A Study On The Mutual Coupling Effects Of The Ultra-Wideband Vivaldi Array

This paper presents a detailed Study on the mutual coupling of the ultra-wideband vivaldi array from 1GHz to 9GHz through the simulation and displays the distribution of the coupling at different frequencies. The active VSWRs of the elements towards to different steering angles are then calculated from S-Matrix of the finite array by summing all the coupled energies surrounding the element, which shows that the active vswrs of some elements in frequency below 3GHz are much bigger than in frequency above 3GHz. However, the total mismatch loss at the lower band is no more than 2.1dB even though active vswrs of some elements go up sharply. Finally, the effect of adding passive elements surrounding the array to reduce the edge effects is evaluated by comparing the total mismatch losses, which indicates that it may not lead to improvement of the performance from view of matching.