Study of radiated emissions from PCB with narrow ground plane

Printed circuit boards (PCB) with narrow ground plane microstrip structure (PCBNGP) find many applications in electronic equipment. In this paper, various PCBNGP with different parameters were fabricated and their radiation was measured. It was found that narrow ground plane increases radiation and common-mode current is the main source of radiation. From the method of moments (MoM), it was found that the PCB structure asymmetry is the main source of the common-mode current. By treating the reference point (at infinity) as a conductor, multiconductor transmission line (MTL) model was developed to simulate radiation from PCBNGP and several factors affecting the radiation were extracted.