmitters -- Part 8: Performance characteristics of vestigial-sideband demodulators used for testing television transmitters and transposers
To be used for type tests and acceptance or factory tests or to check the characteristics of a demodulator measuring television transmitters and transposers.
Meßverfahren für Funksender -- Teil 8: Übertragungseigenschaften von Restseitenband-Demodulatoren zur Prüfung von Fernsehsendern und Umsetzern
Méthodes de mesure applicables aux émetteurs radioélectriques -- Partie 8: Qualité de fonctionnement des démodulateurs à bande latérale résiduelle utilisés pour les essais des émetteurs et réémetteurs de télévision
Destinées à réaliser les essais de type, ainsi que les essais de réception et les essais en usine. Peut servir à évaluer les caractéristiques d'un démodulateur utilisé pour réaliser des mesures sur les émetteurs et les réémetteurs de télévision.
Methods of measurement for radio transmitters - Part 8: Performance characteristics of vestigial-sideband demodulators used for testing (IEC 60244-8:1993)
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 60244-8:1999
01-januar-1999
Methods of measurement for radio transmitters - Part 8: Performance
characteristics of vestigial-sideband demodulators used for testing (IEC 60244-
8:1993)
Methods of measurement for radio transmitters -- Part 8: Performance characteristics of
vestigial-sideband demodulators used for testing television transmitters and transposers
Meßverfahren für Funksender -- Teil 8: Übertragungseigenschaften von Restseitenband-
Demodulatoren zur Prüfung von Fernsehsendern und Umsetzern
Méthodes de mesure applicables aux émetteurs radioélectriques -- Partie 8: Qualité de
fonctionnement des démodulateurs à bande latérale résiduelle utilisés pour les essais
des émetteurs et réémetteurs de télévision
Ta slovenski standard je istoveten z: EN 60244-8:1994
ICS:
33.060.20 Sprejemna in oddajna Receiving and transmitting
oprema equipment
SIST EN 60244-8:1999 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN 60244-8:1999
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SIST EN 60244-8:1999
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SIST EN 60244-8:1999
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SIST EN 60244-8:1999
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SIST EN 60244-8:1999
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SIST EN 60244-8:1999
NORME
CEI
INTERNATIONALE I EC
244-8
INTERNATIONAL
Deuxième édition
STANDARD
Second edition
1993-03
Méthodes de mesure applicables aux émetteurs
radioélectriques
Partie 8:
Qualité de fonctionnement des démodulateurs
à bande latérale résiduelle utilisés pour les essais
des émetteurs et réémetteurs de télévision
Methods of measurement for radio transmitters
Part 8:
Performance characteristics of vestigial-sideband
demodulators used for testing television transmitters
and transposers
© CEI 1993
Droits de reproduction réservés — Copyright — all rights reserved
Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in
utilisée sous quelque forme que ce soit et par aucun pro- any form or by any means, electronic or mechanical,
cédé, électronique ou mécanique, y compris la photocopie et including photocopying and microfilm, without permission
les microfilms, sans l'accord écrit de l'éditeur. in writing from the publisher.
Bureau Central de la Commission Electrotechnique Intern
ationale 3, rue de Varembé Genève, Suisse
Commission Electrotechnique Internationale CODE PRIX
International Electrotechnical Commission PRICE CODE
MescayHaponHaR 3nettrpoTe%HH4ecKaR liomucCHR
IEC
• Pour prix, voir catalogue en vigueur S
For price, see current catalogue
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CONTENTS
Page
FOREWORD 5
INTRODUCTION 7
Clause
1 Scope 9
2 Normative references 9
3 General terms and definitions 11
4 General conditions of operation and measurement 13
5 Measuring arrangements and standard video test signals 15
6 Demodulator input and output characteristics 15
7 Linear distortion 23
8 Non-linear distortion 31
9 Wave-form distortion 33
10 Unwanted modulation 35
11 Special measurements for data signals in the vision signal 37
12 Measurements relative to the synchronous-detection mode 37
13 Performance of the sound section 41
Annex A - Input impedance 47
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INTERNATIONAL ELECTROTECHNICAL COMMISSION
METHODS OF MEASUREMENT
FOR RADIO TRANSMITTERS
Part 8: Performance characteristics of vestigial-sideband
demodulators used for testing television transmitters
and transposers
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization
comprising all national electrotechnical committees (IEC National Committees). The object of the IEC is to
promote international cooperation on all questions concerning standardization in the electrical and
electronic fields. To this end and in addition to other activities, the IEC publishes International Standards.
