TekBox TBCDNE-M2 Coupling Decoupling Networks Emission

CDNEs are a type of Coupling Decoupling Networks used for an alternative technique of measuring radiated emission of lighting equipment in accordance with the CISPR 15 (EN55015) standard.

It avoids the need for emission measurements on Open Area Test Sites. This method was established in CISPR 15 edition 9 as an acceptable alternative to a traditional OATS test configuration that required antennas and calibrated test sites. It is specified for the frequency range from 30 MHz to 300 MHz. The CDNE method and the associated limits up to 300 MHz can be only applied for EUTs with clock frequencies below or equal to 30 MHz. In such a case, the product is deemed to comply with the requirements between 300 MHz and 1000 MHz.

When compared to CDNs, CDNEs are substantially more stringently specified, with reduced common mode (CM) impedance tolerance and additional parameters for CM phase tolerance and differential mode impedance equal to 100 Ω. A minimum 20 dB for longitudinal conversion loss shall prevent symmetrical voltage influencing measurement results.

CISPR 15 edition 9 also specifies that the mains supply cable of the EUT should be terminated with a CDNE positioned on the reference-ground plane for the OATS, SAC or FAR measurement method.

Unlike CDNs, CDNEs are not appropriate for immunity measurements

The Tekbox TBCDNE-M2 is designed for EUTs that do not have a PE (Earth) connection. Tekbox offers the TBCDN-M3 model for measuring EUTs with PE, Neutral, and Line connections.