Patent ID: 6867719

Claim:
A waveform generating module for outputting a pair of synchronous analog signals, comprising: a first digital signal calculating unit for generating a first digital signal on the basis of a first signal frequency component representing a component of each frequency of a first analog signal, which said waveform generating module should output; a second digital signal calculating unit for generating a second digital signal on the basis of a second signal frequency component representing a component of each frequency of a second analog signal, which said waveform generating module should output; a DA converter for converting said first and second digital signals into said first and second analog signals at a predetermined time interval respectively; a skew frequency component calculating unit for calculating a skew frequency component representing a phase error of each frequency of said second analog signal corresponding to said first analog signal, on the basis of a skew of a timing with which said first and second digital signals are converted by said DA converter; and a second signal frequency component correcting unit for correcting said second signal frequency component used for generating said second digital signal by said second digital signal calculating unit on the basis of said skew frequency component.