Advanced Antenna Pattern and Mutual Coupling Prediction Software

Numerical methods have proved to be very successful in low and mid frequency (VHF/UHF) regimes. Although these methods are based on rigorous integral or partial differential equation formulations, they cannot presently solve electrically large problems of EM radiation pattern and coupling prediction associated with antennas on aircraft at higher frequencies (S/X/Ku/Ka bands). On the other hand, asymptotic high frequency (HF) methods, whose accuracy increases with frequency, such as the physical optics (PO) method and its modifications based on the physical theory of diffraction (PTD), require an integration of the surface currents over the lit portion of the platform, so they also do not scale with frequency. At those frequencies uniform geometrical theory of diffraction (UTD) is very efficient and provides a physical picture for antenna radiation mechanisms and EM interactions with the aircraft platform in terms of rays at high frequencies. However, simulation of the platform using UTD so far is accomplished using a combination of canonical objects, limiting the use of codes based on UTD for complex structures such as fight aircraft etc. Applied EM along with its team members successfully demonstrated during Phase II application of UTD for faceted CAD geometries. Applied EM developed an advanced tool, uCAST based on UTD applicable to CAD geometries along with an interface to commercial tools. During Phase II.5, Applied EM will validate uCAST for NAVAIR applications and transition uCAST to NAVAIR programs.