HF radar receiver designed for surface current radar system

The paper presents the design methods of the HF radar receiver for the short-range Ocean State Measuring and Analyzing. The radar system adopts Frequency Modulated Interrupted Continuous Waveform (FMICW) and operates at 12∼14MHz. The receiver has only once mixing and band-pass sampling structure. After sampling the data, a new DDC (Digital Down Converter) algorithm is used during the demodulation. It is a modified DDC algorithm, in which no filter is used. The receiver uses cross-loops/monopole as receiving antenna, and the radar signals are generated by DDS chips. The structure of the system is quite simple and the antenna is portable. It proved that all modules of the system worked well during the field test of the radar system.