IEC 61000-2-13:2005

Electromagnetic compatibility (EMC) - Part 2-13: Environment - High-power electromagnetic (HPEM) environments - Radiated and conducted

IEC 61000-2-13:2005 defines a set of typical radiated and conducted HPEM environment waveforms that may be encountered in civil facilities. Such threat environments can produce damaging effects on electrical and electronic equipment in the civilian sector, as described in IEC 61000-1-5. It is necessary to define the radiated and conducted environments, in order to develop protection methods. For the purposes of this standard, high-power conditions are achieved when the peak electric field exceeds 100 V/m, corresponding to a plane-wave free-space power density of 26,5 W/m2. This criterion is intended to define the application of this standard to EM radiated and conducted environments that are substantially higher than those considered for "normal" EMC applications, which are covered by the standards produced by IEC SC 77B.

General Information

• Status: Published
• Publication Date: 08-Mar-2005
• ICS: 33.100.10 - Emission
• ICS: 33.100.20 - Immunity
• Technical Committee: SC 77C - High power transient phenomena
• Drafting Committee: PT 61000-2-13 - TC 77/SC 77C/PT 61000-2-13
• Current Stage: PPUB - Publication issued
• Start Date: 09-Mar-2005
• Completion Date: 15-Aug-2005

Overview

IEC 61000-2-13:2005 is an International Electrotechnical Commission (IEC) basic EMC publication that defines typical high-power electromagnetic (HPEM) environments - both radiated and conducted - likely to be encountered in civil facilities. The standard establishes representative HPEM waveforms and classification criteria to support the development of protection, mitigation and test methods for equipment and installations exposed to unusually strong electromagnetic threats. For HPEM the standard uses a high-power threshold of peak electric field > 100 V/m (plane-wave free‑space power density ≈ 26.5 W/m²).

Key topics and technical requirements

• Definition of HPEM waveforms: standardized time-domain and spectral waveforms (narrowband, mesoband, hyperband/ultrawideband and bursts) used to characterize threat environments.
• Radiated vs. conducted environments: radiated fields that can couple into systems and conducted HPEM directly injected into wiring or cables.
• Bandwidth classification and bandratio: methods to classify waveforms by spectral content (e.g., low to ultrawideband) and compute bandwidth metrics.
• Coupling and propagation: description of how radiated fields induce conducted voltages/currents (effective coupling length, building coupling effects).
• Examples and empirical data: informative annexes provide examples of HPEM generators, typical waveforms, and experimental conducted propagation scenarios.
• Purpose-driven scope: the standard targets environments substantially stronger than “normal” EMC conditions covered by IEC SC 77B, and is intended to support development of protection measures rather than prescriptive immunity limits.

Practical applications

Who uses IEC 61000-2-13 and why:

• EMC engineers and system designers - to identify HPEM threat waveforms and design resilient electronics and civil systems.
• Test laboratories - to select representative waveforms when developing HPEM test plans and immunity verification.
• Critical infrastructure and facility managers - for risk assessment and specifying mitigation for power, communications, transport and public-safety systems.
• Standards bodies and regulators - as a reference when developing complementary EMC and security guidance.
  Use cases include threat characterization, grounding/shielding design, cable routing and filtering strategies, and development of protection standards and test procedures.

Related standards

Normative references and closely related IEC documents include:

• IEC 61000-1-5 (HPEM effects on civil systems)
• IEC 61000-2-9, 2-10, 2-11 (HEMP/HPEM environment descriptions and classification)
• IEC 61000-4-x series (testing and measurement techniques such as 4-3, 4-4, 4-5, 4-6, 4-12)

IEC 61000-2-13 is a foundational reference for professionals addressing high-power EM threats in civilian environments and for developing practical protection and testing strategies.

Standards Content (Sample)

INTERNATIONAL IEC
STANDARD 61000-2-13
First edition
2005-03
BASIC EMC PUBLICATION
Electromagnetic compatibility (EMC) –
Part 2-13:
Environment –
High-power electromagnetic (HPEM)
environments –
Radiated and conducted
Reference number
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INTERNATIONAL IEC
STANDARD 61000-2-13
First edition
2005-03
BASIC EMC PUBLICATION
Electromagnetic compatibility (EMC) –
Part 2-13:
Environment –
High-power electromagnetic (HPEM)
environments –
Radiated and conducted
 IEC 2005  Copyright - all rights reserved
No part of this publication may be reproduced or utilized in any form or by any means, electronic or
mechanical, including photocopying and microfilm, without permission in writing from the publisher.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: [phone] Telefax: [phone] E-mail: [e-mail] Web: www.iec.ch
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International Electrotechnical Commission
Международная Электротехническая Комиссия
For price, see current catalogue

