DIGITAL MODULATION SIGNAL TEST DEVICE, DIGITAL MODULATOR, DIGITAL DEMODULATOR, AND SEMICONDUCTOR DEVICE USING THE DEVICES

摘要

A test device comprises a digital modulator (20) provided for each of plural channels. A baseband signal generation unit (26a (26b)) retimes data (D1a (D1b)) inputted as an in-phase (orthogonal) component modulation signal by using a timing signal (TG1 (TG2)) the timing of which is adjustable to generate a baseband signal (BBI (BBQ)). A driver (30a) (driver (30b)) generates a multilevel digital signal (VBBI (VBBQ)) having a level corresponding to the value of the baseband signal (BBI (BBQ)) from the baseband signal generation unit (26a (26b)). A multiplier (34a (34b)) amplitude-modulates a carrier signal with the multilevel digital signal. An adder (36) adds output signals from the multipliers (34a, 34b).