Their preparation is entrusted to technical committees; any IEC National Committee interested in
the subject dealt with may participate in this preparatory work. International, governmental and
non-governmental organizations liaising with the IEC also participate in this preparation. The IEC
collaborates closely with the International Organization for Standardization (ISO) in accordance with
conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of the IEC on technical matters, prepared by technical committees on
which all the National Committees having a special interest therein are represented, express, as nearly as
possible, an international consensus of opinion on the subjects dealt with.
3) They have the form of recommendations for international use published in the form of standards, technical
reports or guides and they are accepted by the National Committees in that sense.
In order to promote international unification, IEC National Committees undertake to apply IEC International
4)
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
International Standard IEC 244-8 has been prepared by sub-committee 12C: Transmitting
equipment, of IEC technical committee 12: Radiocommunications.
This second edition cancels and replaces the first edition published in 1980 and its amend-
ment 1 (1983) and constitutes a technical revision.
The text of this standard is based on the following documents:
DIS Report on Voting
12C(CO)223 12C(CO)227
Full information on the voting for the approval of this standard can be found in the report
on voting indicated in the above table.
Annex A is for information only.
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244-8 © IEC: 1993
INTRODUCTION
International Standard IEC 244-8 is one of a series of parts of IEC 244.
A vestigial-sideband (VSB) demodulator is a measuring instrument for assessing the
performance characteristics of television transmitters, for which the method of measure-
ment is described in IEC 244-5. The measuring arrangement and the method of
measurement for the VSB demodulator is therefore in most cases identical with that in
IEC 244-5, with the understanding that the television transmitter is replaced by a high-
quality, double-sideband (DSB) modulator which is capable of delivering test signals
suitable for measuring an instrument which is significantly better in performance than a
television transmitter. Therefore, for most measurements, reference is made to IEC 244-5.
A number of measurements, using radio-frequency generators to simulate vision and
sound carriers and sideband signals, are fully described in this standard.
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METHODS OF MEASUREMENT
FOR RADIO TRANSMITTERS
Part 8: Performance characteristics of vestigial-sideband
demodulators used for testing television transmitters
and transposers
1 Scope
This part of IEC 244 is intended to be used for type tests and acceptance or factory tests
and may be used to check the characteristics of a demodulator used for measuring tele-
vision transmitters and transposers. It is not mandatory to measure all the described
characteristics.
Additional measurements may be carried out by agreement between customer and manu-
facturer.
Measuring performance, characteristics in accordance with this standard, makes the
comparison of the results of measurements, made by different observers, possible. Limit
values for acceptable performance are not normally specified, but, in connection with the
presentation of measured characteristics, some figures can be given for the sake of
clarity.
2 Normative references
The following normative documents contain provisions which, through reference in this
text, constitute provisions of this part of IEC 244. At the time of publication, the editions
indicated were valid. All normative documents are subject to revision, and parties to agree-
ments based on this part of IEC 244 are encouraged to investigate the possibility of
applying the most recent editions of the normative documents indicated below. Members
of IEC and ISO maintain registers of currently valid International Standards.
