Fast switching frequency synthesizer using direct analog techniques for phased-array radar

A frequency synthesizer for modern radars can be designed with a high quality of phase noise or a fast switching time. In this paper, after synthesizing signals by using a direct analog synthesis in low frequency band, the low frequency signals (VHF-band) are upconverted to X-band frequencies. Using the direct analog synthetic techniques, we have implemented an X-band frequency synthesizer with a fast switching time of less than a few μsec and an excellent phase noise of -94 dBc/Hz at 10 kHz offset