EMC TESTING
EMC TESTING
Electromagnetic compatibility (EMC) is the ability of an electronic device to exist in an electromagnetic environment without causing interference or interference with other electronic devices in the environment.
EMC is usually divided into two categories:
1. Radiation-Electromagnetic interference emitted by electronic equipment may cause interference/failure to other electronic equipment in the same environment. Also called electromagnetic interference (EMI).
2. Immunity/susceptibility-Immunity refers to the ability of electronic equipment to operate normally in an electromagnetic environment without interference/failure due to radiation emitted by other electronic equipment. Susceptibility is basically the opposite of immunity, because the equipment is electromagnetic interference The smaller the immunity, the more susceptible it is. Usually immunity testing is not necessary for selling/distributing consumer/commercial products in Australia, New Zealand, North America and Canada.
Electromagnetic compatibility emissions
EMC emissions are further subdivided into two categories:
1. Radiation emissions
2. Carry out emissions
The electromagnetic field consists of the following parts:
1. Electric field (electric field)-usually measured in volts/meter (V/M)
2. Magnetic field (H field)-usually measured in amperes per meter (A/m)
The two components of the electromagnetic field are themselves two independent fields, but they are not completely independent phenomena. The electric field and the H field move at right angles to each other.
Radiation emission (E-Field):
Radiated emission is electromagnetic interference (EMI) or interference originating from frequencies generated inside electronic or electrical equipment. Radiated emissions can cause severe compliance issues. Radiated emissions are transmitted directly from the equipment chassis or through the air through interconnecting cables (such as signal ports, wired ports, such as telecommunication ports or power wires).
A good example is the HDMI port and the related EMI that can be radiated from these cables, in compliance with EMC radiated emission test (EMI). During EMC testing, use a spectrum analyzer and/or EMI receiver and a suitable measurement antenna to perform radiation emission measurements.
EMC radiation emission test method
Radiated emission (H field): The magnetic components of electromagnetic waves use a spectrum analyzer and/or EMI receiver and a suitable measuring antenna. Typical magnetic field antennas include loop antennas, and also include specific antennas according to CISPR 15, such as Van Veen Loop. Van Veen loop antennas are basically three loop antennas, which together constitute the product magnetic field emission of three axes (X, Y and Z).
Conducted emission (continuous and discontinuous):
Conducted emission is electromagnetic interference (EMI) or interference from frequencies generated inside electronic or electrical equipment. These emissions then propagate along interconnected cables, such as wired ports, such as telecommunications ports or power wires. These transmissions can be continuous (continuous transmission at a given frequency) or discontinuous (non-constant, occasionally).
During the EMC test, conduction emission measurement is performed on the EMI receiver through the ISN (Impedance Stabilization Network) located in the test room.
Electromagnetic compatibility immunity
EMC immunity testing can be considered continuous or transient. Continuous testing is applied to the product to simulate the RF proximity that may occur in the real world. Transient phenomena are usually short events involving bursts of energy.
EMC immunity test requirements are usually separated according to how electromagnetic interference is coupled to the equipment:
1. Immunity, chassis port
2. Immunity, signal port and telecommunications port
3. Immunity, input DC power port
4. Immunity, input AC power port
The test level, the type of interference signal, etc. depend on the type of equipment under test and the applied standard.
Continuous immunity test
Radiation immunity: RF signal generators, amplifiers and antennas are used to generate electromagnetic fields of different frequencies. The shell port of the EUT and related cables are exposed to the electromagnetic field through the radiating antenna. The radiation test signal is at a specific amplitude and the modulation is applied for a specific period of time. Most standards that require immunity testing require this test.
Conduction immunity:
During the conducted immunity test, the RF signal generator and amplifier generate electromagnetic fields. The electromagnetic field is coupled to the product signal, data or power port through an injection device (usually a CDN, or "coupling/decoupling network" used as an injection device). This conducted immunity test is continuous in nature and is called "radio frequency continuous conduction" in many standards. Generally, the conducted immunity test is applicable to AC and DC ports and signal cables longer than 3 meters.
Power frequency magnetic field immunity:
The fluctuating magnetic field generated by the electromagnetic coil oscillates at the main power frequency (50/60Hz). The EUT is placed in this fluctuating magnetic field and exposed for sufficient time to evaluate the performance of the product. Magnetic field immunity testing is usually only applicable to magnetically sensitive equipment.