IEC 244-1: 1968, Methods of measurement for radio transmitters - Part 1: General
conditions of measurement, frequency, output power and power consumption (revision
under consideration)
Amendment 2, 1989
IEC 244-5: 1992, Methods of measurement for radio transmitters - Part 5: Performance
characteristics of television transmitters
IEC 244-10: 1986,
Methods of measurement for radiotransmitters. Part 10: Methods of
measurement for television transmitters and transposers employing insertion test signals
IEC 244-12-1: 1989,
Methods of measurement for radio transmitters - Part 12: Guideline
for drawing up descriptive leaflets for transmitters and transposers for sound and tele-
vision broadcasting - Characteristics to be specified
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IEC 244-12-2: 1989,
Methods of measurement for radio transmitters - Part
12: Guideline
for drawing up descriptive leaflets for transmitters and transposers for sound and tele-
vision broadcasting - Specification sheets
IEC 487-1: 1984,
Methods of measurement for equipment used in terrestrial radio-relay
systems - Part 1: Measurements common to sub-systems and simulated radio-relay
systems
IEC 864-1: 1986, Standardization of interconnections between broadcasting transmitters
or transmitter systems and supervisory equipment - Pa
rt 1: Interface standards for
systems using dedicated interconnections
Amendment 1, 1987
CCIR Report 404-2: 1974, Distortion of television signals due to the use of vestigial side-
band emissions
3 General terms and definitions
3.1
Vestigial-sideband demodulator
The term vestigial-sideband demodulator, sometimes referred to as a "Nyquist demodu-
lator", is used in this standard to refer to that equipment with one or more radio-frequency
inputs and with one or more demodulated video and audio outputs.
The demodulator shall include:
- a "zero carrier" reference pulse;
- true synchronous and envelope detection, switchable;
in the case of synchronous detection, a quadrature
video output;
-
a switchable "sound trap" and associated group delay correction filter (with the
sound trap switched out, the phase/frequency characteristic shall be linear);
-
independent (direct) sound demodulation, and intercarrier sound demodulation may
be used;
-
in the case of multiple sound channels, a suitable demodulator and decoder, and
analogue or digital sound outputs depending on the system concerned.
3.2
Description of the television systems and other relevant information
See annex A of IEC 244-5.
3.3 Definitions relating to the demodulator output and input signals
3.3.1 Output voltage
The peak-to-peak voltage of the video output signal.
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3.3.2 Reference output level
An output voltage of 1 V between sync pulse level and white level.
3.3.3 Input voltage
The voltage of the vision signal at the input of a demodulator for negative (or positive)
modulation of the vision carrier is the r.m.s. voltage, expressed in mV or dB(mV), of a
sinusoidal signal with an amplitude corresponding to the synchronizing pulse level (or
white reference level) of that signal.
3.3.4 Input voltage range
The input voltage range of a demodulator is the range of input voltages within which the
demodulator can deliver the reference output level within its performance specifications by
adjusting the input attenuator of the demodulator.
4 General conditions of operation and measurement
The vestigial-sideband demodulator shall be tested under normal operating conditions.
A sufficient warm-up time, in accordance with the demodulator specification, shall be
allowed before commencing measurements.
The power supply and environmental conditions shall be stated with the measurement
results.
If the sources of the demodulator's input test signal have significant interaction between
their generator outputs, it is recommended that circulators be inserted between the gener-
ators and the combining network. If circulators are not available, attenuators of at least
10 dB shall be inserted at the output of each generator.
The instruments used at the input of the demodulator, are connected to the input through
a calibrated attenuator or directional coupler inserted in the connection between the input
signal source and the demodulator.
The impedance presented by the test equipment connected to the video and audio outputs
of the demodulator shall have the nominal value as specified.
Any video and audio output not used for the measurement shall be appropriately
terminated.
In both cases the return loss of the termination shall be within the tolerances specified.
If the sound trap of the demodulator is in circuit, the associated group delay precorrector
in the modulator shall also be in circuit.
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All measurements, except those specifically related to one mode of demodulation only,
shall be made in both modes, synchronous and envelope detection.
If the demodulator is fitted with both radio-frequency (RF) and intermediate frequency (IF)
inputs, the demodulator specification may require that certain tests be repeated at the
intermediate frequency input(s).
5 Measuring arrangements and standard video test signals
Figure 1 gives the measuring arrangements built up from three radio-frequency gener-
ators, simulating vision carrier, sideband signals and/or sound carrier(s).
This arrangement is used for a limited number of measurements. Most of the measure-
ments can be carried out using the arrangements described in IEC 244-5. In such cases,
the television transmitter should be replaced by the DSB test modulator.
Some measurements need modulated sound signals. In these cases, a TV test transmitter
should be used. Alternatively, one or two RF generators in combination with the DSB test
modulator may be used, with sufficient decoupling to avoid intermodulation products,
along with a switchable group delay precorrector. The precorrection should be in
accordance with the standards concerned: see clause A.3 (extract from CCIR Repo rt 624-3)
of IEC 244-5.
rformance of the input test signal arrangements shall be known and
In all cases, the pe
allowed for.
