发明名称 |
Modulation circuit used in an IC-card reading/writing apparatus |
摘要 |
<p>A modulator (240) used in an IC card reader/writer (200) includes a phase variation detector (347) for detecting a varying point of the phase of a modulated signal, a signal processing circuit (340) for modifying the modulated signal for a half period at the phase varying point to have a frequency and amplitude twice those of the modulated signal, a first Miller integrator (350) for integrating the modified signal to produce a triangular wave signal, and a second Miller integrator (360) for integrating the triangular wave signal to produce a sinusoidal wave signal having a continuous phase. A demodulator (250) used in the reader/writer (200) includes a sync control circuit which controls a carrier sync signal (CSS) generation circuit (570) thereby to control the phase of a carrier sync signal in response to the discrimination as to whether the carrier sync signal (CSS) is in lead-phase or lag-phase relative to the signal modulated based on binary phase shift keying (BPSK). A control data signal and non-modulated carrier wave sent from the reader/writer (200) to the IC card (100) are converted into power for use by the IC card. <IMAGE></p> |
申请公布号 |
EP0719014(A2) |
申请公布日期 |
1996.06.26 |
申请号 |
EP19950113246 |
申请日期 |
1995.08.23 |
申请人 |
MITSUBISHI DENKI KABUSHIKI KAISHA |
发明人 |
NAGATA, YOSHISHIGE;TAKAHIRA, KENICHI |
分类号 |
H02J7/00;G06K7/00;G06K7/10;H02J17/00;H04B1/40;H04B7/26;H04L27/18;H04L27/20;H04L27/22;H04L27/233;(IPC1-7):H04L27/20 |
主分类号 |
H02J7/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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