In this article, the interesting constructions of the notch-loaded rectangular patch S-shaped antennas with L-strip feeding for multiband operations are presented. Implementing the L-strip feeding leads to creation of good benefits including several resonating frequencies, no cross-sectional area, simplicity in designing and constructing, stable gains and efficiencies, and the impedance matching. The proposed antennas are realized on the different substrate materials and the dramatic changes in characteristics are reported. These antennas are simulated, tooled, fabricated, and tested to provide the better performances in terms of return loss and bandwidth. Through the proper selection of the dimensions as well as the arrangement of the L-strip, the desired resonant modes of the antennas are excited in between 6–45, 3–20, and 2–16 GHz. Results of the radiation patterns, gains, and efficiencies of the constructed antenna on the foam substrate are studied and discussed. The maximum and minimum values of the gains and radiation efficiencies of this antenna are 10 dBi and 93%, and 1 dBi and 30%, respectively. The simulation results are obtained using method of moment based on the electromagnetic solver IE3D and are in good agreements with the experimental results, which were obtained from the spectrum analyzer.