Standard video test signals are identified by a letter symbol and described in annex B of
IEC 244-5.
6 Demodulator input and output characteristics
6.1 Input voltage range
6.1.1 Introduction
Two different measurements are described
The first measurement using an unmodulated RF signal at the input of the demodulator
(see 6.1.5) is not applicable to a demodulator operating in synchronous detection mode.
6.1.2 Definition
See 3.3.
6.1.3 Measuring arrangement
The measuring arrangement according to 6.1.5, is shown in figure 1 of this standard.
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The measuring arrangement according to 6.1.6, is given in figure 2a of IEC 244-5, but with
the television transmitter replaced by the DSB test modulator.
6.1.4
Test signal
For the measurement according to 6.1.5, one unmodulated RF signal adjusted to the
vision carrier frequency of the channel concerned is used.
For the measurement according to 6.1.6, the DSB test transmitter shall be modulated with
the saw tooth B1 (see annex B of IEC 244-5).
6.1.5 Measuring procedure using an unmodulated RF signal at the input
a) Switch the demodulator to the envelope mode.
b)
Switch the input signal alternately on and off.
c) Set the demodulator's input attenuator to the position corresponding to the lowest
sensitivity.
d) Adjust the output level of the signal generator to produce at the demodulator output
a d.c. voltage of 1,11 V (1,25 V for system I) between zero carrier and peak d.c.
voltage on the oscilloscope. This is equivalent to the reference output level defined
in 3.3 for a modulated input signal.
e)
Measure with an RF voltmeter the peak value of the input signal to the demodulator
and determine the r.m.s.
f)
Repeat the above with the demodulator's input attenuator set to the position corres-
ponding to the highest sensitivity.
g)
Repeat the measurements for other television channels within the specified frequency
range of the demodulator.
6.1.6 Measuring procedure using a vision signal at the input
a)
Switch the demodulator to the envelope detection mode.
b) Switch the zero-carrier reference pulse on.
c)
Set the demodulator's input attenuator to the position corresponding to the lowest
sensitivity.
d)
Adjust the output level of the DSB modulator to produce at the demodulator output
the reference output level defined in 3.3 and which corresponds to a level of 1,11 V
(1,25 V for system I) between zero-carrier level and peak sync level.
e) Measure with an RF voltmeter the peak value of the input signal to the demodulator
and determine the r.m.s.
f)
Repeat the above with the demodulator's input attenuator set to the position corres-
ponding to the highest sensitivity.
g) Repeat the measurement for other television channels within the specified frequency
range of the demodulator.
h) Repeat the measurement in synchronous-detection mode.
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6.1.7
Presentation of the results
The results shall be stated in mV or dB(mV) for each frequency depending on the specifi-
cations.
6.2 Input impedance
For the purpose of this standard, the input impedance of the demodulator is expressed in
terms of return loss relative to its nominal value.
The input impedance shall be measured within the specified input channels and the range
of input levels, using any suitable measuring techniques such as those described in
annex A.
6.3
Video output source impedance
The methods for measuring the input impedance given in items a) and b) of clause A2 of
annex A may also be used for measuring the return loss at video frequencies at the
demodulator output, but with no signal applied to the input.
6.4 Zero-carrier reference
6.4.1 Definition
The zero-carrier reference is used to determine the relative positions of the characteristic
levels of the demodulated video signal. It is in the form of an internally generated pulse of
a few microseconds duration, at a repetition frequency equivalent to the line or frame
frequency of the television standard concerned. For the duration of this pulse, the radio-
frequency section of the demodulator is switched off and the vision signal of the demodu-
lator is suppressed.
6.4.2
Measuring arrangement
The measuring arrangement is given in figure 2a of IEC 244-5, but with the television
transmitter replaced by the DSB test modulator.
6.4.3 Test signal
For items a) and b) of 6.4.4, a radio-frequency signal at the vision carrier frequency of
the channel concerned, modulated with an all-black signal Al is used. See figure lb of
IEC 244-5.
