Text preview for : 5990-7420EN.pdf part of HP 5990-7420EN HP Publikacje 5990-7420EN.pdf
Back to : 5990-7420EN.pdf | Home
Making EMI
Compliance Measurements
Application Note
Table of Contents Introduction to compliance measurements......................................................................3
The compliance measurements process ..........................................................................4
Compliance EMI receiver requirements ............................................................................7
Requirements above 1 GHz ......................................................................................8
Conducted emissions measurements ................................................................................9
Conducted test setup ................................................................................................9
Configuring the receiver............................................................................................9
Performing conducted emissions measurements............................................11
Radiated emissions measurements..................................................................................13
Open site requirements...........................................................................................13
Radiated emissions test setup ..............................................................................14
Measuring radiated emissions ..............................................................................15
Placement of EUT for maximum signals .........................................................................16
Ambient plus EUT measurements........................................................................16
Appendix A - Line impedance stabilization networks ..................................................17
Appendix B - Antenna factors............................................................................................19
Appendix C - Basic electrical relationships ....................................................................21
Appendix D - Detectors used in EMI measurements ...................................................22
Appendix E - EMC regulatory agencies ...........................................................................25
Glossary of acronyms and definitions ..............................................................................26
2
Introduction to compliance Electrical or electronic equipment that uses the public power grid or has
potential for electromagnetic emissions must pass EMC (electromagnetic
measurements compatibility) requirements. These requirements fall into four broad
types of testing: radiated and conducted emissions testing, and radiated and
conducted immunity testing.
Conducted emissions testing focuses on signals present on the AC mains that
are generated by the equipment under test (EUT). The frequency range of these
measurements is typically 9 kHz to 30 MHz. However, MIL-STD measurement
may have a wider frequency range.
Radiated emissions testing searches for signals being emitted from the EUT
through space. The typical frequency range for these measurements is 30 MHz
to 1 GHz or 6 GHz, although FCC regulations require testing up to 40 GHz.
Figure 1 illustrates the difference between radiated emissions, radiated
immunity, conducted emissions, and conducted immunity. Radiated immunity
is the ability of a device or product to withstand radiated electromagnetic fields.
Conducted immunity is the ability of a device or product to withstand electrical
disturbances on power or data lines. Immunity testing will not be covered in
this document.
For an electromagnetic compatibility problem to occur (such as when an
electric drill interferes with TV reception), there must be a generator or
source, a coupling path, and a receptor. Until recently, most efforts to remove
EMC problems have focused on reducing the emissions of the source to an
acceptable level--now both emissions and immunity tests are performed.
Emission Immunity = Susceptibility
Figure 1. Four types of EMC measurements
3
The compliance Before compliance measurements can be performed on a product, some
preliminary questions must be answered:
measurements process
1. Where will the product be sold (for example, the United States,
Europe, or Japan)?
2. What is the classification of the product (for example, information
technology equipment (ITE); industrial, scientific, or medical (ISM);
or automotive and communications)?
3. Where will the product be used (for example, home, commercial, light
industry, or heavy industry)?
With the answers to the above questions, you can determine which testing
requirements apply to your product by referring to Tables 1a and 1b below. For
example, if you have determined that your product is an ITE device that will
be sold in the U.S., then you need to test the product to FCC Part 15 regulations.
International regulations summary (emissions)
CISPR FCC EN Description
11 Part 18 EN 55011 Industrial, scientific, and medical
13 Part 15 EN 55013 Broadcast receivers
14 EN 55014 Household appliances/tools
15 EN 55015 Fluorescent lights/luminaries
16-1-1 Measurement apparatus/methods
22 Part 15 EN 55022 Information technology equipment
25 EN 55025 Automotive
EN 50081-1,2 Generic emissions standards
Table 1a. Comparison of regulatory agency requirements
European Norms (EN)
Equipment type Emissions
Generic equipment EN 50081-1
Residential
Light industrial
Industrial EN 50081-2
Industrial, scientific, medical products (ISM) EN 55011
Sound and broadcast receivers EN 55013
Household appliances EN 55014
Information technology equipment (ITE) EN 55022
Automotive EN55025
Table 1b. Major European requirements
4
European Norms
EN55011 (CISPR 11)
Industrial, scientific, and medical products
Class A: Used in establishments other than domestic areas.
