Improving Scan Gain of Sparse Vivaldi Array with Parasitic Scatterers

This paper presents a densely populated, but sparsely fed antipodal Vivaldi array. Every second element of the array is fed, and the others, parasitic scatterers, are terminated to passive loads. The appropriate terminations of the parasitic elements for improving the scan gain of the array are computed using a principal component analysis-based algorithm. Compared to a reference array without parasitic elements, the main beam realized gain is increased by up to 1.8 dB inside a desired beam-steering sector. The results are verified by measurements of manufactured prototypes.