In the case of positive demodulation, the signal of figure 1c of IEC 244-5 shall be used.
For item c) of 6.4.4, a variable luminance input signal is used.
6.4.4 Measuring procedure
a) Compare the zero-carrier level indicated by the zero-carrier reference pulse with the
zero level obtained when the signal generator is switched on and off alternately.
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b) If required, check the timing of the switching pulse during the line and field intervals
to ensure stability.
c) If required, check the pulse width and synchronization with the test signal and vary
if necessary.
6.4.5 Presentation of the results
The results may be presented in the form of photographs or hard copy of the oscilloscope
display together with any explanatory notes.
6.5 Isolation between video outputs
6.5.1 Introduction
When the demodulator has two or more video outputs which may be used at the same
time, it is necessary to measure the change in video output level at one output with
variations in the impedance of the termination at any other output, and vice versa.
The change in the terminated video output voltage at one of the output connectors, when
any other output connector is open- and then short-circuited, is a measure of the isolation
between those two outputs.
6.5.2 Measuring arrangement
The measuring arrangement is given in figure 5a of IEC 244-5, but with the television
transmitter replaced by the DSB test modulation.
6.5.3 Test signal
The video test signal Ais of IEC 244-5 is used.
6.5.4 Measuring procedure
of the test signal to correspond to a mid-grey picture.
a) Adjust the luminance level x
b) Set the sideband frequency fs to 1 MHz and adjust the peak-to-peak amplitude of
the signal to extend from blanking level to white reference level.
c) Suppress the sound carrier and adjust the output level of the test modulator (or the
test transmitter) to reference input level.
d) Determine the peak-to-peak voltage of the video signal on the oscilloscope when
the other outputs are open-circuited.
Repeat the measurement with the other outputs short-circuited.
e)
f) Calculate the difference between the two measurements.
g) Repeat the measurements for different values of the frequency fs within the video-
frequency range concerned.
h) Repeat the measurement for all the other video outputs.
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6.5.5 Presentation of the results
State the maximum difference obtained in decibels or as a percentage relative to 1 V peak-
to-peak.
7 Linear distortion
7.1 Introduction
This clause deals with the measurement of amplitude/frequency and group-delay
(envelope-delay)/frequency characteristics, the main principles of which are given in
clause 8 of IEC 244-5.
7.2 Amplitude/frequency characteristics
7.2.1 Introduction
The amplitude/frequency characteristics of a VSB demodulator are usually specified in two
ways:
1) as the amplitude/radio-frequency characteristics (sometimes referred to as the
vestigial-sideband response), and
2)
as the amplitude/video-frequency characteristic (sometimes referred to as the
overall video-frequency response).
The amplitude/radio-frequency characteristic is measured with a single-sideband signal for
each sideband separately. From this measurement, it is possible to determine the Nyquist
slope in the double-sideband region and also the response at frequencies in the upper and
lower adjacent channels.
The amplitude/video-frequency characteristic is measured with a double-sideband signal.
This measurement provides the resultant overall video-frequency characteristic by the
combination of both sidebands (including the double-sideband region).
7.3 Amplitude/radio-frequency characteristic (Nyquist slope)
7.3.1 Introduction
The measurement given below is not applicable to all demodulated operating in synchro-
nous detection mode.
7.3.2 Definition
See 8.2.1 of IEC 244-5.
7.3.3 Measuring arrangement
The measuring arrangement given in figure 1 is used, either with a selective video-
frequency voltmeter or a spectrum analyzer, as preferred.
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7.3.4 Test signals
The CW-signals from two radio-frequency generators are used.
Adjust the levels of the signals at the input of the demodulator to the following values
relative to the reference input level:
Vision carrier:
• 8 dB for negative modulation of the vision signal, or
•
4 dB for positive modulation of the vision signal;
these levels correspond to a mid-grey picture.
- Sound carrier: suppressed.
- Sideband signal: -30 dB, unless otherwise specified (see also the note to 7.3.5).
7.3.5 Measurement procedure
a) Switch the demodulator to envelope-detection mode.
b) Vary the frequency of the generator for the sideband signal over the nominal
radio-frequency channel bandwidth on either side of the vision carrier, and as far as
necessary into the adjacent channels, whilst maintaining the amplitude of the input
signal constant.