– 2 – 61000-2-13  IEC:2005(E)
CONTENTS
FOREWORD.4

INTRODUCTION.6
1 Scope .7
2 Normative references .8
3 Terms and definitions .8
4 General .11
5 Description of radiated environments .13
6 Description of conducted HPEM environments .23
Annex A (informative) Four types of intentional electromagnetic environment
interactions .27
Annex B (informative) Examples of low, medium and high-tech generators of HPEM .28
Annex C (informative) Examples of typical HPEM waveforms (conducted and radiated).31
Annex D (informative) Determination of the bandwidth of typical HPEM waveforms .35

Bibliography .39

Figure 1 – Several types of HPEM environments compared with the IEC HEMP
waveform.12
Figure 2 – A damped sinusoidal waveform for hypoband and mesoband HPEM
environments.18
Figure 3 – The spectral magnitude of the time waveform in Figure 2 .19
Figure 4 – Hyperband HPEM environment waveforms for variations in range in metres .21
Figure 5 – Hyperband spectral magnitude of HPEM environments from Figure 4 .21
Figure 6 – Effective coupling length for a 1 m metallic cable .22
Figure 7 – Building used for HPEM conducted propagation experiments .24
Figure 8 – Examples of briefcase generators for producing conducted environments:
CW generator (left) and impulse generator (right) [15] .26
Figure B.1 – Line schematic of a reflector type of an impulse radiating antenna (IRA) .30
Figure C.1 – Half-sinusoid at f = 1 GHz .31
o
Figure C.2 – Full sinusoid at f = 1 GHz .32
Figure C.3 – 20 cycles of sinusoid at f = 1 GHz (N = 20) .32
Figure C.4 – Difference of exponential waveform.33
Figure C.5 – Gaussian waveform .33
Figure C.6 – Sinusoidal waveform with a Gaussian-amplitude modulation .34
Figure D.1 – A waveform spectrum with a large dc content (e.g. the early-time HEMP
from IEC 61000–2-9) .36
Figure D.2 – A waveform with a multipeaked spectral magnitude in units of 1/Hz.36
Figure D.3 – Spectral magnitude of a damped sinusoidal waveform with a low Q and a
bandratio value computed using the 3 dB frequency points .37
Figure D.4 – Spectral magnitude of a damped sinusoidal waveform with a high Q and a
bandratio value computed using the 3 dB frequency points .38

61000-2-13  IEC:2005(E) – 3 –
Table 1 – Definitions for bandwidth classification.14
Table 2 – Range of radiated electric field at various frequencies and power levels .15
Table 3 – Typical HPEM standard environments in the hypoband (or narrowband) and
mesoband regimes .20
Table B.1 – Radiated fields from a microwave oven magnetron fitted with different
antennas .28
Table B.2 – Radiated peak electric fields from a commercial HPEM generator.29
Table B.3 – Examples of reflector types of impulse radiating antennas.30

– 4 – 61000-2-13  IEC:2005(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION
___________
ELECTROMAGNETIC COMPATIBILITY (EMC) –

Part 2-13: Environment –
High-power electromagnetic (HPEM) environments –
Radiated and conducted
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61000-2-13 has been prepared by subcommittee 77C: High power
transient phenomena, of IEC technical committee 77: Electromagnetic compatibility.
It has the status of a basic EMC publication in accordance with IEC Guide 107.
The text of this standard is based on the following documents:
FDIS Report on voting
77C/153/FDIS 77C/155/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

61000-2-13  IEC:2005(E) – 5 –
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

– 6 – 61000-2-13  IEC:2005(E)
INTRODUCTION
IEC 61000 is published in separate parts according to the following structure:
Part 1: General
General considerations (introduction, fundamental principles)
Definitions, terminology
Part 2: Environment
Description of the environment
Classification of the environment
Compatibility levels
Part 3: Limits
Emission limits
Immunity limits (in so far as they do not fall under the responsibility of the product
committees)
Part 4: Testing and measurement techniques
Measurement techniques
Testing techniques
Part 5: Installation and mitigation guidelines
Installation guidelines
Mitigation methods and devices
Part 6: Generic standards
Part 9: Miscellaneous
Each part is further subdivided into several parts, published either as International Standards
or as technical specifications or technical reports, some of which have already been published
as sections. Others will be published with the part number followed by a dash and a second
number identifying the subdivision (example: 61000-6-1).

