Dual-Function Radar-Communication System Design Via Sidelobe Manipulation Based On FDA Butler Matrix

Dual-function radar-communication (DFRC) system has evolved as a solution for frequency-spectrum congestion in recent years. In this letter, we propose a DFRC strategy by employing the concept of sidelobe manipulation. Specifically, we exploit the beam orthogonality associated with $N \times N$ Butler matrix (BM) connected with an $N$ -element frequency diverse array. The proposed scheme utilizes BM parallel excited by radar signals while communication signal is injected into the system alongside the radar signal. In doing so, the communication signal is projected along the null radiation direction of the radar main beam concurrently. Furthermore, because of the beam orthogonality feature of the BM, there is no cross-interference between the communication signal and radar target detection. Numerical examples are provided for performance evaluations and to demonstrate the effectiveness of the proposed system.