To develop missiles to intercept short and medium-range rockets, the effectiveness of the air-to-air radar detector should be analyzed. In this study, to analyze the performance of a Ku- and Ka-band-based detector, we model the monopulse radar system, radar echo, and trajectories of the missile and rocket and perform numerical analysis for the radar cross section (RCS) of a computer aided design (CAD) model that is constructed based on an actual rocket. In addition, both the Swerling model and the analyzed RCS are considered in simulation to analyze the effect of the beam width of the monopulse radar and the power of received signals. As a result of the simulation, the Ka-band radar tracked the target relatively accurately in the presence of multiple targets, whereas the Ku-band radar had a higher probability of detection for low-RCS targets.