MIL-STD-461G!
Draft for Industry Review!
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Here
Ken Javor!
EMC Consultant!
Ken Javor
Content goes here!
•  1!
•  2!
•  3!
30+ YEARS IN EMI/EMC
Consultant to Government and Industry
Industry representative to MIL-STD-461 and
MIL-STD-464 Tri-Service Working Groups…
[email protected]
(256) 650-5261
PURPOSE OF STANDARD
Controls EMI characteristics of equipment/
subsystems procured by DoD
GO/NO-GO or Pass/Fail Requirements*
Increases likelihood of compatibility in its
EME
Easier to build EMC into equipments/
subsystems that to Band-Aid it in during
system integration
* Officially - actually, not so much…
APPLICABILITY
Requirements depend on equipment/subsystem type and use
4
Standard Review /Comment Submission
Your inputs can make a difference!
The MIL-STD-461F change in how
the rod antenna is used was
prompted by an industry review
comment that was submitted in
response to the MIL-STD-461F draft
for industry review (which didn’t
address the issue at all).
5
Standard Review /Comment Submission
MIL-STD-461G draft for industry review released on 01 April (!) and comments
are due to DoD by 18 May.
Comments submitted through a DoD website:
https://assist.dla.mil/online/start/
It should allow you to set-up an account and then log into the specific site for
461 G comments.
If you need a copy of the standard, it can be obtained from one of the industry
reps, via email (3 MB attachment).
6
Electrical Bonding
Requires measuring and recording bond values prior to cable connection and any
further testing. No bond value requirements: bonding results must be in accordance
with installation drawings/requirements.
Requires LISNs bonded ≤ 2.5 milliohms.
Sad But True
(why do we need to put this in the standard?)
4.3.7.2 Excess personnel and equipment
This section already said:
“The test area shall be kept free of unnecessary personnel, equipment, cable racks,
and desks. Only the equipment essential to the test being performed shall be in the
test area or enclosure. Only personnel actively involved in the test shall be permitted
in the enclosure.”
Now the following is added:
“Remove all equipment and ancillary gear not required, including antennas, from
shielded enclosures not being actively used for a particular subset of radiated tests.”
In other words, it’s a test chamber, not a broom closet…
OTOH….
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***Table II - Emission Sweeps***
10
Table II - Emission Sweeps of 1 pps 10 us pulse
Traditional EMI rcvr using 15 ms dwell time
FFT EMI rcvr using 15 ms dwell time
FFT EMI rcvr using 1 second dwell time
From MIL-STD-461G Table II Appendix supporting information
11
General Set-Ups
Expanded ground plane requirement (Figure 5) for equipments tested outside a shielded chamber.
***Detailed requirements (4.3.8.6.1) on cable routing for large floor-standing equipment. ***
***Further in the standard, under RE102 and RS103, more requirements on antenna placement
positions for equipments with height as well as width. ***
12
***4.3.11 Change in Routine Calibration Requirements***
4.3.11 Calibration of measuring equipment.
Primary measurement devices and accessories required for measurement in accordance
with this standard shall be calibrated in accordance with ANSI/ISO/IEC 17025 or ISO
10012 or under an approved calibration program traceable to the National Institute for
Standards and Technology. After the initial calibration, for passive devices such as
measurement antennas, current probes, and LISNs, no further calibration is required. The
measurement system integrity check in the procedures is sufficient to determine
acceptability of passive devices.
Suggested change acknowledges that passive device calibration is quite different than
calibrating an EMI receiver and cycle times and procedures are significantly different.
Balloting on SAE AIR 6236 for such passive device calibration is underway to support the
change.
13
4.3.11 Test Equipment Calibration Change
14
TABLE IV. Emission and susceptibility requirements
CS106 deleted.
New!
New!
15
Table V. Requirements Matrix
16
5.5 CE102
When performing the measurement system integrity check, there is an extra step
that confirms LISN impedance is in tolerance below 2 MHz.
This is in lieu of calibrating LISNs on a periodic cycle.
17
5.6 CE106
Transmit requirement becomes very complex if application is high power Navy ship
topside installation.
The 5% frequency exclusion becomes transmit power dependent:
The Navy topside limit becomes independent of transmit power:
“Transmitters and amplifiers (transmit mode): Harmonics, except the second and third, and all other
spurious emissions shall be at least 80 dB down from the level at the fundamental. The second and
third harmonics shall be suppressed to a level of -20 dBm or 80 dB below the fundamental, whichever
requires less suppression. For Navy shipboard applications, the second and third harmonics will be
suppressed to a level of -20 dBm and all other harmonics and spurious emissions shall be
suppressed to -40 dBm, except if the duty cycle of the emissions are less than 0.2%, then the limit
may be relaxed to 0 dBm.”
18
5.7 CS101 Change
5.7 CS101 Solution
Performance Comparison 800 Hz CS101 Ripple
Performance Comparison 100 Hz CS101 Ripple
The Past Into the Future? – No.
Testing at frequencies below the power frequency.
22
5.11 CS106, Conducted Susceptibility, transients, power leads
DELETED.
No justification exists. Tests indicated that CS115 couples the same
amount of crosstalk into a wire adjacent to the power wire with
transient as when using the transient itself.
From a review of MIL-STD-461F when it was new:
The purpose of this requirement is however entirely different than when CS06 was developed
and required in MIL-STD-826 and MIL-STD-461 A/B/C. CS106 has little to do with electrical
power quality except modeling coupling from power bus transients to signal lines within an
equipment enclosure. It is now a special purpose cross-talk test limited to Navy procurements,
particularly submarines, which requested and justified it, as follows (from the rationale
appendix):
"The Navy submarine community has found the obsolete CS06 of MIL-STD-461 (through
revision C) requirement to be an effective method to minimize risk of transient related equipment
and subsystem susceptibility. This type of transient susceptibility test has been successful in
early identification of transient related EMI problems in naval equipment and subsystems. The
Navy has found good correlation between transient related shipboard EMI problems, including
longevity, degraded performance and premature failures, and CS106 susceptibilities."
