Selective Frequency Spacing and the Half Step Synthesizer

The half step synthesizer uses frequency steps that are half integer multiples of the fundamental frequency spacing. The possible separations between adjacent carriers are 1, 1½, 2, 2½, ... times the fundamental frequency spacing. By providing twice as many potential locations for intermodulation spectra, the inband intermodulation power is distributed so that there is less (about one half) the interference with the carriers.