At each measuring point, record the reading of the voltmeter and the frequency of
c)
the signal corresponding to the sideband component. Note whether the output signal
results from the upper or the lower sideband signal.
d) Repeat the measurement with both the sound trap and any associated group-delay
correction filter switched out of circuit.
If required, repeat the measurements for a number of different levels of the vision
e)
carrier between black level and white reference level. See also the second paragraph
of the note below.
NOTE - Adjusting the sideband signal to a level of -30 dB prevents the measurements being unduly
affected by quadrature distortion.
However, when testing demodulators for negative modulation systems using envelope detection without
provision for reducing quadrature distortion, the value of -30 dB should be decreased to at least -36 dB
when the measurements are made in the vicinity of the white reference level.
7.3.6 Presentation of the results
The results shall be expressed as a percentage or decibels relative to the level of the
demodulator output signal at a specified frequency, for example the frequency of the
vision carrier +1,5 MHz.
The results may be presented in the form of a photograph of the spectrum analyzer
display or plotted on a graph as a function of sideband frequency relative to the frequency
of the vision carrier. The results shall also state the level of the input signals relative to
the reference input level.
Figure 2a shows an example of a template as specified for a demodulator for system G.
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7.4 Amplitude/video-frequency characteristic
7.4.1 Definition
The amplitude/video-frequency characteristic is the variation of the peak-to-peak
amplitude as a function of the frequency of the demodulated vision signal, when the
demodulator is fed with an RF vision signal of constant sideband amplitude but variable
sideband frequency and constant luminance level.
7.4.2
Measuring arrangement
See 8.3.2, figure 3a of IEC 244-5, but with the television transmitter replaced by the DSB
test modulator.
For manual measurement, a selective voltmeter should be used.
7.4.3
Test signal
See 8.3.3 of IEC 244-5.
For manual measurement, a sinusoidal signal is used. The frequency range of the sweep
signal or the sinusoidal signal shall exceed the channel bandwidth by ±10 MHz.
7.4.4 Measuring procedure
a) Adjust the output level of the test signal generator to produce a demodulated side-
band signal s with a peak-to-peak amplitude of an appropriate value, within the range
s
from black level to white reference level (see note 2 below).
b) Vary the frequency of the signal fs over the frequency range corresponding to the
nominal radio-frequency channel bandwidth above the vision carrier frequency, and as
far as required into the upper adjacent channel, whilst maintaining the level constant.
c) When a sweep generator and video analyzer are used, the display on the
oscilloscope will represent the amplitude/video-frequency characteristic. See note 1
below.
d) When the frequency is adjusted manually, for each measuring point, the reading of
the voltmeter and the frequency of the generator should be recorded.
e) Repeat the measurement with the sound trap and any associated group-delay
correction filter switched out of circuit.
f) If required, repeat the measurements for a number of different levels of the
luminance signal.
g) For measurements in envelope-detection mode, see note 2 below.
NOTES
1 The oscilloscope scanning frequency should be in synchronism with the video sweep rate, which may
be equal to, or lower than the field frequency. Generally, the resolution of the signal displayed will increase
with decreasing values of the sweep rate, thus improving the accuracy of the measurement.
2 For testing demodulators which do not incorporate a means of reducing quadrature distortion, in
envelope-detection mode, the peak-to-peak amplitude of the superimposed signal fs should not exceed a
value which corresponds to 13 % of the input level.
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In addition, the amplitude of the sideband signal should be decreased to about 7 % when measurements
are made in the vicinity of white reference level (negative modulation).
7.4.5
Presentation of the results
The results shall be expressed as a percentage or in decibels relative to the level of the
demodulator output signal at a specified frequency, for example vision carrier frequency
+1,5 MHz.
The results may be tabulated or plotted on a graph as a function of video-frequency, or
may be presented as a photograph or hard copy of the oscilloscope display when a sweep
method of measurement is used. Figures 2b and 2c show examples of oscillogram
templates for a demodulator operating on system G. The values of s and
x shall be stated
with the results.
7.5 Group-delay/video-frequency characteristic
7.5.1 Definition
The group-delay/radio-frequency characteristic is the variation of the g
...
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