Patent ID: 7253760

Claim:
A method for the adjustment of a signal generator for inter-leaving a first digital-to-analog converter and a second digital-to-analog converter operated under the same sampling rate and outputting signals obtained by synthesizing the output signals of the first and the second digital-to-analog converters, wherein said method comprises: a first step for adjusting the output offset of said first and second digital-to-analog converters such that when a direct current of the same level has been output from the first and second digital-to-analog converters, or when signals that do not contain a frequency component of said sampling rate have been output as said synthesized signals, the level in the spectrum of said synthesized signals of the frequency component that is the same as said sampling rate becomes lower than a first predetermined level or becomes the minimum, and a second step for adjusting the output level of said first and second digital-to-analog converters such that when signals of a first predetermined frequency have been output as said synthesized signals, the level in the spectrum of said synthesized signals becomes the same for two frequency components separated by said first predetermined frequency from the frequency that is the same as said sampling rate; the difference between said two levels becomes less than a second predetermined value or becomes the minimum; or the sum of said two levels becomes less than a third predetermined value or becomes the minimum, wherein the second step is repeated until the signal integrity value, when signals of the second predetermined frequency have been output as synthesized signals, satisfies a predetermined condition.