A wideband E-shaped microstrip patch antenna for wireless communications is presented. Zig-zag slots and perturbations of the E-shaped metallic patch are employed to excite two resonant modes and achieve a wide-band frequency behavior, featuring a fractional bandwidth of about 30%, and, at the same time, to meet the occupation volume requirements of mobile wireless local-area network enabled communication devices. A locally conformal finite-difference time-domain numerical procedure has been employed to analyze the radiating structure. Numerical results concerning the antenna parameters are in good agreement with experimental measurements.