In wireless sensor networks (WSN), location information is one of the critical issues for both performance and efficiency. This paper presents a new positioning method in WSN with reasonable implementation cost and excellent performance. Given a few reference nodes with known locations and node range estimates based on linear frequency modulation continuous wave (FMCW) technique, all nodes' location information can be derived by solving a set of circle equations. This technique is cost efficient, scalable and easy to be implemented. The simulation results show that the new method is fast convergent and precise.