Field characterization of an air surveillance radar at near-ground locations

When using computational electromagnetics (CEM) for performance analysis of radar and high-gain microwave antennas, the necessary detailed specifications and computer-aided design (CAD) drawings of these systems are seldom readily available from the original equipment manufacturer (OEM). A reasonable estimate of the electromagnetic (EM) field levels radiated by these types of antennas may be computed using a simple 2D aperture model. This technique, known as the aperture field method, assumes that an EM field distribution is produced on an aperture immediately in front of the radiating area of the antenna. Such was the approach employed in this paper to characterize the electric field (E-field) intensity of a deployable air surveillance radar (ASR) at near-ground locations that were directly illuminated by the cosecant-squared fan beam of the radar. Of concern in this study was that the radar might cause EM interference (EMI) issues at near-ground locations within a few kilometer radius from the radar, due to its high radiated power. Hence, this study served as part of a comprehensive radio frequency (RF) safety and EMI assessment of the ASR, based on guidelines for compatibility and safety standards.