A high dynamic range miniature DDS-based FMCW radar

A miniature DDS-based FMCW radar has been realized with dynamic range as high as 80 dB. A FMCW radar has many application as on-board sensor. The FMCW radar is a precision range measuring instrument. Hence it can be used for a variety of applications in aircrafts, helicopters and missiles. This paper describes in brief the design of one unique system which has been designed to operate in various modes. The difference come only at software level and setting of different thresholds for different applications. The major design difference here is the use of DDS to directly generate FMCW waveform and up-convert it to RF. It has many advantages over conventional FMCW signal generation. A linear FMCW system has been designed around this concept which resulted in sensitivity as good as -122 dBm and a high degree of slope linearity and repeatable in multiple units. A variety of antennas designed for different roles have made the system adaptable to various platform. The paper also shows results obtained and a critical comments on performance of total system and subsystems.