61000-2-13  IEC:2005(E) – 7 –
ELECTROMAGNETIC COMPATIBILITY (EMC) –

Part 2-13: Environment –
High-power electromagnetic (HPEM) environments –
Radiated and conducted
1 Scope
This part of IEC 61000 defines a set of typical radiated and conducted HPEM environment
waveforms that may be encountered in civil facilities. Such threat environments can produce
damaging effects on electrical and electronic equipment in the civilian sector, as described in
IEC 61000-1-5. It is necessary to define the radiated and conducted environments, in order to
develop protection methods.
For the purposes of this standard, high-power conditions are achieved when the peak electric
field exceeds 100 V/m, corresponding to a plane-wave free-space power density of
26,5 W/m . This criterion is intended to define the application of this standard to EM radiated
and conducted environments that are substantially higher than those considered for "normal"
EMC applications, which are covered by the standards produced by IEC SC 77B.
The HPEM environment can be:
• radiated or conducted;
• a single pulse envelope with many cycles of a single frequency (an intense narrowband
signal that may have some frequency agility and the pulse envelope may be modulated);
• a burst containing many pulses, with each pulse envelope containing many cycles of a
single frequency;
• an ultrawideband transient pulse (spectral content from tens of MHz to several GHz);
• a burst of many ultrawideband transient pulses.
The HPEM signal could be from sources such as radar or other transmitters in the vicinity of
an installation or from an intentional generator system targeting a civilian facility. Radiated
signals can also induce conducted voltages and currents through the coupling process. In
addition, conducted HPEM environments may also be directly injected into the wiring of an
installation.
There is a critical distinction between the HEMP (high-altitude electromagnetic pulse)
environment and the HPEM environment, in terms of the range or the distance of the affected
electrical or electronic components from the source. In the context of HEMP, the range is
immaterial, as the HEMP environment propagates downward from space to the earth's
surface and is therefore relatively uniform over distances of 1 000 km. On the other hand, in
the HPEM context the environment and its effects decrease strongly with range. In addition,
the HEMP waveshape is a series of time domain pulses while the HPEM environment may
have a wide variety of waveshapes.
Consequently, the standardization process for HPEM environments is more difficult. The
recommended approach is to investigate the various types of HPEM environments that have
been produced to date and are likely to be feasible in the near future, and then to develop
suitable HPEM standard waveforms from such a study. Such HPEM environment standard
waveforms can be amended in due course, depending on emerging technologies that make it
possible to produce them.
– 8 – 61000-2-13  IEC:2005(E)
2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
IEC 60050-161, International Electrotechnical Vocabulary (IEV) – Chapter 161: Electro-
magnetic compatibility
IEC 61000-1-5, Electromagnetic compatibility (EMC) – Part 1-5: General – High power
electromagnetic (HPEM) effects on civil systems
IEC 61000-2-9, Electromagnetic compatibility (EMC) – Part 2: Environment – Section 9:
Description of HEMP environment – Radiated disturbance
IEC 61000-2-10, Electromagnetic compatibility (EMC) – Part 2-10: Environment – Description
of HEMP environment – Conducted disturbance
IEC 61000-2-11, Electromagnetic compatibility (EMC) – Part 2-11: Environment –
Classification of HEMP environments
IEC 61000-4-3, Electromagnetic compatibility (EMC) – Part 4-3: Testing and measurement
techniques – Radiated, radio-frequency, electromagnetic field immunity test
IEC 61000-4-4, Electromagnetic compatibility (EMC) – Part 4-4: Testing and measurement
techniques – Section 4: Electrical fast transient/burst immunity test.
IEC 61000-4-5, Electromagnetic compatibility (EMC) – Part 4: Testing and measurement
techniques – Section 5: Surge immunity test
IEC 61000-4-6, Electromagnetic compatibility (EMC) – Part 4-6: Testing and measurement
techniques – Immunity to conducted disturbances, induced by radio-frequency fields
IEC 61000-4-12, Electromagnetic compatibility (EMC) – Part 4: Testing and measurement
techniques – Section 12: Oscillatory waves immunity test
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-161 as well
as the following apply.
3.1
attenuation
reduction in magnitude (as a result of absorption and scattering) of an electric or magnetic
field or a current or voltage; usually expressed in decibels
3.2
bandratio
br
ratio of the high and low frequencies between which there is 90 % of the energy; if the
spectrum has a large dc content, the lower limit is nominally defined as 1 Hz