Transient immunity test:
The transient phenomenon is a short burst of energy, and the tested product will be exposed in a short period of time. Like continuous immunity, transient immunity applies to product chassis ports, signal/data ports, and power ports (if applicable).
Electrostatic discharge (ESD):
The ESD pulse is directly applied to the housing of the device and indirectly applied to the vertical/horizontal coupling plane, close to the product under test, and the test level is related to the applied standard. For more information about electrostatic discharge effects and possible ESD compatibility solutions, please check the article: Common EMC Solutions for Electrostatic Discharge.
Electrical fast transient (EFT)/burst:
A fast transient is a series of short pulses with a high amplitude and repetition rate, and a short rise time. Fast transient phenomena are usually caused by high-speed switching events, such as inductive load interruption and relay contact bounce. Generally, the fast transient test is suitable for AC and DC ports and signal cables longer than 3 meters.
surge:
Surge is a transient phenomenon caused by high-power switching events, magnetic/inductive coupling and even lightning. Apply the surge test on the power port of the EUT at several phase angles of the main power supply. Generally, surge testing is applicable to AC ports and sometimes to DC ports. The signal cable length in some EMC product standards exceeds 30 meters, or the cable may run outside the building. For more information about surges, please refer to our article Surges EMC test typical problems and solutions.
Voltage dips, short interruptions (VDI) and voltage changes:
The purpose of the voltage dip and short interruption test is to simulate faults in the power network. These faults may be caused by a power failure (power failure/power failure event) or a sudden large change in the load. Voltage changes are usually caused by continuously changing loads connected to the power network. Voltage dips or interruptions are two-dimensional phenomena characterized by residual voltage (the power supply voltage after a specified drop) and duration (how long the nominal voltage drops to the drop of the product). This test is only applicable to the AC input port of the product.
Pulsed magnetic field:
Like the power frequency magnetic field immunity test, the product under test is placed in the magnetic ring. Unlike the power frequency magnetic field test, the EUT does not expose the EUT to a continuously fluctuating magnetic field (oscillating at 50/60Hz), but to a magnetic field pulse provided by a transient generator. The magnetic pulse amplitude is high but the rise time is short, and then the performance of the product is evaluated to ensure normal operation.
EMC is usually divided into two categories:
1. Radiation-Electromagnetic interference emitted by electronic equipment may cause interference/failure to other electronic equipment in the same environment. Also called electromagnetic interference (EMI).
2. Immunity/susceptibility-Immunity refers to the ability of electronic equipment to operate normally in an electromagnetic environment without interference/failure due to radiation emitted by other electronic equipment. Susceptibility is basically the opposite of immunity, because the equipment is electromagnetic interference The smaller the immunity, the more susceptible it is. Usually immunity testing is not necessary for selling/distributing consumer/commercial products in Australia, New Zealand, North America and Canada.
Electromagnetic compatibility emissions
EMC emissions are further subdivided into two categories:
1. Radiation emissions
2. Carry out emissions
The electromagnetic field consists of the following parts:
1. Electric field (electric field)-usually measured in volts/meter (V/M)
2. Magnetic field (H field)-usually measured in amperes per meter (A/m)
The two components of the electromagnetic field are themselves two independent fields, but they are not completely independent phenomena. The electric field and the H field move at right angles to each other.
Radiation emission (E-Field):
Radiated emission is electromagnetic interference (EMI) or interference originating from frequencies generated inside electronic or electrical equipment. Radiated emissions can cause severe compliance issues. Radiated emissions are transmitted directly from the equipment chassis or through the air through interconnecting cables (such as signal ports, wired ports, such as telecommunication ports or power wires).
A good example is the HDMI port and the related EMI that can be radiated from these cables, in compliance with EMC radiated emission test (EMI). During EMC testing, use a spectrum analyzer and/or EMI receiver and a suitable measurement antenna to perform radiation emission measurements.
EMC radiation emission test method
Radiated emission (H field): The magnetic components of electromagnetic waves use a spectrum analyzer and/or EMI receiver and a suitable measuring antenna. Typical magnetic field antennas include loop antennas, and also include specific antennas according to CISPR 15, such as Van Veen Loop. Van Veen loop antennas are basically three loop antennas, which together constitute the product magnetic field emission of three axes (X, Y and Z).
