| 摘要 |
PROBLEM TO BE SOLVED: To measure modulation accuracy, without the provision of a circuit generating a coherent carrier to a modulator in the modulation accuracy measurement device, measuring the modulation accuracy of a digital modulation signal. SOLUTION: The modulation accuracy measurement device that uses a coherent carrier of a digital modulation signal, to measure the modulation accuracy of the digital modulation signal is provided with a phase-locked loop(PLL) 20. A reference signal is given to the PLL 20. The PLL 20 generates a signal with a frequency which is a multiple of k2 /k1 of the frequency of the reference signal, where k1 , k2 are positive integers. The signal generated by the PLL 20 is used for a coherent carrier of the digital modulation signal. Thus, the modulation accuracy of the digital modulation signal is measured. |
