Idle tone dispersion device and frequency ratio measuring device

An idle tone dispersion device that outputs a frequency delta-sigma modulation signal obtained by using either one of a reference signal and a measured signal to perform frequency delta-sigma modulation of the other and dispersion an idle tone,

• the idle tone dispersion device comprising:
• n (n is any natural number equal to or larger than 2) frequency delta-sigma modulation sections;
• a phase adjusting section configured to adjust phases of the measured signal and the reference signal, generate n sets of output measured signals and output reference signals, and supply the output measured signal and the output reference signal of each of the sets to each of the n frequency delta-sigma modulation sections;
• and
• an adder configured to add up output signals of the n frequency delta-sigma modulation sections and output the frequency delta-sigma modulation signal, wherein the phase adjusting section adjusts the phases of the measured signals and the reference signals to differentiate phases of idle tones of output signals of at least a part of the n frequency delta-sigma modulation sections from one another and generates the n sets of the output measured signals and the output reference signals, and
• each of the n frequency delta-sigma modulation sections uses either one of the output reference signal and the output measured signal supplied from the phase modulating section to perform the frequency delta-sigma modulation of the other, and
• at least one of the output reference signal and the output measured signal includes jitter including a frequency component higher than a frequency of the idle tone.