There is an increasing demand for newer microwave and millimeter-wave systems to meet the emerging telecommunication challenges with respect to size, performance and cost. Microstrip antennas offer the advantages of thin profile, light weight, low cost, ease of fabrication and compatibility with integrated circuitry. This paper presents a coaxilly-fed single-layer compact microstrip patch antenna for achieving dual-polarized radiation suitable for applications in the IEEE Radar Band C and X. Simultaneous use of both frequencies should dramatically improve data collection and knowledge of the targets in an airborne synthetic aperture radar system. The designed antenna consists of three rectangular patches which are overlapped along their diagonals. The design and simulation of the antenna were performed using 3D full wave electromagnetic simulator IE3D. The antenna with a bandwidth of VSWR<2 reaches 154MHz (f0=6.83GHz) and 209MHz (f0=9.73GHz) was designed and simulated successfully.