High SFDR Programmable Radar Waveform Generation Using PLL-DD

Modern radar systems are designed to perform a variety of advanced functions, such as target tracking, detection, and classification, in addition to their primary function of range measurement. Radar waveforms are designed based on the intended applications and operating conditions. Furthermore, based on the requirements, especially in configurable radars and radar simulators, waveform parameters, such as pulse width, pulse repetition frequency (PRF), modulation, and carrier frequency, may need to be adjusted in real time. The paper presents the proposed architecture of a real-time programmable radar waveform generator with high Spurious-Free Dynamic Range (SFDR), based on a hybrid of Direct Digital Synthesizer (DDS) and Phase-Locked Loop (PLL). It also demonstrates the system’s capability to simulate the transmission characteristics of various radar systems. Our proposed architecture combines the spectral purity of a Phase-Locked Loop with the flexibility and fast frequency-switching capabilities of a Direct Digital Synthesizer. The algorithms are analyzed and simulated using MATLAB, and the simulation results are presented.