Conducted emission (continuous and discontinuous):
Conducted emission is electromagnetic interference (EMI) or interference from frequencies generated inside electronic or electrical equipment. These emissions then propagate along interconnected cables, such as wired ports, such as telecommunications ports or power wires. These transmissions can be continuous (continuous transmission at a given frequency) or discontinuous (non-constant, occasionally).
During the EMC test, conduction emission measurement is performed on the EMI receiver through the ISN (Impedance Stabilization Network) located in the test room.
Electromagnetic compatibility immunity
EMC immunity testing can be considered continuous or transient. Continuous testing is applied to the product to simulate the RF proximity that may occur in the real world. Transient phenomena are usually short events involving bursts of energy.
EMC immunity test requirements are usually separated according to how electromagnetic interference is coupled to the equipment:
1. Immunity, chassis port
2. Immunity, signal port and telecommunications port
3. Immunity, input DC power port
4. Immunity, input AC power port
The test level, the type of interference signal, etc. depend on the type of equipment under test and the applied standard.
Continuous immunity test
Radiation immunity: RF signal generators, amplifiers and antennas are used to generate electromagnetic fields of different frequencies. The shell port of the EUT and related cables are exposed to the electromagnetic field through the radiating antenna. The radiation test signal is at a specific amplitude and the modulation is applied for a specific period of time. Most standards that require immunity testing require this test.
Conduction immunity:
During the conducted immunity test, the RF signal generator and amplifier generate electromagnetic fields. The electromagnetic field is coupled to the product signal, data or power port through an injection device (usually a CDN, or "coupling/decoupling network" used as an injection device). This conducted immunity test is continuous in nature and is called "radio frequency continuous conduction" in many standards. Generally, the conducted immunity test is applicable to AC and DC ports and signal cables longer than 3 meters.
Power frequency magnetic field immunity:
The fluctuating magnetic field generated by the electromagnetic coil oscillates at the main power frequency (50/60Hz). The EUT is placed in this fluctuating magnetic field and exposed for sufficient time to evaluate the performance of the product. Magnetic field immunity testing is usually only applicable to magnetically sensitive equipment.
Transient immunity test:
The transient phenomenon is a short burst of energy, and the tested product will be exposed in a short period of time. Like continuous immunity, transient immunity applies to product chassis ports, signal/data ports, and power ports (if applicable).
Electrostatic discharge (ESD):
The ESD pulse is directly applied to the housing of the device and indirectly applied to the vertical/horizontal coupling plane, close to the product under test, and the test level is related to the applied standard. For more information about electrostatic discharge effects and possible ESD compatibility solutions, please check the article: Common EMC Solutions for Electrostatic Discharge.
Electrical fast transient (EFT)/burst:
A fast transient is a series of short pulses with a high amplitude and repetition rate, and a short rise time. Fast transient phenomena are usually caused by high-speed switching events, such as inductive load interruption and relay contact bounce. Generally, the fast transient test is suitable for AC and DC ports and signal cables longer than 3 meters.
surge:
Surge is a transient phenomenon caused by high-power switching events, magnetic/inductive coupling and even lightning. Apply the surge test on the power port of the EUT at several phase angles of the main power supply. Generally, surge testing is applicable to AC ports and sometimes to DC ports. The signal cable length in some EMC product standards exceeds 30 meters, or the cable may run outside the building. For more information about surges, please refer to our article Surges EMC test typical problems and solutions.
Voltage dips, short interruptions (VDI) and voltage changes:
The purpose of the voltage dip and short interruption test is to simulate faults in the power network. These faults may be caused by a power failure (power failure/power failure event) or a sudden large change in the load. Voltage changes are usually caused by continuously changing loads connected to the power network. Voltage dips or interruptions are two-dimensional phenomena characterized by residual voltage (the power supply voltage after a specified drop) and duration (how long the nominal voltage drops to the drop of the product). This test is only applicable to the AC input port of the product.
Pulsed magnetic field:
Like the power frequency magnetic field immunity test, the product under test is placed in the magnetic ring. Unlike the power frequency magnetic field test, the EUT does not expose the EUT to a continuously fluctuating magnetic field (oscillating at 50/60Hz), but to a magnetic field pulse provided by a transient generator. The magnetic pulse amplitude is high but the rise time is short, and then the performance of the product is evaluated to ensure normal operation.