Electromagnetic Interference (EMI) and Electromagnetic Compatibility (EMC)
[Copy link]
邀请：@54chenjq
参与回复
Did you know that 50% of projects fail to pass EMI/EMC testing in one go? According to a report by Intertek Testing Services, about half of products fail to pass initial EMC testing due to failure to apply EMC principles, lack of EMC/EMI knowledge, incorrect application of EMC regulations, unpredictable interactions between circuit components, or inclusion of non-compliant modules or components in the final product.
By performing pre-compliance testing, you can greatly increase the probability of passing comprehensive EMI compliance testing on the first try, helping you save a lot of time and money. Companies designing products for medical, automotive, military, and even multimedia applications can benefit from investing in a pre-compliance test setup. This page discusses spectrum analyzers to add pre-compliance testing to your product development process to accelerate product development and reduce project costs.
What are EMI and EMC?
When it comes to regulatory testing of electronic components and consumer products, the terms electromagnetic interference (EMI) and electromagnetic compatibility (EMC) are often used interchangeably. Because they are related in many ways, it is easy to confuse the two. Any electronic device generates a certain amount of electromagnetic radiation. We think of electronic devices as closed systems, however, the current flowing through circuits and wires can never be completely controlled. This energy can propagate through the air as electromagnetic radiation, and/or be conducted along (or coupled to) interconnecting I/O or power cables, which is often referred to as "interference voltage."
Testing requirements for EMI and EMC can become very complex, with a wide range of industry and application-specific influences that must be considered when bringing a product to market.
What is EMI?
Electromagnetic interference (EMI) is an unwanted signal that can have a harmful effect on the normal operation of electronic equipment or systems. At the same time, each electronic device will also generate EMI signals to varying degrees, which may be emitted in the form of electromagnetic radiation or conducted through cables or power cords. The generation of EMI should have three factors: the source of the conducted and radiated electromagnetic waves, the medium through which the electromagnetic waves propagate, and the receiver that is interfered by the received signal. If any of the three is eliminated, EMI will not occur.
While EMI can be generated from any electronic device, some devices and components, such as cell phones, welders, motors, and LED screens, are more likely to generate interference than others.
Since electronics rarely operate in isolation, products are often designed to operate in the presence of a certain amount of EMI. This is particularly important in military-grade and avionics equipment, as well as equipment that requires high reliability in all situations.
What is EMC?
EMC measures the ability of a device to operate as intended in its shared operating environment while not affecting the ability of other devices in the same environment to operate as intended. Evaluating how a device reacts when exposed to electromagnetic energy is one component of this, known as immunity (or susceptibility) testing. Measuring the amount of EMI generated by the device's internal electrical system - another process known as emissions testing.
Both aspects of EMC are important design and engineering considerations in any system, and failure to correctly predict the EMC of a device can have many negative consequences, including safety risks, product failure, and data loss. Therefore, a variety of test equipment for EMC and EMI has been developed to give engineers a clearer understanding of how a device will operate under real-world conditions.
Spectrum analyzer can provide troubleshooting prompts and speed up debugging work
To debug effectively, look for a solution that allows you to quickly identify problem areas and provides a level of signal insight that helps catch intermittent violations. This is achieved through a combination of hardware and software.
Some of the features you should look for in a software solution include:
Quasi-peak detector that allows you to bypass non-fault problems and zero in on the desired frequency.
Harmonic Check, which allows you to test only specific harmonics and find sources of radiation on your board using near-field probes.
Harmonic markers can detect harmonic emissions of known frequencies.
By using multiple spectra, you can compare the device under test (DUT) to environmental noise, previous device iterations, etc.
Automatic or manual re-measurement of multiple faults allows you to determine if a fault is intermittent or recurring.
Report multiple measurements in multiple formats in the same user-configurable report.
For hardware, real-time spectrum analyzers make EMI debugging easier. Some of the advantages provided by real-time spectrum analyzers include:
Capable of capturing transient and intermittent signals.
Ability to tune multiple signal sources at the same frequency.
Instantaneous Feedback - Traditional swept spectrum analyzers may require longer sweep times, resulting in failure to capture important signals.
Common standards for pre-compliance solutions
| 
提升卡
变色卡
千斤顶
京公网安备 11010802033920号
