Investigation of phase compensation lens to improve the gain of Vivaldi antenna in Ka-band

We present in this paper a method to increase the gain of our directive Vivaldi antenna without increasing the size of the antenna. Based on the theory of E-field phase difference correction, a phase compensation lens (PCL) has been added to the antenna. The most basic unit cell, rectangular unit cell, has been used to build the lens to facilitate the evaluation of the advantages and the limitations of this method. Our antennas have a good impedance matching in the Ka-band (26-40 GHz). The antenna gain enhancement is about 0.4 - 1.4 dBi using this method while the size of the antenna is unchanged.