Information

EMI Pre-Compliance Guide RIGOL Technologies
RIGOL Technologies CO., LTD. 09.09.2021
Figure 10: NFP-3 (near field probe set) for EMI debugging
Near Field Probing
Near field analysis is a very important part in pre-compliance analysis and root cause
debugging. RIGOL offers with the set of near fields (NFP-3) 4 different H probes for failure
detection (see figure 10). It is a special form of emission analysis, because the measurement
is done in reactive nearfield range (up to 0.159 * λ)
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. In near field magnetic and / or electric
field needs to be measured separately because both have a phase shift of up to 90° and
nearfield stores blind energy without radiation. For most radiated emission root causes can
be detected with locating the near field strength.
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Near field distance of 3 GHz: up to 0,0159 m (1,59 cm); near field distance of 30 MHz: up to 1,59 m
Figure 9: Interference measurement of power supply with acq. time of 143 µsec and Z marker evaluation