The measuring receiver (spectrum analyzer or EMI receiver) is among the most valuable pieces of equipment available in an Electromagnetic Compatibility (EMC) lab or engineering facility. Measuring receivers of various types are used to detect and fix EMI issues that frequently emerge during the early stages of the product development phase. After the design team makes all EMI adjustments, measurement receivers are utilized to undertake full-compliance certification testing before shipping the finished product to customers. Let’s find out more about these units.
Purpose of a Measuring Receiver
To detect the radiated and conducted emissions generated by electronic equipment, EMI receivers or spectrum analyzers are used in combination with the appropriate cables and transducers (antenna, LISN, E/ H field probe, etc.).
These measuring receivers and spectrum analyzers, like oscilloscopes, are fundamental instruments for viewing RF signals. On the other hand, as a measuring receiver looks at signals in the frequency domain, oscilloscopes look at signals in the time domain.
As a result, the magnitude of an RF signal on the vertical scale and the frequency of the RF signal on the horizontal scale are shown by the EMI receiver or spectrum analyzer.
What is EMI/EMC Testing?
Electromagnetic compatibility (EMC) refers to an electronic device’s ability to function in an electromagnetic environment without interfering with or being affected by other electronic devices in that space. EMC testing is generally classified into two types:
- Emissions are electromagnetic disturbances emitted by a piece of electronic equipment that may cause disruptions or failure in another electronic device in the very same environment.
- Immunity/Susceptibility – Immunity is an electronic equipment’s capacity to perform properly in an electromagnetic environment without encountering disruption as a result of emissions from another electronic device.
The nature of the equipment being tested, its intended purpose, and the regulatory constraints regulating its usage all influence the EMC testing process. EMC testing may simulate the following electromagnetic phenomena:
- Magnetic fields, like those emitted by electric lines
- Voltage lowers as a result of a brownout or other power outage.
- Lightning-caused electromagnetic spikes
- Electromagnetic noise that is both conducted and emitted
- Static electricity causes electrostatic discharges.
Why Conduct an EMI Test?
There are numerous factors why EMI testing is postponed till the end of a project. The first is the apparent difficulty of conducting this sort of testing. However, there are specialized labs with all of the necessary equipment and personnel on hand to assist.
Another frequent misperception is that power supplies are the primary source of EMC problems and that if a power supply passes its standalone testing, the system into which it is plugged will likewise pass. It does not operate that way as power supplies serve as the “messenger” rather than the source of EMC issues.
There’s also the matter of cost. Making modifications to your design as you approach production is much more costly than doing it earlier in the process. Also, the cost of earlier screening tests is far cheaper than those of full-scale certification testing. The earlier you detect issues, the less expensive they are to repair.
So, this was an introduction to an EMI receiver and the EMI test system. Hopefully, you will find this article helpful.