Application Case: Finding a Radiated-Emissions Peak Before Lab Booking

An anonymous electronics manufacturer case where a SIGLENT pre-compliance analyzer and a fixed test workflow narrowed a radiated-emissions problem before an accredited laboratory booking.

Last updated: 2026-09-18

Project context

A manufacturer of industrial control electronics found a radiated-emissions peak late in development. The first screenshot identified a frequency but did not record the cable arrangement, product mode, antenna polarization, or even whether the peak detector and resolution bandwidth matched the later laboratory scan. The risk was not simply a failed test; it was spending paid laboratory time rediscovering the problem.

The normal troubleshooting sequence

The EMC engineer first locks the EUT firmware build, I/O activity, power supply, support table, cable lengths, and cable positions. Near-field probes are then used around switching devices, cable exits, clock regions, and enclosure seams to compare relative changes. A separate antenna scan checks whether a change that looks better on the board also improves the complete product. The two operations answer different questions and should not be mixed.

Equipment selected

The development group selected a SIGLENT SVA1032X with the SVA1000X-EMI option and SRF5030T probe set. The 3.2 GHz range covered the product's diagnostic range; the option added EMI filtering, quasi-peak detection, and limit-line functions. This Chinese-brand configuration was chosen for iterative pre-compliance diagnosis, not as a substitute for the final accredited test.

For a site running regular in-house compliance work, the purchasing review also listed Rohde & Schwarz ESR/EPL receiver configurations with calibrated accessories and traceable reporting.

Result in use

The team located the dominant energy near a cable connector and linked it to a fast switching loop. After adjusting the return path and adding a common-mode control measure, the pre-compliance peak fell consistently in the fixed setup. The external laboratory then confirmed the improvement under its formal configuration.

What to verify before publishing

Confirm that the distinction between diagnostic pre-compliance and formal certification reflects your own service position. The case deliberately avoids claiming that a named company purchased or certified with a particular model.