发明名称 |
Method and system for detecting a marker |
摘要 |
An electronic article surveillance system is provided having a transmitter for generating two alternating magnetic fields by way of a single transmitter coil fed with a transmitter signal current, and a receiver that detects harmonics and intermodulation products of the alternating magnetic fields by way of a receiver coil that generates a receiver signal current. The receiver comprises a wide-bandwidth phase detector locked on to a frequency p.f2+/-q.f1, where p and q are positive integers, one of which may be zero, and a digital signal processor adapted to carry out a full time-domain analysis of the waveform of the receiver signal current, and wherein the transmitter signal current corresponds to the linear super position of two alternative currents with a relatively low frequency f1 and high frequency f2 respectively.
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申请公布号 |
US5414410(A) |
申请公布日期 |
1995.05.09 |
申请号 |
US19940194285 |
申请日期 |
1994.02.10 |
申请人 |
ESSELTE METO INTERNATIONAL GMBH |
发明人 |
DAVIES, DAFFYD G.;DAMES, ANDREW;CROSSFIELD, MICHAEL D. |
分类号 |
G01V3/10;G01V3/00;G01V15/00;G08B13/24;(IPC1-7):G08B13/187 |
主分类号 |
G01V3/10 |
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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