Patent ID: 7388926

Claim:
A quadrature modulation system wherein a first inphase signal component and a first orthogonal signal component are input, and are provided to a quadrature modulator for outputting an output signal that is quadrature modulated by the quadrature modulator, a part of said output signal serving as a feedback signal consisting of a second inphase signal component and a second orthogonal signal component, comprising: time difference calculating means for obtaining a first cumulative total of results of calculation based on the first inphase signal component and the second inphase signal component, obtaining a second cumulative total of results of calculation based on the first orthogonal signal component and the second orthogonal signal component, and obtaining a time difference between the first inphase signal component and the second inphase signal component, and a time difference between the first orthogonal signal component and the second orthogonal signal component based on said first cumulative total and said second cumulative total, respectively; and delay adjustment means for adjusting the first inphase signal component and the first orthogonal signal component that are provided to the quadrature modulator such that said time differences are compensated for.