EMC tester (Electromagnetic compatibility tester) is a combination of test instruments that are used to analyze and identify the level of interference, mitigation, noise, and electromagnetic susceptibility of RF and Microwave devices.
EMC tester ensures the safety of the RF and Microwave electrical system in industries like aerospace, automotive, health care etc.
To learn more about RF and microwave components and systems, we recommend you refer to the bestsellers listed in the below articles.
To understand the EMC tester in a better way, we recommend you to understand the following RF instruments associated with them.
In this EMC tester article, we will cover,
The testing process of an EMC tester needs to follow the following procedures to ensure the quality of the electronic products and systems.
Before starting, Need to identify the standard which needs to follow for a specific DUT (component or instrument) as per the need of the industry.
The pre-Compliance test includes the physical verification of the DUT and also the EMC test equipment and its compatibility.
Identification of the suitable EMC test lab includes the selection of a Lab with engineering and instruments capabilities needed to match the required measurement standards.
EMC test consists of the following parts of the test. Each test needs to execute one after the other for the identification of the perfect compliance of the system to the EMC standards.
EMC Immunity and the EMC Emissions are the two important tests needed as part of the EMC test to the DUT for confirming compliance to the EMC standards.
EMC immunity test for the DUT ( Device under test) is to measures the device performance when it is subjected to interference and disturbances, such as electromagnetic noise. During the EMC immunity test, the reliability of DUT can be verified against certain operating conditions. The Immunity test setup consists of an RF and Microwave Signal Source, Power Amplifier and Electric Field Generator.
In RIT the system performance is checked in a broadband RF noise environment. Radiated immunity test is used to ensure that DUT will not malfunction when it got disturbed by a signal source from other instruments operated very close to the device.
A CIT is used to measures the level of RF energy conducted into the DUT when RF and microwave energy incident on cables.
EMC emissions tests are used to identify the level of electromagnetic noise generated by a DUT (operating device under test). EMC emissions tests determine that the device emissions level is within the acceptable limits and it does not produce harmful emissions to affect the operation of other devices.
Emissions test on DUT is performed by operating it on an AC power supply to ensure that it does not disturb other nearby systems performance during operation.
EMI and EMC testing is used to identify the emission levels, or its tendency to generate, transmit or receive electromagnetic interference for military or commercial devices. EMC testing is important for measuring and identifying the accurate EMC immunity of the DUT and for detecting the radiation level of DUT in labs and manufacturing sites.
Electromagnetic compatibility (EMC) testing is used to measures the ability of a system like dishwashers, coffee makers, microwaves ovens, communication transceivers etc to function satisfactorily in an electromagnetic environment without introducing intolerable internal electromagnetic disturbance to other nearby devices.
To execute the EMC testing in a Lab, many other RF and Microwave components and systems are required along with the closed environment with EMC adsorbent materials for the perfect measurement.
Current probes are RF current transformers that are used to sense current flowing through a conductor. Current probes convert current flowing in a conductor into an equivalent voltage that can be measured on an oscilloscope. Two types of Current Probes that are mainly used in EMC measurements are Immunity Current Probes ( To conducted immunity testing to inject noise onto a cable ) and Emission Current Probes (For measuring conducted noise from the cable).
Electric Field Generators are used to convert RF and microwave energy into equivalent Electromagnetic fields (E-Field) for EMC Immunity Testing. E-Field generators are worked on the principle of faraday's electromagnetic induction law.
E-Field Generators will have coils of electric conductors, (normally copper wire), that are tightly and uniformly wound onto a metal core and are mounted to turn around inside a large magnet. This generator creates a required Electric field for the testing.
The EMC absorbent is used to absorb the radiated electromagnetic energy from the DUT or from the test equipment. The high performance, carbon loaded polystyrene, are used for the construction of the EMC absorbent. The absorbers are with white end caps is used to improve EMC chamber interior illumination and further protection.
An EMC Antenna Kit consists of various types of EMC testing antennas and accessories like cables, adapters, connectors, tripods etc. The antennas in the kits are basically biconical, horn, log periodic, monopole antennas etc.
