This work describes a demonstration platform for frequency-modulated continuous wave (FMCW) based ranging systems operating in the 5.8 GHz ISM band. The goal is to gain insight into system behavior and determine critical system parts prior to integration on chip. The versatility and configurability of the presented system allows testing different synchronization and ranging principles. A synchronization scheme is proposed which is robust against imperfections of the system. Distance measurements using this scheme are carried out in an indoor and outdoor scenario.