| 摘要 |
PURPOSE:To reduce the deterioration of characteristics and to attain large scale integration(LSI) by detecting the quadrature phase of a composite modulated wave obtained by modulating the phase of a quadrature modulating wave, digitally computing two obtained modulating data and reproducing a main data signal and a sub-data signal. CONSTITUTION:An input signal IN is the composite modulated wave with an intermediate frequency band which is obtained by allowing a subdata signal S to modulate the phases of quadrature amplitude modulating waves modulated by main data signals X1, X2, Y1, Y2 and detected at its quadrature phase by a quadrature phase detector 3. The modulated data P0, Q0 are amplified by base band amplifiers 4, 5 and converted into demodulated data Dp, Dq by A/D converters 6, 7. A sub-data signal reproducing circuit 8 reproduces the signal S by digital operation and a main data signal reproducing circuit 9 removes a phase modulating component based upon the signal S from the data Dp, Dq on the basis of digital operation and reproduces the signals X1, X2, Y1, Y2. Thus, the deterioration of characteristics can be reduced and LSI can be easily attained. |
