公开(公告)号：US06473028B1

公开(公告)日：2002-10-29

申请号：US09543220

申请日：2000-04-05

Applicant: Wuidart Luc

Inventor： Wuidart Luc

IPC: G01S1336

CPC classification number: G06K7/0008 ,  G06K19/0723

Abstract: A method and apparatus for determining the distance separating an electromagnetic transponder from a terminal generating a magnetic field by a first oscillating circuit, the transponder including a second oscillating circuit, upstream of a rectifying circuit adapted to providing a D.C. voltage. The method includes storing a first information relative to the level of the D.C. voltage when the second oscillating circuit is tuned on a determined frequency; storing a second information relative to the level of the D.C. voltage after having caused a frequency detuning of the second oscillating circuit; and comparing the two stored pieces of information.

Abstract translation: 一种用于确定通过第一振荡电路分离电磁应答器与产生磁场的端子的距离的方法和装置，所述应答器包括适于提供直流电压的整流电路上游的第二振荡电路。 该方法包括当第二振荡电路在确定的频率上调谐时，存储相对于直流电压的电平的第一信息; 在引起第二振荡电路的频率失谐之后，存储相对于直流电压电平的第二信息; 并比较两个存储的信息。