AbstractThe finite‐difference time‐domain (FDTD) method is used to model the response of microstrip patch antennas on magnetized ferrite substrates. The proposed FDTD model utilizes the auxiliary differential equation approach to represent the frequency dependent permeability tensor in the time domain equations. The resulting 3D full‐wave numerical model is tested and verified against experimental data showing very good agreement. This model, being efficient, stable, and robust, is expected to assist in the design and characterization of wideband ferrite‐based antenna structures. © Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1848–1851, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23526