AbstractIn this paper, the analysis of patch antennas with U‐shaped metalization loaded by bianisotropic media is developed. A theoretical study is performed to obtain transmission‐line equations for bianisotropic materials, and then a method‐of‐lines (MoL) procedure is applied to obtain the radiative characteristics. Presented results assure, for particular patch dimensions and feed application geometry, a multifrequency operation in the microwave range, even for isotropic substrates. The application of bianisotropic materials gives better performances for bandwidth and input impedance at the central frequency, but degrades other frequency operation performances. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 3–5, 2002.