61000-2-13  IEC:2005(E) – 9 –
3.3
bandratio decades
brd
bandratio expressed in decades as: brd = log (br)
3.4
burst
typically a time frame in which a series of pulses occurs with a given repetition rate. When
multiple bursts occur, the time between bursts is usually defined
3.5
conducted HPEM environment
high power electromagnetic currents and voltages that are either coupled or directly injected
to cables and wires with voltage levels that typically exceed 1 kV
3.6
continuous wave
CW
time waveform that has a fixed frequency and is continuous
3.7
electromagnetic compatibility
EMC
ability of an equipment or system to function satisfactorily in its electromagnetic environment
without introducing intolerable electromagnetic disturbances to anything in that environment
3.8
electromagnetic disturbance
any electromagnetic phenomenon which may degrade the performance of a device, equip-
ment or system
3.9
electromagnetic interference
EMI
degradation of the performance of a device, transmission channel or system caused by an
electromagnetic disturbance
NOTE Disturbance and interference are respectively cause and effect.
3.10
(electromagnetic) shield
electrically continuous housing for a facility, area, or component used to attenuate incident
electric and magnetic fields by both absorption and reflection
3.11
(electromagnetic) susceptibility
inability of a device, equipment or system to perform without degradation in the presence of
an electromagnetic disturbance
NOTE Susceptibility is a lack of immunity.
3.12
high-altitude electromagnetic pulse
HEMP
electromagnetic pulse produced by a nuclear explosion outside the earth’s atmosphere
NOTE Typically above an altitude of 30 km.

– 10 – 61000-2-13  IEC:2005(E)
3.13
high-power microwaves
HPM
narrowband signals, nominally with peak power in a pulse, in excess of 100 MW at the source
NOTE This is a historical definition that depended on the strength of the source. The interest in this document is
mainly on the EM field incident on an electronic system.
3.14
hyperband signal
signal or waveform with a pbw value between 163,64 % and 200 % or a bandratio >10
3.15
hypoband signal
narrowband signal
signal or waveform with a pbw of <1 % or a bandratio <1,01
3.16
intentional electromagnetic interference
IEMI
intentional malicious generation of electromagnetic energy introducing noise or signals into
electric and electronic systems, thus disrupting, confusing or damaging these systems for
terrorist or criminal purposes
3.17
L band
radar frequency band between 1 and 2 GHz
3.18
mesoband signal
signal or waveform with a pbw value between 1 % and 100 % or a bandratio between 1,01
and 3
3.19
percentage bandwidth
pbw
bandwidth of a waveform expressed as a percentage of the centre frequency of that waveform
NOTE The pbw has a maximum value of 200 % when the centre frequency is the mean of the high and low
frequencies. The pbw does not apply to signals with a large dc content (e.g., HEMP) for which the bandratio
decades is used.
3.20
point-of-entry
PoE
port-of-entry
PoE
physical location (point) on an electromagnetic barrier, where EM energy may enter or exit a
topological volume, unless an adequate PoE protective device is provided
NOTE 1 A PoE is not limited to a geometrical point.
NOTE 2 PoEs are classified as aperture PoEs or conductive PoEs according to the type of penetration. They are
also classified as architectural, mechanical, structural or electrical PoEs according to the functions they serve.
3.21
pulse
a transient waveform that usually rises to a peak value and then decays, or a similar
waveform that is an envelope of an oscillating waveform

61000-2-13  IEC:2005(E) – 11 –
3.22
radiated HPEM environment
high power electromagnetic fields with peak electric field levels that typically exceed 100 V/m
3.23
sub-hyperband signal
a signal or a waveform with a pbw value between 100 % and 163,64 % or a bandratio
between 3 and 10
3.24
transient
pertaining to or designating a phenomenon or a quantity which varies between two
consecutive steady states during a time interval which is short compared with the time-scale
of interest
NOTE A transient can be a unidirectional impulse of either polarity or a damped oscillatory wave with the first
peak occurring in either polarity.
3.25
ultrawideband
UWB
a signal that has a percent bandwidth greater than 25 %
4 General
Figure 1 is provided to help understand the relationship of HPEM environments to other
electromagnetic environments. Note that the fast portion of the HEMP electric field Fourier
transform from IEC 61000-2-9 is generally most important at frequencies below 300 MHz. The
two major types of radiated HPEM environments (narrowband and wideband) are typically
found at higher frequencies, as shown.
It is noted in Figure 1 that the wideband spectral density will decrease at very high
frequencies (typically above 3 to 5 GHz), however the figure is not intended to portray a
specific UWB pulse. Lightning environments are also variable, but they often contain some
)
content up to 10 MHz [19] . It is important to understand that the differences shown in the
environments can produce different types of effects in electronic systems.
___________
1)
Figures in brackets refer to the bibliography.

