A frequency agile fast switching hybrid synthesizer for radar applications

Design and development of a frequency agile fast switching hybrid synthesizer in the X-band is described. Direct Digital Synthesizer (DDS) technology offers very fine (sub-hertz) frequency tuning and very fast frequency switching due to its digital structure. On the other hand DDS cannot produce frequencies higher than a few hundred megahertz. Conventional PLL circuits can operate at very high frequencies but they lack in fine frequency tuning and fast switching as compared to DDS. The purpose of this development is to combine the benefits of both the technologies into a single hybrid synthesizer.