Spiral antenna irradiation into lossy media with Debye dispersion

This paper presents the analysis of single arm Archimedean spiral antennas radiating into a lossy medium (i.e. water) characterized by Debye dispersion. Conformal Finite Difference Time Domain (CFDTD) method is used for simulation. The error due to the staircase approximation of FDTD mesh is remedied by using CFDTD algorithm. The reflection coefficient simulation result with Debye dispersion is presented and compared with the measurement. CFDTD was also applied to analyze spiral antennas’ near-field beam (SAR) in the water medium.