A compact multi-layer phase correcting lens to improve directive radiation of Vivaldi antenna

摘要

Gain of the conventional Vivaldi antenna (CVA) decreases at higher frequencies. A phase correcting lensrn(PCL) made up of nonresonant rectangular patch unit cells (UCs) is proposed to correct this problem. Thernlayout of the UCs is specially designed taking into account the actual phase error at antenna aperture. Therndetailed analysis, design and discussion for the CVA with the proposed PCL are performed. The CVA, CVArnwith one-layer PCL (CVA-OPCL), and three-layer PCL (CVA-TPCL) are fabricated and measured. Thernmeasured results agree well with the simulated ones. The measured results show that the proposed CVATPCLrnprovides a gain variation of 5.75-14.9 dBi in the wide operating range from 3.5 to 16 GHz, whichrnleads to 1.1-6.1 dBi gain enhancement than that of the CVA. In addition, the E-plane half powerrnbeamwidths become narrowed significantly at higher frequencies. An average improvement of 4.54 dB isrnachieved in terms of the front-to-back ratio. The sidelobe levels, on average, are reduced by 4.1 dB andrn2.8 dB for E-plane and H-plane, respectively.