A set of time- and frequency-domain mixed indexes considering both guidance loop overall performance and hardware constraint was presented. However, the autopilot response using the index exhibited slowly. A general autopilot design procedure synthesized optimal control and frequency-domain constraint was thus proposed. Wherein, the weights selection was transformed into an optimization problem. A four-loop topology was examined to deal with the special case of low-frequency actuator. The analysis and simulation results show that relaxing the static stability of a missile is only benefit to improve missile steady performance. Though a static unstable missile can be stabilized, the finite resource of...