Class B: Suitable for use in domestic establishments.
Group 1: Laboratory, medical, and scientific equipment. (For example, signal
generators, measuring receivers, frequency counters, spectrum analyzers,
switching mode power supplies, weighing machines, and electronic
microscopes.)
Group 2: Industrial induction heating equipment, dielectric heating equipment,
industrial microwave heating equipment, domestic microwave ovens, medical
apparatus, spark erosion equipment, and spot welders. (For example, metal
melting, billet heating, component heating, soldering and brazing, wood gluing,
plastic welding, food processing, food thawing, paper drying, and microwave
therapy equipment.)
EN55014 (CISPR 14)
Electric motor-operated and thermal appliances for household and similar
purposes, electric tools, and electric apparatus. Depending on the power rating
of the item being tested, use one of the limits shown in Table 1c.
EN55014 Conducted household appliances QP
EN55014 Conducted household appliances AVE
EN55014 Conducted < 700 W motors QP
EN55014 Conducted < 700 W motors AVE
EN55014 Conducted > 700 W < 1000 W motors QP
EN55014 Conducted > 700 W < 1000 W motors AVE
EN55014 Conducted > 1000 W motors QP
EN55014 Conducted > 1000 W motors AVE
EN55014 Radiated household appliances QP
EN55014 Radiated household appliances AVE
EN55014 Radiated < 700 W motors QP
EN55014 Radiated < 700 W motors AVE
EN55014 Radiated > 700 W < 1000 W motors QP
EN55014 Radiated > 700 W < 1000 W motors AVE
EN55014 Radiated > 1000 W motors QP
EN55014 Radiated > 1000 W motors AVE
Note: The conducted range is 150 kHz to 30 MHz and the radiated range is 30 MHz to 300 MHz.
Table 1c. Tests based on power rating
5
EN55022 (CISPR 22)
Information technology equipment
Equipment with the primary function of data entry, storage, displaying,
retrieval, transmission, processing, switching, or controlling. (For example,
data processing equipment, office machines, electronic business equipment,
and telecommunications equipment.)
Class A ITE: Not intended for domestic use.
Class B ITE: Intended for domestic use.
Federal Communications Commission (FCC)
Equipment FCC
Broadcast receivers
Household appliances/tools
Part 15
Fluorescent lights/luminaries
Information technology equipment (ITE)
Industrial, scientific, medical products (ISM)
Conducted measurements: 450 kHz - 30 MHz Part 18
Radiated measurements: 30 MHz - 1000 MHz, 40 GHz
Table 1d. FCC regulations
Federal Communications Commission
FCC Part 15
Radio frequency devices--unintentional radiators
Equipment that unintentionally produces emissions that could interfere with
other devices. (For example, TV broadcast receivers, FM broadcast receivers,
CB receivers, scanning receivers, TV interface devices, cable system terminal
devices, Class B personal computers and peripherals, Class B digital devices,
Class A digital devices and peripherals, and external switching power supplies).
Class A digital devices are marketed for use in a commercial, industrial, or
business environment.
Class B digital devices are marketed for use in a residential environment.
For assistance, contact the agency for conformation of the applicable
requirement--see Appendix E for contact information.
6
Compliance EMI receiver There are several requirements for making compliance EMI measurements.
The first is an EMI receiver that meets CISPR 16-1-1 1, such as the N9038A
requirements MXE EMI receiver.
A CISPR 16-1-1 receiver must have the following functionality in the range
9 kHz - 18 GHz: