Physical aspects of mutual coupling in finite broadband tapered slot (Vivaldi) arrays

A notch antenna, or Vivaldi antennas, or also known as tapered slot antenna (TSA) is widely used as a single radiator but mostly as an array element in transmitting, receiving and combined arrays, focal-plane imaging and other system-oriented broadband applications. Full-wave analysis of such arrays is required that is a big numerical challenge because of large electrical size for such typical problems. Only infinite arrays or very small arrays are treatable with available EM tools. However, all elements of moderate in size arrays can be impacted by edge truncation because of strong mutual coupling within TSA array environment. Thus, accurate performance prediction and design can be achieved through: (1) enhancing EM simulation numerical tools; and (2) exploring underlying physical phenomenology of array behaviour. We follow both the above ways. This work demonstrates some basic physics related to mutual coupling is small finite arrays.