Patent ID: 8018295
Filing Date: 2011-09-13
Classification: H03K,H04L

Abstract:
1. A modulation device for modulating a frequency or a phase of a carrier signal according to a baseband signal, the modulation device comprising: a signal selection circuit selecting two carrier signals from a plurality of carrier signals having the same frequency according to a defined control signal and outputting the selected carrier signals; a phase interpolator adjusting the phase in smaller units than a phase difference between the plurality of carrier signals according to the control signal and modulating the frequency or the phase of the carrier signal according to the baseband signal based on the carrier signals selected by the signal selection circuit to generate a carrier wave signal; and a phase modulation signal generation circuit generating the control signal that is to control the signal selection circuit to select the two carrier signals and the phase interpolator to generate the carrier wave signal, wherein the plurality of carrier signals have the same phase difference, and wherein, when i is an integer from 1 to m, N wherein, when the phase of the carrier wave signal is changed from 360°×pa to 360°×pb with respect to the phase of the carrier signal according to the baseband signal, a phase difference that is to be switched in every Ni period of the carrier wave signal is 360°×Ti.