– 12 – 61000-2-13  IEC:2005(E)

Spectral
density
(V/m)/Hz
Frequency  Hz
Narrow band extending from ~0,2 to ~5 GHz
Not necessarily HPEM
Significant spectral components up to ~10 MHz depending on range and application
IEC  1531/04
NOTE The magnitude of the electric field spectrum is plotted on the y-axis.
Figure 1 – Several types of HPEM environments compared with the IEC HEMP waveform
The IEC recognises certain major trends in civilian electronic systems as follows:
a) increasing use of automated electronic systems in every aspect of civilized societies –
communication, navigation, medical equipment, etc.,
b) increasing susceptibility of electronic systems due to higher package densities, use of
monolithic integrated circuits (MIC) (system on a chip), multi-chip modules (MCM) (mixing
analogue, digital, microwave, etc.), and
c) increasing use of EM spectrum which includes radio, TV, microwave ovens, aircraft
electronics, automobile electronics, cell phones, direct broadcast satellites, etc. It is easy
to envision a component failure leading to a subsystem and consequently a system-level
failure, due to an intense HPEM signal. Several such effects are documented in
IEC 61000-1-5.
Two examples of accidental electrical system failures due to RF fields include:
a) the firing of an aircraft missile due to a radar exposure of an improperly mounted shielded
connector on a missile cable on the U.S. aircraft carrier Forrestal in 1967, and
b) U.S. FDA documented medical equipment problems (1979-1993) in devices such as blood
cell counters, cardiac monitors, neo-natal monitors, etc. due to exposures to
electromagnetic fields. These and many other documented examples of accidental
electronic system failures argue for the creation of an HPEM standard that can be useful
to manufacturers of electronic components, subsystems and systems in many industries.

61000-2-13  IEC:2005(E) – 13 –
Annex A presents four types of intentional electromagnetic environment, coupling and
interference combinations that can create system malfunctions. In Annex B, some examples
of HPEM generators are presented, categorized on the basis of the technical sophistication
level involved in assembling and deploying them. Annex C documents typical HPEM
waveforms (radiated and conducted) in time and frequency domains. Annex D defines a way
of determining the bandratios of waveforms representing the HPEM environments.
A logical extension of recently developed HEMP standards (IEC 61000-2-9, IEC 61000-2-10,
and IEC 61000-2-11) is to define and classify the man-made HPEM threat environment, in the
context of civilian electrical and electronic systems. In a manner similar to the HEMP
standards, the HPEM environment consists of two major parts: a radiated environment and a
conducted environment; in the interest of efficiency, both aspects are considered in this
standard.
5 Description of radiated environments
The present interest is the potential high-power electromagnetic threat to civilian electronic
systems and facilities. It is now well established that sufficiently intense electromagnetic
signals in the frequency range of 200 MHz to 5 GHz are known to cause electronic damage in
many systems. The operating wavelengths range from 1,5 m to 6 cm. HPEM generators are
effective in this frequency range for the following reasons.
– There are deliberate antennas operating in this frequency range, which provide a path into
the system (intentional coupling paths).
– Typical apertures, slots, holes and hatch openings have their resonance in this frequency
range (inadvertent coupling paths).
– Typical rivet spacings at the junction of two metallic surfaces at the skin level are about a
quarter to a full wavelength in this frequency range (1 GHz to 2 GHz).
– Physical dimensions of circuit boxes are themselves resonant in this frequency range
(1 GHz to 2 GHz).
– The interior coupling paths (e.g., transmission lines, cables at a height above the ground
plane) are roughly a quarter to a full wavelength in this frequency range (1 GHz to 2 GHz).
One can classify the potential HPEM threats into three categories, based on frequency
coverage, as narrow bandwidth, moderate bandwidth and ultrawideband. Various definitions
of bandwidths have been suggested in the literature, and an accepted definition [1] is:
2(f −f )
h l
fractional bandwidth = (1)
( f + f )
h l
2(f −f )
h l
percent bandwidth = x 100 (2)
( f + f )
h l
Basically, this definition is the ratio of bandwidth (difference between the high and low
frequencies in the signal, traditionally the 3 dB points) to the centre frequency f , which is the
c
average of the high and low frequencies, f and f . It is easily seen that the maximum
h l
possible value for the percentage bandwidth is 200. A DARPA panel [1] has defined a
definition of ultrawideband signal as a signal that has a pbw (percentage bandwidth) >25 %
using the following classification:
– Narrowband signal percent bandwidth <1 % (ex: AM radio signal)
– Moderate bandwidth signal percent bandwidth ~ 1 % to 25 % (ex: TV signal)
– Ultrawideband signal percent bandwidth >25 % (ex: see Annex D)

