Design and simulation of harmonic radar baseband system

The baseband system serves as the core component responsible for signal processing in harmonic radar systems. However, designing a baseband system that meets requirements poses several challenges. In this study, we addressed the design and simulation of a baseband system for a 3.6GHz harmonic radar. A fundamental signal at a frequency of 3.3MHz was selected, with 90° phase-shift binary phase shift keying (BPSK) modulation employed as the modulation scheme for the baseband system. MATLAB was utilized for program development to simulate the reception of nonlinear target-reflected harmonic signals. Results of signal processing for the second and third harmonics were provided. Furthermore, an FPGA-based hardware circuit for the harmonic radar was designed, followed by hardware testing and target data collection. The practical feasibility of the design approach was validated. Comparative analysis between measured and simulated data revealed the system's proficiency in identifying harmonic signals during signal processing.