Asymmetric Artificial Networks (AAN) for balanced telecommunications cables conducted common mode emissions testing

The Artificial Asymmetrical Network (AAN) defined in CISPR 16-1-2 Edition 1.2 (2006-08) is used primarily for the measurement of Common Mode (Asymmetric) conducted emissions on balanced telecommunications cables. In CISPR 22 (now CISPR 32), these AANs are referred to as Impedance Stabilization Networks (ISN). The AAN is intended to control several parameters when installed between the Equipment Under Test (EUT) and the Associated Equipment (AE) including the Common Mode Impedance, the Longitudinal Conversion Loss (LCL), and the decoupling of conducted Common Mode signals originating from the AE. While the LCL parameter receives the most attention, it is only 1 of 4 possible contributors to the conducted Common Mode emissions the AAN can respond to. These contributors will be discussed in the paper along with some general AAN information. The possible impact to the conducted Common Mode voltage and current by the insertion of the AAN between the EUT and AE will be discussed.