Use A Near-Field Probe To Find The Source Of Electromagnetic Interference On The Pcb - Saluki SER Series User Manual

EMI Receiver Instructions for Use
Figure 4.1 Measuring Electromagnetic Emissions from Equipment with Near Field Probes
After seeing a relatively large interference signal, reduce the sweep width and IF bandwidth to observe the details of the spectral line
part. If the measured signal is too small, then
—Press the [BW] key to reduce the IF bandwidth, and press the [Attenuator] key to reduce the attenuation
You can also turn on the internal preamplifier, or use an external low noise amplifier to amplify the measured signal.
—Press[AMPT]key to adjust [reference level], and adjust the amplitude of the signal under test to a position convenient for observation.
Observe while moving the probe. Find the relatively large radiation frequency and amplitude. It is also possible to use the maximum hold
Function record signal line
—Press [Trace]key to select [Maximum Hold] function
—Press[Marker]key to move the cursor to the spectral line to be measured

4.1.2 Use a near-field probe to find the source of electromagnetic interference on the PCB

Electronic circuits are composed of many components (resistors, capacitors, inductors, transistors, integrated circuits, semiconductors
Switching devices and high-frequency clock processor chips, etc.) are connected by wires, cables and connectors. each element
Devices have their inherent characteristics, and some components can generate strong electromagnetic radiation.
Some cables are often bundled together, which creates a potential hazard for near-field coupling or crosstalk. wire
It can be equivalent to a dipole antenna and can act as a radiation antenna, thus becoming a part of the electromagnetic interference radiation source
It can also function as a receiving antenna and becomes an important part of the system that is sensitive to radiated emissions. use near field
The diagnostic probe can find out the components with large electric field radiation and the magnitude of the electromagnetic field radiation.
The measurement method is the same as 4.1.1.
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