Design and construction of a prototype vivaldi antenna Mid-Frequency Aperture Array

A prototype Mid-Frequency Aperture Array (MFAA), using Vivaldi antennas, was designed. This type of array is a contender for the MFAA of the Square Kilometer Array Phase 2, SKA Mid. The construction was made from scratch and it was low-cost. Sixteen antenna elements, made of aluminium, were erected on a wooden platform. The orientation allows polarization on the E-plane as well as the H-plane. Each antenna had a feed board riveted to it. The unique design of the feed board enables an ultra-wide bandwidth and reduction of mutual coupling. Each antenna element has a frequency range of 450 MHz to 1550 MHz. It fits the design coverage range of the the SKA MID. The radiation pattern of the Vivaldi antenna was found using a signal generator and a spectrum analyzer and a second Vivaldi antenna. The results gave a maximum when both antenna were facing each other. This confirms the end-fire characteristics of the Vivaldi antenna. Our aim is to understand the antenna intricately, to be able to handle such an array on the near future. No other African country, in the SKA consortium is working on this type of array.