Influence of finite ground planes on the transmission line current distribution

Abstract

The knowledge of the current distribution on the ground plane of a Printed Circuit Board (PCB) is important to overcome many electromagnetic compatibility (EMC) problems. In this paper a Method of Moments (MOM) algorithm is used to evaluate the surface current distribution on the ground (GND) plane. In order to consider the effects of GNDplanes to the signal behaviour on transmission lines, infinite planes are often assumed to reduce the calculation time. The comparison of the currents using finite and infinite ground planes shows a significant modification of the coupling to transmission lines placed in the layer above.

Pattern Reconfigurable Cubic Slot Antenna

“…3 that front to back ratio, defined as the ratio of gain in front direction to the gain in the back direction, along with gain increases from model 1 to model 3. The substantial increase in the density of surface currents on the outer boundary of truncated ground plane in model 1 is responsible for low gain and rather poor front to back ratio as was previously proven in experimental [18] and numerical studies [19], [20]. Whereas, in model 2 and model 3, the substrate extended beyond the ground plane attenuates the undesired surface currents to a higher degree, resulting in higher gain and improved front to back ratio.…”