The signal analysis-synthesis problems at a few femtosecond time scale demand the generation and study of broadband similaritons. We generate similariton of ~100 nm bandwidth and characterize it experimentally to reveal its nature and distinctive properties, and to describe it mathematically. We carry out the complete characterization of the broadband similariton by means of its chirp measurement through the technique of spectral compression and frequency tuning in the sum-frequency generation process. Our studies are of interest in view of applications of similariton to the solution of signal analysis and synthesis problems in ultrafast optics, particularly for similariton-induced temporal lensing and similariton-based spectral interferometry. Our developed method of similariton chirp measurement can also serve for the fiber characterization.© (2010) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.