Design of Half Impulse Radiating Antenna (HIRA) With Tapered Transverse Electromagnetic (TEM) Horn–Based Novel Feeding Mechanism for Intentional Electromagnetic Interference (IEMI) Applications

Half impulse radiating antenna (HIRA) is commonly used in high‐power ultrawideband (UWB) systems. These systems come under the class of Intentional Electromagnetic Interference (IEMI) systems, which are intended to generate intense electric fields (∼10 kV/m and above) in a far field range. Conventionally, coplanar transverse electromagnetic (TEM) feed is used as feed for HIRA. In this paper, a novel feed mechanism utilizing exponentially tapered half TEM horn for HIRA antenna is suggested, resulting in higher radiated peak electric field values. Time‐domain simulations of HIRA with new feed antenna confirm that higher electric field values observed are due to the gain improvement throughout the frequency range of interest. A detailed analysis of field illumination pattern at reflector shows that gain improvement observed is due to uniform distribution of electric field at the aperture of reflector. The presented new feed mechanism results in peak electric field enhancement by ∼60%. For a high‐power UWB radiator, this results in significant improvement of Figure of Merit (FOM) by a factor of 1.6. The proposed feed mechanism is very useful in cases where the input pulse in UWB is having significant low frequency content. Initial experimental results for the new antenna and standard feed HIRA antenna with the UWB pulse generator system are also compared.