An innovative approach in the design of fast-switching microwave synthesizers

This paper presents a compact, broadband frequency synthesizer module, which covers 0.1 to 10 GHz frequency range with a 0.001 Hz step size. The synthesizer combines fast switching speed, low phase noise, and low spurious characteristics. The measured phase noise at an output frequency of 10 GHz and 10 kHz offset is -122 dBc/Hz. For an output frequency of 0.1 GHz and 10 kHz offset the phase noise is -150 dBc/Hz. Spurs do not exceed the -70 dBc level and the switching time of the main PLL is less than 10 uSec. This module can be used as a broadband, agile, high-fidelity signal source in a variety of test-and-measurement, communication, and surveillance systems.