公开(公告)号：EP1489684A1

公开(公告)日：2004-12-22

申请号：EP04013534.5

申请日：2004-06-08

申请人： Sensormatic Electronics Corporation

发明人： Balch, Brent F. ,  O'Connell, John ,  Hurd, William H. ,  Spalding, Tom

IPC分类号： H01Q7/00 ,  H01Q7/04 ,  H01Q1/22 ,  G08B13/24 ,  G06K7/08

CPC分类号： H01Q1/2216 ,  G06K7/10316 ,  G06K7/10336 ,  G08B13/2474 ,  H01Q1/22 ,  H01Q3/26 ,  H01Q3/30 ,  H01Q7/00 ,  H01Q7/04 ,  H01Q7/06 ,  H01Q21/29

摘要： A system for minimizing the effect of null zones in an interrogation zone of a marker detection system. The system includes a reference antenna system configured to produce a first reference electromagnetic field during a first time period. The antenna system also includes a phase canceling antenna system configured to produce a second electromagnetic field substantially in phase with the reference electromagnetic field during the first time period and a third electromagnetic field substantially out of phase with the reference electromagnetic field during the first time period. The phasing of the first field or the second and third fields may be continuously switched while the phase of the other is held constant. A method of spatially shifting null zones in an interrogation zone of a marker detection system is also provided.

摘要翻译： 用于最小化标记检测系统的询问区中的空区域的影响的系统。 该系统包括被配置为在第一时间段期间产生第一参考电磁场的参考天线系统。 天线系统还包括相位消除天线系统，其被配置为产生与第一时间段期间的参考电磁场基本上同相的第二电磁场，以及在第一时间段期间基本上与参考电磁场不同相的第三电磁场。 第一场或第二和第三场的定相可以连续地切换，而另一个的相位保持不变。 还提供了一种在标记检测系统的询问区中空间移位空区域的方法。