本发明提供用于侦测外来对象之系统、方法及设备。在一态样中，提供一种用于侦测一对象之一存在之设备。该设备包括一谐振电路，该谐振电路具有一谐振频率。该谐振电路包括一传感电路，该传感电路包括一导电结构。该设备进一步包括一耦合电路，该耦合电路耦合至该传感电路。该设备进一步包括一侦测电路，该侦测电路系经由该耦合电路而耦合至该传感电路。该侦测电路经组态以回应于侦测取决于该谐振电路正在谐振之一频率之一测定特性与取决于该谐振电路之该谐振频率之一对应特性之间的一差而侦测该对象之该存在。该耦合电路经组态以缩减在不存在该对象的情况下由该侦测电路进行的该谐振频率之一变化。

This disclosure provides systems, methods and apparatus for detecting foreign objects. In one aspect an apparatus for detecting a presence of an object is provided. The apparatus includes a resonant circuit having a resonant frequency. The resonant circuit includes a sense circuit including an electrically conductive structure. The apparatus further includes a coupling circuit coupled to the sense circuit. The apparatus further includes a detection circuit coupled to the sense circuit via the coupling circuit. The detection circuit is configured to detect the presence of the object in response to detecting a difference between a measured characteristic that depends on a frequency at which the resonant circuit is resonating and a corresponding characteristic that depends on the resonant frequency of the resonant circuit. The coupling circuit is configured to reduce a variation of the resonant frequency by the detection circuit in the absence of the object.