An X-band frequency agile source with extremely low phase noise for Doppler radar

Doppler radar systems frequently impose severe demands on spectral purity in order to discriminate between targets and clutter. In the case of radars operating at X-band, the region from a few hundred Hz out to a few kHz from carrier is normally the most critical as far as phase noise and spurious signal performance are concerned. The author presents a 25 channel fast switching X-band frequency agile source design capable of achieving a repeatable phase noise performance of -125 dBc/Hz at 1 kHz from carrier. Given that the current state of the art for this type of unit is around -110 dBc/Hz at 1 kHz, the design described represents a significant advance in the technology