Most of the problems uncovered by the heritage CS06 requirement were not with the power
input circuitry, but rather other circuits which were affected by cross-talk between power and
signal wiring within the test sample.
23
***5.12 CS114, Conducted Susceptibility, Bulk Cable Injection***
S
E-field spatial variation
E-field spatial variation
line is electrically short
E
length = λ/4
Field-To-Wire Coupling
(Vi/E), Normalized
coupling efficiency
Vi
= 2h sin (πl/λ)
Ei
length = λ/2 (max coupling)
line length = λ ( 1st null)
f = (2n+1)c / 2L,
n an integer
0
-10
-20
f = n c / L,
n an integer
-30
-40
L = λ/200
L = λ/20
L = λ/2
electrical length
24
***5.12 CS114 – Major Impact on
Shielded Cables! ***
Level on current as present or on precalibrated forward power?
IN Compliance magazine, October 2014
issue
5.12 CS114
When performing forward power calibration, the current probe used to monitor
injected current must also be verified.
***5.15 CS117 – Lightning Indirect Effects***
Purpose: Lightning is not a new requirement for DoD platforms; but it is being included
in MIL-STD-461 so as to eliminate the need to separately call out a non-DoD standard.
Borrowed from RTCA/DO-160G Section 22.
At present time, no pin injection.
Levels don’t exceed RTCA/DO-260 section 22 Level 4.
Includes multiple stroke and multiple burst.
If a test facility has a section 22 lightning capability to Level 4, they can perform the
MIL-STD-461 version.
***5.16 CS118 – ESD***
Personnel borne electrostatic discharge
Applicable to electrical, electronic, and electromechanical subsystems and
equipment which does not interface with or control ordnance items
Leverage from Industry ESD standards
RTCA/DO-160 section 25
IEC 61000-4-2
“Gun” definition per RTCA/DO-160 section 25. Target per IEC 61000-4-2
Levels from 2 to 15 kV. Levels below 15 kV are default contact discharge; 15 kV is
air discharge.
Risetime 0.6 ≤ tr ≤ 1 ns
5.18 RE102
Issues under discussion for -461G (no guarantee of concrete action due to time
constraints:
Rod antenna optimization
Proper set-up – was in draft2, not in released draft
Proper measurement system integrity check using correct capacitor value – YES.
Proper capacitance based on counterpoise size: TBD…
Proper illumination of test samples with
height larger than antenna spot-size.
5.18 RE102
Three things you don’t want to see:
Sausage-making
Law-making
Standard-making
5.18 RE102
-461F fixed a resonance issue with the rod antenna measurement. -461G was trying to make the
-461F connection not dependent on a ground plane connection.
The idea is to use isolation, either transformer, or optical. Optical has been done, and it works, but $
$$.
-461F
-461G desiderata
No floor
connection
required
XFMR or
optical
isolation
5.18 RE102
Transformer trials
1:1 isolation 50 Ohm XFMRs
with little or no loss 10 kHz to
30 MHz
5.18 RE102
Rod antenna measuring
electric field from wire
over ground plane.
5.18 RE102
Rod antenna measuring electric field
from wire over ground plane, using
MIL-STD-461E connection.
5.18 RE102
Rod antenna measuring electric field
from wire over ground plane, using
MIL-STD-461F connection.
5.18 RE102
Rod antenna measuring electric field
from wire over ground plane, using
isolation transformer connection.
5.18 RE102
Rod antenna measuring electric field
from wire over ground plane, using a
different isolation transformer
connection.
5.18 RE102
-461E connection
Looks
pretty
good
here, but
WPAFB
gets
different
results.
-461F connection
Not
resolved.
Isolation XFMR
Not ready
for prime
time L
Second isolation XFMR
5.19 RE103, Radiated Emissions, Antenna
Spurious and Harmonic Outputs,
The same Navy topside high power transmitter changes apply to RE103
(frequency exclusion and fixed transmit limit) as for CE106
39
5.21 RS103, Radiated Susceptibility, Electric Field
5.20.1 RS103 applicability (-461F).
This requirement is applicable to equipment and subsystem enclosures and all interconnecting
cables. The requirement is applicable as follows:
a. 2 MHz to 30 MHz Army ships; Army aircraft, including flight line; Navy
(except aircraft); and optional* for all others
b. 30 MHz to 100 MHz all (except Navy aircraft)
c. 100 MHz to 1 GHz all
d. 1 GHz to 18 GHz all
e. 18 GHz to 40 GHz optional* for all
*Required only if specified in the procurement specification
There is no requirement at the tuned frequency of antenna-connected receivers except for surface
ships and submarines.
5.21.1 RS103 applicability (-461G). Much simpler, due to NAVAIR changes.
This requirement is applicable for equipment and subsystem enclosures and all interconnecting cables. The
requirement is applicable as follows:
a.
2 MHz to 30 MHz
Army ships; Army aircraft, including flight line; Navy; and optional* for all
others
b.
30 MHz to 18 GHz
All
c.
18 GHz to 40 GHz
Optional* for all
*Required only if specified in the procurement specification
For Air Force only:
There is no requirement at the tuned frequency of antenna-connected receivers.
40
5.21 RS103, Radiated Susceptibility, Electric Field
MIL-STD-461F 5.20.3.4.c(2) RS103 Receive Antenna (calibration) procedure (>
1 GHz)
is eliminated in MIL-STD-461G
41
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