A Tri-band low profile symmetrical center S-shaped monopole antenna for WiMAX/Radar communication and X-band application is proposed. The proposed antenna consists of T shaped slot with S-shape at the center which is symmetrical loaded patch. The antenna operates in the 3.3/3.03–3.46 GHz for WiMAX, 8.2/8.00–8.4 GHz for radar communication and 9.3/9.04–9.57 GHz for X band and has a very compact size of 16 × 23 × 1.6 mm3 with a less than − 10 dB input impedance frequency response can be achieved. The design was simulated and verified by constructing the antenna on a FR4 di-electric substrate and measuring its impedance and radiation characteristics at all the bands. By adjusting the positions and the lengths of these structures, three different current paths can be produced at different frequency bands, respectively.