EMC antennas are used to receive signals from a device or transmit the electromagnetic signals to a device under test to conduct various EMC testing on a device to measure radiated emissions and radiated immunity. The test accessories are used along with the EMC antennas for frequent handling and rapid replacement even in rugged environments.
EMC immunity test systems and the standard instruments which will work in tandem with other instruments and accessories to conducted susceptibility tests and radiated susceptibility of the device under test in a required frequency range. These instruments will have dedicated control front panels and software with a graphical user interface for remote operations that allow a simple setup for EMC testing.
EMC Power Amplifiers is an RF Amplifier used for EMC Testing, used to boost the generate Electromagnetic Fields for the Immunity EMC Testing. The Power amplifier will boost the generated RF signal from the signal generator and send it to the E-Field Generator, which converts the output signal from the amplifier to an Electromagnetic Field. The power amplifier gain must be in a range which is able to deliver high levels of power across the frequency band of interest for EMC immunity testing of the DUT with low total harmonic distortion.
EMC test preamplifiers are used to increase the received signal strength of the measurement system (sensitivity) during EMC compliance testing. The high-gain and low-noise RF pre-amplifier help to improve the system sensitivity and it will allow the measurement of signals which are ‘hidden’ in the noise which is close to the radiated emission limits.
EMC Power meter is used to measure the received RF power level for testing. EMC power meter is capable of measuring effective energy consumption.
EMC lab is a state-of-the-art facility that has anechoic chambers with adequate instrumentation and a place for setting the EMC absorbent to support the EMC requirements of DUT. These Labs will meet the industrial and defence/military standards and have all the calibrated equipment to execute all the EMI and EMC testings.
EMF measurements are the measurements of ambient electromagnetic fields, which are part of EMC testing. For the testing of EMF, the test setup required particular sensors and probes, such as EMF meters and EMF probes.
EMF broadband measurements using a broadband probe, capable of sensing any signal across a wide frequency range usually made with diode detectors which may respond to fields only on one axis. The frequency selective measurements are executed using a field antenna and a frequency selective receiver in the range of interest.
Electromagnetic interference (EMI) Receivers are the special receivers that have very low sensitivity. Most of the receivers will have built-in pre-amplifiers and the control and tuning circuit to improve the measurement capabilities.
Near-field probes are used the make measurements of the electric and magnetic fields at high-frequency. They are mainly used to measure undesirable electromagnetic radiation and other electrical noise from the DUT. Near field, probes tap the signal and connect to oscilloscope or spectrum analyzers to measure the E-Field and H-field using the respective probes.
For executing the EMC test first need to consider the type of test required and the standards that need to comply.
Test type indicates the type of tests like EMC immunity and EMC Emissions. For the immunity test, transmit parameters need to consider more and for the Emission test, receiver test systems parameters need to consider as the prime spec.
The configuration of the Test Setup like the Turn-key Test System or the individual DUT test set need to decide as per the test requirement. EMC Standards which need to meet like MIL-STD-461 is need to consider for the selection. For the Higher standards, all the instruments used for the testing need to meet the required standard level specified in the respective industry.
The frequency range of the EMC tester indicates the range of frequency over which need to execute the test for the DUT. For the wideband DUT’s it is ideal to select all the instruments which support the wideband frequency range.
The specification of the individual test equipment’s like Power Amplifier, Field Probe Signal Generator, Receiver and the associated Software etc need to select as per the requirements. All the Instruments need to qualify the test standers for the ideal test setup.
Electromagnetic compatibility (EMC) test is used to evaluate the performance and integrity of any electrical product or device used in any industry. It can be used for consumer goods such as cellular phones, microwave ovens, laptops and satellite TV dishes to ensure they do not cause harmful interference or it will not be affected by other instruments operated in real-world conditions.
If you are looking for any specific or customized RF and Microwave EMC tester please feel to share with us, we will direct it to the respective person in your regional manufacturer. Please feel free to contact us if you would like to add or modify any information about EMC tester or manufacture details on this page.
Thanks & Regards
RFMWC: RF & Microwave Community