A 0.7 to 30 GHz Coplanar Vivaldi Antenna

ABSTRACT

In the literature there are multiple Vivaldi antenna designs that have a wide impedance bandwidth; however, the usable bandwidth is often limited by pattern degradation at the higher frequencies of the band. This paper presents the design and implementation of a coplanar Vivaldi antenna with a 42.9:1 usable bandwidth ratio (0.7–30 GHz). The antenna achieves a VSWR below 2:1 over the band and a maximum gain of 14.1 dBi. To achieve this improved bandwidth a thin low dielectric constant substrate was used, the dielectric was cut away in the flare region of the Vivaldi, and the feed transition and flare profile were optimized. The design was simulated in CST Studio Suite, and a prototype was measured in an anechoic chamber.