– 14 – 61000-2-13  IEC:2005(E)
However, we observe that the above pbw (percent bandwidth) definition comes from a
“communication signal” view point and is inadequate, in the context of ultrawideband signals,
when practical waveforms have already achieved percent bandwidths of >190 % out of a
possible maximum of 200 %. Therefore one shall use the following definitions [2]:
f
h
bandratio = br = bandratio decades = brd = log (br) (3)
f
l
pbw
[1 + ]
(br − 1)
pbw = 200 br = (4)
(br + 1) pbw
[1 − ]
Using the inherent features of above definitions, and in a manner consistent with the
emerging technologies, the following definitions for bandwidth classification are defined below
in Table 1.
Table 1 – Definitions for bandwidth classification
Band type Percent bandwidth (pbw) Bandratio (br)
Hypoband or ≤1 % ≤ 1,01
narrowband
Mesoband 1 % < pbw ≤ 100 % 1,01 < br ≤ 3
Sub-hyperband 100 % < pbw ≤ 163,64 % 3 < br ≤ 10
Hyperband 163,64 % < pbw ≤ 200 % br > 10

One can provide examples of HPEM generators that employ current and emerging
technologies, for each category of the four-band classification.
The above classification is necessary to describe potential HPEM threat environments.
Another way of categorising the environments is based on the level of sophistication of the
underlying technologies involved in producing the environment as low, medium and high-tech
systems, as outlined in Annex B.
5.1 General attributes of HPEM
In the context of civilian electronics systems and facilities, various elements of electro-
magnetic threat environments shall include:
a) source characterisation;
b) feed and antenna system;
c) propagation distances and losses;
d) coupling to the facility exterior;
e) transfer function to the system interior.
The source shall be characterised by its output power, frequency, frequency agility, duration
and repetition rates for pulsed sources and burst lengths. Feed and antenna systems in the
frequency range of 200 MHz to 5 GHz consist of electromagnetic horns and reflectors.
– Frequency range 200 MHz to 5 GHz
– Wavelength range 150 cm to 6 cm
– CW source power (rms) 1 kW (microwave oven) to 10 MW (radar tubes)
– CW source power (peak) P = 2 kW to 20 MW (2 times rms power for sinusoids)

