Multifunction impulse radiating antennas: theory and experiment

A Multifunction IRA is an extension of a standard Impulse Radiating Antenna that has the additional flexibility of an adjustable beamwidth. This adjustability is implemented by defocusing the feed, in order to select between a narrow or broad beam. We provide here the theory of operation of the antenna, for both in-focus and out-of-focus situations. Furthermore, we built and tested a design with a 46 cm diameter. We found good agreement of the experiment with theory.