L-band and S-band Helicone Antennas

Diversified Technologies, Inc., (DTI) proposes to build, test, and deliver two ruggedized portable antenna systems (one L-band and one S-band), capable of reliably handling 1 GW pulses with a FWHM of 10 ns which can be mounted on a military truck. The L-band antenna will radiate with gain greater than 21 dBi at 1.1 GHz, and the S-band antenna will radiate with gain greater than 27 dBi at 2.8 GHz.  In this effort, DTI will use an array of antennas to transmit the peak power. This is intended to work with multiple phased microwave sources thus  reducing the electric field on the coax entry to each antenna. The sources will be phased so the antennas operate as single large aperture with large aperture area which will fit in 1.5 cubic meter volume with a 1GW capability.  DTI has also demonstrated an HPM feedthrough that can withstand 14 MV/m at 520 kV, which will be utilized for the antenna feedthrough. Furthermore, this approach can be easily adapted and scaled in power, gain and frequency for different numbers of sources simply by adding or removing antennas to the array as necessary. In Phase I, DTI will model, analyze, and optimize the L- and S-band antenna arrays. This will lay the groundwork for a complete design and prototype construction in Phase II. This design will be optimized further to meet MIL-STD-810g shock and vibration and enable DTI to address any real-world manufacturing issues early in the design. The antennas will be characterized experimentally using AFRL-supplied HPM sources, including frequency-dependent gain, antenna pattern, and polarization. DTI will identify supply chains for critical materials and processes with the aim of using COTS materials and common manufacturing processes to the greatest extent practical.