| 摘要 |
<p>An ultrahigh-speed A/D convertor having a simple circuit construction without using optical signals. A phase difference is detected between a signal modulated in phase by an analog signal and its carrier signal. At this time, the phase modulation factor is subjected to binary weighting for A/D conversion. Alternatively, (2n-1) different steps (n: resolution) of delay are given between an analog phase-modulated signal and its carrier. The phase of the signal having this delay and the phase of the signal not having the delay are compared with each other at the (2n-1) steps. An n-bit digital signal is generated and outputted on the basis of this comparison result. The carrier wave is phase shifted in n steps by the analog signal, and the output phases of the phase modulation in n steps are compared with the phase of the carrier wave, respectively. The n-bit digital signal is generated and outputted on the basis of this comparison result. In this case, the hardware quantity can be reduced by using this method in combination with the method described above. In this way, ultrahigh-speed A/D conversion can be executed. Further, accuracy, reliability and frequency can be increased, and noise characteristics, signal quality and modulation efficiency can be improved, too.</p> |
