Phase center controlling in Vivaldi antenna: review and development of the story

The Vivaldi antenna is developed as an ultra-wideband antenna with a directive pattern and high gain, which is attractive for radar application and microwave sensing. We have modeled various kinds of Vivaldi antenna and attempted to achieve linear or constant phase center. We realized that the phase center can be controlled by controlling the distribution of fields in level and around the antenna leading to phase control. Also, Vivaldi antennas are used in radar bands and are studied in this paper. In this review paper, we have focused on two main methods for phase controlling and we have debated on their basic theory. In addition, mutual coupling is considered as one of the benefits of these antennas. The open aperture and the photonic band gap substrate are known as two main methods for achieving the constant phase center. The first method discusses combining horn antenna with Vivaldi antenna, and so we have obtained a higher gain and directivity and in parallel way the PBG is used for phase controlling and it shows more gain and directivity enhancement. Here, we compare them and discussed in the background theory of this method. In contrast, we suggest five categories for phase center modification.