Single Layer Vivaldi Antenna Feed Analysis

For many applications tapered slot antennas are attractive with broad bandwidth, medium gain and good pattern stability. Many designs can be found in the literature but the exponentially tapered slot (i.e., Vivaldi aerial) has good performance. The frequencies of interest are 8 to 10 GHz where planar antenna designs are considered for ease of fabrication and integration. A single layer planar Vivaldi tapered slot-type antenna is simulated and fabricated to investigate the simplest way to feed such antennas without limiting performance. The results show that a SMA connector from the rear and soldered on the front can be used but requires an air gap so the SMA does not touch the substrate. This paper summarizes a numerical investigation using FEKO to provide feed alternatives. The results serve to guide the selection of antenna elements and unbalanced feed arrangements for RF system developers.