61000-2-13  IEC:2005(E) – 15 –
– Antenna aperture area A = up to 10 m (a practical sized antenna that can be
truck mounted and be driven under overpasses and on
bridges)
– Peak E-field on radiating aperture, where Z is the impedance in ohms
E = PZ /A
a
– Peak radiated E-field E = E A/(r λ )
f a
– 2
Assuming an antenna aperture area of 10 m and an impedance of 377 ohms
2 kW < P < 20 MW
274 V/m < E < 27,4 kV/m (no antenna losses)
a
4,57 kV < r E (at f = 0,5 GHz) < 457 kV
f
9,13 kV < r E (at f = 1 GHz) < 913 kV
f
18,27 kV < r E (at f = 2 GHz) < 1,83 MV
f
27,40 kV < r E (at f = 3 GHz) < 2,74 MV
f
CW sources that can produce average power levels in the range of 1 kW (continuous) to
10 MW (pulsed) are readily available today, and the estimates above appear to be
environments that can be easily produced. We can now estimate the electric field levels as a
function of frequency and range with the above commercial sources. This leads to the results
in Table 2.
Table 2 – Range of radiated electric field at various frequencies and power levels
Variation of E-field with an antenna aperture
Frequency Range
of 10 m and output powers of 2 kW to 20 MW
300 m 15,23 V/m to 1,52 kV/m
500 MHz
1 km 4,57 V/m to 457 V/m
300 m 30,43 V/m to 3,04 kV/m
1 GHz
1 km 9,13 V/m to 913 V/m
300 m 60,90 V/m to 6,09 kV/m
2 GHz
1 km 18,27 V/m to 1,83 kV/m
300 m 91,33 V/m to 9,13 kV/m
3 GHz
1 km 27,40 V/m to 2,74 kV/m
The CW results indicate that with the commercially available sources that have rms outputs
ranging from 1 kW to 10 MW, it is indeed possible to produce greater than 100 V/m signals at
kilometre distances, with modest sized antennas. The frequency range of sources in the L-
band is likely to cause more electronic damage than higher bands (10 GHz radar for example)
[21].
In the context of hyperband HPEM systems, TEM horns and reflectors fed by TEM trans-
mission lines are established as efficient radiators. For example, half-cycle and single cycle
sine wave generators at 1 GHz, with amplitudes of 100 kV (peak-to-peak) are realistic and
practical sources. One could consider a single TEM horn antenna for radiating such a pulse.
In summary, the parameter space for a hyperband system from commercial components is:
– source waveform half-cycle or full-cycle sine wave
– amplitude, V 100 kV peak-to-peak for full cycle
p
50 kV for the half cycle
– “frequency” 1 GHz (nominal)
– antenna type a TEM horn
– 16 – 61000-2-13  IEC:2005(E)
– antenna volume 30 cm × 30 cm × 30 cm
(1 wavelength in each dimension)
– peak field at 1 km distance, E ~ 50 V/m (time domain peak)
f
– bandwidth ~ 100 MHz to a few GHz
A calculation of the TEM horn radiation indicates (rE / V ) of about 0,5. This antenna is not
f p
necessarily an optimal design, however one could still produce an impulse-like signal with
amplitude of about 50 V/m at 1 km with a hyperband capability.
As in the case of narrowband sources, it is possible to make an array of sources and
antennas. The time domain field at early times will be additive. For example, a 3 m × 3 m
array could contain about 150 elements, and the peak signal can reach up to 7,5 kV/m at a
distance of 1 km.
5.2 HPM waveform characteristics: phaser (hypoband or narrowband)
The term "phaser" stands for pulsed high-amplitude sinusoidal electromagnetic radiation. A
progression of potential phaser designs are referred to as Mark N phasers and are defined by
N
source powers of 10 GW [3]. Thus a Mark 0 phaser has a power out from the source of
1 GW. The power out of the source is typically referenced to the lowest order waveguide
mode which can be coupled into a pyramidal horn antenna as described in detail in [3]. A
good example is a relativistic magnetron source that is commercially available [4] with the
following capabilities.
– Frequency = 1,1 GHz
– Peak power = 1,8 GW (average power = 0,9 GW)
– Pulse width = 60 ns (contains 66 cycles)
This commercial source can easily be modified to produce an average power of 1 GW, with a
slightly increased pulse duration of 100 ns to contain greater than 100 cycles of L-band
sinusoidal signal. This makes the quality factor Q = πM = 314, pbw = (100/Q) = 0,32, and
br = 1,0032. With an antenna of about 10 m aperture area, it is estimated that such a source
can easily produce fields of 2,3 kV/m at 3 km and 700 V/m at 10 km. These generator
systems can also be truck-mounted and can come in close proximity to civilian electronics
systems and facilities, producing much higher field levels.
Several narrowband generator systems in the frequency range of 0,4 GHz to 15 GHz exist.
Examples are:
– the Swedish Microwave Test facility, Linkoping, Sweden;
– the Orion system in U.K., which uses relativistic magnetrons and horn-fed reflector
antennas;
– Super Reltron based system in CEG, Gramat, France, called the Hyperion;
– Super Reltron based system at WIS, Munster, Germany.
It is noted that these systems are used in studying the vulnerabilities of electronic systems.
However, systems such as these may also be acquired by organizations/groups intent upon
harming civilized societies. Therein lies the potential threat in the present context of civilian
electronics systems and facilities.
5.3 Dispatcher (mesoband)
The term "dispatcher" stands for damped intensive sinusoidal pulsed antenna, thereby
creating highly energetic radiation. While the phaser is a narrowband device in which about
100 cycles of a single frequency radiation are produced in each pulse, Baum [5, 6] has
described certain sources that integrate an oscillator into the antenna system. Examples are:

