Intelligence is the most important characteristic for cognitive wireless networks.A cognitive engine built on reconfigurable wireless networks is the key to implementing this characteristic.The design and implementation of a cognitive engine is important in research on the theory of initiative cognition for cognitive wireless networks.This paper first discusses research on cognitive loops,then investigates cognitive functions in the loop through the design of a universal cognitive engine functional architecture,and finally verifies the architecture on the platform of a cognitive engine prototype system. Intelligence is the most important characteristic for cognitive wireless networks. A cognitive engine built on reconfigurable wireless networks is the key to implementing this characteristic. Design and implementation of a cognitive engine is important in research on the theory of the initiative cognition for cognitive wireless networks. This paper first discusses research on cognitive loops, then investigates cognitive functions in the loop through the design of a universal cognitive engine functional architecture, and finally verifies the architecture on the platform of a cognitive engine prototype system.