A Benchtop Approach to Conducted Emissions Testing According to CISPR 25 Using the Voltage Method

This paper presents a structured and repeatable benchtop methodology for performing conducted electromagnetic emission measurements in accordance with CISPR 25 / DIN EN IEC 55025 using the voltage method. The work details the implementation of a largely standard-compliant test setup, including reference ground plane, line impedance stabilization network configuration, power-supply conditioning, cabling, and device-under-test support, with particular emphasis on measurement repeatability and practical constraints encountered outside accredited test facilities. Pre-compliance measurements are carried out using a modern spectrum analyzer controlled by dedicated EMC measurement software, with appropriate application of correction factors, detector settings, and bandwidths as required by the standard. In addition, a non-standard extension for separating differential-mode and common-mode noise components is demonstrated as an effective diagnostic aid for emission source localization and filter development. While the proposed benchtop approach does not replace accredited compliance testing in shielded environments, the results show that it provides reliable and meaningful pre-compliance data, enabling early detection of conducted-emission issues, informed design iteration, and increased confidence prior to formal certification testing.