61000-2-13  IEC:2005(E) – 17 –
a) a low–impedance quarter wave transmission line oscillator feeding a high-impedance
antenna, and
b) a low-impedance quarter wave transmission line feeding a TEM fed reflector.
The transmission line oscillator consists of a quarter wave section of a transmission line
(perhaps in oil or high-pressure gas medium for voltage stand off) that is charged by a high
voltage source and a self-breaking switch across the transmission line. When the switch
closes, a pulsed signal is fed into the antenna connected to this transmission line that
radiates an HPEM signal.
As an example, 500 MHz corresponds to a quarter wavelength in transformer oil of 10 cm,
which is very compact. The charge voltages can be in the range of 100s of kV. The half wave
section doubles the length for a given frequency and thus increases the stored energy. This is
included here as an emerging system that may be used in creating HPEM environments on
electronic systems such as civilian electronics systems and facilities.
5.4 Disrupter (sub-hyperband and hyperband)
A "disrupter", which is not an acronym, is basically a sub-hyperband or hyperband source/
antenna system such as the impulse radiating antenna (IRA), and it produces an HPEM signal
that has a bandratio greater than or equal to 10 [7–9]. If such a system operates from
200 MHz to 2 GHz, it has a bandratio of 10. Examples of IRAs are provided in Annex B.
The disadvantage of such a system is that the energy is spread over an extremely wide band
of frequencies. Although there can be very intense values of peak power, the power in the
narrow band of frequencies is low. This is the reason to call them disrupters in distinction to
phasers, which have high power levels at narrow bands of frequencies. As an example of a
disrupter, consider a 500 kV transient source, with a 5 ns duration into a 200 ohm antenna,
and a repetition rate of 1 kHz. Such a system would have a peak power of 1,25 GW, but an
average power of 6,75 kW. Such a system, which is quite practical, can result in severe
disruption of electronic systems.
In this clause, we have given examples of potential electromagnetic generator systems that
can, in principle place harmful levels of HPEM fields on civilian electronic systems and
facilities. No effort is made to evaluate the likelihood of such threats. It is felt that it would be
useful to assess the vulnerabilities of commercial facilities to such emerging threats and to
harden against them in the cases where it makes economic sense. The HPEM threats can
come in many forms, such as narrowband, moderate band and ultrawideband. They all have
different levels of disruption or damage potential. The HPEM threats can also vary in their
level of sophistication in terms of their design and fabrication. This makes the development of
environment standards more difficult; however, the test procedures are expected to be
straightforward, once reasonable standards are developed.
5.5 Impact of technology on radiated environments
An important distinction between HEMP and HPEM is that the HEMP environments are range
independent, while the radiated HPEM environments are a strong function of the range, or the
relative distance between the source and the intended or unintended victim system. At a
given range, the HPEM signal strength depends on the developing and emerging source
technologies and the sophistication of the antenna design.
5.5.1 Hypoband and mesoband HPEM environments
Mark 0 phasers (1 GW of narrowband average power) are state-of-the art generator systems,
but in the future, more powerful phasers will become commercially feasible. A (rE ) product of
p
15 MV is easily feasible with a Mark 0 phaser. This translates to 5 kV/m at a range of 3 km.
Developments in high-power microwave source technology, such as better cathode materials
etc., will easily enhance these numbers in the future.

– 18 – 61000-2-13  IEC:2005(E)
This environment standard combines the hypoband (or narrowband) and the mesoband HPEM
signals. The waveform to be applied is a damped sinusoid given by
−αt
E(t) = E e sin(ω t) u(t) (5)
o o
The normalised waveform (E(t) / E ) has been plotted in Figure 2 for the parametric values of
o
f = 1 GHz, ω = 2π f and the damping constant of α = 10 radians/s.
o o
o
Note that the three parameters that uniquely define the proposed waveform for the
environment are the "peak" signal E (the value of the envelope at t = 0 in Figure 2), the
o
damping constant α (radians/s) and the fundamental frequency f (Hz). The Fourier transform
o
and the corresponding spectral magnitude of the above signal are analytically known, and the
spectral magnitude is plotted in Figure 3.
It is also observed that the time-domain peak, the spectral content, the dc component, the
bandwidth, and the quality factor Q of this standard waveform are all known in closed form, as
listed below:
 
-α
E = E exp ; ω = 2πf (time domain peak value) (6)
 
p o
4f
 
o
~ ~
ω E ω E
o o o o
E(f ) = ; | E(f)| = (7)
2 2
2 2 2 2 2
(α + ω − ω )+ 2 jαω
o (α + ω − ω ) + 4α ω
o
~
ω E E
o o o
| E(0)| = ; spectral peak = (8)
2α
α + ω
o
1,0
ep(t) = exp(−αt)
ep(t) = −exp(−αt)
E(t)/E = exp (−αt)sin(ω t)
o o
0,5
0,0
−0,5
−1,0
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Time  ns
IEC  476/05
Figure 2 – A damped sinusoidal waveform for hypoband
and mesoband HPEM environments

E(t)/E
o
61000-2-13  IEC:2005(E) – 19 –

−9
5,0 × 10
−
4,0 × 10
Upper and lower
3 dB points
−
3,0 × 10
−
2,0 × 10
−9
1,0 × 10
8 8 9 9 9
5,00 × 10 7,50 × 10 1,00 × 10 1,25 × 10 1,50 × 10

Frequency  Hz
IEC  477/05
Figure 3 – The spectral magnitude of the time waveform in Figure 2
 
ω f f ω π f
o o o o o
Q = = = = = = πM
Quality factor (9)
 
Δω Δf f −f  2α α
h l
 
Δf 100 100 100α 200α
percent bandwidth pbw = 100 = = = = (10)
 
 f  Q π M πf ω
o o o
f ω ω + α
h h o
= =
bandratio br = (11)
f ω ω −α
l l o
α α
   
where f = f −  and f = f +  .
l o h o
2π 2π
   
For an illustrative example, given E = 102,532 (V/m), f = 1 GHz, and α
...